Association between provider volume and comorbidity on hospital utilization and outcomes of total hip arthroplasty among National Health Insurance enrollees.

BACKGROUND/PURPOSE: The impact of provider volume, comorbidity and adverse outcomes on hospital utilization of total hip arthroplasty (THA) has not yet been studied scientifically in Taiwan. This study aimed to examine the relationship between surgeon/hospital volume, perioperative complications, acute infections and hospital utilization for patients who underwent primary (THA).

METHODS: We analyzed National Health Insurance (NHI) annual reimbursement data for all hospital admissions due to primary THA between January 2005 and December 2006. A total of 9335 patients with rheumatoid arthritis, osteoarthritis, avascular necrosis and other joint disorders were identified. Multivari-ate regression analyses were used to assess the relationship between provider volume and hospital utilization and the risk of adverse outcomes. Statistical analyses were adjusted for patient age, gender, comorbidity, type of arthritis, as well as hospital attributes.

RESULTS: Reversed linear associations were found among hospital utilization, surgeon volume, and comorbidity score. Patients with acute infection tended to stay 8 days more and cost NT$32,451 more than their counterparts. Patients with perioperative complication tended to stay 2.30 days more and cost NT$15,327 more than their counterparts. Longer hospital stay and higher total hospital charge were associated with patient's age and Charlson index.

CONCLUSIONS: This study revealed that the volume of THAs performed by individual surgeons was a more important determinant of hospital utilization than hospital volume. Perioperative adverse events were associated with patients' age and comorbidity.