Information

Scottish Health Survey 2012 - Volume 2 Technical Report

Technical report accompanying the release of the 2012 Scottish Health Survey

This document is part of a collection


Appendix B Measurement Protocols

Physical measures and biologicalsample collection protocols - cover

Contents - part 1

contents - part 2

contents - part 3

1 HOW TO USE THIS MANUAL

This manual sets out the protocols and procedures for all measurements and samples that interviewers take across all National Centre for Social Research (NatCen) surveys.

Protocols are of paramount importance in collecting data and measurements. Having such strict protocols and procedures means that the information that is collected from respondents is valid, reliable and consistently obtained. It further allows the results to be compared across various factors such as age and location and ultimately means that the highest quality research is conducted and accurate information is given to our clients and policy makers.

The protocols and procedures outlined in this manual provide valid and reliable results but they are also the safest way for the measures to be conducted for both the respondents and the interviewer.

This is to be used as an instruction book and a quick reference guide when in field.

2 POINTS TO NOTE BEFORE STARTING

2.1 Consent

The issue of consent is of key concern in any of the projects conducted by NatCen. We are required to seek ethical approval for all of the projects we undertake involving physical measures or samples, and as a result the protocols pertaining to consent within this manual are based on recommendations by an external medical Ethics Committee.

Consent must always be obtained for every measurement and sample taken. As a general guideline the measurements require verbal consent, while the samples require written consent. Written consent may also be asked for the storage of samples.

Respondents aged 16 years and older give consent on their own behalf.

We recognise that respondents aged 16 and 17 years are legally classed as minors, however the external ethics committee recommends that respondents of this age are competent enough to make their own decisions in regards to participating in the survey measurements and samples. Note that if 16‐17 year olds are living with their parents you should ensure that their parents are aware of what you will be doing.

All of the measurements and samples outlined require at least verbal consent. Unless otherwise stated, in the protocol for a particular measurement / sample, only verbal consent is required. If written consent is required it will be clearly stated in the protocol.

2.2 Exclusion criteria and eligibility

Most of the procedures in this manual have exclusion criteria that need to be considered when conducting a measurement or taking a sample. These criteria are listed under each measurement and sample heading. It is important that the exclusion criteria are followed as they help to ensure the safety of, and prevent injury to both the respondent and the interviewer.

Note that no measurements or samples are taken from pregnant women.

Each of the measurements and samples also has eligibility rules to consider. These rules are not listed here as they differ among the surveys. The eligibility rules can be found in the project specific instructions for each survey.

2.3 General equipment care

All of the measurements and samples require some type of equipment. Please take care when using the equipment. In each protocol is a list of the equipment required as well as information on how to use it. Please follow these guidelines.

This equipment is expensive and most of it is easily damaged if it is not transported and/or stored correctly. Please use the bags and boxes provided to store and transport the equipment as it will help to prevent it from being damaged.

Calibrated instruments are particularly fragile and if they are knocked it could cause them to provide inaccurate measurements. Please handle the calibrated instruments with care and maintain them according to guidelines in the manual.

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Always ensure that the equipment is in good working order before you go to an interview e.g. batteries are fully charged, and that you are carrying a set of spare batteries with you.

If you suspect that any of the equipment is faulty and/or damaged, please report this to Brentwood who will be able to advise you on what action to take.

You are given a packet of Milton wipes to use for cleansing the equipment. Always make sure that you wipe the surfaces coming in contact with respondents between respondents and between households. If you are running out of wipes, please contact your project manager to arrange for additional packets to be sent to you.

2.4 Recording measurements

The anthropometric measurements require the results to be recorded in the metric format. Within the metric system, there are 10 millimetres (mm) in a centimetre (cm) and 100 centimetres (cm) in a metre (m). CAPI requires that measurements be recorded in centimetres (cm) to one decimal place only (e.g. 123.4cm).

2.5 Respondent feedback

Most surveys provide immediate feedback to respondents of some measurements by recording the results on a Measurement Record Card. If the respondent wishes to know their results they should be recorded here.

Please do not comment on the meaning of a respondent's results in general or on their results in relation to other people taking part in the survey. The only exception to this rule is the blood pressure measurement where some comments can be given to the respondent, according to the instructions outlined in the blood pressure protocol.

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3 RECORDING AMBIENT AIR TEMPERATURE

3.1 Introduction

Many of the physical measures taken fluctuate considerably due to air temperature. To be able to standardise the results that are obtained air temperature must be recorded. CAPI will tell you when to record the air temperature.

3.2 Equipment

You will need:

  • A digital thermometer
  • A probe

3.2.1 Using the thermometer

1. This instrument is very sensitive to minor changes in air temperature and thus it is important that ambient air temperature be recorded at the appropriate times, as prompted by CAPI.

2. It can take a few minutes to settle down to a final reading if it is experiencing a large change in temperature.

3. When "LO BAT" is shown on the display the battery needs replacing, take no further readings.

4. To preserve battery power, the thermometer may switch itself off after 7 minutes.

5. The battery in the thermometer is a long‐life battery and should last at least one year. However should it run low please purchase a new battery. Take the old one with you to ensure it is the same type. Claim in the usual way.

6. To remove an old battery and insert a new one, unscrew the screw on the back of the thermometer, insert the new battery and replace the cover.

3.3 Procedure

1. Set up the thermometer by plugging the probe into the socket at the top of the instrument. Do not let the probe touch anything and ensure that it is not near a radiator or in the sun. It is recommended that the probe hang over the edge of a table.

2. When prompted by CAPI to take a reading, turn on the thermometer by pressing the completely white circle.

3. Wait for the reading to stabilise and take a reading.

4. Record the air temperature in CAPI to one decimal place e.g. 21.4. Do not round this to a whole number.

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5. To preserve battery life, please ensure that after taking the reading the thermometer is switched off by pressing the white ring.

digital thermometer and probe

PLACE PROBE

CONNECTOR

HERE

Ensure probe is not touching anything and is not placed near any heat source (such as your laptop).

Figure 1 Digital Thermometer

4 HEIGHT MEASUREMENT

4.1 Introduction

The height measurement is a measure of anthropometry, which provides information on the size and proportions of the human body. When taken in conjunction with other anthropometric measures it is an indicator of, and can predict, the nutritional status, performance, health and survival of a population and can thus be used to determine public health policies. Moreover, height is often used as an indicator of people's quality of life. This is based on evidence that final height is a combination of genetic and environmental factors, where a taller population is indicative of a better quality of life due to access to health services and nutrition.

4.2 Exclusion criteria

Respondents are excluded from the height measurement if:

  • They are pregnant
  • They are too stooped to obtain a reliable measurement
  • After a discussion with the respondent it becomes clear that that they are too unsteady on their feet
  • They are chair bound
  • If the respondent finds it painful to stand or sit up straight

4.3 Equipment

You will need:

  • A portable stadiometer (see figure 2 below)
  • A Frankfort Plane card

Figure 2 The stadiometer

Figure 2 The stadiometer

4.3.1 Caring for the stadiometer

The stadiometer will be sent to you in a box. Always store the stadiometer in the box when it is not in use and always pack the stadiometer carefully in the box whenever you are sending it on by courier. Inside the box with the stadiometer is a special bag that you should use for carrying the stadiometer around when you are out on assignment.

