Comparative Interrupted Time Series Analysis of Medical Expenses in Patients with Intertrochanteric Fracture Who Underwent Internal Fixation and Hemiarthroplasty.

Abstract

The objective of this study was to assess postoperative direct medical expenses and medical utilization of elderly patients who underwent either hemiarthroplasty (HA) or internal fixation (IF) for treatment of a femoral intertrochanteric fracture and to analyze differences according to surgical methods and age groups. Data from the 2011 to 2018 Korean National Health Insurance Review & Assessment Service database were used. Risk-set matching was performed for selection of controls representing patients with the same sex, age, and year of surgery. A comparative interrupted time series analysis was performed for evaluation of differences in medical expenses and utilization between the two groups. A total of 10,405 patients who underwent IF surgery and 10,405 control patients who underwent HA surgery were included. Medical expenses were 18% lower in the IF group compared to the HA group during the first year after the fracture (difference-in-difference [DID] estimate ratio 0.82, 95% confidence interval [CI] 0.77-0.87, P<0.001), and 9% lower in the second year (DID estimate ratio 0.91, 95% CI 0.85-0.99, P=0.018). Length of hospital stay was significantly shorter in the IF group compared to the HA group during the first two years after time zero in the age ≥80 group. A noticeable increase in medical expenses was observed for patients who underwent HA for treatment of intertrochanteric fractures compared to those who underwent IF over a two-year period after surgery. Therefore, consideration of such findings is critical when designing healthcare policy support for management of intertrochanteric fractures.