The hospital frailty risk score outperforms other risk stratification indices at predicting complications following total shoulder arthroplasty

Background

Frailty and comorbidity indices are commonly used to stratify risk in orthopedic patients. The purpose of this study was to examine the hospital frailty risk score (HFRS), Elixhauser Comorbidity Index (ECI), Charlson-Deyo Comorbidity Index (CCI), and Modified 5-Item Frailty Index (mFI-5) to determine which index more accurately predicted complications following primary total shoulder arthroplasty (TSA).

Methods

The Nationwide Readmissions Database was queried from 2016 to 2021 to identify primary TSAs. HFRS, ECI, CCI, and mFI-5 scores were calculated. Generalized additive models were used to evaluate each index. Accuracy was assessed using the area under the curve of the receiver operative curve (AUC of ROC).

Results

HFRS was superior at predicting any complication, any medical complication, any surgical complication, revision, periprosthetic fracture, prosthetic loosening, complications requiring débridement, transfusion, Acute Respiratory Disease Syndrome (ARDS), acute renal failure, pneumonia, sepsis, and urinary tract infection. ECI was superior at predicting readmission, postoperative bleeding, and pulmonary embolism. CCI and mFI-5 were not superior to the other indices.

Discussion

The HFRS outperformed all other risk stratification indices at predicting rates of any complication, any surgical complication, any medical complication, revision, infection requiring débridement, periprosthetic fracture, prosthetic loosening, ARDS, acute renal failure, pneumonia, sepsis, transfusion, and urinary tract infection. ECI was the second-best index and outperformed all other indices at predicting rates of readmission and pulmonary embolism. No index was acceptable (AUC of ROC >0.7) at predicting surgical complications, readmissions, or revisions. These results indicate the HFRS may be the best risk stratification index for predicting complications following primary TSA.