Association of experiencing homelessness with hospital utilization and medical bills among people who have injected drugs: A community-based cohort and data linkage study.

BACKGROUND

Housing instability is common among people who inject drugs and is associated with poor health. We examined the association of homelessness with emergency department (ED) and inpatient (IP) utilization and charges among people who have injected drugs.

METHODS

Participants were enrolled 2015-2024 in ALIVE, a cohort of Baltimore adults who have injected drugs. Past-six-month homelessness was reported at twice-annual study visits. ED and IP admissions and resulting charges to patients were ascertained through linkage to a state hospital billing registry. We estimated differences in rates of admissions and charges per-six-months comparing periods when participants did and did not experience homelessness, and adjusting for confounders such as substance use behaviors using balancing weights.

RESULTS

Among 1365 participants' 9896 study visits (66% male, 87% age 40-69), mean past-six-month rates of admissions and charges were 0.92 and $1408 respectively for the ED, and 0.19 and $4051 for IP. After confounding adjustment, ED admission rates (adjusted rate difference (aRD) = 1.37, 95% CI 0.79-2.42), IP admission rates (aRD 0.11, 95% CI 0.04-0.19), ED charges (aRD = $1720, 95% CI $1027 to $2726), and IP charges (aRD $2072, 95% CI $516 to $3760) were significantly higher during periods of homelessness.

DISCUSSION: When people who injected drugs were experiencing homelessness, they experienced significantly elevated rates of ED and IP admissions and charges.