JMIR Publications

ABSTRACT

Background:

Heart failure (HF) readmission rates vary across geographic regions in the United States, yet the impact of external exposome factors, such as contextual-level social determinants of health (SDoH), on adverse HF outcomes is not well understood.

Objective:

To examine the association between external exposome factors and the risk of HF readmission and all-cause mortality using a data-driven approach.

Methods:

We conducted a retrospective cohort study using electronic health records (EHR) data from the OneFlorida+ network, including patients hospitalized for HF (HHF) from 2016 to 2022. A total of 1,308 external exposome factors, covering a wide range of SDoH (e.g., economic stability, education, healthcare access, natural and built environments, and social context), were linked to patients’ EHR data based on their residential location at the county level. Patients were followed for one year after their first HHF to capture readmission and mortality events. We applied LASSO regularization to preselect candidate variables, followed by a two-phase External Exposome-Wide Association Study (ExWAS) using mixed-effects logistic regression to identify key factors associated with the composite outcome of one year HF readmission and mortality.

Results:

Among 63,940 HF patients (30,475 [48%] women; mean age 65 years, SD 14), higher maximum temperature in May was significantly associated with increased risk of the composite outcome (aOR: 1.04, 95% CI: 1.02–1.06; P < 0.001). Subgroup analyses showed consistent associations across age, sex, race, socioeconomic status, and rural/urban strata.

Conclusions:

Using a data-driven approach, we found that elevated maximum temperature in May (late spring) was significantly associated with HF readmission and mortality in Florida. Further investigations are warranted to uncover the intricate mechanisms through which extreme heat potentially influences HF outcomes. Clinical Trial: NA