The rods

There are four rods marked with a measuring scale divided into centimetres and then further subdivided into millimetres. The rods are made of plastic and are susceptible to bending if any pressure is put on them. Be careful not to damage the corners of the rods as this will prevent them from fitting together properly and will lead to a loss of accuracy in the measurements.

The base plate

Protruding from the base plate is a pin onto which you attach the rods in order to assemble the stadiometer. Be careful not to damage the corners of the base plate as this could lead to a loss of accuracy in the measurements.

The head plate

There are two parts to the head plate, the blade and the cuff. The blade is the part that rests on the respondent's head while the measurement is taken and the cuff is the part of the head plate that slips over the measurement rods and slides up and down the rods. The whole unit is made of plastic and will snap if subjected to excessive pressure. Grasp the head plate by the cuff whenever you are moving the headplate up or down the rods, this will prevent any unnecessary pressure being applied to the blade which may cause it to break.

4.3.2 Assembling the stadiometer

Practise assembling your stadiometer before you visit a respondent's home.

You will receive your stadiometer with the four rods banded together and the head plate attached to the pin so that the blade lies flat against the base plate. Do not remove the head plate from this pin.

Note that the pin on the base plate and the rods have symbols to guide you through the stages of assembly. The stages are as follows:

1. Lay the base plate flat on the floor area where you are to conduct the measurements. It should be as flat as possible, ideally on an uncarpeted floor or with a thin carpet; you should avoid a deep pile carpet or rug if at all possible.

2. Take the first rod, on which the measuring scale start with 'zero'. Making sure the measuring scale is on the right hand side of the rod as you look at the stadiometer face on, place the rod onto the base plate pin. It should fit snugly without you having to use force.

3. Using the symbols on the edge of the rod to guide you, take the rod with the same symbols at the edges as the first rod. Again make sure that the measuring scale connects with the scale on the first rod and that the numbers run on from one another. (If they do not, check

that you have the correct rod). Put this rod onto the first rod, matching the symbols at the edges, in the same way you put the first rod onto the base plate pin.

4. Take the remaining rods and put them together masking sure the symbols match and the numbers on the measuring scale run consecutively.

4.3.3 Dismantling the stadiometer

Follow these rules:

1. Before you begin to dismantle the stadiometer you must remember to lower the head plate to its lowest position, so that the blade is lying flat against the base plate.

2. Remove one rod at a time.

4.4 Procedure for adults

1. Ask the respondent to remove their shoes.

2. Assemble the stadiometer, near a wall if possible, and raise the headplate to allow sufficient room for the respondent to stand underneath it. Double check that you have assembled the stadiometer correctly.

3. Ask the respondent to stand with their feet flat on the centre of the base plate, feet together and heels against the rod as this helps people to 'be at their highest'. The respondent's back should be as straight as possible, preferably against the rod but NOT leaning on it. They should have their arms hanging loosely by their sides. They should be facing forwards.

4. Move the respondent's head so that the Frankfort Plane is in a horizontal position (i.e. parallel to the floor). The Frankfort Plane is an imaginary line passing through the external ear canal and across the top of the lower bone of the eye socket, immediately under the eye (see Figure 3). This position is important if an accurate reading is to be obtained. An additional check is to ensure that the measuring arm rests on the crown of the head, i.e. the top back half. To make sure that the Frankfort Plane is horizontal, you can use the Frankfort Plane Card to line up the bottom of the eye socket with the flap of skin on the ear. The Frankfort Plane is horizontal when the card is parallel to the stadiometer arm.

Figure 3 The Frankfort Plane

Figure 3 The Frankfort Plane

5. Instruct the respondent to keep their eyes focused on a point straight ahead, to breathe in deeply and to stretch to their fullest height. If after stretching up the respondent's head is no longer horizontal, repeat the procedure. It can be difficult to determine whether the stadiometer headplate is resting on the respondent's head. If so, ask the respondent to tell you when s/he feels it touching their head.

6. Ask the respondent to breathe out and step forwards. If the measurement has been done correctly the respondent will be able to step off the stadiometer without ducking their head. Make sure that the head plate does not move when the respondent does this.

7. Look at the bottom edge of the head plate cuff. There is an arrowhead pointing to the measuring scale. Take the reading from this point and record the respondent's height in centimetres and millimetres.

8. If the respondent wishes, record their height onto the measurement record card.

9. Push the head plate high enough to avoid any member of the household hitting their head against it when getting ready to be measured. Once you have finished measuring everyone, lower the head plate to its lowest position, ready for dismantling.

10. Before dismantling and storing the stadiometer in the bag, wipe the footplate and headplate with Milton wipes.

4.5 Procedure for children (2‐15)

The protocol for measuring children differs slightly to that for adults. You must get the co‐ operation of an adult household member. You will need their assistance in order to carry out the protocol, and children are much more likely to be co‐operative themselves if another household member is involved in the measurement. If possible measure children last so that they can see what is going on before they are measured themselves.

Children's bodies are much more elastic than those of adults. Unlike adults they will need your help in order to stretch to their fullest height. This is done by stretching them. This is essential in order to get an accurate measurement. It causes no pain and simply helps support the child while they stretch to their tallest height.

It is important that you practice these measurement techniques on any young children among your family or friends. The more practice you get before going into the field the better your technique will be.

1. In addition to removing their shoes, children should remove their socks as well. This is not because the socks affect the measurement. It is so that you can make sure that children don't lift their heels off of the base plate. (See 3 below).

2. Assemble the stadiometer and raise the head plate to allow sufficient room for the child to stand underneath it.

3. The child should stand with their feet flat on the centre of the base plate, feet together and heels against the rod. The child's back should be as straight as possible, preferably against the rod, and their arms hanging loosely by their sides. They should be facing forwards.

4. Place the measuring arm just above the child's head.

5. Move the child's head so that the Frankfort Plane is in a horizontal position (see diagram). This position is as important when measuring children as it is when measuring adults if the measurements are to be accurate. To make sure that the Frankfort Plane is horizontal, you can use the Frankfort Plane Card to line up the bottom of the eye socket with the flap of skin on the ear. The Frankfort Plane is horizontal when the card is parallel to the stadiometer arm.

6. Cup the child's head in your hands, placing the heels of your palms either side of the chin, with your thumbs just in front of the ears, and your fingers going round towards the back of the neck. (See diagram).

7. Firmly but gently, apply upward pressure lifting the child's head upwards towards the stadiometer headplate and thus stretching the child to their maximum height. Avoid jerky movements, perform the procedure smoothly and take care not to tilt the head at an angle: you must keep it in the Frankfort plane. Explain what you are doing and tell the child that you want them to stand up straight and tall but not to move their head or stand on their tip‐ toes.

8. Ask the household member who is helping you to lower the headplate down gently onto the child's head. Make sure that the plate touches the skull and that it is not pressing down too hard.

9. Still holding the child's head, relieve traction and allow the child to stand relaxed. If the measurement has been done properly the child should be able to step off the stadiometer without ducking their head. Make sure that the child does not knock the head plate as they step off.

