Background
The Critical Access Hospital (CAH) designation was established to provide rural residents local access to emergency and inpatient care. CAHs, however, have poorer short-term outcomes for pneumonia, heart failure, and myocardial infarction compared to other hospitals. We assessed whether 30-day risk-standardized mortality rates (RSMRs) and readmission rates (RSRRs) after ischemic stroke differ between CAHs and non-CAHs.
Methods
The study included all fee-for-service Medicare beneficiaries ≥65 years old with a primary discharge diagnosis of ischemic stroke (ICD-9 433, 434, 436) in 2006. Hierarchical generalized linear models calculated hospital-level RSMRs and RSRRs, adjusting for patient demographics, medical history, and comorbid conditions. Non-CAHs were categorized by hospital volume quartiles and the RSMR and RSRR posterior probabilities in comparison to CAHs were determined using linear regression with Markov chain Monte Carlo simulation.
Results
There were 10,267 ischemic stroke discharges from 1,165 CAHs and 300,114 discharges from 3,381 non-CAHs. The RSMRs of CAHs were higher than non-CAHs (11.9%±1.4% vs. 10.9%±1.7%, p<0.001), but the RSRRs were comparable (13.7%±0.6% vs. 13.7%±1.4%, p=0.3). The RSMRs for the two higher volume quartiles of non-CAHs were lower than CAHs (posterior probability of RSMRs higher than CAHs=0.007 for quartile 3, probability<0.001 for quartile 4), but there were no differences for lower volume hospitals; RSRRs did not vary by annual hospital volume.
Conclusions
Critical Access Hospitals had higher RSMRs compared with non-CAHs, but readmission rates were similar. The observed differences may be partly explained by patient characteristics and annual hospital volume.