A Text Message Outreach Intervention to Increase Health Insurance Enrollment for Self-Pay Patients.

Background: Self-pay patients may be unaware of their eligibility for health insurance coverage through government or hospital-based medical assistance programs.

Objectives: We aimed to evaluate the effect of behaviorally informed text message outreach on insurance enrollment among self-pay patients discharged from the emergency department (ED) at a safety-net hospital.

Research design: We emulated a single-arm trial with a historical comparison. Our eligible population included self-pay ED patients aged 18-64 years who were discharged between October 31 and November 24, 2022 (outreach group) or between April 1 and July 31, 2022 (historical comparison). We used entropy balancing weights to adjust for baseline characteristics and estimated overall and race/ethnicity-specific risk ratios (RR), risk differences (RD), and 95% confidence limits (CL) for the effect of the text outreach on insurance enrollment.

Results: The study population comprised 748 patients in the intervention and 6199 in the comparison group. The median age was 36 years (interquartile range=28-47), 58% were male, and 65% were racial/ethnic minorities. Overall outreach effect on any coverage enrollment (RR=1.4, 95% CL: 1.2, 1.6; RD=7.1%, 95% CL: 3.7%, 10%) was larger than the effect on hospital-based medical assistance program and Medicaid enrollment (RR=1.2, 95% CL: 1.0, 1.4; RD=2.7%, 95% CL: -0.24%, 5.7%). The latter effect was largest in the Hispanic population.

Conclusions: Our results suggest behaviorally informed text outreach increases insurance enrollment among self-pay patients discharged from the ED at a safety-net hospital and may complement broader strategies to increase health insurance enrollment. Future studies should compare different text message strategies.