10. Read the height value in metric units to the nearest millimetre and enter the reading into the computer at the question "Height." At the question "MbookHt" you will be asked to check that you have entered the child's height onto their 'stage 1 leaflet for children'. At that point the computer will display the recorded height in both centimetres and in feet and inches.

11. Push the head plate high enough to avoid any member of the household hitting their head against it when getting ready to be measured.

REMEMBER YOU ARE NOT TAKING HEIGHT AND WEIGHT MEASUREMENTS FOR CHILDREN UNDER 2 YEARS OLD

Figure 3 The Frankfort Plane

PLEASE NOTE:

The child stretch on the Scottish Health Survey is different to that used on Child of the new century. Please use the SHeS stretch when measuring children for SHeS interviews

PROTOCOL

  • SHOES OFF
  • CHILDREN - SOCKS OFF
  • FEET TO THE BACK
  • BACK STRAIGHT
  • HANDS BY THE SIDE
  • FRANKFORT PLANE
  • LOOK AT A FIXED POINT
  • CHILDREN - STRETCH & BREATHE IN
  • ADULTS - BREATHE IN
  • LOWER HEADPLATE
  • BREATHE OUT
  • STEP OFF
  • READ MEASUREMENT

4.6 Additional points

  • Some surveys require the respondent to be measured more than once; this will be stated in the project specific instructions. The protocol for taking the additional height measurements remains the same. Both measurements are to be recorded in CAPI and if they differ significantly CAPI will instruct you to take a third measurement.
  • If the respondent cannot stand upright with their back against the stadiometer and have their heels against the rod (e.g. those with protruding bottoms or curvature of the spine) then give priority to standing upright.
  • If the respondent has a hair style which stands well above the top of their head, or is wearing a religious head dress, with their permission, bring the headplate down until it touches the hair/head dress. You should never ask someone to remove a religious head dress. With some hairstyles you can compress the hair to touch the head. If you cannot lower the headplate to touch the head and think that this will lead to an unreliable measure, record this on CAPI. If it is a hairstyle that can be altered e.g. a bun, if possible ask the respondent to change/undo it.
  • If the respondent is tall, it can be difficult to line up the Frankfort Plane in the way described. When you think that the plane is horizontal, take one step back to check from a short distance that this is the case.
  • You may need to tip the stadiometer to read the height of tall respondents.
  • If the respondent has long hair then they may need to tuck it behind their ear in order for the head to be positioned properly. Always ask the respondent to tuck their hair behind their ears.

5 WEIGHT MEASUREMENT

5.1 Introduction

Similar to the height measurement, the weight measurement is an indicator of and can predict the nutritional status and health of a population. When used in conjunction with the height measurement it can be used to derive the Body Mass Index, a statistical measure used to determine if an individual's weight falls within a healthy range.

5.2 Exclusion criteria

Respondents are excluded from this measurement if they are:

  • Pregnant

If the woman wishes to be weighed, you can but do not enter the results into the computer.

  • Too frail or unable to stand upright

If you are concerned that being on the scales may cause them to be too unsteady on their feet then do not weigh them. Alternatively you can place the scales next to something that they can steady themselves on.

  • Over 130kg (20 ½ stone) in weight

The maximum weight registering accurately on the scales is 130kg. If you think that they exceed this limit then code it appropriately in CAPI and follow the prompts. Do not attempt to weigh them.

5.3 Equipment

There are two different sets of scales in circulation on NatCen projects. You will be provided with either:

  • Tanita THD-305 scales

The weight is displayed in a window on the scales. The scales are switched on by pressing the button on the bottom right hand corner of the scales. They are battery operated and require four 1.5v AA batteries, which should be sent with the scales. They may be packed separately or one of the batteries may be turned around, to prevent the batteries from going flat, as there is no on/off switch. Ensure that you have spare batteries, just in case you need them.

  • Seca 870 scales

The weight is displayed in a window on the scales. The scales are switched on by briefly covering the solar cell (for no more than one second). The solar cell is on the right hand side of the weight display panel. NB You may experience difficulties switching the scales on if there is insufficient light for the solar cell. Make sure that the room is well lit. The scales have a fixed battery which cannot be removed.

Please check which scales you have been provided with and make sure that you are familiar with how they operate.

5.3.1 Calibrating the scales

The scales will need to be sent to Brentwood at regular intervals to be recalibrated to ensure that they provide accurate measurements. On each set of scales there is a label

with a date that they need to be recalibrated by, ensure that they have been sent to Brentwood by this date.

5.3.2 Technical faults

Please refer to Table 1 when experiencing technical difficulties with the scales.

Table 1 Troubleshooting for the scales

Fault Action
Tanita THD 305 scales
No row of 8s when turned on or will not turn on
  • Replace batteries
  • If not solved, report to manager/Brentwood
Inconsistent readings
  • Make sure on hard flooring
  • Ensure 0.0 on display when respondent steps on scales
  • Replace batteries
  • If not solved, report to manager/Brentwood
Seca 870 scales
No '1888' when turned on or will not turn on
  • Insufficient light to operate solar cell
  • If not solved, report to manager/Brentwood
Inconsistent readings
  • Make sure on hard flooring
  • Ensure 0.0 on display when respondent
steps on scales
  • Insufficient light to operate solar cell
  • If not solved, report to manager/Brentwood

5.4 Procedure for adults

1. Weigh the respondent on a hard and even surface if possible. Carpets may affect measurements.

2. Ask the respondent to remove shoes, heavy outer garments such as jackets and cardigans, heavy jewellery, and to empty their pockets of all items.

3. Switch on the scales and wait for 888.8 (for the Tanita scales) or 1888 (for the Seca scales) to be momentarily displayed in the window. Do not attempt to weigh anyone at this point.

4. When the display reads 0.0, ask the respondent to stand with their feet together in the centre and their heels against the back edge of the scales. Their arms should be hanging loosely at their sides and their head should be facing forward. Having the respondent stand in this position means that the most accurate weight measurement can be obtained. Ensure that they keep looking ahead - it may be tempting for the respondent to look down at their weight reading. Ask them not to do this and assure them that you will tell them their weight afterwards if they want to know.

5. The scales will need to stabilise. The weight reading will flash on and off when it has stabilised. If the respondent moves excessively while the scales are stabilising you may get a false reading. If you think this is the case reweigh the respondent.

6. The scales are calibrated in kilograms and 100 gram units (0.1 kg). Record the reading in CAPI before the respondent steps off the scales.

7. If the respondent wishes, record the reading on their measurement record card.

8. The scales should switch off automatically a few seconds after the respondent steps off them.

5.5 Procedure for children

1. You must get the co-operation of an adult household member. This will help the child to relax and children, especially small children are much more likely to be co-operative themselves if an adult known to them is involved in the procedure.

2. Children who wear nappies should be dry. If the nappy is wet, please ask the parent to change it for a dry one and explain that the wetness of the nappy will affect the weight measurement.

3. Weigh the child, following the same procedure for adults. Encourage the child to 'Be as still as a statue' for an accurate reading. If you think that the results are inaccurate, code this in CAPI.

