Access, Adherence and Patient-Reported Outcomes of Hydroxyurea Therapy in Sickle Cell Disease: A Cross-Sectional Study from Nigeria

Abstract

Background: Hydroxyurea is the most accessible disease-modifying therapy for sickle cell disease (SCD), but in many low- and middle-income countries its real-world benefit is constrained by gaps in awareness, uptake, continuity, and adherence. We analyzed the full hydroxyurea pathway—uptake, discontinuation, adherence, and patient-reported outcomes—in a Nigerian cross-sectional cohort. Methods: We conducted a cross-sectional analysis of questionnaire data from 117 adult respondents with self-reported sickle cell disease. Composite scores were derived for patient-reported quality of life (QoL) and disease burden using ordinal survey items. Four multivariable logistic regression models were fitted to identify predictors of current hydroxyurea uptake (all respondents), discontinuation (ever-users), full adherence (current users), and better patient-reported outcome defined as a high QoL composite score. Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were reported. Results: The mean age was 30.8 ± 10.2 years, and 83 (70.9%) were female. Current hydroxyurea use was reported by 50 (42.7%), while 17 (14.5%) had discontinued and 8 (6.8%) had never heard of hydroxyurea. Among ever-users, 50 (74.6%) were current hydroxyurea users, while 17 (25.4%) had discontinued treatment. Full adherence among current users was 36 (72.0%). In multivariable analysis, higher disease burden independently predicted hydroxyurea uptake (aOR 2.06, 95% CI 1.02–4.13; p=0.043), whereas lower disease burden predicted full adherence (aOR 0.27, 95% CI 0.08–0.89; p=0.032). Higher disease burden strongly predicted worse patient-reported outcome (aOR 0.19, 95% CI 0.08–0.44; p<0.001). Adherent current users had lower disease-burden scores than non-adherent current users (median 2.00 vs 2.71; p=0.009) and numerically higher QoL scores (median 3.75 vs 3.25; p=0.111). Cost was the dominant barrier to use. Conclusion: Hydroxyurea use was limited by gaps in uptake, continuity, and adherence. The greatest benefit was seen among patients able to sustain regular treatment, while cost remained the major barrier. These findings support hydroxyurea subsidization, adherence support, and stronger integration of hydroxyurea into comprehensive SCD care in Nigeria.