MAIN OUTCOME MEASURES
Data on patient demographics and diagnoses were abstracted
at the time of initial recruitment. Pharmacy data were used to
derive a comorbidity index, the chronic disease score. Chronic
disease scores have been associated with physician-rated patient
disease severity, patient-rated health status, hospitalization,
and mortality.27,28
The primary outcome measure was the rate of nonelective
rehospitalization (including the contracted hospital and any noncontracted
hospitals) at 30, 90, and 180 days after discharge
from the index hospitalization. An a priori established secondary
outcome measure was the rate of rehospitalization for the
same condition that prompted the index hospitalization. Rehospitalization
data were abstracted from the study delivery system’s
administrative records