key: cord-1037558-8j1l9r7u authors: Gulliford, M. C.; Rezel-Potts, E. C. title: MORTALITY OF CARE HOME RESIDENTS AND COMMUNITY-DWELLING CONTROLS DURING THE COVID-19 PANDEMIC IN 2020: MATCHED COHORT STUDY date: 2021-04-27 journal: nan DOI: 10.1101/2021.04.24.21255968 sha: 01221e5efe90e7c5b790ccc7139229534602d41a doc_id: 1037558 cord_uid: 8j1l9r7u Objective: To estimate mortality of care home residents during the Covid-19 pandemic from primary care electronic health records. Design: Matched cohort study Setting: 1,421 general practices contributing to the Clinical Practice Research Datalink Aurum Database in England. Participants: 217,987 patients aged 18 to 104 years with recorded care home residence in England in the period 2015 to 2020. There were 86,371 care home residents contributing data in 2020, with 29,662 deaths; 83,419 (97%) were matched on age, gender and general practice with 312,607 community-dwelling adults. Main outcome measures: All-cause mortality. Analysis was by Poisson regression adjusting for age, gender, long-term conditions, region, year and calendar week. Results: The highest first wave age-specific mortality rate was 6.02 (95% confidence interval 5.97 to 6.07) per 100 patients per week in men aged 95-104 years between 13th-19th April 2020. Compared with community-dwelling controls, the adjusted rate ratio for mortality of care home residents was 4.95 (4.62 to 5.32) in February 2020, increasing to 8.34 (7.95 to 8.74) in April 2020, declining to 3.93 (3.68 to 4.20) in December 2020. During the week of 13th to 19th April 2020, mortality of care home residents was 10.74 (9.72 to 11.85) times higher than for matched community-dwelling controls. Conclusions: Individual-patient data from primary care electronic health records may be used to estimate mortality in care home residents. Mortality is substantially higher than for community-dwelling comparators and showed a disproportionate increase in the first wave of the Covid-19 pandemic but not the second wave. This study provides evidence to support earlier, decisive action to protect these vulnerable populations in the event of further outbreaks. Prospective investigations of care home mortality are warranted. nursing/care home' would have lower than average lengths of stay. In sensitivity analyses, we found that varying this assumed duration between 14 and 365 days had negligible influence on estimates. For each patient, the start date was the latest of the patient's start of registration, 1 st January 2015 or the first care home code. The end of the patient's record was the earliest of the end of patient registration, the death date recorded by CPRD and the last data collection date for the practice. We included patients aged 18 to 104 years of age. For 86,371 care home residents contributing person-time during 2020, a matched comparison cohort of community-dwelling adults was sampled from the list of all patients registered in the CPRD Aurum March 2021 release after excluding care home residents. year, from the list of atrial fibrillation, cancer, chronic kidney disease, chronic obstructive pulmonary disease, dementia, depression, diabetes mellitus, epilepsy, frailty fractures, heart failure, haemorrhagic stroke, hypertension, ischaemic heart disease, ischaemic stroke, other mental health diagnoses, peripheral arterial disease, palliative care, rheumatoid arthritis or transient ischaemic attack. Data for frailty index scores recorded into electronic health records were also evaluated but, as these were more sparsely recorded and did not add useful information after allowing for a count of morbidities, these were not considered further. We analysed eligible patient records between 1 st January 2015 and 31 st January 2021. We initially divided records into calendar months, calculating the number of deaths and person time at risk for each month. We fitted a Poisson regression model, using data up to the end of 2019 as the training dataset, with counts of observed deaths as dependent variable and age-group, gender, region, multiple morbidity, calendar month and calendar year as predictors. Month was fitted as a factor, while year was fitted as a continuous predictor with a quadratic term to allow for possible non-linearity. Multiple morbidity was fitted as a factor with categories from one to nine or more morbidities, with a separate category for 'none recorded'. From the fitted Poisson model, we obtained predicted deaths by month for the period 2015 to 2020. We compared predicted and observed deaths graphically. In order to evaluate mortality in 2020 in more detail, we divided patient records into calendar weeks, analysing counts of deaths and patients resident in each week. Predicted deaths were estimated from a Poisson model fitted to data for 2015 to 2019 and excess deaths were estimated as the difference between observed and predicted deaths. An equivalent Poisson regression model was used to estimate the adjusted morality rate ratio for care home residents compared with controls, for each month of 2020. Analyses were performed using the 'statsmodels' 16 package in Python 3.8.3. The 'matplotlib' 17 package in Python and the 'ggplot2' 18 package in the R program were used for graphics. All rights reserved. No reuse allowed without permission. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. Patients and the public were not involved in the design of the study, the conduct of the analysis nor the interpretation and reporting of the results. There were 217,987 patients who were registered at general practices in England, were recorded as resident in a Care Home, and contributed follow-up after 1 st January 2015. ( Table 2 shows the Poisson model fitted to data for 2015 to 2019, which was employed to estimate predicted deaths. Mortality was greater in men and increased with age. There was a graded association of mortality with number of morbidities, except for the category of patients with no morbidities recorded. In order to investigate the pandemic peak in mortality in more detail, analyses were repeated using calendar weeks for analysis, with data presented as deaths per 100 patients per week by age-group and gender ( Figure 2 , upper panel). There was a peak in observed deaths between 6 th April 2020 and 26 th April 2020. Mortality rates were higher in men than women and increased in successive age-groups. The highest age-specific mortality rate was 6.02 All rights reserved. No reuse allowed without permission. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted April 27, 2021. ; https://doi.org/10.1101/2021.04.24.21255968 doi: medRxiv preprint (95% confidence interval 5.97 to 6.07) per 100 patients per week in men aged 95-104 years between 13 th -19 th April. Excess deaths, calculated as the difference between observed and predicted deaths, were summed across all age-groups ( Figure Table 3 ) but there was a slight deficit of controls in the oldest age-group consistent with a smaller number of eligible controls available. Care home residents generally had more long-term conditions than controls. Figure 3 presents weekly mortality rates for care home residents and community dwelling controls during 2020. Mortality was higher for care home residents throughout the year. The first wave peak of mortality was evident in care home patients and controls but was substantially greater in the former. In the final weeks of 2020, mortality increased in community-dwelling controls, but this was less apparent in care home residents. Table 2 presents deaths and counts of persons at risk by month during 2020, together with rate ratios adjusted for age-group, gender, region and long-term conditions. In February 2020, mortality was 4.95 (4.62 to 5.32) times higher in care home residents than controls; by April All rights reserved. No reuse allowed without permission. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted April 27, 2021. ; https://doi.org/10.1101/2021.04.24.21255968 doi: medRxiv preprint 2020, mortality was 8.34 (7.95 to 8.74) times higher. During the week of 13 th to 19 th April 2020, analysis of data from Figure 3 showed adjusted mortality of care home residents was 10.74 (9.72 to 11.85) times higher than for community-dwelling controls. The rate ratio declined from May 2020 onwards, reaching 3.93 (3.68 to 4.20) in December 2020. The first wave of the Covid-19 pandemic is acknowledged to have had a particularly severe impact on patients living in care homes and nursing homes. However, there is a lack of patient-level data concerning the health outcomes of social care during the pandemic. 11 This analysis shows that primary care electronic health records have potential to provide timely and relevant information concerning the care home population. Analyses quantified the first wave of Covid-19 mortality in April 2020 and showed that mortality peaked between 6 th and 26 th April, being strongly associated with advanced age and male gender. In men aged 95 and older, our analyses estimated that there were approximately 6 deaths per 100 patients per week at the height of the first wave. Regional variations in the impact of Covid-19 were also evident. Compared with community-dwelling control patients, mortality for care home residents was four to five times higher before the onset of the pandemic. Care home residents were disproportionately affected and during the month of April 2020, after allowing for differences in case-mix, mortality of care home residents was more than eight times higher than for community-dwelling patients and more than 10 times higher at the peak of the first wave. All rights reserved. No reuse allowed without permission. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. An important strength of this study was the use of longitudinal health records to estimate predicted mortality during 2020 based on data for the preceding five years, taking into account differences in age and gender distribution, morbidities, region, calendar month and secular trends over years. This enabled us to quantify excess deaths during the pandemic months. We were also able to draw on a matched population-based comparison cohort to quantify changes in the relative risk of mortality in care homes during the pandemic after adjusting for covariates. We drew on a well-described database, 13 and the quality of data offered by electronic health records has been shown to be generally high. 19 However, we acknowledge that there could be misclassification of care home status and it is possible that care home residence might be under-recorded. Misclassification might generally have the effect of reducing associations. We included a count of important long-term conditions, but we did not find records of frailty index scores to be informative. In the cumulative deficit model, frailty and multiple morbidity are closely related concepts 20 but more accurate phenotypic characterisation of patients frailty status over time would have added to the study. 21 Deprivation is associated with reduced healthy life expectancy, which could lead to care home admission. Patients were matched for general practice, so it was not possible to adjust for deprivation at the general practice-level. We did not employ individual postcodelevel deprivation scores as these might have presented difficulties if the care home postcode did not reflect deprivation exposures over the life-course. We employed a Poisson model adjusting for covariates, which provided plausible estimates. A hierarchical model allowing for general practice clustering and overdispersion did not lead to convergence. It is possible that estimated confidence intervals might be slightly too narrow, but effects of interest were unequivocal. Control sampling was with replacement and duplicated controls were included to reduce bias. 15 All rights reserved. No reuse allowed without permission. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. reported to the care quality commission and estimated that over the first seven months of 2020, deaths accounted for 6.5% of care home beds. The estimates from our analyses are not directly comparable because we estimated the mortality rate per 100 residents per week. Dutey-Magni et al. 22 analysed data collected by care homes for incidence of Covid-19 and mortality. Their findings, like our study, suggested that deaths were frequent among residents who were probably infected with SARS-CoV-2 but were not tested. Burton et al. 23 found that outbreaks of Covid-19 between March and August 2020 in one Scottish region were frequent within care homes and most deaths occurred in the context of outbreaks. 10 23 We did not have data to identify individuals at the same care homes and the possible clustering of deaths at care homes could not be investigated in our data. Hollinghurst et al. 24 analysed linked primary care and administrative records for the population of Wales and found that care homes showed increased mortality during the first wave of the pandemic. Their estimates were generally lower than we present here. However, their analysis using the Cox model could be associated with non-proportional hazards because analysis time encompassed a period when risks were changing daily. We estimated adjusted relative risks for each week of the pandemic and showed that there was a substantial increase in the relative risk of mortality associated with care home residence during the first wave. Other studies confirm that background mortality is very high in care home residents. Vossius et al. 25 found that annual mortality of nursing home residents was 31.8%. Shah et al. 26 analysing the THIN primary care database for 2009 found that the age and sex standardised mortality ratio for nursing home residents was 419 and for residential home residents was 284, consistent with the elevated relative rates observed in the present analyses. All rights reserved. No reuse allowed without permission. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. Despite awareness since the very early stages of the UK pandemic of evidence from other contexts that Covid-19 severity was likely to be greatest among the elderly, 27 there were delays in policy guidance which correspond with the timing of Covid-19 mortality peaks in care home observed in April 2020. In the event of future transmission increases, earlier implementation of testing and isolation strategies and greater consideration of the effects of hospital discharge to care homes may be crucial. This study has also highlighted that there is heterogeneity in the care home population, indicating that the most elderly males may require particular protection or shielding during periods of high transmission. Regional variations in mortality might also indicate that more localised approaches should be explored. Further assessment is required of longer-term issues that have may have contributed to higher rates of care home Covid-19 mortality such as decreases in local authority social care spending since 2010, increased privatisation, 28 staff shortages 29 30 and the lack of integration of health and social care services. 31 The high mortality of care home residents during non-pandemic months, even after allowing for the level of morbidity, might be accounted for by admissions for end-of-life care. Nevertheless, prospective investigations of mortality in care homes are justified. Individual-patient data from primary care electronic health records may be used to estimate mortality in care home residents either in comparison with non-pandemic periods or with population controls. Analyses confirmed the disproportionate impact of the first-wave of the Covid-19 pandemic on the care home population, especially in comparison with communityliving comparators. Estimation of deaths per calendar week were mapped against delays in action to isolate care home residents. In the event of further outbreaks, this study provides evidence for earlier, decisive action to protect these vulnerable populations. All rights reserved. No reuse allowed without permission. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted April 27, 2021. ; https://doi.org/10.1101/2021.04.24.21255968 doi: medRxiv preprint Coronavirus (COVID-19) in the UK. London: UK Government Race, socioeconomic deprivation, and hospitalization for COVID-19 in English participants of a national biobank Office for National Statistics. Care home resident deaths registered in England and Wales, 17. Hunter JD. Matplotlib: A 2D Graphics Environment Elegant graphics for data analysis Validity of diagnoses in the general practice research database Frailty in elderly people Frailty in older adults: evidence for a phenotype Mortality in older care home residents in England and Wales National Audit Office. Adult social care at a glance. London: National Audit Office The King's Fund. International recruitment in adult social care. London: the King's Fund Factors associated with SARS-CoV-2 infection and outbreaks in long-term care facilities in England: a national cross-sectional survey Covid-19: why we need a national health and social care service No reuse allowed without permission. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity