Variations in both structure and process are known to affect clinical outcomes in intensive care units (ICUs). With both increasing demand and cost in adult critical care, it is important to understand how to best reduce variations in care.  The Critical Illness Outcomes Study organized through the auspices of the United States Critical Illness and Injury Trials Group ( USCIITG- CIOS) was formed to characterize the organizational structure, processes of care, use of protocols and outcomes of ICUs, and to determine which of these structural and process of care factors might be associated with patient outcomes such as inpatient mortality.

We surveyed 69 ICUs in the United States participating in the Critical Illness Outcomes Study (CIOS) about organization, size, volume, staffing, processes of care, and use of protocols of their ICUs; and investigated the relationship of structure and process to  ICU mortality. 69 ICUs of the 94 approached are participating in the study: 25 (36%) were medical, 24 were surgical (35%) and 20 (29%) were mixed.

We collected patient demographic, treatment information one day a week until at least one hundred patients were enrolled into each participating ICU. We have completed enrollment with > 6400 patients and are currently validating the data collected. USCIITG- CIOS is currently a planning second study to better determine which factors might be associated with high performing ICUs.