Risk for hospitalization due to COVID-19 in relation to occupational exposures as estimated by two different job-exposure matrices

IntroductionThe COVID-19 pandemic has profoundly challenged occupational safety and health. We assessed risk for hospitalization for COVID-19 in relation to potential routes and degree of occupational exposure.Material and MethodsThe study includes 1 105 042 subjects in the county of Stockholm of age 18–64 years, with an occupational code, followed regarding hospitalization from 1 March 2020 until 15 September 2022. We used two different job-exposure matrices (JEMs), based on survey data (Office for National Statistics 2020) and expert assessment (Oude Hengel et al 2022, module for Denmark), respectively. Hazard ratios (HRs) and 95% confidence intervals (CI) were obtained with Cox´s proportional hazards models. Fully adjusted models included age, sex, vaccination (time-dependent), household size, living space per person, income quintile, proportion of smokers in the occupation, and country of birth.ResultsWe observed 6523 hospitalizations with COVID-19 as the main diagnosis. HRs increased incrementally with the exposure dimensions in both JEMs and were increased already from the low-exposed categories.The fully adjusted HRs (95% CI) for the highest exposure category were for the survey-based JEM: Closeness to other people (very close, almost touching): 1.51 (1.42–1.59);Exposure to other people´s diseases (daily): 1.41 (1.33–1.50). Similarly, we found for the expert-based JEM: Number of co-workers in close vicinity (>30/day): 1.47 (1.39–1.57);Nature of contact with other people (regular contact with COVID-19 patients): 1.51 (1.40–1.63);Location of work (>4h/day indoors): 1.25 (1.19–1.31);Inability to keep social distancing (can never maintain >1m): 1.42 (1.33–1.51).ConclusionsDimensions of potential occupational exposure in both the survey- and expert-based JEMs were consistently associated with hospitalization for COVID-19 and may thus guide risk assessment. Increased risks observed already in the lower exposure categories indicate a need for enhanced preventive measures also in those settings.

The early impact of vaccination against SARS-CoV-2 in Region Stockholm, Sweden (preprint)

Vaccination against SARS-CoV-2 started in Region Stockholm, Sweden in December 2020 with those in long-term care facilities or receiving home care vaccinated first followed by those aged over 80 years. In this population-based, retrospective cohort study, we performed a Poisson regression to model the expected incidence of infections and deaths which we compared to the observed incidence and compared this to an unvaccinated control group of those aged 18-79 years. The aim of this study was to measure the early impact of the vaccination programme in Region Stockholm. Infections and deaths reduced substantially amongst the first two groups targeted for SARS-CoV-2 vaccination with an estimated total 3112 infections prevented, and 854 deaths prevented in these two groups from 4 weeks after the introduction of vaccination through to 2nd May 2021.

Risk factors for COVID-19-related death, hospitalization and intensive care: A population-wide study of all inhabitants in Stockholm (preprint)

Since the beginning of the Covid-19 pandemic, the scientific community has explored determinants of Covid 19 disease severity. However, the majority of studies are based on in-hospital patients with high risk of collider- or selection bias. The present investigation details risk factors associated with overall mortality, hospitalization and intensive care unit (ICU) admission in Covid-19 infections, with complete population coverage and high-resolution data on patient characteristics and comorbid conditions. Methods: This population-based observational study comprises all residents 18 years and older in Stockholm Region – 1.8 million inhabitants - using the real-time Covid-19 monitoring framework. The observation period lasted between March 1 to December 31, 2020. Hazard ratios (HR) for risk factors of Covid-19 disease severity were assessed using Cox proportional hazard models. Results: In total, 3,322 deaths, 11,508 hospitalizations and 1,423 ICU-admissions related to Covid-19 occurred during the study period. Kidney failure, diabetes and obesity increased risk of mortality and so did heart failure and ischemic heart disease. However, atrial fibrillation and hypertension did not. Risk of hospitalization follow a similar pattern, whereas admission to intensive care differs; triage processes where clearly present as certain co-morbid conditions were associated with lower ICU-admission. Conclusions: Observed differences in risk of mortality and hospitalization among patients with Covid 19 raise important questions about potentially protective co-medication which will be further addressed using the real-time Covid-19 monitoring framework.