Effects of Hospital’s Characteristics on the Length of Stay in Middle-aged Gonarthrosis Inpatients

Abstract

This study purposed to analyze the effects of characteristics of hospitals on the length of stay in mid-aged gonarthrosis inpatients after controlling the differences of patients’ risks among hospitals. HIRA-NPS (Health Insurance Review & Assessment Service-National Patient Sample) data in 2011 was used. International classification of Disease-10 (ICD-10) codes, M17.0, M17.1, M17.2, M17.3, M17.4, M17.5, and M17.9 were applied to define gonarthrosis inpatients, and found 7,094 inpatients in 72 of general hospitals and 170 of hospitals. Age, gender, insurance type, Elixhauser comorbidity index, and surgery status of gonarthrosis inpatients were included in the risk-adjustment model. Hospital characteristics such as number of doctors per 100 beds, bed size, hospital region, internal-herfindahl index, and number of gonarthrosis patients were included in the analysis model. All variables included in the risk-adjustment model were statistically significant and they had positive relationships with the length of stay. Number of beds >=300 (reference: