Abstract
OBJECTIVE: The current study aimed to systematically and quantitatively evaluate the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) in predicting mortality among surgical patients with hip fractures through a systematic review and meta-analysis. DESIGN: Systematic review and meta-analysis. METHODS: Four databases-The Cochrane Library, PubMed, Embase, and Web of Science-were comprehensively retrieved to identify studies published from database inception to May 2025 that investigated NLR as a predictor of postoperative survival in hip fracture individuals. Two independent researchers performed study selection, data extraction, and quality assessment, with consistency verified via cross-checking. Statistical analyses were performed using Stata 15.0 for meta-regression and heterogeneity testing, while prognostic performance metrics (sensitivity, area under the curve [AUC], specificity) were synthesized via Meta-Disc 1.4. RESULTS: Our meta-analysis incorporated 12 studies, involving 10,015 individuals who underwent surgery for a hip fracture. With cut-off values ranging from 3.2 to 8.4, preoperative NLR demonstrated high prognostic efficacy for mortality prediction, yielding a combined sensitivity of 0.69 (95% CI 0.55-0.83), specificity of 0.84 (0.74-0.93), diagnostic odds ratio (DOR) of 12 (6-26), and an area under the summary receiver operating characteristic curve (sAUC) of 0.84 (0.81-0.87). Subgroup analysis of preoperative NLR thresholds revealed that higher cut-off values (NLR > 5) significantly improved prognostic performance. NLR exhibited superior sensitivity but slightly lower specificity in patients from developing countries, with particular prognostic utility for long-term mortality (≥ 1 year). Postoperative NLR showed moderate prognostic efficacy, with a combined sensitivity of 0.64 (0.57-0.70), specificity of 0.58 (0.55-0.61), DOR of 2 (2-3), and sAUC of 0.62 (0.58-0.66). CONCLUSION: This meta-analysis confirms that the preoperative NLR is a promising albeit preliminary predictor of postoperative mortality in hip fractures.