Is higher volume of postacute care patients associated with a lower rehospitalization rate in skilled nursing facilities?

This study determined whether higher patient volume of skilled nursing facility (SNF) care was associated with a lower hospital transfer rate. Using the nursing home Minimum Data Set and the Online Survey, Certification, and Reporting file, we assembled a national cohort of Medicare SNF postacute care admissions between January and September of 2008. Multivariable analyses based on Cox proportional hazards models found that patients admitted to high-volume SNFs (annual number of admissions in the top tertile group) showed an approximately 15% reduced risk for 30-day rehospitalization and an approximately 25% reduced risk for 90-day rehospitalization, compared with patients admitted to low-volume SNFs (annual number of admissions in the bottom tertile group, or <45). Similar patterns of volume-outcome associations were found for hospital-based and freestanding facilities separately. The inverse volume-outcome association in postacute SNF care may reflect a "practice makes perfect" effect, a "selective referral" effect, or both.