Compliance with penicillin prophylaxis in patients with sickle cell disease.

OBJECTIVE: To assess factors related to compliance with penicillin prophylaxis among patients with sickle cell disease.
DESIGN: Prospective case series.
SETTING: Urban pediatric medical center where universal penicillin prophylaxis is recommended for all patients with any sickle cell hemoglobinopathy independent of age. PARTICIPANTS: Eligible patients with sickle cell hemoglobinopathies were enrolled in either the emergency department or the sickle cell clinic. MAIN OUTCOME MEASURES: Compliance was assessed by structured interview and by urine assay with an established method (Micrococcus luteus with disk diffusion) that detects excreted penicillin up to 15 hours after each dose administration.
RESULTS: Of the 159 patients actively followed up at the sickle cell center, 123 (77.3%) eligible patients were enrolled. Reported compliance by structured interview (> or = 1 dose of penicillin V potassium within 15 hours of enrollment) was 83 of 123 patients (67.5%; 95% confidence interval, 59.2%-75.8%), whereas measured compliance as determined by urine assay was 53 of 123 patients (43.1%; 95% confidence interval, 31.3%-51.7%). Measured compliance was significantly greater in patients younger than 5 years than in those older than 5 years (25/41 [61%] vs 28/82 [34%], respectively; P = .004), and was significantly greater in patients with private insurance than in those with public insurance (17/28 [61%] vs 33/90 [37%], respectively; P = .02). Measured compliance was not significantly associated with sex, site of recruitment, hemoglobinopathy, or chief complaint in the emergency department.
CONCLUSIONS: Measured compliance was poor, and patients and/or their families frequently misrepresented their compliance when interviewed. These data suggest that efforts are necessary to improve overall compliance, and they identify groups at greatest risk for noncompliance.