Correlation between C-reactive protein and postoperative mortality in patients undergoing hip fracture surgery: a meta-analysis

Background: Hip fracture is a common but devastating disease with a high mortality rate in the older adult population. C-reactive protein (CRP) is a predictor of the prognosis in many diseases, but its correlations with patient outcomes following hip fracture surgery remain unclear. In this meta-analysis, we investigated the correlation between perioperative CRP level and postoperative mortality in patients undergoing hip fracture surgery. Methods: PubMed, Embase, and Scopus were searched for relevant studies published before September 2022. Observational studies investigating the correlation between perioperative CRP level and postoperative mortality in patients with hip fracture were included. The differences in CRP levels between the survivors and nonsurvivors following hip fracture surgery were measured with mean differences (MDs) and 95% confidence intervals (CIs). Results: Fourteen prospective and retrospective cohort studies comprising 3986 patients with hip fracture were included in the meta-analysis. Both the preoperative and postoperative CRP levels were significantly higher in the death group than in the survival group when the follow-up duration was ≥ 6 months (MD: 0.67, 95% CI: 0.37–0.98, P < 0.0001; MD: 1.26, 95% CI: 0.87–1.65, P < 0.00001, respectively). Preoperative CRP levels were significantly higher in the death group than in the survival group when the follow-up duration was ≤ 30 days (MD: 1.49, 95% CI: 0.29–2.68; P = 0.01). Conclusions: Both higher preoperative and postoperative CRP levels were correlated with higher risk of mortality following hip fracture surgery, suggesting the prognostic role of CRP. Further studies are warranted to confirm the ability of CRP to predict postoperative mortality in patients with hip fracture.