For very young children who are unable to stand unaided or small children who find this difficult follow the procedure below you will need to ask for the assistance of an adult as the following procedure requires you to measure the adult and then the adult holding the child:

1. Explain to the adult what you are going to do and the reasons why.

2. Code in CAPI the procedure used to measure the weight of the child.

3. Weigh the adult as normal following the protocol as set out above. Enter this weight into CAPI.

4. Weigh the adult and child together and enter this into CAPI. CAPI will calculate the difference between the two weights to get the child's weight.

5. If the respondent wishes record this reading on their measurement record card.

6 DEMISPAN MEASUREMENT

6.1 Introduction

The demispan measurement is an alternative measure of height. It is the distance between the midline of the sternal notch and the base of the fingers between the middle and ring fingers, with the arm out-stretched laterally (see Figure 5).

Figure 1 The Demispan Measurement

Figure 1 The Demispan Measurement

The demispan measurement is taken when it is difficult to measure height accurately. For example if the respondent cannot stand straight or is unsteady on their feet as is quite often in the case of the elderly and some disabled people. It is used as a proxy for a height measurement as there is a relationship between demispan and 'true height'. Additionally, height decreases with age to a varying degree depending on individuals, and thus the standard measure of height may be less useful for some older respondents. The long bones in the arm do no get shorter however, and thus can be used to estimate accurately a respondent's 'true height'.

6.2 Exclusion criteria

Respondents are excluded from the demispan measurement if:

  • They cannot straighten either arm without pain or discomfort.

6.3 Equipment

You will need:

  • A thin retractable demispan tape calibrated in cm and mm
  • A skin marker pencil
  • Micropore tape

6.3.1 Using the demispan tape

A hook is attached to the tape and this is anchored between the middle and ring fingers at the finger roots. The tape is then extended horizontally to the sternal notch.

The tape is fairly fragile. It can be easily damaged and will dent or snap if bent or pressed too firmly against the respondent's skin. Also the ring connecting the hook to the tape is a relatively weak point. Avoid putting more strain on this ring than necessary to make the measurements. When extending the tape, hold the tape case rather than the tape itself

as this puts less strain on the hook and tape. When placing the tape against the sternal notch, do not press into the sternal notch so much that the tape kinks.

6.4 Preparing the respondent

Explain to the respondent the purpose of conducting the demispan measurement and explain the procedure. Further explain that the measurement requires minimal undressing because certain items may affect the accuracy of the measurement. The items of clothing that will need to be removed include:

  • Ties
  • Jackets, jumpers and other thick garments
  • Jewellery items such as chunky necklaces/bracelets
  • Shoulder pads
  • High heeled shoes
  • Shirts should be unbuttoned at the neck

If the respondent does not wish to remove any item that you think might affect the measurement, record that the measurement was not reliable in CAPI.

For the purpose of consistency, where possible the right arm should always be used. If this is not possible, carry out the measure on the left arm and make a note of this in CAPI.

6.5 Procedure

1. Locate a wall where there is room for the respondent to stretch his/her arm. They need to stand with their back to the wall but not support themselves on it, standing approximately 3 inches (7cm) from the wall.

2. Ask the respondent to stand with weight evenly distributed on both feet, head facing forward.

3. Have them raise their right arm and extend it horizontally to their side until it is parallel with the floor. The right wrist should be in neutral rotation and neutral flexion. Rest your left arm against the wall allowing the respondent's right wrist to rest on your left wrist.

4. When the respondent is in the correct position, mark the skin at the centre of the sternal notch using the skin marker pencil. This mark must be made when the respondent is standing in the correct position. Explain to the respondent that the mark will wash off afterwards.

5. If clothing, jewellery or subcutaneous fat obscures the sternal notch, use a piece of micropore tape on the clothing or jewellery. If the respondent refuses to the use of the marker pen or the tape, proceed with the measurement but record it as unreliable in CAPI.

6. Ask the respondent to relax while you get the demispan tape.

7. Place the hook between the middle and ring fingers of the respondent so that the tape runs smoothly across the arm.

8. Ask the respondent to get into the position they were in previously, with their arm raised horizontally, the wrist in neutral flexion and rotation. Check they are in the correct position.

9. Extend the tape to the sternal notch. If no mark was made, feel for the correct position and extend the tape to this point.

10. Ask the respondent to stretch his/her arm checking that they remain in the same position, the hook has not moved on their fingers and that the respondent is not leaning on the wall or bending at the waist.

11. Record the measurement in CAPI, in centimetres and millimetres. Always report to one decimal place. If the length lies halfway between 2 millimetres, then round to the nearest even millimetre (see section 2.4).

12. Ask the respondent to relax and loosen up the right arm by shaking it gently.

13. Repeat steps 2-11. Explain to the respondent that the measure needs to be taken again for accuracy. If the second measure is significantly different to the first, CAPI will give you an error message. At this point you can check to make sure that you have entered the readings correctly or take a third measure if there is another reason for the measurements being different. This is to be taken in the same way as the previous two. CAPI will work out which two of the three readings to use.

14. If the respondent wishes, record the results on their measurement record card. You can use the conversion chart on your showcards to convert the results into inches.

6.6 Additional points

  • If the respondent is unable to stand in the correct position or finds it difficult to stand steadily, ask them to sit for the measurement. Use an upright chair and position it close to a wall. If a respondent is unable to sit or stand, the measurement can be taken when the respondent is lying down. In both cases still try to support the arm if possible. You may need to sit or kneel to take the reading.
  • Record in CAPI how the measurement was taken (i.e.. with respondent standing, sitting, etc).
  • If there is no wall available for the respondent to stand in front of and extend their arm horizontally, have them stand in front of any other flat surface e.g. in front of a cupboard or window, ensuring that they are not supporting their body weight on this surface.
  • If the respondent is much taller than you take the measurement with the respondent sitting.
  • If the respondent's arm is much longer than yours is, support the arm close to the elbow rather than wrist level. Your arm must not be between the elbow and shoulder, as this will not provide sufficient support.

7 WAIST CIRCUMFERENCE

7.1 Introduction

There has been increasing interest in the distribution of body fat as an important indicator of increased risk of cardiovascular disease. The waist circumference is a measure of the distribution of body fat. Waist circumference is probably a more important predictor of health risk than the body mass index (BMI), which is weight relative to height.

7.2 Exclusion criteria

Respondents are excluded from the waist circumference measurement if they:

  • Are pregnant
  • Are chair bound
  • Have a colostomy / ileostomy (This is a surgical opening drawing the intestine or colon to the surface of the skin in the lower abdominal area. Bodily waste is collected in a pouch outside the body). Respondents may volunteer this information. Do not ask a respondent directly if they have a colostomy.

7.3 Equipment

You will need:

  • A measuring tape calibrated in millimetres

7.4 Preparing the respondent

The respondent needs to be wearing light clothing. Never measure directly onto the skin. Explain to the respondent the importance of this measurement and that layers of clothing can substantially affect the reading. If possible the respondent needs to remove:

  • All outer layers of clothing, such as jackets, heavy or baggy jumpers, cardigans and waistcoats
  • Shoes with heels as this alters the natural position of the torso
  • Tight garments intended to alter the shape of the body, such as corsets, lycra body suits and support tights/underwear (if the respondent is unable or unwilling to remove these then continue the measurement but record a note in the CAPI
  • Belts (can be loosened if not removed)

Some respondents may be wearing religious or other symbols which they cannot remove and which may affect the measurement. Do not embarrass or offend the respondent by asking them to remove such items. Record in CAPI if the measurement is likely to be affected by this.

