Cataract and risk of fracture: a systematic review, meta-analysis, and bayesian network meta-analysis

Topic: To evaluate the odds ratio (OR) and hazard ratio (HR) of bone fracture in phakic subjects with cataract compared to phakic subjects without cataract and pseudophakic individuals. Clinical relevance: Despite the growing recognition of the potential link between cataract and fracture, the available evidence remains inconclusive. Methods: The results of this systematic review and meta-analysis were reported according to the PRISMA guidelines. The study protocol was prospectively registered on the International Prospective Register of Systematic Reviews (ID: CRD42024587477). Four electronic databases were searched from their inception to May 2024: PubMed, EMBASE, Web of Science, and CINAHL. Two independent reviewers performed title and abstract screening, full-text assessment, and study quality appraisal. Frequentist inference meta-analysis and Bayesian network meta-analysis (NMA) were conducted to assess OR and HR of fracture among the three groups of interest. Results: Sixteen articles met the predefined inclusion and exclusion criteria, with 11 included in the quantitative synthesis, encompassing a population of 4,713,458 subjects and reporting on 284,811 fractures. The certainty of evidence was rated from low to moderate. Compared to subjects without cataract, the OR and the HR for fractures in the cataract group were 1.44 (95% CI: 0.75 to 2.75; p > 0.05) and 1.51 (95% CI: 1.14 to 2.01; p = 0.0152), respectively. Bayesian NMAs indicated that subjects with cataracts have an increased odds and hazard of fractures compared to both phakic subjects without cataracts (OR: 3.0 [95% Credible Interval (95% CrI): 2.8 to 3.3]; HR 1.1 [95%CrI: 1.09 to 1.12]) and pseudophakic individuals (OR: 1.7 [95%CrI: 1.6 to 1.8]; HR: 1.28 [95%CrI: 1.24 to 1.31]). Pseudophakic individuals exhibit a 27% reduction in fracture risk compared to phakic individuals with cataract, with 1 fewer fracture event occurring for every 8 pseudophakic subjects. Conclusion: Low-certainty evidence suggests a higher fracture risk in individuals with cataract compared to those without. Moderate-certainty evidence indicates that pseudophakic individuals have the lowest fracture risk compared to phakic patients, with or without cataracts. Further research should explore the causal link between cataracts and fracture risk and evaluate the impact of cataract surgery on fracture prevention.