Offering Vouchers to Low-Income Minority Populations Increases Follow-up for Free Glaucoma Services

Purpose: Despite limited availability of free eye care services in Baltimore City, utilization by low-income at-risk minority individuals remains low. This may be driven by a lack of perceived value for these free services. We examine the effect of providing vouchers redeemable for free eye care services on uptake among participants in the ongoing SToP Glaucoma study.

Methods: A cluster randomized trial was conducted within the SToP Glaucoma study, an investigation of a community-based screening program which identifies glaucoma suspects and offers them free follow-up appointments at the Wilmer Eye Institute. Appointments are scheduled at the time of screening and reminder calls are made for all patients. Screening events were randomized to standard verbal and written counseling offering the individual a free appointment, or counseling in addition to provision of one of two types of vouchers redeemable for free appointments. Both voucher types included the patient’s name, the appointment date and an expiration date 90 days following the screening. One also included the approximate monetary value of the service ($250). The primary outcome was presenting for follow-up within the voucher eligibility period. A hierarchical mixed-effects logistic model allowing for random effects from the screening event was used to assess the effects of each voucher type on presentation to a follow-up appointment. Data collection is ongoing.

Results: Follow-up through November 2017 yielded complete data for 431 glaucoma suspects identified at one of 64 screening events. Overall, 76% of individuals were African American, 65% were female, and the mean age was 69. There were no significant differences in these factors between study arms. Those referred in the traditional manner had a 49% attendance rate, whereas 67% of individuals receiving a voucher without monetary value information and 62% of individuals receiving a voucher with monetary value information presented. For a given screening event, offering vouchers without monetary value information increased the odds of presenting for follow-up by 152% (p =.03) compared to not offering a voucher. Offering vouchers with monetary value information increased the odds of presenting by 112%, but this effect was not significant (p=0.09).

Conclusions: Offering vouchers for redemption of free eye care services increases utilization. Voucher provision may increase perceived value for these services, particularly among low-income minority populations. Further investigation into the elements of vouchers that drive this effect is warranted.