Outcomes of surgery in the Medicare aged population: rehospitalization after surgery.

Using 1979 and 1980 data, rehospitalization rates following eight common surgical procedures are examined for aged Medicare beneficiaries. Rehospitalization rates within 30 days after discharge from the surgical stay varied considerably among procedures and were higher for older beneficiaries. Patients residing in the Northeast had the lowest rates of rehospitalization, although their rehospitalizations tended to be lengthier than those elsewhere. Rehospitalization rates were also tracked for 9 months following discharge from the surgical stay. For all procedures, rehospitalization rates decreased during the 9 months after discharge, but they remained above the prevailing hospitalization rate for the Medicare aged population for the entire 9 months. Principal diagnoses associated with rehospitalizations within 30 days were often related to the body system on which surgery was initially performed, suggesting that many rehospitalizations are for continuing problems related to the initial condition that necessitated surgery. Rehospitalization rates presented in this article will serve as baseline data for monitoring trends under Medicare's prospective payment system for hospitals.