Understanding articles comparing outcomes among intensive care units to rate quality of care. Evidence Based Medicine in Critical Care Group.

OBJECTIVES: Comparisons of risk-adjusted outcomes among intensive care units (ICUs) is a relatively new but rapidly expanding area of ICU health services research. By investigating those factors that lead ICUs to have patient outcomes that differ from the average, the overall quality of care across ICUs may be improved. Our goal is to teach clinicians how to evaluate these types of articles. CLINICAL EXAMPLE: An article describing the development and application of an index used to assess the clinical performance and cost-effectiveness of 25 ICUs. RECOMMENDATIONS: Valid comparisons of the outcomes among ICUs are made when: a) the outcome measures are accurate and comprehensive; b) the ICUs being compared serve similar patients; c) the sampling of patients is sufficient and unbiased; d) appropriate risk adjustment is undertaken by applying a valid model to reliably collected data; and e) the comparisons focus on care delivered in the ICU. To evaluate the results of the study, clinicians must evaluate how confident they are that the outcome differences being described are clinically important. Before changes in ICU policy are made based on these outcome differences, it is important to clarify which factors might have resulted in these extreme outcomes and whether these results are applicable in the ICU population that will see the impact of the changes. CONCLUSION: The potential for misinterpretation of outcome performance ratings may decrease if articles describing outcome differences are evaluated, using the criteria outlined in this article.