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The Friday Report – Issue 26
By Matthew Fletcher, Nicola Oliver and John Roberts
COVID-19 Actuaries Response Group – Learn. Share. Educate. Influence.
COVID-19 is still one of the hottest topics for scientific papers and articles. The COVID19 Actuaries Response Group will provide you with a regular Friday update with a curated list of the key papers and articles that we’ve looked at recently
Clinical and Medical News
Evolution and effects of COVID-19 outbreaks in care homes
Care homes have suffered disproportionately during the pandemic; indeed, care homes in a 79 percent increase in excess deaths at the height of the pandemic.
This study published in The Lancet Healthy Longevity Journal describes the evolution of outbreaks of COVID-19 in 188 registered care homes located in the NHS Lothian region which encompasses Edinburgh and surrounding region (this included 5,843 beds, of which 5,227 (89%) were in care homes for older people).
Data for COVID-19 testing (PCR testing of nasopharyngeal swabs for SARS-CoV-2) and deaths (COVID- 19-related and non-COVID-19-related) were obtained, and several variables including type of care
home, number of beds, and locality were analysed. (Availability and quality of personal protective equipment (PPE) were not included because no reliable data were available at the care home level during the study period.)
Around a third of care homes (69 of 189 [37%]) had a confirmed COVID-19 outbreak, but with wide variation in the size, duration, and pattern of outbreaks. The number of beds was strongly associated with the presence of an outbreak; (odds ratio per 20-bed increase 3·35, 95% CI 1·99–5·63).
Deaths were largely concentrated in care homes with known outbreaks.
Asymptomatic and presymptomatic infection rates in skilled nursing facilities
Additional insights into the impact of COVID-19 in care homes are provided here. Asymptomatic and presymptomatic infection rates in a large multistate sample of US skilled nursing facilities (SNFs) are presented
Data was drawn from a multistate long-term care provider with roughly 350 SNFs.
The table shows that around 40% of cases were asymptomatic, 40% symptomatic and 20% presymptomatic. It was also reported that SNFs located in areas with high SARS-CoV-2 prevalence detected higher numbers of asymptomatic and presymptomatic cases during initial point prevalence surveys, building on emerging evidence that SNF location is an important predictor of outbreaks.
Tocilizumab
Tocilizumab is a monoclonal antibody drug used for its immunosuppressive properties to treat rheumatoid arthritis, juvenile idiopathic arthritis and cytokine storm syndrome for patients treated with CAR-T cell therapies. It has been investigated as a potential treatment for patients hospitalised
with COVID-19.
Two studies have reported results this week.
The first, entitled the Boston Area COVID-19 Consortium (BACC) Bay Tocilizumab Trial, is a randomized, double-blind, placebo-controlled trial of tocilizumab administered relatively early in the
disease course, with the aim of preventing progression of COVID-19.
The second is part of the CORIMUNO-19 Cohort, a series of trials testing different therapeutic regimens in France. This is also a randomised controlled study testing the effectiveness of
Tocilizumab in patients with moderate to severe pneumonia requiring oxygen support but not admitted to the intensive care unit.
At this stage, neither study report any impact on mortality.
Characteristics associated with racial/ethnic disparities in COVID-19 outcomes
Many previous studies have reported that those from BAME populations are overrepresented in the number of COVID-19 infections, hospitalizations, and deaths. In this analysis from the US, the researchers set out to determine patient characteristics associated with racial/ethnic disparities in COVID-19 outcomes.
The study cohort consisted of 5,698 tested or diagnosed patients, including 5,548 patients who were tested at University of Michigan Medical School (MM) from March 10, 2020, to April 22, 2020.
The main outcomes were: being tested for COVID-19, having a positive test result for COVID-19 orbeing diagnosed with COVID-19, being hospitalized for COVID-19, requiring intensive care unit (ICU) admission for COVID-19, and COVID-19–related mortality (including inpatient and outpatient).
