How COVID-19 has changed the unselected medical take: an observational study

Discussion

We believe our study is the first to specifically investigate the effect of the COVID-19 pandemic on the unselected medical take in an NHS hospital. Perhaps surprisingly, our data demonstrate that the number of admissions during the month of March remained constant. However, the proportion of patients admitted with COVID-19 increased dramatically towards the end of March. This was compensated by a decrease in patients being admitted onto the medical take with other conditions. There have been several reports of altered health behaviour during the month of March, such as reduction in emergency department attendances, reduction in emergency hospital admissions and doubling of calls to NHS 111.⁷ A study demonstrated a 40% fall in patients admitted for acute coronary syndrome from mid-February to late-March 2020, with a greater decline for non-ST elevation myocardial infarctions (NSTEMI) compared to STEMI.⁸ In contrast, a report suggested no change to ambulance demand for both myocardial infarctions or cerebrovascular disease.⁹ It is likely that even though there may have been a drop in absolute numbers attending the hospital, a higher proportion of patients requiring hospitalisation counterbalanced the trend.

Our data suggest firstly that comorbidities such as diabetes mellitus and hypertension were more common in COVID-19 compared to non-COVID-19 patients, although we found that a smoking history was more common in non-COVID-19 patients. Furthermore, there were worse clinical outcomes for patients admitted with COVID-19 compared to non-COVID-19 patients. Our multivariate logistic regression modelling suggested statistically significant associations in predicting inpatient and 30-day mortality, even when the effects of age, gender and comorbidities were factored in. Our findings are broadly in line with several larger studies which have been published looking at outcomes of COVID-19 patients in hospital. A UK multicentre series of 20,133 patients found that the median age of admission was 73 and 60% of patients were male.¹⁰ Increasing age, male gender, diabetes, hypertension, cardiovascular disease and chronic respiratory disease were all associated with worse outcomes. The mortality rate was 26%, although 34% were still inpatient at time of reporting. 16% were treated with non-invasive ventilation, and 10% were intubated. Meanwhile an American study had an intubation rate of 12% and mortality rate of 21%, while a Chinese study had 14% of patients treated with non-invasive ventilation, an intubation rate of 17% and a mortality rate of 28%.^11,12 One stark contrast is that compared with the UK series, despite a younger cohort in our population, there was a similar mortality rate. Notably, it has been reported that the London Borough of Newham recorded the highest COVID-19 mortality rate in England and Wales.¹³ 78% of residents are from ethnic minorities, and there are likely to be further socioeconomic factors which led to worse outcomes in our patients.^14,15 Although we were unable to demonstrate a clear relationship between mortality and ethnicity, a recent study of 1,996 COVID-19 patients based in our Trust showed that Black and Asian patients had higher mortality even after adjustment for age and sex, as well as admission to intensive care and requirement for intubation.¹⁶ Moreover, while in our study intubation rates were similar with published studies, we had a higher rate of non-invasive ventilation use.^10–12 This is probably because at the beginning of the pandemic there was limited intensive care capacity, and non-invasive ventilation was often trialled first. These statistics further demonstrate how the COVID-19 pandemic created an unprecedented burden on healthcare resources and offers a glimpse as to how quickly and drastically the NHS had to adapt in response. As an example, workforce changes in our hospital included lengthening to 12.5 hour shifts for consultants and junior doctors, equal staffing numbers during the working week and weekend and redeployment of doctors from other Trust sites and research to our hospital.

Although our data found that patients with suspected COVID-19 testing positive for SARS-CoV-2 had a higher median length of stay and likelihood for intubation compared with patients testing negative, there was no difference in other outcomes such as mortality. In our cohort 22% of patients who had suspected COVID-19 but a negative admission SARS-CoV-2 test subsequently tested positive as an inpatient. However, only 44% of patients underwent repeat testing, and an early study from Wuhan found that 63% of hospitalised patients had negative initial tests.¹⁷ While it is entirely possible that nosocomial spread may be a factor, it is more likely that false negative tests were the culprit. A preprint systematic review consisting of five studies showed false negative rates of 2% to 29% for the SARS-CoV-2 RT-PCR test, although there was considerable heterogeneity in sensitivity estimates.^18,19 A sensitivity of 70% for a SARS-CoV-2 RT-PCR test is felt to be a reasonable estimate, given at present there is no clear reference standard which RT-PCR tests are measured against.¹⁸ This therefore demonstrates the need to not be over-reliant on initial swab test results, take a repeat sample and to treat clinically if COVID-19 is suspected.