Prognostic factors of in-hospital complications after hip fracture surgery: a scoping review

Introduction: To examine prognostic factors that influence complications after hip fracture surgery. To summarize proposed underlying mechanisms for their influence. Methods: We reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Scoping Review extension. We searched MEDLINE, Embase, CINAHL, AgeLine, Cochrane Library, and reference lists of retrieved studies for studies of prognostic factor/s of postoperative in-hospital medical complication/s among patients 50 years and older treated surgically for non-pathological closed hip fracture, published in English on January 2008–January 2018. We excluded studies of surgery type or in-hospital medications. Screening was duplicated by two independent reviewers. One reviewer completed the extraction with accuracy checks by the second reviewer. We summarized the extent, nature, and proposed underlying mechanisms for the prognostic factors of complications narratively and in a dependency graph. Results: We identified 44 prognostic factors of in-hospital complications after hip fracture surgery from 56 studies. Of these, we identified 7 patient factors—dehydration, anemia, hypotension, heart rate variability, pressure risk, nutrition, and indwelling catheter use; and 7 process factors—time to surgery, anesthetic type, transfusion strategy, orthopedic versus geriatric/co-managed care, multidisciplinary care pathway, and potentially modifiable during index hospitalization. We identified underlying mechanisms for 15 of 44 factors. The reported association between 12 prognostic factors and complications was inconsistent across studies. Conclusions: Most factors were reported by one study with no proposed underlying mechanism for their influence. Where reported by more than one study, there was inconsistency in reported associations and the conceptualization of complications differed, limiting comparison across studies. It is therefore not possible to be certain whether intervening on these factors would reduce the rate of complications after hip fracture surgery.