Burden of chronic diseases in migrant workers (MW) in Singapore and impact on COVID-19: A large single-centre cohort study during the peak MW 2020 outbreak

Background

The COVID-19 pandemic unmasked systemic inequities amongst migrants globally. In Singapore, dormitory residing migrant workers (MWs) were disproportionately impacted accounting for over 54,500 COVID-19 cases (93% of all cases) in 2020. Their limited health insurance did not cover outpatient acute or chronic illness care. There is a lack of systematic data on the chronic disease prevalence amongst MWs.

Methods

In this cohort study, we analysed the electronic medical data of all MWs with PCR-confirmed symptomatic COVID-19 admitted to the National Centre for Infectious Diseases (NCID), Singapore from 1st to 30th April 2020, the peak of the MW outbreak. We aimed to ascertain the prevalence of chronic diseases and their impact on COVID-19 disease severity.

Results

2,498 male MWs were included. Majority (>90%) were of South Asian origin. Median age was 34 years (IQR 29-40). 247 (9.9%) had at least one chronic disease; 99 (4.0%) had diabetes mellitus (22 (22.2%) newly diagnosed), 69 (2.8%) had dyslipidaemia (26 (37.7%) newly diagnosed), and 135 (5.4%) had hypertension (21 (15.5%) newly diagnosed). While 278 (11.1%) had pneumonia, only 16 (0.6%) required oxygen or intensive/high-dependency care, with no mortality. Charlson’s score ≥ 1 (compared to 0) was associated with 80% higher odds of moderate-severe COVID-19 outcome, aOR (adjusted odds ratio) 1.83 (1.16-2.90), P=0.01, adjusted for age and nationality in multivariable analyses.

Conclusions

Although MWs had favourable COVID-19 medical outcomes during their acute illness, our study demonstrates a considerable burden of undiagnosed chronic diseases predisposing to cardiovascular disease and highlights health disparities that should be addressed by health policies.