Risk factors associated with the development of complications after a hip fracture

Aims: Mortality after a hip fracture has declined in recent years, but the risk of complications remains high. The aim of this study was to identify non-modifiable and, specifically, modifiable factors associated with the development of complications after hip fracture. Methods: This was a multicentre, prospective cohort study of adults aged ≥ 60 years with a hip fracture who were treated in 77 hospitals in England, Wales, and Northern Ireland between July 2014 and November 2021. A total of 24,523 patients were enrolled into the study. Cox proportional hazards regression models were used to assess associations between prespecified (a priori) covariates and the development of surgery-specific and general complications at 120 days, postoperatively. Results: For surgery-specific complications, male sex was associated with reoperation (hazard ratio (HR) 1.23 (95% CI 1.01 to 1.51)) and surgical site infection (SSI) (HR 1.20 (95% CI 1.00 to 1.43)); American Society of Anesthesiologists (ASA) grade ≥ III with prosthetic dislocation (HR 2.19 (95% CI 1.40 to 3.41)), reoperation (HR 1.35 (95% CI 1.06 to 1.72)), and surgical site infection (SSI) (HR 1.26 (95% CI 1.02 to 1.56)); treatment with a cephalomedullary nail with periprosthetic or peri-implant fracture (HR 4.09 (95% CI 1.62 to 10.32)) and reoperation (HR 1.94 (95% CI 1.29 to 2.92)); and treatment with total hip arthroplasty (THA) with prosthetic dislocation (HR 2.43 (95% CI 1.54 to 3.82)). For general complications, age was associated with acute kidney injury (AKI) (HR 1.04 (95% CI 1.03 to 1.05)), the requirement of a blood transfusion (HR 1.02 (95% CI 1.01 to 1.02)), lower respiratory tract infection (LRTI) (HR 1.02 (95% CI 1.01 to 1.03)), and urinary tract infection (UTI) (HR 1.02 (95% CI 1.01 to 1.02)); ASA grade ≥ III with AKI (HR 1.52 (95% CI 1.18 to 1.95)), the requirement of a blood transfusion (HR 1.35 (95% CI 1.16 to 1.58)), LRTI (HR 2.02 (95% CI 1.72 to 2.37)), and UTI (HR 1.33 (95% CI 1.13 to 1.56)); male sex with AKI (HR 1.30 (95% CI 1.09 to 1.55)) and LRTI (HR 1.33 (95% CI 1.20 to 1.48)); delayed mobilization with AKI (HR 1.68 (95% CI 1.13 to 2.44)), LRTI (HR 1.96 (95% CI 1.75 to 2.19)), UTI (HR 1.52 (95% CI 1.32 to 1.74)), myocardial infarction (MI) (HR 2.05 (95% CI 1.35 to 3.10)), and pulmonary embolism (HR 1.70 (95% CI 1.05 to 2.74)); and delayed surgery with MI (HR 1.66 (95% CI 1.13 to 2.44)). Conclusion: Patient-related factors such as increasing age, male sex, and higher comorbidity were associated with a number of complications, which may explain the higher mortality and worse recovery seen in these groups. We also identified a number of potentially modifiable treatment-related factors which may influence the development of complications and which warrant further investigation.