Patient Comorbidity Status and Incremental Total Hospitalization Costs in Elective Orthopedic Procedures

This study examined the correlation between patient comorbidity status, hospitalization length of stay (LOS), and cost for total knee arthroplasty (TKA), total hip arthroplasty (THA), and 1- to 3-level lumbar spinal fusion procedures. Using the Premier Perspective Database, adults older than 18 years who underwent primary unilateral TKA, THA, or spinal fusion between January 1, 2008, and June 30, 2014, were identified. Generalized linear models controlling for age, sex, region, hospital size, academic status, payor, and procedure year predicted the incremental total hospitalization cost among the sickest patients (Charlson Comorbidity Index [CCI] ≥3) vs healthy controls (CCI=0). The study cohort included 536,582 TKAs, 275,953 THAs, and 177,493 spinal fusion procedures. The percentages of patients with a CCI of 3 or greater were 5.4%, 4.7%, and 4.3%, for TKA, THA, and spinal fusion procedures, respectively. Mean (SD) LOS was longer by 0.9 (1.5), 1.4 (2.3), and 2.3 (3.8) days for patients with a CCI of 3 or greater vs 0 for TKA, THA, and spinal fusion procedures, respectively. Unadjusted total hospitalization costs were $17,512 for TKA, $18,915 for THA, and $32,932 for spinal fusion procedures; generalized linear models showed an incremental total hospitalization cost for CCI scores of 3 or greater of $2211, $3041, and $3922 vs CCI equal to 0 for each procedure type, respectively. Although representing a relatively small proportion of all patients undergoing elective orthopedic procedures, highly comorbid patients were associated with a greater total hospitalization cost burden. With the average patient comorbidity burden growing nationally, this study warrants further examination of improved standards of care for comorbid patients undergoing elective orthopedic procedures. [Orthopedics. 2016; 39(4):237-246.].