# Association of COVID-19 Severity with Comorbidities: Results from the World Trade Center Health Registry

## TL;DR

This study found that pre-existing health conditions diagnosed after 9/11 are linked to more severe COVID-19 outcomes in World Trade Center disaster-exposed populations.

## Contribution

The study identifies how timing and type of comorbidities affect COVID-19 severity in 9/11-exposed individuals.

## Key findings

- Having four post-9/11 health conditions increased risk of prolonged symptoms in rescue workers.
- Post-9/11 respiratory conditions increased hospitalization risk in rescue workers and prolonged symptoms in non-workers.
- Pre-9/11 cardiovascular conditions increased hospitalization risk in non-workers.

## Abstract

The impact of physical health conditions on coronavirus disease of 2019 (COVID-19) severity in World Trade Center disaster-exposed populations remains understudied. We examined the association of type, number and diagnosis time of pre-existing health conditions with COVID-19 severity, using the WTC Health Registry (WTCHR). We analyzed 3568 WTCHR enrollees with self-reported severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a 2021 follow-up survey. COVID-19 severity was measured by self-reported symptom duration (<2, 2–4, and >4 weeks) and hospitalization (hospitalized versus not). Pre-existing gastroesophageal reflux disease (GERD), respiratory conditions, cardiovascular conditions, and diabetes were self-reported and categorized into four groups (no diagnosis, post-9/11, pre-9/11, and undefinable). We used multinomial logistic regression and binary logistic regression to analyze the association of comorbidities with COVID-19 symptom duration and hospitalization, respectively, adjusting for post-traumatic stress disorder and demographic factors. Analysis was also conducted separately by enrollee type: rescue and recovery workers (RRW) vs. community members (non-RRW). Having all four health conditions post-9/11 was associated with longer symptom duration after SARS-CoV-2 infection (>4 weeks) among RRW (AOR: 2.66, 95% CI: 1.03–6.87). Reporting a post-9/11 respiratory condition was associated with an increased risk of being hospitalized among RRW and an increased risk of longer symptom duration (>4 weeks) among non-RRW. While post-9/11 diabetes was associated with an increased risk of longer symptom duration among RRW, post-9/11 GERD and pre-9/11 cardiovascular conditions were associated with an increased risk of longer symptom duration and being hospitalized among non-RRW, respectively. The impact of certain health conditions on COVID-19 severity varied across enrollee types and time of diagnosis. Given the lasting health impacts of 9/11-related exposures, targeted medical surveillance and proactive healthcare interventions are critical for mitigating the risk of severe COVID-19 illness in this population.