Fig. 1

Comparison of critically ill populations defined by ICU care and CC services utilizing PHIS. Population characteristics (Demographics, Invasive Procedures, and Categories of Critical Illness) are compared to contextualize the CC services (ICD-9-CM based) definition of critical illness among discharges identified by ICU care (revenue code based definition). Proportions are delineated with the upper 95 % confidence interval for each group. Statistical comparisons are shown with respective p values