Identifying highly effective psychotherapists in a managed care environment.

OBJECTIVE To investigate the variability and stability of psychotherapists' effectiveness and the implications of this differential effectiveness for quality improvement in a managed care environment. STUDY DESIGN Subset archival outcome data for patients receiving behavioral health treatment were divided into 2 time periods to cross-validate the treating therapists' effectiveness. After categorizing the therapists as "highly effective" and "others" during the baseline period, the stability of their individual effectiveness was cross-validated in the remaining time period. METHODS Outcomes for 10 812 patients (76.0% adults, 24.0% children and adolescents) treated by 281 therapists were included. Patients initiated treatment between January 1999 and June 2004. Mean residual change scores obtained by multiple regression were used to adjust for differences in case mix among therapists. Raw change scores as well as mean residualized change scores were compared between the 71 psychotherapists identified as highly effective (25%) and those identified as other (remaining 75%). RESULTS During the cross-validation period, mean differences in residualized change score between highly effective therapists and others were statistically significant (difference = 2.8; P < .001), which corresponded to an average of 53.3% more change in raw change scores with the highly effective therapists. Results could not be explained by case mix differences in diagnosis, age, sex, intake scores, prior outpatient treatment history, length of treatment, or therapist training/experience. CONCLUSION Behavioral health outcomes for a large system of care could be significantly improved by measuring clinical outcomes and referring patients to therapists with superior outcomes.