The Association of Social Determinants of Health and Penicillin Allergy Labels: a case-control study.

Background: Penicillin allergy labels (PAL) are associated with numerous adverse outcomes including poor infectious outcomes and antimicrobial resistance. Studies assessing the association of social vulnerability (SV) characterized by social determinants of health factors (SDoH) and PAL epidemiology are lacking.

Methods: This retrospective case-control study included patients encountering a US academic medical center between 2014-2023. Cases were defined as patients with PAL; controls were defined as patients without PAL and with a penicillin medication order. The primary independent variable was SV defined by the Community Vulnerability Compass including twenty indicators of SV. The primary outcome was PAL documentation. Bivariate analyses were performed to examine the association between SV, covariates, and PAL.

Results: 32,952 PAL cases and 171,189 controls were included (mean [SD] age, 36.3 [21.4] years; 107,498 [52.7%] Hispanic, 4,566 [2.2%] non-Hispanic Asian, 55,422 [27.1%] non-Hispanic Black, 31,680 [15.5%] non-Hispanic White). An inverse relationship between SV and PAL was observed. The highest SV quintile was associated with decreased PAL (unadjusted odds ratio [OR], 0.52; 95% CI, 0.50-0.54). Adjusting for SV, non-Hispanic White identification was significantly associated with PAL; with significantly decreased PAL observed in other groups, Hispanic aOR 0.38, 95% CI 0.36-0.41; non-Hispanic Black aOR 0.45, 95% CI 0.42-0.48; non-Hispanic Asian aOR 0.40, 95% CI 0.34-0.45.

Conclusions: A significant inverse relationship between SV and PAL was observed, with lower SV associated with increased PAL. Significant racial disparities in PAL persisted despite adjusting for SDoH, suggesting that racial- and ethnic-identified groups interact differently within the healthcare system with regards to acquiring PAL.