Effects of intervention on antibiotic compliance in patients in general practice.

This study used a randomized clinical control design to test first, whether decreasing the complexity of antibiotic regimens resulted in increased compliance and, secondly, whether the added component of written information and behavioural tailoring increased compliance in patients with twice-a-day schedules. Twenty-eight general practitioners who were selected at random and 232 of their patients took part in the study. Patients were allocated at random to receive either doxycycline (one dose a day); co-trimoxazole (two doses a day); amoxycillin (three doses a day); or co-trimoxazole (two doses a day) with a written instruction sheet and advice on how to best fit the tablets into a daily routine. Decreasing complexity of the regimen significantly increased the probability that patients would not miss any doses of the course (absolute compliance: chi 2 = 25.04; df = 2; P less than 0.001). There was also a significant association between complexity and non-compliance at a level which might be clinically significant (chi 2 = 6.78; df = 2; P = 0.03). Written information and behavioural tailoring did not further augment compliance in patients with one- or two-doses-a-day schedules. It was also shown that general practitioners predicted potential non-compliance in patients at a rate no better than would be expected by chance.