Case-mix adjustment of consumer reports about managed behavioral health care and health plans.

Although effective treatments exist for most mental health disorders, many individuals with mental illness receive inadequate care (McGlynn 2003). This is worrisome because mental illnesses and substance abuse impose substantial burdens on patients, employers, and the health care system (Kessler et al. 1999; Pincus and Pettit 2001; Wang, Simon, and Kessler 2003). Patients' reports about their care experiences can provide important information that is not available from other sources (Cleary and Edgman-Levitan 1997) and provide insight into access and delivery concerns that can influence patients' decisions to seek care and adhere to treatment, which can affect health outcomes (Fremont et al. 2001; Wells et al. 2004). Increasingly, plan-level summaries of patient experiences are being used in public reports about care quality (Goldstein et al. 2001) and by accreditation agencies (National Committee on Quality Assurance [NCQA] 2005). Policy makers and payers have become interested in assessing quality by comparing the experiences of patients across behavioral health organizations in an effort to increase accountability and better inform quality improvement efforts (Eisen et al. 2001). The Experience of Care and Health Outcomes (ECHO™) survey was developed under the CAHPS® quality measurement program (Shaul et al. 2001) to assess the experiences of patients receiving behavioral health care through managed care plans, specialized managed behavioral health organizations, and other organizations (Eisen et al. 2001). Plan differences in patient reports about aspects of care such as patient–provider interactions and customer service may be meaningful to plans engaged in quality improvement or accreditation processes, to payers and consumers choosing among plans, and to regulators and policy makers interested in determining whether plans are meeting requirements or benchmarks. However, comparisons may be misleading if scores are not adjusted for differences in the underlying characteristics of the patient populations across plans (Zaslavsky 2001a). For example, patients' health status or age may influence how patients evaluate their experiences independently of the quality of care received. Moreover, quality of care may differ between certain types of patients (e.g., younger and older patients) in a consistent way within all health plans. If plans are compared using the average score of all enrollees, relative rankings may not accurately reflect quality-of-care differences. Ideally, health plan ratings would reflect how plans would be rated by an identical patient population. Thus, it is important to control for underlying patient characteristics when calculating plan-level scores. Even if the adjustment to scores is modest, it is important to adjust scores for differences in patient characteristics to ensure both the actual and perceived fairness of the comparisons. The goals of this study are twofold. First, we identify patient characteristics that are associated with consumer ratings of behavioral health plans. Second, we develop a statistical model to adjust plan-level summaries of patients' ratings of behavioral health care plans so that ratings more accurately reflect quality of care received. Because commercial and Medicaid plan populations may systematically differ, we develop separate models for these two plan types. A priori, we expect self-reported mental health status, general health status, and age to be important adjusters based on prior research in the general health care sector (Zaslavsky et al. 2001b). Education, income, gender, race/ethnicity, and seeking care for alcohol or drug use may also be important case mix adjusters and are tested.