Author Affiliation: Institute for Clinical Outcomes Research, Salt Lake City, Utah.
Performance measures are created and used to improve clinical outcomes, so it is important to know which measures are associated with better outcomes. The study by Werner and Bradlow1 in this issue of JAMA evaluates the association between performance measures and clinical outcomes in routine hospital care. Despite their large sample size and the use of numerous statistical adjustments and sensitivity analyses, the authors found only small statistically significant or nonsignificant associations between rates of application of performance measures and patient mortality rates for acute myocardial infarction, heart failure, and pneumonia in US hospitals. Even when the associations were statistically significant, the clinical importance was questionable because the mortality rate when a performance measure was applied frequently differed only slightly from the rate when the performance measure was applied infrequently. The authors recognize that “ . . . Hospital Compare measures discrete aspects of care delivery rather than assessing global quality. While these measures have been tightly linked to patient outcomes in clinical trials and are included in clinical practice guidelines [developed by medical experts], risk-adjusted mortality rates are likely influenced by many factors that are independent of these measures . . . .” Although their results suggest slightly larger differences in mortality rates between high- and low-performance hospitals when all the performance measures are combined (Table 4 in the article), the authors acknowledge that these findings still “capture information about only a small portion of the overall care delivered during a hospital stay.”
Horn SD. Performance Measures and Clinical Outcomes. JAMA. 2006;296(22):2731-2732. doi:10.1001/jama.296.22.2731