Patient compliance with drug therapy for postmenopausal osteoporosis

ABSTRACT

To determine compliance and factors affecting compliance to antiresorptive drugs in osteoporosis, and to compare compliant and non compliant groups in a tertiary care setting. Cross sectional study from May 2004 to April 2007. Hamdard University Hospital, Karachi. A total of 800 patients with postmenopausal osteoporosis were included in the study. The demographic and reproductive characteristics of all the patients were recorded Type of anti-resorptive drugs prescribed, degree of compliance, time and reasons for discontinuation were studied and analyzed. Results: The mean age of the patients was 64 [ +/- 9] years and their mean duration of follow-up 18 [ +/- 5] months. The prevalence of risk factors for osteoporosis were evenly distributed among treatment groups; 73% patients had a co-morbidity besides osteoporosis while 27% were osteoporotic alone. One or more previous vertebral fractures due to osteoporosis was reported by 14.5% of patients, whereas 35.5% had at least one non-vertebral fracture in their medical history. Out of the total patients 21.5% discontinued the prescribed drug before attending the bone mass re-evaluations, more than half of these within first six months of starting the drugs. The medication that was most frequently discontinued within one year was calcium and vitamin-D [33.7%, p < 0.01] while the least discontinued medication was Alendronate [5.9%, p < 0.01] which is taken once a week. In this study the most important determinant of compliance was the type of drug prescribed and its dose frequency, with a definite preference for Alendronate once a week. Treatment compliance was particularly poor for calcium and vitamin-D regimen, thereby emphasizing the need to find new ways of administering supplements, particularly for vitamin-D