Compliance assessed by the Medication Event Monitoring System

The accurate assessment of patient compliance is especially crucial in evaluating the efficacy of a new treatment. Because of the problems associated with parenteral desferrioxamine, the development of a safe, effective, and convenient iron chelator is of high priority. The high morbidity and mortality associated with iron overload requires careful evaluation of the ability of any new agent to promote long term effective iron chelation. Patients' compliance with an orally available chelating agent, 1,2,-dimethyl-3-hydroxypyrid-4-one (L1), that has been demonstrated to induce in vivo iron excretion equivalent to that of desferrioxamine during supervised short term administration, was examined. Compliance was assessed in seven patients by patient interview, by daily diaries reviewed monthly with each patient, and with the use of the Medication Event Monitoring System (MEMS) standard pill bottles with microprocessors in the cap that record the timing and frequency of bottle openings. L1 was dispensed in MEMS containers to the patients, who, unaware of their significance, recorded compliance using a daily diary. Overall compliance rate (% of prescribed doses taken) measured by MEMS was 88.7 +/- 6.8%. When 'doubling of doses' was accounted for, significantly poorer compliance with L1 was noted by MEMS (91.7 +/- 7.4%) than by patients' diaries (95.7 +/- 5.2%). There was no significant difference in patient compliance recorded between the first and last 30 day period of drug administration. MEMS can eliminate the confounding variable of erratic patient compliance in the evaluation of a new drug's efficacy. As MEMS cannot distinguish a missed dose from one doubled at the next bottle opening, the use of patient diaries is a useful adjunct to the accurate assessment of compliance and should be combined with the use of MEMS.