Osteoporosis and venous thromboembolism: A retrospective cohort study in the UK General Practice Research Database

Abstract

Summary: In a retrospective cohort study using the General Practice Research Database (GPRD), there was a greater association of venous thromboembolism (VTE) in osteoporotic than in non-osteoporotic female patients. No greater association was shown in treated patients with strontium ranelate or alendronate compared to untreated osteoporotic female patients. Introduction: We explored the risk of VTE in usual practice in osteoporotic and non-osteoporotic women with and without anti-osteoporotic treatment. Methods: A retrospective study was conducted using the GPRD in the UK. The cohorts consisted of untreated osteoporotic women (N=11,546), osteoporotic women treated with alendronate (N=20,084), or strontium ranelate (N=2,408), and a sample of non-osteoporotic women (N= 115,009). Cohorts were compared using a Cox proportional hazards regression model. Results: There was a significantly increased relative risk for VTE in untreated osteoporotic women versus non-osteoporotic women (annual incidence 5.6 and 3.2 per 1,000 patient-years, respectively; relative risk 1.75 [95% confidence interval (CI), 1.09-1.84]). Results were confirmed using adjusted models. The annual incidences of VTE in osteoporotic patients treated with strontium ranelate and alendronate were 7.0 and 7.2 per 1,000 patient-years, respectively, with no significant difference between untreated and treated patients whatever the treatment. Adjusted hazard ratios for treated versus untreated osteoporotic women were 1.09 (95% CI, 0.60-2.01) for strontium ranelate and 0.92 (95% CI, 0.63-1.33) for alendronate. Conclusion: This study shows a greater association of VTE in osteoporotic compared to non-osteoporotic patients, but does not show any greater association in treated patients with strontium ranelate or alendronate compared to untreated osteoporotic patients. © The Author(s) 2009.