Chronic pharmacologic treatments have the risk of low adherence and persistence which depend on the disease severity, preventive objectives, co-morbidity, other concurrent medications (polymedication) and adverse events. Wade and colleagues  reported follow-up data regarding osteoporosis medication persistence and switching at 24 months and 36 months in postmenopausal women from the cohort of the US Prospective Observational Scientific Study Investigating Bone Loss Experience (POSSIBLE). Postmenopausal women ([i]n[/i] = 3011) were enrolled by 134 primary-care physicians who were considered to be the top 40% prescribers of osteoporosis medications in 2003. Medications initially prescribed were oral bisphosphonates (alendronate, risedronate, or ibandronate), oral or transdermal postmenopausal estrogen (PME), parathyroid hormone, calcitonin, raloxifene, or a non-prescription agent (calcium and/or vitamin D supplement).
At baseline, bone mineral density (BMD) corresponded in 50% to osteopenia, in 44% to osteoporosis, and the remaining 6% did not have a densitometry measurement or had another diagnosis. Mean body mass index and age for the entire population were 26.5 kg/m[+]2[/+] (95% confidence interval 26.3–26.7) and 64.6 years, respectively. Twenty-three percent had a history of fractures since the age of 45 years and 9% were current smokers. Patients completed questionnaires at baseline and at semi-annual intervals regarding sociodemographic and lifestyle characteristics, the osteoporosis medications they used, the European osteoporosis-specific health-related quality of life (EuroQoL EQ-5D) and the short version of the Osteoporosis Assessment Questionnaire. Physician-relevant medical data were updated at routine visits during the 3 years of follow-up. Persistence of treatment at 24-month follow-up was 46.2% and at 36 months 36.8%. Women who initiated with a bisphosphonate and then switched during follow-up persisted using the same type of medication. Women who switched from a non-bisphosphonate treatment (including PME) were most likely to switch to a bisphosphonate. In addition, those who used PME at study entry were more likely to completely discontinue therapy both at the 24- and 36-month follow-up.
Predictors of non-persistence in newly initiating therapy or switching to a new treatment were side-effects, low quality of life, smoking and site of residency. Forty-two percent of participants had at least 24 months of treatment persistence and 28% persisted under treatment at the 36 months of follow-up.
Faustino R. Pérez-López
Professor of Obstetrics & Gynecology, University of Zaragoza Faculty of Medicine and Lozano Blesa University Hospital, Zaragoza, Spain