The following were observed:
Black patients were significantly more likely to be tested for COVID-19 and have positive test results than White patients (OR, 6.11 [95%CI, 4.83-7.73]; P < .001)
Every 10-year increase in age was associated with increased odds of having positive test results (OR, 1.09 [95% CI, 1.05-1.14]; P < .001)
In addition, higher BMI was associated with increased odds of having positive test results (OR per 1-unit increase, 1.03 [95%CI, 1.02-1.04]; P < .001), as well as alcohol consumption (ever
vs never: OR, 1.58 [95%CI, 1.29-1.95]; P < .001)
Residential population density was also associated with positive test results (OR per 1000 persons/square mile, 1.12 [95%CI, 1.08-1.16]; P < .001) A higher comorbidity burden was associated with worse outcomes overall, with statistically significant differences by race. The figure below displays the results of the multivariate analysis.
In conclusion, the findings suggest that racial disparities exist in COVID-19 outcomes that cannot be explained after controlling for age, sex, socioeconomic status, and comorbidity score.
Modelling
Estimating the infection-fatality risk of SARS-CoV-2 in New York City during the spring 2020 pandemic wave: a model-based analysis (Yang et al)
The infection-fatality risk (IFR) of COVID-19 (the risk of death amongst those infected, including asymptomatic and mild infections) is a key factor when considering how many might die from COVID-19 in future.
This paper estimates the IFR in New York City, the first American city to experience significant levels of mortality from the pandemic.
The estimates produced are based on over 200,000 laboratory confirmed infections and over 21,000 confirmed and probable COVID-19 related deaths of city residents between 1 March and 6 June 2020. Infection figures were adjusted based on a model for the proportion of infections that were not detected, with the model estimates validated using three independent serology datasets.
The overall IFR estimated is 1.39% (95% interval 1.04-1.77%) – the study also estimated IFR by different age bands, ranging from 0.12% for those aged 25-44 and 14.2% for those aged 75 and above. These figures are broadly in line with previous estimates (see for example our earlier report on IFR).
Living risk prediction algorithm (QCOVID) for risk of hospital admission and mortality from coronavirus 19 in adults: national derivation and validation cohort study (Clift et al )
This paper derives and validates an approach to estimate hospital admissions from COVID19 in adults. It draws on data from the QResearch database which covers 1,205 general practices in England, with linkage to COVID-19 test results, death registry data and Hospital Episode Statistics.
The algorithm aimed to predict time to death from COVID-19, with a secondary outcome being time to hospital admission following confirmed SARS-CoV-2 infection. The data used for the initial derivation of the algorithm was from 24 January to 30 April 2020, and the second validation covered May to 30 June 2020 – multiple predictor variables were considered, with the final approach being based on age, ethnicity, deprivation, BMI, and various comorbidities.
The algorithm performed well – it explained 73% of the variation in time to death, and those in the top 20% of the predicted risk of death accounted for 94% of all deaths from COVID-19.
Because the algorithm appears to pinpoint those at highest risk of death, it may be possible to use it to help clinicians and patients in decision making, as well as targeting recruitment for clinical trials and prioritising vaccination.
However, the authors caution that the models will need to be re-calibrated as absolute risks vary over time.
Quarantine and testing strategies in contact tracing for SARS-CoV-2 (Quilty et al ).
This paper has not yet been peer reviewed.
In many countries, there is a quarantine period of 14 days following exposure to a COVID19 case, to limit onward transmission. ]
This paper looks at whether PCR testing can be used to reduce the length of quarantine. The approach taken is to simulate various characteristics of an exposed contact’s possible infection (for example, time between exposure and detection, chance of being infected, incubation period, infectivity profile), using the UK as a case study.
The study finds that self-isolation on symptom onset can prevent 39% of onward transmission – a further 14 days’ quarantine for all contacts reduces transmission by 70%.
A negative PCR test taken once traced, with no quarantine requirements after a negative result, can reduce transmission by 62% – alternatively, a negative PCR test taken after a 7 day quarantine period (with no requirementfor further quarantine after a negative test) can reduce transmission by 68%.
This suggests that PCR testing combined with a shorter quarantine period could achieve similar results to the longer quarantine period.
However, structural issues in contact tracing (delays in tracing and / or poor adherence of traced individuals to the quarantine requirements) reduces the ability of quarantine and testing to reduce
transmission – the authors suggest that addressing these should be a key focus of future policy.
Data
Excess Home Deaths
The ONS has released a study which notes around 25,000 additional home deaths (up 30%) since the start of the pandemic. This was widely reported by the media, often with the implication that these were all additional deaths. In fact, the majority of these were displaced from other settings, most notably from hospital.