7.5 Procedure

1. Ensure that the respondent is standing erect in a relaxed manner and breathing normally. Weight should be evenly balanced on both feet and the feet should be about 25‐30cm (1

foot) apart. The arms should be hanging loosely at their sides. This position will provide the most accurate and easy measurement of the waist.

2. Ask the respondent to point to his or her navel or tummy button.

3. Instruct the respondent to place the tape around their body, over their clothing, at the level of the navel. You should then click the popper in place and pull to tight the tape around the waist of the respondent overlying their navel. The tape should be snug but not tight. If the respondent is not able to pass the tape around his/her waist, you may have to hold onto one end of the tape measure at their navel, and walk around the respondent with the other end.

4. Check that the tape is not twisted and that it is horizontal all the way around the respondent. To do this you must look round the participant's back from his/her left side to check that it is level. This will be easier if you are kneeling or sitting on a chair to the side of the respondent.

4. Ask the respondent to breathe normally and to look straight ahead.

5. Take the measurement at the end of a normal breath by holding the tape flat against the body.

6. Record the measurement in CAPI in centimetres, to one decimal place.

7. Repeat steps 1‐6 to record a second measurement. If the second reading differs significantly from the first, CAPI will report an error message. At this point check that you have entered the results into CAPI correctly. Otherwise take a third measurement, following the procedure above. Enter this result into CAPI. The computer will know which two results to use.

8. If the respondent wishes, record the waist measurement on their measurement record card.

7.6 Additional points

  • The tape should be tight enough so that it doesn't slip but not tight enough to indent clothing.
  • Some respondents will be wearing clothing where the waistband of the trousers/skirt sits on the waist. Do not ask them to move the clothing or take the measurement at a different position. Measure the waist circumference over the waistband and make a note of this in CAPI. If the waistband is not horizontal all the way around the body i.e. it may be lower at the front, always ensure that the tape is horizontal which may mean that it passes over the waist band in some places and not in others.
  • We only want to record problems that will affect the measurement by more than would be expected when measuring over light clothing. As a rough guide only record a problem if you feel it affected the measurements by more than 0.5cm.
  • Wipe the measurement tape with Milton wipes between households.

8 BLOOD PRESSURE

8.1 Introduction

Blood pressure is the exertion that the blood applies to the arterial walls as it is pumped through the circulatory system by the heart. Having a high blood pressure is an important risk factor for cardiovascular disease, particularly heart disease and stroke. The exact cause(s) of high blood pressure is not completely known however some factors known to affect blood pressure are smoking, alcohol consumption, family history, physical fitness and diet. It is important that we examine blood pressure using a standard method to see the distribution of blood pressure measurements across the population. This is vital for monitoring change over time.

8.2 Exclusion criteria

Respondents are excluded from the blood pressure measure if they are:

  • Pregnant (If a pregnant woman wishes to have her blood pressure measured, you may do so, but do not record the readings in CAPI)

8.3 Equipment

You will need:

  • An Omron HEM 907 blood pressure monitor
  • Child/ small adult cuff (17‐22 cm)
  • Standard adult cuff (22‐32 cm)
  • Large adult cuff (32‐42 cm)
  • An AC adapter

8.3.1 Using the Omron HEM 907

Figure 4 shows the monitor of the Omron

Figure 4 The Omron HEM 907 monitor

Figure 4 The Omron HEM 907 monitor

1. Switch the monitor on by pressing the ON/OFF button. Wait for the READY TO MEASURE symbol to light, indicating the monitor is ready to start the measurement (approximately 2 seconds).

2. Check that the MODE selector is set to AVG (average) and P‐SET Volume (pressure setting) is set to auto.

3. Press the start button to begin the measurement. The cuff will start to inflate and take the first measurement. When the first measurement is complete, the LCD screen will show the systolic pressure, diastolic pressure and pulse rate. It will continue to do this at one minute intervals.

4. Press the ON/OFF button to turn it off.

5. If at any stage while you are taking the measurement you need to stop the monitor, press STOP and start the procedure again.

8.3.2 Charging the battery

The Omron HEM 907 is equipped with a rechargeable battery, which is usable for approximately 300 measurements when fully charged.

When the battery symbol in the BATTERY display starts to flash there are 20‐30 measurements left, you need to charge the battery soon. When a light battery symbol appears in the BATTERY display the battery needs to be put on charge immediately.

To recharge the battery:

Connect the monitor to the mains by connecting the AC adapter to the DC jack of the main unit and the electric outlet (as shown in figure 5). A battery symbol will appear in the CHARGING display when the battery is charging. When ready to use the symbol will disappear. A dark battery symbol in the BATTERY display indicates that the battery is charged and the machine is usable. The battery can be charged in approximately 12 hours.

Plug AC adapter into this port on the left side of the monitor.

Figure 5 Charging the battery

Figure 5 Charging the battery

NOTE: when the AC adapter is connected and the unit is turned off, the AC adapter charges the installed rechargeable battery. The Omron 907 is NOT designed to work off the mains adaptor; it should be run off the battery power pack. The mains adaptor should ONLY be used to charge the battery pack.

8.3.3 Technical faults/error readings

Refer to table 1 when error readings appear on the LCD screen.

Table 2 Troubleshooting for the Omron HEM 907

Error No. Action
Er1, Er2
  • Check that the tube connecting the cuff to the monitor is properly inserted and is not bent
  • Check that the cuff is properly wrapped around the arm
  • Repeat the measure
Er3
  • Check that the tube connecting the cuff to the monitor is not bent
  • Repeat the measure
Er4
  • Ask the respondent to sit as still as possible
  • Repeat the measure
  • If it persists, it may be because the respondent has very high blood pressure
  • Reset the P‐SET Volume to 260 and repeat the measure.
Er5, Er6
  • Check that the cuff is properly wrapped around the arm
  • Repeat the measure
Er7, Er8
  • Ask the respondent to sit as still as possible
  • Repeat the measure
  • If it persists, it may be because the respondent's pulse is irregular, record that it wasn't possible and explain that this sometimes happens.
Er9
  • Technical fault - Contact Brentwood and report that fault

8.4 Preparing the respondent

Before the procedure CAPI will instruct you to ask the respondent if they have eaten, smoked, drunk alcohol or participated in vigorous exercise in the past 30 minutes. You should note their response in CAPI.

Select the right arm unless this is impossible. Ask the respondent to remove outer garment (e.g. jumper, cardigan, jacket) and expose their upper right arm by rolling up their sleeve. If the sleeve constricts the arm, restricting the circulation of blood, ask the respondent if they would mind taking their arm out of the sleeve for the measurement.

8.4.1 Selecting the correct cuff

Do not measure the upper arm circumference to determine which cuff size to use. Instead, choose the correct cuff size based on the acceptable range which is marked on the inside of the cuff. You will note that there is some overlap between the cuffs. If the respondent falls within this overlap range then use the standard cuff where possible.

