Social Determinants of Health and 90-Day Mortality After Hospitalization for Heart Failure in the REGARDS Study

Abstract

Background Outcomes following heart failure (HF) hospitalizations are poor, with 90-day mortality rates of 15% to 20%. Although prior studies found associations between individual social determinants of health (SDOH) and post-discharge mortality, less is known about how an individuals' total burden of SDOH affects 90-day mortality. Methods and Results We included participants of the REGARDS (Reasons for Geographic and Racial Differences in Stroke) Study who were Medicare beneficiaries aged ≥65 years discharged alive after an adjudicated HF hospitalization. Guided by the Healthy People 2020 Framework, we examined 9 SDOH. First, we examined age-adjusted associations between each SDOH and 90-day mortality; those associated with 90-day mortality were used to create an SDOH count. Next, we determined the hazard of 90-day mortality by the SDOH count, adjusting for confounders. Over 10 years, 690 participants were hospitalized for HF at 440 unique hospitals in the United States; there were a total of 79 deaths within 90 days. Overall, 28% of participants had 0 SDOH, 39% had 1, and 32% had ≥2. Compared with those with 0, the age-adjusted hazard ratio for 90-day mortality among those with 1 SDOH was 2.89 (95% CI, 1.46-5.72) and was 3.06 (1.51-6.19) among those with ≥2 SDOH. The adjusted hazard ratio was 2.78 (1.37-5.62) and 2.57 (1.19-5.54) for participants with 1 SDOH and ≥2, respectively. Conclusions While having any of the SDOH studied here markedly increased risk of 90-day mortality after an HF hospitalization, a greater burden of SDOH was not associated with significantly greater risk in our population.

Keywords: cohort study; heart failure; mortality; social determinants of health.

Figure 1

Healthy People 2020 Framework's 5 domains and corresponding social determinants of health (SDOH) studied. Adapted from Social Determinants of Health.24 Black race, social isolation (having 0–1 visits from a family or friend in the past month); social network (whether the participant reported having someone to care for them if ill); low educational attainment (< high school education), low annual household income (<$35 000), living in a rural area (defined as living in an isolated or small rural area, based off of Rural Urban Commuting Area codes); living in a zip code with high poverty (>25% of residence below the federal poverty line), living in a Health Professional Shortage Area, living in a state with poor public infrastructure (assessed using data from the America's Health Ranking; states that fell into the bottom 20th percentile for their ranking for ≥8 years were considered to have poor public health infrastructure).

Figure 2

Age- and fully adjusted hazard ratios for SDOH count and 90‐day mortality. ^Numbers are from the pre-imputation data set. Estimates computed from multiple imputation data set; *Incident rates per 1000 person-years. HR indicates hazard ratio; REGARDS, Reasons for Geographic and Racial Differences in Strokes; and SDOH, social determinants of health.