Case‐Mix Adjustment of Consumer Reports about Managed Behavioral Health Care and Health Plans

Abstract
To develop a model for adjusting patients' reports of behavioral health care experiences on the Experience of Care and Health Outcomes (ECHO) survey to allow for fair comparisons across health plans. Survey responses from 4,068 individuals enrolled in 21 managed behavioral health plans who received behavioral health care within the previous year (response rate = 48 percent). Potential case-mix adjustors were evaluated by combining information about their predictive power and the amount of within- and between-plan variability. Changes in plan scores and rankings due to case-mix adjustment were quantified. The final case-mix adjustment model included self-reported mental health status, self-reported general health status, alcohol/drug treatment, age, education, and race/ethnicity. The impact of adjustment on plan report scores was modest, but large enough to change some plan rankings. Adjusting plan report scores on the ECHO survey for differences in patient characteristics had modest effects, but still may be important to maintain the credibility of patient reports as a quality metric. Differences between those with self-reported fair/poor health compared with those in excellent/very good health varied by plan, suggesting quality differences associated with health status and underscoring the importance of collecting quality information.