Risk of hospital admission after discharge from postpartum psychiatric emergency department visits: A focus on the social determinants of health.

Objective: Of those with postpartum psychiatric emergency department (ED) visits, a minority of receive hospital admission at their initial visit. Among those discharged, we aimed to determine subsequent risk of psychiatric admission, and understand how social determinants of health (SDOH) - individually and collectively - impact this risk.

Method: From all postpartum individuals discharged from psychiatric ED visits in Ontario, Canada (2008-2020)(n = 13,130), we generated adjusted relative risks (aRR) for psychiatric inpatient admission within 365 days post-ED visit by four SDOH (age, neighbourhood income, community size, immigration) and other clinical factors. Using latent class analysis (LCA) to identify subgroups based on clustering of SDOH, we then compared adjusted risk across subgroups.

Results: Psychiatric admission occurred for 9.5% (n = 1242) within 365 days. Across SDOH, risk was lower among adolescents (vs. ≥35 years aRR 0.80, 95%CI 0.65-0.97) and immigrants (<5 years in Canada vs. Canadian-born/long-term residents 0.70, 0.51-0.96; ≥5 years in Canada 0.79, 0.65-0.95). Among four identified subgroups, compared to the "older/urban/high-income" subgroup (11.1% admission), the "urban/immigrant/low-income" (7.6%; 0.68, 0.55-0.82) and "young/rural/low-income" subgroups (9.7%; 0.78, 0.63-0.96), but not the "semi-urban/middle-income" subgroup (9.5%; 0.86, 0.73-1.01), were at lower admission risk.

Conclusions: Future research is needed to explore reasons for SDOH-based differences in admission risk, and inform equitable postpartum services.