The aim of this study was to investigate the effect of bisphosphonates on preventing osteoporotic hip fracture in patients with or without prior major osteoporotic fracture. Randomized controlled trials (RCTs) and observational studies (OSs) based on electronic health records were used to assess bisphosphonate efficacy and were searched using PubMed, Scopus, and the Cochrane Library databases. Eight RCT studies and 14 OSs were extracted from the studies and quantitatively combined by random-effects meta-analysis. The odds ratio (OR) for all hip fractures in RCTs of 0.66, with a 95% confidence interval (CI) of 0.55-0.79, was lower than that in the OSs (OR 0.83; CI 0.74-0.94). The OR in patients with prior fracture was significantly reduced by bisphosphonates in both RCTs and OSs. Conversely, significant fracture reduction was not apparent in patients without prior fracture. A moderate relationship between prior major fracture rates and OR in hip fractures was defined. In patients with an average age of over 80 years, similar results were confirmed. In this meta-analysis, the efficacy of bisphosphonates was significant in patients with prior major fracture, recommending to prescribe for such patients. Their effect in patients without prior fracture, in contrast, remains unclear.
Keywords: Bisphosphonate; Cross-design synthesis; Hip fracture; Meta-analysis; Prior fracture.