Identifying social determinants of health subgroups and their associations with health outcomes in a prospective US adult COVID-19 cohort: an analysis of the INSPIRE registry.

Abstract

To identify subgroups with similar social determinants of health (SDOH) characteristics using latent class analysis (LCA) and examine their associations with physical and mental health, cognitive function and missed workdays at 3 and 6 months post-SARS-CoV-2 infection. We hypothesised that intersecting SDOH factors would differentially influence COVID-19-related health outcomes across subgroups. Prospective cohort study from the Innovative Support for Patients with SARS-CoV-2 Infections Registry (INSPIRE), with longitudinal data collection and cross-sectional analyses at baseline, 3-month and 6-month follow-ups. Multicentre registry across eight US academic medical centres (Chicago, Dallas, Houston, Los Angeles, New Haven, Philadelphia, San Francisco and Seattle). Adults aged ≥18 years, fluent in English or Spanish, with self-reported acute COVID-19 symptoms and a confirmed positive SARS-CoV-2 test within 42 days before enrolment (9 December 2020 to 12 August 2022), and access to an internet-connected device. Exclusions included incarceration, inability to provide informed consent, lack of confirmed SARS-CoV-2 infection or no internet access. Of 3791 eligible participants with complete baseline data, 2897 (76.4%) completed the 3-month follow-up and 2666 (70.3%) completed the 6-month follow-up; most were aged 18-49 years (74-75%), female (66-67%), white (86.6-87.5%) and non-Hispanic (86.6-87.5%). Prespecified primary outcomes were physical and mental health (Patient-Reported Outcomes Measurement Information System (PROMIS)-29 V.2.1 T-scores for depression, anxiety, fatigue, sleep disturbance, pain interference, physical function and social participation), cognitive function (PROMIS Cognitive Function Short Form 8 T-scores) and missed workdays due to illness (binary: >1 week vs ≤1 week, from a single-item survey). All measures were self-reported and collected at baseline, 3 months and 6 months; no changes from protocol. LCA identified a 4-class model as optimal (lowest Bayesian Information Criterion (BIC) after evaluating 1-7 class models; significant demographic differences (χ² p<0.001 for gender, age, race, ethnicity, education and income distributions)). Sensitivity analysis using four age groups (18-29, 30-49, 50-64, ≥65 years) yielded higher BIC (45 430.8) than three groups (18-49, 50-64, ≥65 years; BIC=42 150.9), confirming the primary model. Class 3 (middle-aged, high-income non-Hispanic; n=599 (15.8%)) was the reference group. Compared with Class 3, Class 1 (lower-income, predominantly Hispanic young to middle-aged adults; n=499 (13.2%)) and Class 2 (lower-income, older, predominantly Black non-Hispanic; n=1828 (48.2%)) exhibited significantly worse outcomes across physical and mental health domains (eg, Class 1 3-month anxiety β=4.41 (95% CI 3.25 to 5.56, p<0.001); Class 2 3-month depression β=3.58 (95% CI 2.53 to 4.64, p<0.001)). Classes 1 and 2 also reported significantly worse cognitive function at both time points (eg, Class 1 3-month β=-3.29 (95% CI -4.77 to -1.82, p<0.001)) and Class 2 had significantly higher odds of missed workdays at 6 months (OR=1.853 (95% CI 1.192 to 2.880, p=0.006)). In contrast, Class 4 (young to middle-aged, highly educated, high-income non-Hispanic; n=865 (22.8%)) consistently reported the most favourable outcomes, including better physical function (3-month β=2.04, p<0.001) and lower pain interference compared with the reference group. In this US prospective cohort, SDOH-based subgroups showed persistent disparities in health outcomes post-SARS-CoV-2 infection. Findings highlight the urgent need for intersectional approaches to address systemic inequities in post-COVID-19 recovery. NCT04610515.