Date of Award

January 2026

Document Type

Open Access Thesis

Degree Name

Medical Doctor (MD)

Department

Medicine

First Advisor

Kristen H. Nwanyanwu

Abstract

Proliferative diabetic retinopathy (PDR) affects approximately 7% of individuals with diabetes and requires consistent follow-up to prevent irreversible vision loss. Despite this, lapses in PDR care are common, but poorly characterized. We conducted a two-phase mixed-methods evaluation, including a quantitative retrospective national cohort study of individuals with PDR, followed by a qualitative study investigating participant perspectives on their own lapses in PDR care. In the quantitative component, we used data from 13 academic health systems in the Sight Outcomes Research Collaborative (SOURCE) Repository between 2008 and 2023 to identify adults aged ≥18 with PDR and ≥6 months of ophthalmic follow-up. We defined a lapse in care as any interval ≥6 months between ophthalmology visits. We used multivariable logistic and linear mixed effects regression models to assess factors associated with lapse occurrence and duration. We compared visual acuity between lapse duration groups after return to care and at 6- and 12-month post-lapse visits. In the qualitative phase, we conducted semi-structured interviews with individuals with PDR who had experienced a lapse in care. We coded transcripts using a codebook developed through iterative discussion. We conducted thematic analysis to review and synthesize coded data for core themes and subthemes. Of 15211 individuals in the quantitative phase, 71.8% (10915) experienced a lapse in care. Mean lapse duration was 383 days and 14.2% had a lapse >24 months. Lapses were more common among non-Hispanic Black individuals (aOR 1.26; 95% CI 1.07-1.48) and individuals with disabilities (aOR 1.52; 95% CI 1.23-1.88) and complicated hypertension (aOR 1.34; 95% CI 1.02-1.77), and less common for younger individuals (e.g., age 56-65 relative to ≤55, aOR 0.81; 95% CI 0.69-93), those with poor vision (e.g., visual acuity 20/50-20/200 relative to 20/40 or better, aOR 0.79; 95% CI 0.70-0.90), or prior PDR treatment (e.g., panretinal photocoagulation only relative to none, aOR 0.60; 95% CI 0.48-0.75). Older age (e.g., age 56-65 relative to ≤55, Mean lapse duration ratio 0.94; 95% CI 0.91-97) and PDR treatment (e.g., panretinal photocoagulation only relative to none, Mean lapse duration ratio 0.96; 95% CI 0.92-1.00) predicted shorter lapses, and residence in distressed areas predicted longer lapses (highest quartile distress relative to lowest, Mean lapse duration ratio 1.06, 95% CI 1.02-1.10). Visual acuity worsened following lapses (all p<0.001), with greater declines after longer lapses. From 17 interviews in the qualitative phase, we identified seven major themes affecting participants’ adherence to retina subspecialist follow-up: (1) perceived importance of eye care, (2) clinic processes, (3) resource availability, (4) competing obligations, (5) physician-patient relationship, (6) treatment experience, and (7) affective response. We synthesized these themes as relating to the perceived importance, accessibility, and desirability of attending follow-up care. Notable subthemes included worsening vision as a wake-up call, the compounding effect of diabetic retinopathy, expectation versus reality of the treatment experience, and emotional exhaustion associated with medical demands. This work demonstrates that prolonged lapses in PDR were common, disproportionately affected racially and ethnically minoritized, sicker, older, and better-seeing groups, and were associated with persistent vision loss. Our qualitative findings highlight important barriers and facilitators that may contribute to these lapses in care.

Comments

This is an Open Access Thesis.

Download
Open Access

This Article is Open Access

Share

COinS