Does physicians' case volume impact inpatient care costs for pneumonia cases?

BACKGROUND: Increasing physician case volumes are documented to reduce costs and improve outcomes for many surgical procedures but not for medical conditions such as pneumonia that consume significant health care resources. OBJECTIVE: This study explored the association between physicians' inpatient pneumonia case volume and cost per discharge. DESIGN: The design was a retrospective, population-based, cross-sectional study, using National Health Insurance administrative claims data. SETTING: The setting was Taiwan. PARTICIPANTS: The participants were a universal sample of 270,002 adult, acute pneumonia hospitalizations, during 2002-2004, excluding transferred cases and readmissions. MEASUREMENTS: Hierarchical linear regression modeling was used to examine the association of physician's volume (three volume groups, designed to classify patients into approximately equal sized groups) with cost, adjusting for hospital random effects, case severity, physician demographics and specialty, hospital characteristics, and geographic location. RESULTS: Mean cost was NT$2,255 (US$1=NT$33 in 2004) for low-volume physicians (≤100 cases) and NT$1,707 for high-volume physicians (≥316 cases). The adjusted patient costs for low-volume physicians were higher (US$264 and US$235 than high- and medium-volume physicians, respectively; both P