Although significant excess home deaths continued throughout the summer, overall there was no excess during this period, reflecting continuing displacement. ]
Many of the deaths were from causes that typically accompany end of life care in the elderly. With very limited visiting in care homes and hospitals, a possible conclusion is that many relatives have chosen to provide end of life care at home where at all possible.
Whilst hospitals have been open for all emergency care throughout the period, there will undoubtedly have been some instances where, possibly through perception that emergency care would be lacking, or fear of entering the hospital environment, the appropriate help was not sought.
This emphasises the need to reiterate the messages are hospitals are open for emergencies as usual.
ONS Surveillance Report
The latest report published today shows continued increases in infectivity in England, with numbers infected during the week reported of 433,000 (up from 336,000), or 1 in 130 people (1 in160).
New infections per day are estimated at 35,200 (27,900), which has doubled in the last fortnight
The regional analysis continues to show some signs of a levelling off in the North East and Yorkshire regions, to which can now be added the East Midlands.
We also see a marked downturn in the late teens age group,though the level at older ages continues to rise, which is clearly of most concern in terms of hospitalisations and outcomes. The age analysis suggests that we should be cautious about those regions showing improvement, as it is likely to be driven by the younger age reductions.
New this week we have some data on Scotland, which shows infectivity at 1 in 180, consistent with Wales. For completeness Northern Ireland is at 1 in 100. All these figures have wider confidence intervals than England, so need to be treated with some caution.
Additionally this week we have an update on antibody prevalence.
There are signs of a gradual drift downwards in prevalence, although the confidence intervals for earlier periods are wider, so it’s not compelling evidence. The latest level is 5.6%.
Finally, there has been some comment of late noting that the ONS surveys typically show a reduction in growth rate in the most recent week, which is then revised upwards in the following week.
The reasons for this are unclear, and it will be interesting to see whether ONS responds to the criticism.
R Estimate
The latest estimate of R for the UK is put at between 1.2 and 1.4 (compared with 1.3 to 1.5 last week). As usual this estimate is based on those with symptoms and requiring healthcare, so is lagged by a couple of weeks in relation to the current position.
For England, SAGE also estimates 1.2 to 1.4 – this is consistent with our own view, published yesterday, which has also suggested a small reduction in the past week. Regionally, SAGE puts the northern regions, along with London, at 1.1 to 1.3, with the South West an outlier at 1.3 to 1.6.
CDC Survey
Finally under data, and taking a less parochial view, in the US we note the recent CDC Report which suggests that 299,000 excess deaths had occurred up until early October.
Whether the reporting date was set to avoid breaching the significant milestone of 300,000 deaths is a moot point, but even so it is unlikely that the timing of the report was welcome for one of the presidential candidates.
When adjusted for population size the figure is broadly consistent with the estimates of 60,000 excess deaths for the UK, but the proportion not attributed to COVID is much higher at a third. ]This is likely to reflect differences in the policy for recording cause of death between the two countries as much as any true underlying difference in the proportions of COVID-19 deaths between the two populations.
A notable feature in the UK has been the increased mortality amongst ethnic minorities. That pattern is also seen in the US, with Hispanic, Asian and black communities all showing much higher excess percentages.
Other
13 cases, 10 million tests: China swabs city of Qingdao after COVID-19 outbreak
This article sets out some details of a mass testing effort in China. In the days following the discovery of 13 COVID-19 cases linked to a hospital in Qingdao, health workers have carried out almost 10 million tests and returned over 7.5 million results – they are on track to test 9.4 million residents and 1.5 million visitors within 5 days of launching the programme. They have not found any additional cases.
This effort is clearly very impressive; however, it remains to be seen whether it is possible to replicate over the longer term, either in China or elsewhere.
And finally….
Perhaps we can learn a little more about the current pandemic from medieval history. This fascinating paper reports that during plague outbreaks in the 14th century, the number of people infected during an outbreak doubled approximately every 43 days. By the 17th century, the number was doubling every 11 days.
Researchers believe that population density, living conditions and cooler temperatures could potentially explain the acceleration, and that the transmission patterns of historical plague epidemics offer lessons for understanding COVID-19 and other modern pandemics.