8.5 Procedure

1. Ensure the respondent is sitting in a comfortable chair with a suitable support so that the right arm is resting at a level to bring the elbow to approximately heart level. They should be seated in a comfortable position with legs uncrossed and feet flat on the floor.

2. Place the monitor on a flat stable surface close to the respondent's right side and at the level of the heart. Position the monitor so that it faces away from the respondent.

3. Turn the monitor on.

4. Using the right arm, unless this is impossible, ensure that the upper arm is either exposed or has a single layer of thin clothing only. If the left arm is used, record this in CAPI.

5. Wrap the correct sized cuff round the upper right arm and check that the index line falls within the range lines. Do not put the cuff on too tightly as bruising may occur on inflation. Ideally it should be possible to insert two fingers between the cuff and the arm.

6. Position the arrow on the lower end of the cuff (near the elbow) over the artery just medial to the biceps muscle. The lower edge should be about 1‐2 cm above the elbow crease.

7. Explain to the respondent that you need them to sit quietly for five minutes and that during that time they cannot talk, eat, drink or smoke.

8. During this 'quiet time' follow the procedure for taking ambient air temperature (section 3) and just before taking the blood pressure reading, make a note of the air temperature.

9. After five minutes explain that you are starting the measurement, also explain that the cuff will inflate three times and each time they will feel some pressure on their arm. Ask them to relax, be seated in the position detailed in step 1 and not to speak until the measurement has been completed, as it may affect their reading.

10. Press start on the Omron HEM 907 to start the measurement. When the first measurement is complete it will be displayed on the LCD screen.

11. The unit will produce readings at one minute intervals thereafter, you will then have threesets of readings. A further (4th) reading will appear which is the Average reading. All of these readings need to be recorded. To check the readings press the 'Deflation' button.

12. Record the measures into CAPI in the following order:

a. Average - the reading that the Omron shows you once the measures are all complete

b. 1st - To show this press the grey 'deflation' button once.

c. 2nd - To show this press the grey 'deflation' button again.

d. 3rd - To show this press the grey 'deflation' button again.

If you press the deflation button again it scrolls back round to the 'Average' reading. It is important that three readings are recorded as the first reading is usually higher, and thus less accurate, than the other two readings as the respondent may be feeling nervous. NB - be recorded before the Omron turns itself off (after approx 3 mins) as the measures are not held in the memory then.

13. Press ON/OFF on the Omron to switch the unit off and remove the cuff from the respondent's arm.

14. If the respondent wishes, you should record details of their readings on the measurement record card.

15. Ensure that the cuffs stay clean. If the cuffs get soiled or you have concerned about potential or actual contamination dispose of the cuff and contact Brentwood for a replacement.

8.6 Respondent feedback

When answering queries about a respondent's blood pressure it is very important to remember that it is NOT the purpose of the survey to provide respondents with medical advice, nor are you in a position to do so.

What you may say in each situation has been agreed with the Survey Doctor and CAPI will instruct you to read out the appropriate interpretations of the respondent's results. It is very important that the agreed script in the CAPI is read word for word and that personal interpretation is never offered.

The respondent feedback protocol should be strictly followed. It is very important that as little anxiety as possible is caused, but at the same time we have a duty to advise people to see their GP if the measurements indicate that blood pressure is raised.

8.6.1 Adult respondents

As stated previously we have a duty to inform people that they need to see their GP if their blood pressure is high. It is important that the instructions below are carefully read and guidelines always followed precisely.

The computer tells you which readings your advice should be based on. This will be based on the lowest systolic and lowest diastolic reading from the last two readings. This will usually, but not always, be from the same reading. For example, occasionally it may be the systolic from the second reading and the diastolic from the third reading. Furthermore if the lowest systolic reading falls in one category and the lowest diastolic reading falls in another category, the higher of the two categories will be used to trigger the advice to respondents. For example the lowest systolic reading is 138 (normal) and the lowest diastolic is 96 (mildly raised) then the advice given will be based on a mildly raised reading. If the first reading is higher than the other two it should be explained that the first reading can be high because people are nervous of having their pressure taken.

Definitions of raised blood pressure differ slightly. The Survey Doctor has recommended the blood pressure ratings given below based on the most recent guidelines from the British Hypertension Society. It is important that you adhere to these definitions, so that all respondents are treated in an identical manner. These are shown in table 2.

Table 3 Definition of blood pressure ratings

ADULTS ONLY

SURVEY DEFINITION OF BLOOD PRESSURE RATINGS

For men and women aged 16+

Rating Systolic Diastolic
Normal <140 and <90
Mildly raised 140 ‐ 159 or 90 - 99
Raised 160 ‐ 179 or 100 - 114
Considerably raised 180 or more or 115 or more

Points to make to a respondent about their blood pressure (given on screen):

Normal:

'Your blood pressure is normal.'

Mildly raised:

'Your blood pressure is a bit high today.'

'Blood pressure can vary from day to day and throughout the day so that one high reading does not necessarily mean that you suffer from high blood pressure.'

'You are advised to visit your GP within 2 months to have a further blood pressure reading to see whether this is a one‐off finding or not.'

Raised:

'Your blood pressure is a bit high today.'

'Blood pressure can vary from day to day and throughout the day so that one high reading does not necessarily mean that you suffer from high blood pressure.'

'You are advised to visit your GP or practice nurse within 2 weeks to have a further blood pressure reading to see whether this is a one‐off finding or not.'

Considerably raised:

'Your blood pressure is high today.'

'Blood pressure can vary from day to day and throughout the day so that one high reading does not necessarily mean that you suffer from high blood pressure.'

'You are strongly advised to visit your GP or practice nurse within 5 days to have a further blood pressure reading to see whether this is a one‐off finding or not.'

8.7 Action to be taken after the visit

If you need to contact the Survey Doctor do not do this from the respondent's home ‐ you may cause unnecessary distress.

8.7.1 Adults

Table 3 summarises what action to take based on the readings you have obtained for a respondent. For this purpose you should only take into account the last two of the three readings you take, as the first reading is prone to error.

Table 4 Action due to blood pressure readings

BLOOD PRESSURE READING Interviewer ACTION
Normal Mildly raisedRaised Systolic less than 180 mmHg
and
Diastolic less than 115 mmHg
No further action
necessary
Considerably raised Systolic at or greater than 180
mmHg or
Diastolic at or greater than 115
mmHg
Contact the Survey
Doctor at the earliest
opportunity.*

* You must still contact the Survey Doctor even if respondents tell you that their GP knows about their raised BP.

The Survey Doctor will look at all high or unusual readings when they reach the office. If the reading is high, then the Survey Doctor will contact the respondent directly.

Contact details for your Survey Doctor can be found in the project instructions. The Survey Doctor is generally available from 8.00‐22.00. Calls outside these hours are either unnecessary or an emergency, in which case, the survey doctor is unlikely to be in a position to do anything practical and you should be using your judgement whether to call an ambulance or seek other urgent advice.

9 SALIVA

9.1 Introduction

Saliva samples are taken from respondents for analysis to detect various chemical compounds (depending on the aims of the individual surveys) to provide information on peoples health and lifestyle. These compounds include:

  • Cortisol, indicating an individual's stress levels.
  • Cotinine, a derivative of nicotine showing levels of exposure to tobacco smoke.

9.2 Exclusion criteria

Respondents are excluded from giving a saliva sample if they:

  • Are pregnant
  • Are HIV positive
  • Have Hepatitis B or C

Do not ask for information regarding HIV and Hepatitis B or C, however if they volunteer it, record them as unable to give a sample and make a note.

9.3 Consent

There is a separate consent form for the saliva sample. This must be signed and dated by the respondent or by the parent or legal guardian in the case of children aged 15 years and below. Please make it clear to respondents that they will not receive results regarding their saliva sample (see section 2.5).

9.4 Preparing the respondent

Explain to the respondent what you will require them to do and the reasons behind why saliva samples are taken.

There are two different procedures that can be followed depending on the aims/requirements of the survey. Please refer to the project instructions for the preferred method.

9.5 Procedure One

9.5.1 Equipment

You will need:

  • A plain 5ml tube
  • A short wide bore straw
  • Kitchen paper
  • Gloves

9.5.2 Procedure

1. Remove the cap from the plain tube Give the straw to the respondent. Explain that you want him/her to collect their saliva in their mouth and then let it dribble down the straw into the tube. The saliva does not need to go through the straw, the straw is intended to direct the saliva into the tube. Ensure that you are not getting sputum i.e. they are not clearing their chest to collect their saliva.

2. Allow the respondent 3 minutes to do this, collecting as much as you can in this time. The saliva will be frothy and will look greater in volume than it actually is, so do not give up too soon. You need at least 0.5cm on depth in the tube, not including froth.

3. If respondents find it difficult to use the straw they may dribble into the tube directly. This is acceptable, but encourage them to use the straw where possible.

4. If a respondent's mouth is excessively dry and they cannot produce saliva allow them to have a drink of plain water. Wait for 5 minutes before collecting the sample to ensure that water is not retained when the sample is given.

5. Replace the cap on the tube and report any problems in CAPI. You should wear gloves at all times when you come in contact with a saliva sample.

6. Label and package as directed in the project specific instructions.

9.6 Procedure Two

9.6.1 Equipment

You will need:

  • Salivettes
  • Gloves

9.6.2 Procedure

1. Figure 10 is a picture of a salivette. 'A' shows the salivette correctly assembled and 'B' shows the four different parts that it consists of: the cap, absorbent swab, inner tube and outer tube.

2. To obtain the saliva sample, remove the inner tube from the outer tube. Remove the cap from the inner tube and instruct the respondent to take the absorbent swab from the inner tube, without touching it, by lifting the tube to their lips and letting the absorbent swab fall into their mouth. Further explain that they must leave it in their mouth until it is saturated with saliva.

3. Ask them to move it around in their mouth, gently biting on it, as this helps to ensure thorough wetting of the absorbent swab. It will vary from person to person, however 3 minutes will usually be ample.

4. If a respondent's mouth is excessively dry and they cannot produce saliva allow them to have a drink of plain water. Wait for 5 minutes before collecting the sample to ensure that water is not retained when the sample is given.

5. When the absorbent swab is sufficiently wet, ask the respondent to remove it from their mouth and put the absorbent swab back into the inner tube, avoiding touching it if they can.

6. Wearing gloves, check that the swab is saturated. The tube should feel noticeably heavier than an unused one. If the swab rattles around in the tube then it is not wet enough and you need to give it back to the respondent to put back in their mouth.

7. Once you are satisfied that it is saturated replace the cap on the inner tube and put the inner tube back in the outer one (the inner tube has a hole in the bottom so will leak in the post if not placed in the outer tube). Record in CAPI any problems you may have had. You should wear gloves at all times when you come in contact with a saliva sample.

8. Label and package as directed in the project specific instructions.

Figure 2 ‘A’: an assembled salivette, ‘B’: the various components

Figure 2 'A': an assembled salivette, 'B': the various components

10 SPOT URINE

10.1 Introduction

Urine, a waste product of human bodily functioning, can be analysed to provide information on various factors depending on the compound to be analysed (table 7). The information that is obtained is highly accurate and cannot be taken from any other source. Please note that the compounds that are analysed are dependent on the individual survey.

Table 5 Compounds in urine analysis

Chemical Definition
Potassium Potassium is both an electrolyte and a mineral which works
to keep a balance in bodily fluids and has an important role in
nerve and muscle functioning. Potassium is found in fruit and
vegetables and thus also indicates the fruit and vegetable
intake of individuals.
Sodium (salt) Sodium is both an electrolyte and a mineral which works to
keep a balance in bodily fluids and has an important role in
nerve and muscle functioning. Sodium is found in most foods
and has been shown to contribute to high blood pressure
which is a major risk factor in the development of
cardiovascular disease.
Urea and Nitrogen Urea and nitrogen are natural by-products of the human
body. They are analysed to give an indication of kidney
function. They also provide information on the amount of
protein in an individual's diet.

10.2 Exclusion criteria

Respondents are excluded from giving a urine sample if they:

  • Are pregnant
  • Are HIV positive
  • Have Hepatitis B or C

Do not ask for information regarding HIV and Hepatitis B or C, however if they volunteer it, record them as unable to give a sample and make a note.

Women who have their period are not excluded from giving a urine sample. Respondents with a catheter are also not excluded. If the sample is taken from a catheter bag, this should be recorded in CAPI. It does not matter how long the urine has been in the collection bag.

10.3 Consent

There is a separate consent form for the urine sample. This must be signed and dated by the respondent or by the parent/legal guardian in the case of respondents aged 15 years and below. Please make it clear to respondents that they will not receive results regarding their urine sample.

10.4 Equipment

You will need:

  • A 100ml Polypropylene disposable beaker
  • A 10ml Sarstedt urine collection syringe and extension tube containing a small amount of a preservative
  • An instruction leaflet on how to use and fill the Sarstedt syringe
  • Coloured labels
  • Gloves
  • A polythene bag to store the equipment in and can be used to discard the used equipment once the sample has been taken (optional).

10.5 Preparing the respondent

Explain to the respondent that you need a urine sample and why it is important. Explain the equipment to them and show them how to use the Sarstedt syringe. A demonstration consisting of a syringe and a beaker filled with water can be used for this purpose. The instruction leaflet, similar to Section 16.5.1, can be left with the respondent for easy reference while performing the urine collection in private, if required. Explain the procedure below to the respondent. Tell them that you need them to follow the procedure as carefully as possible.

10.5.1 Urine sample syringe instructions

Urine sample syringe instructions

NB: Person in pictures should be wearing gloves!

10.6 Procedure

1. Respondents are to wash their hands with soap and water prior to voiding to avoid contaminating the sample with substances which may be on their hands. It is important that the inside of the urine collection beaker is not touched or allowed to come into contact with any part of the respondent's body, clothing or any external surfaces.

