PATTERNS OF DRUG COMPLIANCE WITH MEDICATIONS TO BE TAKEN ONCE AND TWICE-DAILY ASSESSED BY CONTINUOUS ELECTRONIC MONITORING IN PRIMARY-CARE

Adherence to drug treatment is difficult to assess in routine medical practice. Therefore, electronic compliance monitoring and a new comput er software program, the PC-RDP (Reader, Display, Printer) system was used. It allows instant evaluation of a patient's dosing record, at th e patient's return to the practice. Compliance was measured in 24 pati ents on antihypertensive treatment, either continuous (n = 8) or newly prescribed treatment (n = 16) in primary care, for a total period of 5144 patient days. Fifteen patients received compliance feedback by th eir physician, 9 did not receive feedback. The drugs prescribed were t riamterene plus hydrochlorothiazide, as a single dose, once daily (QD) , and nifedipine twice daily (BID). The mean percentages of prescribed doses taken were 89% (QD) and 88% (BID). Partial compliance was 10 ti mes more often (1243 days) than overcompliance (114 days), and days wi thout dosing were observed twice as frequently with the QD than the BI D regimen. Omissions of doses occurred more often on weekends than any other day of the week. With the BID regimen, evening doses were omitt ed twice as often as morning doses. When treatment was initiated, comp liance was consistently high until the end of the study period, wherea s in patients on continuous treatment, it decreased over time. Both co mpliance feedback (n = 11/16) and the beginning of treatment may be im portant factors to explain the difference in compliance behavior. An i mplementation of compliance monitoring into practical patient care see ms to be feasible and promising.