The objective was to identify medical conditions associated with 30-day readmission, determine patient characteristics for which outpatient follow-up is most associated with reduced readmission, and evaluate how readmission risk changes with time to outpatient follow-up within a mobile integrated health-community paramedicine (MIH-CP) program. This retrospective observational study used data from 1,118 adult patient enrollments in a MIH-CP program operating in Baltimore, Maryland, from May 14, 2018, to December 21, 2021. Bivariate analysis identified chronic disease exacerbations associated with higher 30-day readmission risk. Kaplan-Meier curves and Cox proportional hazard regressions were used to measure how hazard of readmission changes with outpatient follow-up and how that association may vary with other factors. Receiver operating characteristic analysis was used to evaluate how well time to follow-up could predict 30-day readmission. Timely outpatient follow-up was associated with a significant reduction in hazard of readmission for patients aged 50 and younger and for patients with fewer than 5 social determinants of health needs identified. No significant association between readmission and specific chronic disease exacerbations was observed. An optimal follow-up time frame to reduce readmissions could not be identified. Timely outpatient follow-up may be effective for reducing readmissions in younger patients and patients who are less socially complex. Programs and policies aiming to reduce 30-day readmissions may have more success by expanding efforts to include these patients.
Keywords: health services research; policy evaluation; primary care; quality improvement; utilization.