Impact of Compliance and Side Effects on the Clinical Outcome of Patients Treated With Oral Erythromycin

STUDY OBJECTIVE: To determine the relationship among compliance, side effects, and self-reported outcome for patients in an erythromycin trial. DESIGN: A retrospective analysis of data from a multicenter, prospective, single-blind, randomized trial. SETTING: Five metropolitan ambulatory care offices. PATIENTS: The 252 adults (> 18 yrs) were prescribed oral erythromycin 1.0 g/day (base equivalent) for infectious disorders. INTERVENTION: Subjects received erythromycin for 10 days and reported compliance, drug efficacy, and side effects in a daily diary. Compliance was measured by tablet count. RESULTS: A negative correlation was found between gastrointestinal symptom severity score and percentage of tablets taken (p < 0.001). A significant positive correlation was seen between compliance and outcome (p < 0.001). Subjects who took greater than 80% of the drug achieved the treatment goal more frequently than those taking 80% or less (94% vs 59%, p < 0.001). CONCLUSIONS: Side effects of erythromycin adversely affected compliance. Compliance had a positive effect on self-reported outcome.