2. Ask the respondent to collect a mid flow sample of their urine in the disposable collection beaker.

3. Immediately after voiding they need to collect a sample of the urine by using the syringe as you have demonstrated to them and by following the instructions on the card. The collection of the urine sample needs to happen immediately after voiding to minimise specimen exposure to air.

4. Ask the respondent to wash the outside of the filled and sealed syringe and dry it using toilet roll, once the sample collection is complete.

5. If the respondent is unable to fill the syringe him/herself, or would rather not do so, you can do this for them. Emphasise that the sample needs to be taken from the sample straight away in order to minimise specimen exposure to air, so as soon as they have finished they need to bring it to you or leave it in the bathroom and notify you that the sample is ready. Please ensure that you are wearing gloves before attempting to fill the syringe for this respondent, you should wear gloves at all times when you come in contact with a urine sample.

6. Make sure that the plastic cap is securely sealed and the syringe plunger stalk snapped.

7. Label and package the sample according to the project specific instructions.

8. To dispose of the sample, pour the remaining urine in the toilet and throw the beaker and used equipment in the rubbish bin (if the respondent prefers, this can be put in a polythene bag first and then thrown in the rubbish bin).

11 DRIED BLOOD SPOT COLLECTION

11.1 Introduction

Dried blood spots will be collected and sent for storage at a secure facility. Written consent must be obtained before proceeding with the blood spot sample. You must complete the respondent's details on the consent form and make sure they sign all the relevant forms before obtaining the sample. Please refer to the project instructions for information on how to use and fill in the consent booklet for specific projects.

11.2 Exclusion criteria

Respondents are excluded from blood spot collection if they:

  • Are pregnant
  • Have a clotting or bleeding disorder or are on medication that thins the blood (anticoagulant) such as Warfarin, Sinthrome (Acenocoumarol), Pradaxa (Dabigatran Etexilate), Xarelto (Rivaroxaban) or Phenindione.
  • Are HIV positive*
  • Have Hepatitis B or C*

There will be questions in the CAPI program to establish whether the respondent meets any of the exclusion criteria. With regard to HIV and Hepatitis, respondents will be asked whether they are aware of any reason why they should not give a blood sample and will indicate their answer using a show card.

11.3 Equipment

You will need:

  • Isopropyl Alcohol Hand gel
  • Disposable gloves x 4
  • Disposable table mat
  • Blood collection kit containing

- Auto‐retracting lancet x 2

- Blood spot collection card

- Gauze pad x 2

- Alcohol wipe

- Eureka alcohol free cleansing wipes (if respondent allergic to alcohol on their skin)

- Plaster

- Micropore tape and gauze pad (if respondent allergic to plasters)

  • Sharps bin
  • Sealable disposal bag
  • Dispatch packaging

11.4 Preparing the respondent

Inform the respondent that you are going to need to prick one of their middle fingers or their thumb. The finger prick can be done on either hand, whichever the respondent prefers. Read the appropriate text in the CAPI to the respondent and ensure that signed consent has been obtained.

11.5 Procedure

1. Wash or cleanse your hands as appropriate for the setting.

2. Place the disposable mat on a hard, clean and dry surface (you may use the same mat if previously used for saliva collection).

3. Put on a pair of disposable gloves.

4. Remove all parts of the blood collection kit and place on the disposable mat in close proximity. If any item is opened or broken do not use. Ensure that all equipment and materials are out of the reach of children.

5. Ask the respondent to rub their hands together or massage them so that the blood is flowing to finger tips.

6. Ask the respondent whether they'd rather use their left or right hand. Choose a finger or thumb for the finger prick

- Avoid fingers with thick calluses or with tight rings as they may obstruct blood flow.

7. Clean the respondent's finger or thumb with alcohol wipe or with a Eureka wipe if allergic to alcohol on their skin and make sure that the finger is dry before proceeding (wait at least 30 seconds).

Clean the respondent’s finger or thumb with alcohol wipe or with a Eureka wipe if allergic to alcohol on their skin and make sure that the finger is dry before proceeding (wait at least 30 seconds)

8. Remove the blue tip from the lancet in order to activate it. While holding the respondents hand firmly, place the lancet on the side of the pad of the respondent's finger or thumb.

Remove the blue tip from the lancet in order to activate it. While holding the respondents hand firmly, place the lancet on the side of the pad of the respondent’s finger or thumb.

9. Trigger the lancet to prick the finger. If necessary instruct the respondent to gently squeeze his/her finger from the base several times to form a large drop of blood.

10. With the sterile gauze pad, wipe away the first drop of blood. Place the used gauze pad on the disposable mat.

With the sterile gauze pad, wipe away the first drop of blood. Place the used gauze pad on the disposable mat

11. When the next large drop of blood is formed, allow the blood to drop onto the left‐most box on the blood collection card. If a single drop of blood does not completely fill the area, you may add additional drops as soon as they form. If the blood does not absorb into the card, gently tap the card to break the surface tension of the blood and allow it to flow through to the card below.

12. Collect remaining drops of blood onto the filter paper card. Attempt to obtain five good spots.

Collect remaining drops of blood onto the filter paper card. Attempt to obtain five good spots.

- allow each drop of blood to fully form before dropping onto the filter paper

- do not "milk" the finger to increase blood flow-instead, gently knead the hand from palm down in order to stimulate blood flow

- wipe away blood that begins to clot or spreads unevenly with a gauze pad

DO NOT:

- drop spot before full drop has formed - this creates small spots that should be avoided

- drop spots close enough that they overlap

- blot finger onto filter paper. Instead, you should let the blood drop naturally or touch the blood drop (not the finger) to the filter paper card

13. Provide the respondent with a gauze pad to press on their finger and offer them an adhesive plaster or alternative dressing.

14. Dispose of the lancet in the sharps bin.

15. Place or ask the respondent to place the used gauze pad, alcohol wipe and wrappers in the disposal bag, along with your disposable gloves and seal the bag. Dispose, or ask the respondent to dispose, of the waste.

16. Put the blood spot card in a safe place and allow the blood sample to air dry for a minimum of 20 minutes.

17. Once the blood spots are dry, ensure that you put on a new pair of disposable gloves before packaging the samples. Close the blood sample card and package with a desiccant pack using the dispatch materials as directed by the project instructions.

18. Use hand gel to cleanse hands after sample packaged

Respondents who declare that they are HIV positive or have Hepatitis B or C should be excluded from this measurement. If, however, they declare this during or after the procedure you should continue with the sample collection and then dispose of all waste in the sharps bin rather than the disposable bag. You should allow the samples to dry and package as you would in any other case but these should not be dispatched through the post. After you leave the respondent's house you should also dispose of the blood spot cards in the sharps bin.

12 CONTACTS

Should you have any questions regarding the protocols then please do not hesitate to contact your project manager. You can also contact the Survey Doctor, whose details can be found in the project instructions.

Should you have any questions regarding the project on which you are working then please contact the relevant operations team in Brentwood or the research team in London. These details are also found in the project instructions.

13 USEFUL NATCEN REFERENCE GUIDES

1. CMS User Guide

For all queries on using the CAPI menu system.

2. Operations Safety Handbook

A guide for interviewers, nurses and researchers

3. Project Instructions

Contact

Email: Julie Landsberg

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