Frontiers in Medicine · Oct 31, 2026
Admission pan-immune-inflammation value and long-term mortality after hip fracture surgery in older adults: a retrospective cohort study
By Si-Cheng Wang, Xincun Qiao, Xiao-Jie Cheng et al.
Abstract Objective: To evaluate the association between admission pan-immune-inflammation value (PIV) and long-term all-cause mortality after hip fracture surgery in older adults, with particular attention to the shape of this association. Methods: This retrospective cohort included surgically treated adults aged ≥65 years with femoral neck or intertrochanteric fractures at a tertiary hospital between January 2015 and September 2019. PIV was calculated from the first blood sample collected within two hours of admission. Multivariable Cox regression, restricted cubic splines, exploratory piecewise modeling, and sensitivity analyses were performed. Results: Among 2,305 patients, 709 deaths occurred (30.8%), and median potential follow-up was 45.21 months. The highest versus lowest PIV tertile was associated with greater mortality (adjusted HR 1.3429, 95% CI 1.1204–1.6096). The full-cohort spline showed a nonlinear association (overall P=0.0039; nonlinearity P=0.0033), with increasing hazard across the central PIV range and an attenuated slope at higher values. The exploratory piecewise point was 1,958.6: HRs per 100 units were 1.0246 (95% CI 1.0107–1.0386) below and 0.9992 (95% CI 0.9943–1.0042) above this point. Its bootstrap interval was broad (209.2–2,375.5), and curve shape was sensitive to upper-tail handling. The highest-tertile association persisted after expanded adjustment and multiple imputation (HR 1.4968, 95% CI 1.2435–1.8017). The single raw-scale linear term was not significant. Conclusion: Higher admission PIV was associated with greater long-term all-cause mortality after hip fracture surgery in older adults. This readily available marker may complement assessment of physiological vulnerability, while its added prognostic value and any clinical cutoff require external validation.