Peripheral arterial disease and risk of hip fracture: A systematic review and meta-analysis of cohort studies

Background: Previous studies have suggested an increased risk of hip fracture among patients with peripheral arterial disease (PAD), however, the results have been inconsistent. This meta-analysis was conducted with the aim to summarize all available evidence to better characterize the risk of incident hip fracture among these patients. Materials and Methods: A comprehensive literature review was conducted using the MEDLINE and EMBASE databases through October 2017 to identify all cohort and case-control studies that compared the risk of subsequent hip fracture between patients with PAD and individuals without PAD. Effect estimates of the included studies were extracted and combined using the random-effect, generic inverse variance method of DerSimonian and Laird. Results: The systematic review process yielded six eligible cohort studies comprising 15,895 patients with PAD. There was a significant association between incident hip fracture and PAD with the pooled relative risk (RR) of 1.64 (95% CI, 1.17-2.29; I-2, 80%), comparing patients with PAD and individuals without PAD. Subgroup analysis by study design revealed significant results for both prospective studies (pooled RR 1.60; 95% CI, 1.12-2.28; I-2, 0%) and retrospective studies (pooled RR 1.72; 95% CI, 1.07-2.77; I-2, 92%). The funnel plot is relatively asymmetric suggesting publication bias. Conclusion: This study found a significant association between PAD and hip fracture with the pooled RR of 1.64 (95% CI, 1.17-2.29) on comparing patients with PAD and individuals without PAD. Major limitations include high between-study heterogeneity, possibility of publication bias, and lack of data on the characteristics and type of hip fracture which may limit the clinical significance of the observations.