Efficacy of the modified Frailty Index and the modified Charlson Comorbidity Index in predicting complications in patients undergoing operative management of proximal humerus fracture.

BACKGROUND

Comorbidity indices such as the 5-factor modified Frailty Index (mFI-5) and modified Charlson Comorbidity Index (mCCI) are widely used in outcomes research.

METHODS

A total of 3893 patients who underwent total shoulder arthroplasty (n=975), hemiarthroplasty (n=495), or open reduction and internal fixation (n=2423) for the treatment of proximal humerus fracture from 2005-2017 were identified from the National Surgical Quality Improvement Program database. Data regarding demographics, comorbidities, American Society of Anesthesiologists class, and postoperative complications were collected, and the mFI-5 and mCCI were calculated for each case. Multivariate logistic regression models and receiver operating characteristic curve analyses were performed.

RESULTS

The patient population had a mean age of 68.0 ± 13.2 years, body mass index of 29.1 ± 8.1 and mean operative time of 119.9 ± 55.5 minutes. The most common complications within this cohort were extended length of stay (4 days or more) (1085/3893; 27.87%), transfusion (377/3893; 9.68%), unplanned reoperation (97/3893; 2.49%), urinary tract infection (43/3893; 1.10%), death (42/3893; 1.08%), and deep vein thrombosis (40/3893; 1.03%). After accounting for patient demographics, the mFI-5 (odds ratio [OR] = 1.105, P < .001) and mCCI (OR = 1.063, P < .001) were significantly associated with incidence of any adverse event. Both comorbidity indices had low positive predictive value and high negative predictive value for all adverse events.

CONCLUSION

The comorbidity indices mCCI and mFI-5 are both strongly associated with adverse events but have moderate ability to predict complications following surgical treatment of proximal humerus fractures.