Global quantitative indices reflecting provider process-of-care: data-base derivation

Area of Science:

• Critical Care Medicine
• Health Services Research
• Econometrics

Background:

• The relationship between risk-adjusted mortality and process-of-care in intensive care units (ICUs) is debated.
• There is a need for global quantitative indices to represent the diversity of process-of-care at the database level.

Purpose of the Study:

• To establish global quantitative indices of process-of-care using patient data.
• To determine the relationship between these indices and mortality outcomes in ICUs.

Main Methods:

• Retrospective cohort study of 223,129 patients from 99 ICUs (1993-2003).
• Process-of-care indices developed using pharmaco-kinetic methods (area under the hazard-curve, time-to-peak-hazard) and econometric techniques (stochastic frontier analysis for technical efficiency).
• Multivariate correlation analysis between indices and summed mortality probability for geographic and ICU-level descriptors.

Main Results:

• Significant differences in process-of-care indices (AUC, TMAX, TE) were observed across various ICU descriptors (P
• Maximal AUC was found in rural/for-profit ICUs for survivors and tertiary ICUs for non-survivors.
• Maximal TMAX and TE varied between tertiary and for-profit ICUs depending on survival status.
• Total explained variance was maximized by index combinations showing low correlation with mortality probability.

Conclusions:

• Global process-of-care indices can be formally established using national patient databases.
• These developed indices appear orthogonal to mortality outcomes, suggesting they measure distinct aspects of care quality.