Nevertheless, overestimation may reflect general improvements in ICU care and patient outcomes since the development of APACHE III, differences in discharge practices of the current hospitals with triage of ill patients to skilled nursing facilities, differences in ICU utilization with higher numbers of discretionary admissions, or the provision of more effective care in the current hospitals. Although the clinical ramifications of these calibration differences is likely small, the overestimation of risk in the current sample highlights the need to recalibrate validated predictive methods for local applications to reflect potential improvements in care or differences in clinical prac-tice.
Third, severity of illness at the time of ICU admission, as measured by predicted death rates, varied widely across hospitals, suggesting that thresholds for admitting and treating patients in ICUs vary, and likely depend on institutional practice styles and the availability of critical care resourc-es. However, despite the wide variation in admission severity, variation in standardized mortality was relatively small. Indeed, the range in hospital SMRs reflected less than a 1.5-fold difference. Flovent inhalers itat on In addition, variations in SMRs tended to decline over time. The degree of variation observed in the current study was somewhat lower than the nearly twofold variation in hospital SMRs observed in an earlier national study of 40 US hospitals, and may reflect the larger hospital sample sizes of the current study or its examination of a single geographic area. Nevertheless, SMRs tended to be somewhat lower in the major teaching hospitals than other hospitals, confirming an earlier observation using a different risk-adjustment method that was based on patients admitted with six medical diagnoses (myocardial infarction, heart failure, pneumonia, stroke, GI bleeding, and obstructive airway disease).