Comparing Methods to Denote Treatment Outcome in Clinical Research and Benchmarking Mental Health Care.

Approaches based on continuous indicators (the size of the pre-to-post-test change; effect size or ΔT) and on categorical indicators (Percentage Improvement and the Jacobson-Truax approach to Clinical Significance) are evaluated to determine which has the best methodological and statistical characteristics, and optimal performance, in comparing outcomes of treatment providers. Performance is compared in two datasets from providers using the Brief Symptom Inventory or the Outcome Questionnaire. Concordance of methods and their suitability to rank providers is assessed. Outcome indicators tend to converge and lead to a similar ranking of institutes within each dataset. Statistically and conceptually, continuous outcome indicators are superior to categorical outcomes as change scores have more statistical power and allow for a ranking of providers at first glance. However, the Jacobson-Truax approach can complement the change score approach as it presents outcome information in a clinically meaningful manner.