Application of the Combined Quality Improvement Ratio in the Evaluation of a Quality Improvement Activity in a Managed Care Organization

Abstract

Assessing the impact of clinically relevant quality improvement activities (QIA) is important to managed care organizations; yet, turnover in enrollment can reduce the data available for analyses, thus decreasing the chance that a difference post-QIA will be detected. The Combined Quality Improvement Ratio (CQuIR) uses matching of patients into pairs pre-and post-QIA to systematically and validly increase the data included in the analysis for evaluation of the QIA. Using a paired cohort study design, 456 pairs of patients with diabetes were identified using the Health Plan Employer Data Information Set (HEDIS) specifications. Patients having retinal examinations were identified pre and post-QIA. The change in retinal examination rates was analyzed and results compared using repeated pairs (RP), matched pairs (MP), and combined pairs (CP). The CQuIR methodology (which uses CP = RP + MP) resulted in an increase in sample size (n = 456 [CPI versus n = 156 [RP] and n = 300 [MP]) and consequently an increase in power (0.92 [CP] versus 0.38 [RPI and 0.82 [MPI) and a decrease in the confidence interval range (0.97 [CP] versus 2.06 [RP] and 1.14 [MPI). The CQuIR uses a statistically valid approach to increase the data available for the evaluation of QLAs.