Assessment of the scientific soundness of clinical performance measures: a field test of the National Committee for Quality Assurance's colorectal cancer screening measure.

BACKGROUND: Relatively few studies have evaluated the scientific soundness of widely used performance measures. This study evaluated quality measures by describing a field test of the colorectal cancer screening measure included in the Health Plan Employer Data and Information Set of the National Committee for Quality Assurance.
METHODS: We conducted a field test in 5 health care plans that enrolled 189 193 individuals considered eligible for colorectal cancer screening. We assessed measurement bias by calculating the prevalence of colorectal cancer screening while varying the data sources used (administrative data only, a hybrid of administrative data and medical record data, and enrollee survey data only) and the minimum required enrollment period (2-10 years).
RESULTS: Across the 5 health care plans, the percentage of health care plan enrollees counted as screened varied according to the data used, ranging from 27.3% to 47.1% with the administrative data, 38.6% to 53.5% with the hybrid data, and 53.2% to 69.7% with the survey data. The relative ranking of plans also varied. One health care plan ranked first based on administrative data, second based on hybrid data, and fourth based on survey data. Survey respondents were more likely than nonrespondents to have evidence of colorectal cancer screening (62.7% vs 46.5%; P < .001).
CONCLUSIONS: Administrative data seem to underestimate colorectal cancer screening and survey data seem to overestimate it, suggesting that a hybrid data approach offers the most accurate measure of screening. Implementation of performance measures should include evaluation of their scientific soundness.