Prescription of anti-osteoporosis drugs during 2004-2007-a nationwide register study in Norway

To assess 1-year prevalence, incidence rates and minimum refill of anti-osteoporosis drug use in Norway by age, gender and place of residence during 2004-2007. Data from patients aged a parts per thousand yen 40 years receiving anti-osteoporosis drugs (AOD) were retrieved from the Norwegian Prescription Database (NorPD). AOD were defined as bisphosphonates (alendronate with or without cholecalciferol, risedronate, ibandronate and etidronate with or without calcium), raloxifene, teriparatide and nasal calcitonin. The NorPD covers the total Norwegian population in ambulatory care. Key measurements were 1-year prevalence, incidence rate and minimum refill. Among Norwegian women and men a parts per thousand yen 40 years, 4.3 and 0.45% respectively used AOD in 2004. In 2007, the prevalence of AOD use had slightly increased to 4.6% in women and to 0.52% in men. In 2007, 90% of users were women. The use of alendronate, representing 88% of all AOD use in 2007, increased from 2004 to 2007 while the use of other bisphosphonates decreased. The counties with highest overall bisphosphonate use were the counties with the historically lowest incidence of osteoporotic fractures. The incidence rate of overall bisphosphonate use decreased from 2005 to 2007. Among those patients who were dispensed a bisphosphonate in 2005, 72% refilled at least one prescription both in 2006 and 2007. There was an increasing prevalence and a decreasing incidence of AOD use over this limited time period. There was substantial geographical variation in the prevalence of anti-osteoporosis drugs. We also observed a high minimum refill rate.