Visit adherence and visual acuity outcomes in patients with diabetic macular edema: a secondary analysis of DRCRnet Protocol T.

ABSTRACT

PURPOSE: To quantify the association between visit adherence and visual acuity (VA) in diabetic macular edema (DME). METHODS: This secondary analysis of the 2-year DRCRnet Protocol T study of 656 patients required one visit every 4 weeks in the first year, then at variable 4-16-week intervals in the second year. Visit adherence measured as number of missed visits, average (avg days) and longest (max days) visit interval, average (avg missed days) and longest (max missed days) unintended visit interval, and visit constancy (percentage of 3-month periods with at least 1 visit). Avg and max missed days were categorized as on time (0 days), late (> 0-60 days), and very late (> 60 days). Primary outcome was change in ETDRS VA between baseline study visit and last attended visit, using multivariate linear regression models controlling for age, gender, race, ethnicity, treatment arm, baseline VA, hemoglobin A1c, insulin use, and number of lasers and injections. RESULTS: Mean number of missed visits was 1.7. 616 (94%) patients had 100% visit constancy. A total of 331 (51%) patients were on time, 171 (26%) late, and 154 (23%) very late in avg missed days. Max missed days ranged 0-696 days. Adjusted, each missed visit was associated with 0.3-letter decrease (95%CI - 0.6, - 0.1, p = 0.02); being very late in avg and max missed days saw - 4.2 letters (95%CI - 6.4, - 2.0, p < 0.001) and - 4.0 letters (95%CI - 6.1, - 1.9, p < 0.001), respectively, than on time. Those that averaged > 4 days missed per attended visit saw 4.6 letters worse (95%CI - 7.3, - 2.0, p < 0.001). CONCLUSIONS: Visit adherence is associated with visual acuity outcomes in DME patients.