4 screening and detecting problems
4.1 Screening is the use of formal tests or examination procedures on a population basis to identify those who are apparently well, but who may have a disease or defect, so that they can be referred for a definitive diagnostic test. Some defects can only be detected by health professionals if a search is made or through the use of specific screening tests.
4.2 The UK National Screening Committee ( NSC) was established in 1996 to advise the Department of Health and the devolved administrations in Scotland, Wales and Northern Ireland on all aspects of screening policy. In forming its proposals, the NSC draws on the latest research evidence and the skills of specially convened multi-disciplinary expert groups, which always include patient and service user involvement. The NSC assesses proposed new screening programmes against a set of internationally agreed criteria. In 1996, the NHS was instructed not to introduce any new screening programmes until they had been reviewed by the NSC. The NSC has endorsed the recommendations in Hall 4.
4.3 Hall 4 found that much existing screening activity did not meet the criteria for screening tests, yet cogent arguments were often made for their continued usefulness in the evaluation and care of apparently healthy children.
4.4 Whilst screening has the potential to save lives or improve quality of life through early diagnosis of serious conditions, the process is not 100% accurate - in any screening programme, there are some false positive results (wrongly reported as having the condition) and false negative results (wrongly reported as not having the condition). Screening can reduce the risk of developing a condition or its complications, but it cannot guarantee protection. Parents should be made aware of the benefits and limitations of screening tests so that they can make informed decisions about whether to participate. Patient information leaflets on screening are already produced by and available from NHS Health Scotland. Parents should also be provided with information, including sources of support, following diagnosis.
4.5 Staff should always know when, where and how to refer a child whose screening test result gives cause for concern. The route of referral will depend on the particular condition and local protocols. Early detection has implications for other aspects of the child's care, including diagnostic and treatment facilities. Planning and monitoring of screening programmes must take into account the implications for these other services.
4.6 Children's services professionals across a range of settings should also be clear about sources of advice and referral protocols when they suspect that a child may have a problem which requires health assessment.
4.7 In line with national guidance from the UK National Screening Committee and HDL(2001)51 53, all NHS Boards are expected to have introduced Universal Newborn Hearing Screening ( UNHS) in 2005.
4.8 In line with the recommendations made in Hall 4, once UNHS is in place, universal distraction testing at 7-9 months should be abandoned. The National Newborn Hearing Screening Implementation Group has recommended that universal distraction testing should be discontinued once UNHS has been in place for one full year. The Group has already recommended increased vigilance amongst professionals in relation to risk groups such as children who have suffered from meningitis, received ototoxic drugs (i.e. those which may damage the hearing mechanism), children with middle ear disease and children with developmental disorders which may mimic hearing loss or be associated with hearing loss.
4.9 If the school entry hearing sweep test is currently in place, this should continue whilst further evidence about its effectiveness is collected and evaluated. No further routine hearing testing should be undertaken. Similarly, no new hearing screening programmes should be introduced until further evidence is available.
4.10 Audiology services must be able to respond to the concerns of referrers and parents promptly. NHS Boards should therefore review the local arrangements for access to paediatric audiology services and staff training to ensure efficient referral and testing for children with suspected hearing loss. Audiological assessment and follow up should be arranged automatically for any child who:
- Has had bacterial meningitis.
- Has had prolonged treatment with ototoxic drugs.
- Has had a severe head injury.
- Is experiencing learning, behavioural or speech and language difficulties.
4.11 NHS Boards should ensure co-ordination of the local paediatric audiology programme, including screening, training, audit and monitoring.
4.12 All children should be screened by an orthoptist in their pre-school year, between the ages of four and five years, removing the need for vision testing on school entry. This reflects recommendations by the UK National Screening Committee and Hall 4, and is already being implemented in some areas using a database to manage orthoptist screening in pre-school centres, health centres and primary schools to maximise coverage and accessibility.
4.13 Until an orthoptist pre-school vision screening programme is in place, children's visual acuity should be tested on school entry by an orthoptist, or through a programme which is supervised by an orthoptist or an optometrist. The evidence for screening in secondary school remains inconclusive. On that basis, if screening on a single occasion is already in place, it should continue, but more frequent screening should cease, and no new vision screening should be introduced in secondary school.
