Adherence to anti‐osteoporotic regimens in a Southern Taiwanese population treated according to guidelines: a hospital‐based study

Abstract Aim This study was designed to investigate adherence to anti‐osteoporotic regimens in a population following therapeutic guidelines; and to assess whether this experience differs from that in other administrative surveys. Methods We reviewed an outpatient database to retrieve information on prescription of anti‐osteoporotic medications at a medical centre in T aiwan from 2001 to 2007. Adherence was determined by compliance and persistence. Compliance was calculated by the medication possession ratio ( MPR ), and persistence by the time from treatment initiation to discontinuation. All anti‐osteoporotic regimens were considered equivalent in this study. Results A total of 3589 patients (3256 women and 333 men), with a mean age of 68.6 years, were included. The median MPR at 1 year and at 2 years were 99.7% (interquartile range [ IQR ] 26.8–100) and 61.4% ( IQR 15.3–100), respectively. Good compliance ( MPR ≥ 80%) was 56% at 1 year and 43% at 2 years. Regarding the 30‐day refill gap, mean duration of persistence at 1 year and at 2 years was 243 and 400 days, respectively. About 50.8% of patients continued to receive therapy at 1 year, while 36.1% at 2 years. Our findings are not different from those of other claims‐based studies. The subgroup with MPR ≥ 80% had a higher persistence rate than that with MPR < 80%. Conclusion Overall adherence to anti‐osteoporotic regimens based on guidelines was sub‐optimal in the current study. Our results are in line with previous studies using a claims database. Non‐adherence commonly occurs early after drug initiation, which indicates that efforts should be made to improve adherence as soon as possible.