Outpatient compliance with theophylline and phenytoin therapy

Poor compliance with prescribed medication is a significant problem in chronic disease states and is often responsible for the apparent failure of therapy. The determinants and extent of non-compliance are commonly incorrectly perceived by doctors. During routine therapeutic drug monitoring of epileptic and asthmatic outpatients at a local day hospital, non-compliance was identified as a significant problem. A compliance study was conducted on 80 epileptic and asthmatic patients to determine the nature and extent of this problem. Non-compliance was measured using four different methods, which were then compared using chi 2 tests. Overall incidence of non-compliance was found to be 63%. Age, sex, standard of education and duration of disease were found to have no association with non-compliance. The most clinically significant finding was that almost half the patients were unaware of the necessity of taking their medication on a continuous basis. No significant differences existed between assessing non-compliance using tablet counts, patient interview and clinic attendance, whereas the method using blood levels gave significantly different results from all the other methods used.