4.14 There is little evidence of the benefits of screening for colour vision defects and no attempt should be made to screen for colour vision defects in primary school. If screening is already in place for adolescents, it should continue, but no new colour vision screening should be introduced. Adolescents whose career planning might be affected by a colour vision impairment should be advised to visit an optometrist for expert advice and assessment. Children and young people who are found to have a colour vision defect should be advised that this may be an important issue in relation to certain career choices.
4.15 Arrangements should be made for any child undergoing assessment for educational under achievement or other school problems to have a visual acuity check. Vision screening should also be undertaken in schools for children with hearing impairment.
4.16 One person in each NHS Board area should be designated to take overall responsibility for monitoring vision screening programmes.
Screening for postnatal depression
4.17 The universal child health surveillance programme offers a clear opportunity to detect those at high risk, and those who have developed symptoms and signs of a mental health problem.
4.18 Guidance on the identification and treatment of postnatal depression and perinatal mental illness has already been published in MEL(1999)27 and in the Framework for Mental Health Services in Scotland54. This suggests that detection of postnatal depression may be done in the course of a routine assessment interview or by using the 10-item self-report Edinburgh Postnatal Depression Scale 55. Although Hall 4 reiterates the advice of the National Screening Committee that screening for postnatal depression should not be routinely offered at present, the National Screening Committee has advised that, whilst the Edinburgh Postnatal Depression Scale ( EPDS) should not be used as a screening tool, it may be used as a checklist as part of a mood assessment for postnatal mothers, alongside professional judgement and clinical interview. The SIGN guideline on postnatal depression 56 suggests that the EPDS should be used at approximately six weeks and three months following delivery and should be administered by trained health visitors or other health professionals.
4.19 Perinatal and Postnatal depression services are being expanded across Scotland.
Screening for obesity
4.20 Hall 4 advises that where there is concern that a child may be overweight, his/her height and weight should be measured and the body mass index ( BMI) calculated and recorded. It also recommends that health professionals should offer support to children and families who want to control their weight. However, Hall 4 recommends against use of BMI for universal screening until there is consensus about the effectiveness of intervention programmes.
4.21 During the consultation on draft guidance, some argued that height and weight should be measured and BMI recorded more regularly than Hall 4 advises. Hall 4 advises against regular universal height and weight measurement as this takes up valuable practitioner time and there is little evidence of proven benefit in terms of outcome.
4.22 However, Hall 4 does recognise that population trends in BMI might be useful for monitoring the impact of public health interventions and recommends that measurement of height and weight should be made at or around the time of school entry and measurements stored so that BMI can be calculated and used as a public health indicator. In Scotland, height and weight data have also been collected (though not consistently) for a number of years at P7 (age 10/11) and S3 (age 13/14). In order to ensure continued study of longitudinal trends, universal recording of height, weight and BMI should continue at P7, but only on a periodic basis, every three years. This will be triggered through the Child Health Surveillance School System and will commence in academic year 2007/08. Where it is in place, recording of height, weight and BMI at S3 should discontinue. This is reflected in Annex 1. Arrangements for identifying and monitoring obesity in children and young people will be kept under review.
4.23 Public health strategies to prevent obesity are reflected in the Health Promotion section of this guidance.
Developmental disorders and disabilities
4.24 Although routine developmental screening examinations may detect extreme variations from normal development, most disabilities and disorders are found by other means. They are often identified by examination in the period immediately after birth. They are often also detected by a child's parents or family, or professionals who are in regular contact with the child, by close observation and follow up of children at risk, or noted opportunistically when a child presents to health services for other reasons. Development is a continuum and it is sometimes difficult to separate 'normal' from 'abnormal' presentation at any precise age.
4.25 Evidence suggests that formal universal screening for developmental delay and disorder, speech and language delay, autism and co-ordination disorder makes little contribution to the detection of serious impairments, and it is not, therefore, recommended. Hall 4 found that developmental screening programmes also performed poorly when tested against the National Screening Committee criteria.
4.26 The detection of problems is discussed further in the following two sections on surveillance in the early years and in school-age children and young people.