Adherence and clinical outcomes among patients with sickle cell disease receiving prophylactic therapy in Bamenda, Cameroon: a cross-sectional study

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Abstract Background Long-term prophylactic therapy is central to sickle cell disease (SCD) care, but evidence on medication adherence and patient-reported outcomes in Cameroon remains limited. We assessed SCD medication adherence and compared clinical outcomes before and during clinic-based prophylactic therapy. Methods A cross-sectional study was conducted at St Maria Soledad Catholic Hospital in Bamenda, Cameroon, from August to October 2024. Participants with SCD who had received hydroxyurea and folic acid, with age-appropriate penicillin prophylaxis, for at least 12 months were consecutively recruited. An adapted Hill-Bone medication adherence scale questionnaire was scored from 0 to 7, with higher scores indicating better adherence. Self-reported outcomes during the 12 months before enrollment in the prophylaxis program and the subsequent 12 months in the program were compared using paired McNemar tests. Factors associated with medication adherence score were examined using linear regression with Huber-White robust standard errors. A p-value < 0.05 was considered significant. Results Among 105 participants, the median age was 11 years (interquartile range [IQR], 7–16), and the median age at SCD diagnosis was 5 years (IQR, 2–6). The median adherence score was 5 (IQR, 5–6); 80 participants (76.2%) had a score of at least 5. Forgetting medication was reported by 59.0%, intentional nonuse by 30.5%, and running out of medication by 21.0%. Compared with the preceding 12 months, the proportions requiring transfusion (65.7% vs. 14.3%), experiencing at least three pain crises (67.6% vs. 30.5%), having at least three SCD-related hospitalizations (71.4% vs. 31.4%), having at least three non-SCD physician consultations (66.7% vs. 29.5%), and having a maximum hospital stay of at least 5 days (81.0% vs. 49.5%) were lower during prophylaxis (all p < 0.001). Age 10 years or younger was associated with a higher adherence score only in univariable analysis; no covariate was independently associated with adherence after adjustment. Conclusions Within this single-center clinic cohort, medication adherence to SCD prophylaxis was generally favorable, although forgetfulness, intentional nonuse, and medication supply interruptions remained significant barriers. The marked reductions in selected clinical and healthcare-utilization outcomes during prophylaxis highlight the potential value of sustained, comprehensive SCD care. Strengthening access, continuity of treatment, and adherence support should remain clinical and public health priorities, while prospective controlled studies are needed to confirm causality.