title: Potential clinical and economic impact of nonadherence with osteoporosis medications.
abstract: This study aims to estimate the potential clinical and economic implications of therapeutic adherence to bisphosphonate therapy. A validated Markov microsimulation model was used to estimate the impact of varying adherence to bisphosphonate therapy on outcomes (the number of fractures and the quality-adjusted life-years [QALYs]), health-care costs, and the cost-effectiveness of therapy compared with no treatment. Adherence was divided into persistence and compliance, and multiple scenarios were considered for both concepts. Analyses were performed for women aged 65 years with a bone mineral density T-score of -2.5. Health outcomes and the cost-effectiveness of therapy improved significantly with increasing compliance and/or persistence. In the case of real-world persistence and with a medical possession ratio (MPR; i.e., the number of doses taken divided by the number of doses prescribed) of 100%, the QALY gain and the number of fractures prevented represented only 48 and 42% of the values estimated assuming full persistence, respectively. These proportions fell to 27 and 23% with an MPR value of 80%. The costs per QALY gained, for branded bisphosphonates (and generic alendronate), were estimated at 19,069 euros (4,871 euros), 32,278 euros (11,985 euros), and 64,052 euros (30,181 euros) for MPR values of 100, 80, and 60%, respectively, assuming real-world persistence. These values were 16,997 euros (2,215 euros), 24,401 euros (6,179 eruos), and 51,750 euros (20,569 euros), respectively, assuming full persistence. In conclusion, poor compliance and failure to persist with osteoporosis medications results not only in deteriorating health outcomes, but also in a decreased cost-effectiveness of drug therapy. Adherence therefore remains an important challenge for health-care professionals treating osteoporosis.
authors.affiliation: HEC-ULg Management School, University of Liège, Boulevard du Rectorat 7, Bât. B31, 4000 Liège, Belgium. m.hiligsmann@ulg.ac.be
authors.forename: Mickaël
authors.initials: M
authors.lastname: Hiligsmann
authors.forename: Véronique
authors.initials: V
authors.lastname: Rabenda
authors.forename: Henry-Jean
authors.initials: HJ
authors.lastname: Gathon
authors.forename: Olivier
authors.initials: O
authors.lastname: Ethgen
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Reginster
mesh_terms: D000368:Aged; D001530:Belgium; D050071:Bone Density Conservation Agents / Q000008:administration & dosage / Q000191:economics*; D002908:Chronic Disease / Q000188:drug therapy; D017281:Cost of Illness; D003362:Cost-Benefit Analysis / Q000706:statistics & numerical data / Q000639:trends; D004164:Diphosphonates / Q000008:administration & dosage / Q000191:economics*; D018450:Disease Progression; D004334:Drug Administration Schedule; D016527:Drug Costs / Q000706:statistics & numerical data* / Q000639:trends; D005252:Fees, Pharmaceutical / Q000706:statistics & numerical data / Q000639:trends; D005260:Female; D050723:Fractures, Bone / Q000209:etiology / Q000517:prevention & control; D017048:Health Care Costs / Q000706:statistics & numerical data / Q000639:trends; D006801:Humans; D008390:Markov Chains; D018803:Models, Economic; D009313:National Health Programs / Q000191:economics / Q000706:statistics & numerical data / Q000639:trends; D010024:Osteoporosis / Q000188:drug therapy* / Q000191:economics*; D010349:Patient Compliance / Q000706:statistics & numerical data*; D016896:Treatment Outcome
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates