Of the 70 patients admitted during the study period, two thirds were men. The median age of the patients was 59 years, and 40 % of those admitted were immigrants. The most common comorbid conditions were obesity, chronic coronary artery disease and diabetes. However, about one fifth of patients had no comorbidities, consistent with previous reports suggesting that it is not only elderly people with pre-existing conditions who become seriously ill
(4, 18). Most patients reported multiple symptoms prior to hospitalisation. The median duration of symptoms was one week, with respiratory symptoms, fever and general malaise typically reported. The vast majority of patients were screened by the primary health care service, and the reason for admission was usually reduced general condition or respiratory difficulties.
The month of March saw the largest number of admissions during the study period (57 %). A higher percentage of patients developed ARDS and died in the first two weeks than in the study period as a whole. With no previous experience of COVID-19, we had to rely on the international literature and WHO guidelines. As the pandemic progressed, healthcare professionals were trained in the management of patients with COVID-19, with a focus on early pulmonary rehabilitation and the prevention of atelectasis. Monitoring equipment was installed on wards to enable continuous monitoring of patients at risk of decompensation. Intensive care specialists and anaesthesiologists were involved in the daily assessment of the most seriously ill patients.
Guidelines for the management of patients with COVID-19 changed significantly over the course of the study period. Initial reports from China recommended early intubation, but we subsequently switched to trying a non-invasive approach
(19, 20). About half of all patients received anti(retro)viral therapy and/or immunomodulatory therapy, the vast majority before the hospital was enrolled in the WHO Solidarity Trial. In line with guidelines at the time, we limited the use of corticosteroids (21).
Fifty-eight patients (83 %) received antibiotics during their hospital stay, but only 14 had a clinical diagnosis of bacterial pneumonia. Microbiological assays were positive for respiratory pathogens in four patients, none of whom were considered critically ill. Nevertheless, we observed a low threshold for initiating antibiotic treatment, most likely due to inexperience with COVID-19 and the discrepancy between biochemical and clinical status. Bacterial superinfection does not appear to be a frequent complication of COVID-19, and current guidelines advise against antibiotic prophylaxis
Many patients (29 %) became critically ill while in hospital. Biochemical markers such as elevated CRP, lymphopenia, thrombocytopaenia and elevated D-dimer have proven to be prognostic markers of severe disease
(24, 25). These abnormalities were more pronounced in the patients in intensive care. The intensive care cohort also had significantly higher levels of inflammatory markers (CRP, leukocytes, procalcitonin) and higher levels of coagulopathy (D-dimer) and cardiac, renal and hepatic dysfunction than patients treated on a standard ward. Intensive care patients tended to have had symptoms for longer prior to hospitalisation (median eleven days) than patients with less severe illness (median seven days). Moreover, patients who had had symptoms for at least ten days scored more highly on clinical scoring tools on admission, and were twice as likely to become critically ill as patients with a shorter disease history. This may indicate that patients hospitalised late in the disease course (tend to) become more seriously ill. In common with Bærum Hospital, we found that NEWS2 appears to be better than SIRS for identifying patients at risk of serious illness (6).
The age of our patients was lower than that of patients at Bærum Hospital (median 71 years), and in the UK (73 years) and Italy (69 years), but comparable to that in certain cohort analyses from the USA and Spain (median 61 years)
(2, 7, 26) (26–28). However, those studies reported far higher case mortality rates than in our cohort (23.5 % and 20.7 %, respectively) and a higher percentage of intensive care admissions (27.9–32.0 % and 19 %, respectively). Immigrants were overrepresented among the inpatients in our study (40 %) compared to the proportion of immigrants in the local area (approximately 16 %) (29). The explanation for this is probably multifactorial, with underlying comorbidities as well as socioeconomic and demographic factors playing a part. Since the study was conducted early in the pandemic, it is possible that information about COVID-19 had not reached these communities to a sufficient degree. The proportion of critically ill patients in our study (29 %) was approximately the same as at Bærum Hospital (26 %), but mortality at our hospital was far lower. The patients who died at Bærum Hospital were older than those who died at our hospital (mean 79.5 years vs 70.9 years), and a greater proportion of those who died at Bærum had never received mechanical ventilation. We believe age can account for many of the differences seen between the two hospitals.
Cardiovascular complications are often seen in cases of COVID-19, and may predict an increased risk of death
(30). The most common non-respiratory complications observed in our study were cardiac manifestations (26 %) and acute kidney injury (13 %). The proportion of patients with myocardial injury was in the upper range of figures reported internationally (20–28 %) (30, 31). We observed a similar incidence of kidney injury to that seen at Bærum Hospital. However, we had far fewer cases of confusion or delirium, and believe these to have been underreported.
Our study includes all patients who were hospitalised in our region, and thus provides a population-based overview. Non-interventional studies can be a valuable source of information on COVID-19 for future reference, and our dataset is presented unadjusted. Our study population was small, however, which naturally makes it difficult to draw conclusions and to make comparisons with larger international populations.
The 70 patients admitted to Østfold Hospital were younger on average than those admitted to a comparable Norwegian hospital. Twenty per cent required intensive care, and 20 % were diagnosed with bacterial superinfection. Many became seriously ill, and the cohort mortality rate was 10 %.