Publication - Independent report

Coronavirus (COVID-19): care home outbreaks - root cause analysis

Published: 3 Nov 2020

Findings of the rapid review of COVID-19 outbreaks in four care homes, including a list of recommendations based on risk factors that were found to be common in at least two of the homes.

Coronavirus (COVID-19): care home outbreaks - root cause analysis
1. Residents and care home risk factors

1. Residents and care home risk factors

1.1 Residents

All four of the care homes in this review were in geographical areas (in the central belt of Scotland) with a high community prevalence of COVID-19 at the time of the outbreaks in the homes. This is an important fact to start with for this review as what is seen in care homes and other health and care settings with COVID-19, is a reflection of what is happening in the wider community. Underlying health conditions, the advanced age of many care home residents, and the shared location of residents in one facility; places residents at risk of transmission and severe impact from COVID-19. The homes reviewed in this Root Cause Analysis (RCA) reported high levels of residents with dementia, and many residents receiving end of life care. These factors make control measures, such as isolation, a challenge to manage and the risk of transmission high, when there is a single case of SARS-CoV-2 in a member of staff or a resident.

Managing transmission risk in relation to isolation of those residents with dementia was also reported as constrained by the built environment within the care home and required enhanced monitoring.  Some of the IPC advice was also challenging in the context of balancing harms, as keeping an individual's environment familiar to them, in terms of personal belongings, is an important aspect of care in this context.

Symptom recognition in older people is key to control of COVID-19, SGHSCD issued guidance detailing the wider spectrum of symptoms seen in older people, which should be considered for all care homes with older people (SGHSCD May 2020): 'Many older people may not present with the commonly reported symptoms of COVID-19 (such as a new persistent cough and temperature). Reported symptoms include loss of appetite or smell, vomiting and diarrhoea, shortness of breath, falls, dehydration and increased confusion, delirium or excessive sleepiness.' In some of the homes we reviewed there was a lack of awareness of these broader signs and symptoms and a focus on the three common ones used for the wider population. We heard of situations where primary care and emergency services colleagues had brought this to the attention of care home staff during a review of a deteriorating resident during the current outbreaks. 

1.2 Care home size

There is emerging evidence which indicates that the size of a care home may be associated with the rates of infection from COVID-19 and resident deaths. This was referenced in the Care Inspectorate review of role, purpose and learning during COVID-19 report (2020)[9], and in a review in one region in Scotland which found that homes containing fewer than 20 residents had an outbreak probability of 5%, but in homes with 60 to 80 residents the likelihood increased to between 83% and 100% (Burton et al 2020). [10]Two of the four homes in this review had more than 60 residents and therefore were in the higher risk group in terms of size. The average size of care homes in Scotland is 48 resident places and the recently published PHS report >[11]Two indicated that in the first half of this year the percentage of care homes with an outbreak increased progressively with care home size, from 3.7% of care homes with <20 registered places to 90.2% of care homes with 90+ registered places and that almost all outbreaks (336/348) occurred in care homes for older people. Around 1 in 4 of the care homes in Scotland have <20 registered places, although few of these would be older adult care homes where the risk is higher. The four homes included in this review all had more than 20 registered places and all provided care for older adults, placing them in the higher risk group for likelihood of an outbreak. We may continue to see outbreaks emerge in older adult care homes, those with >20 resident places are the majority, so it is likely we will see outbreaks over the coming months, as cases in the community surge again. 

Pre-existing care assurance, derived as a measure of inspection, and size of care homes has been suggested to be a characteristic to be considered as a condition for poorer outcomes [12]which may include outbreak propensity.> The data from the first half of 2020, presented in the care inspectorate report9, indicated that there was no evidence that previous inspection scoring was associated with propensity to have an outbreak in the first wave in Scotland. 

Outbreaks in this second wave are reportedly occurring more frequently (80%)[13] in those care homes not impacted in the first half of the year. None of the four homes included in this review had experienced previous outbreaks of COVID-19. There are therefore a number of alternate hypotheses to size of the home as the main factor for risk of an outbreak. For example, care homes who had not experienced a previous outbreak may be less experienced in early identification and management of the risks, or may have the most vulnerable residents, or were not a focus for IPC preparedness and support from NHS boards, and/or by chance did not experience an outbreak previously, or they may have had some change to demographics of residents, structures, or processes of care that made them more vulnerable to outbreaks. 

1.3 Occupancy

In order to be commercially viable, care homes need to have high occupancy rates, and maintain a balance between residents whose care is entirely funded from the public purse and those who contribute to the cost of their care from savings or capital. In all the four homes we looked at, occupancy levels had declined recently. One home told us that they usually had 97% occupancy, but it was currently at 75%. Significantly low levels of occupancy will potentially reduce risk of transmission, however will be a threat to the viability of homes in the longer term. 

High occupancy rates in care homes have been associated with higher rates of infection from COVID-19. A UK study of electronic health records from 8,713 residents and daily counts of infection for 9,339 residents and 11,604 staff across 179 UK long term care facilities showed that the adjusted hazard ratio for confirmed infection was 2.5 times greater in homes with 85% to 100% occupancy than homes with 70% to 85% occupancy rates.[14]  The occupancy recorded in the data submitted to the review team (TURAS data for the week preceding the outbreak and data from care homes) for the four homes involved in this review ranged from 89% - 100% and in the week of the review was 71%-90%. It should be noted that occupancy is subject to variation on a day to day basis.   


  • It is important to recognise that any care home, irrespective of size or number of residents, is vulnerable to outbreaks, and prevention strategies at care home level and HSCP level should take account of this
  • A campaign of awareness-raising amongst Care Home staff of the particular symptoms in older people should be undertaken