Conducting an observational study during an economic crisis: analysis of the treatment and follow-up phase of Greek patients participating in the ExFOS study.

OBJECTIVE: We present the subanalysis of the Greek cohort of the Extended Forsteo Observational Study (ExFOS), a multicenter, non-interventional, prospective, observational study evaluating the effect of teriparatide on fractures, back pain (BP), health-related quality of life (HR-QoL), and safety and compliance, in patients with osteoporosis treated for up to 24 months, with a post-treatment follow-up of at least 18 months.

DESIGN: A total of 439 osteoporotic patients (92.2% female) were enrolled in Greece. New or worsened fractures, based on their physicians' assessment, as well as patients' self-assessment of HR-QoL and BP, compliance, and safety profile, were captured by validated questionnaires.

RESULTS: In the ExFOS Greek cohort, fracture rates were low and mean bone mineral density (BMD) was numerically improved. Compliance with teriparatide remained high throughout the study, with 81.5% of subjects completing treatment. Only 0.7% of patients reported discontinuation due to adverse effects. A sustainable improvement in patient-perceived BP and HRQoL throughout treatment and follow-up was similar to that achieved by the European Forsteo Observational Study (EFOS). A lower than expected percentage of patients using antiresorptives following teriparatide was recorded.

CONCLUSIONS: ExFOS reproduces the outcomes of EFOS, with a 6.5-year time interval between studies, in comparable cohorts of osteoporotic patients. Data should be interpreted in the context of observational study data collection, although summary statistics computed at each time point may overstate drug effect.