A systematic review including 29 studies with a total of 12 835 subjects was abstracted in DARE. Statistically significant improvements in adherence were observed in single-blind trials of worksite care, physician education, and an electronic vial cap, and in unblinded trials of patient cards and calendar packaging. There was insufficient evidence to support the effectiveness of mailed reminders alone, according to unblinded trials. Adherence results were conflicting for patient education and inconclusive for patient counselling. Self-monitoring was deemed ineffective according to single-blind trials.
The results for meeting the goal diastolic blood-pressure, when evaluated (if data were available), were generally in accordance with those for adherence.
Comment: The quality of evidence is downgraded by inconsistency (heterogeneity in interventions and outcomes).