We analyzed administrative data provided by 67 hospitals participating in the Quality Indicator/Improvement Project (QIP). The study included 2,134 patients with hip fractures who were 60 years of age or older, underwent surgical treatment, and were discharged from the hospitals between April 2007 and March 2008. We excluded patients whose lengths of stay were longer than 150 days.
First, we conducted a patient-level multiple linear regression analysis to identify patient-risk factors associated with LOS. Using this model, we calculated the risk-adjusted mean LOS for each hospital. Secondly, we categorized patients into two groups according to discharge destination: home or other facilities. We conducted a multiple linear regression analysis to identify institutional factors and processes of care associated with risk-adjusted mean LOS in each subgroup (discharge to home or discharge to other facilities).
In this analysis, the dependent variable was the risk-adjusted mean LOS of hip fracture in each hospital. Explanatory variables included the following:
• Surgical procedure (hip replacement or internal fixation)
• Timing of operation (within 48 hours or later)
• Timing of rehabilitation (within two days after operation or later)
• Frequency of rehabilitation (rehabilitation was provided for more than 80% of total LOS or less than 80%)
• Number of acute care beds >400 or ≦400)
• Inpatient volume per physician per year (>150 or ≦150)
• Case volume of physical therapist (PT) per year (>2000 or ≦2000)
• Number of medical social workers (MSW) per bed (>1 or ≦1)
• Hospital ownership (a local government hospital, private hospital, or public hospital)
• Presence of sub-acute care beds in the hospital