Measurement equivalence of the Revised Helping Alliance Questionnaire across African American and non-Latino White substance using adult outpatients

Analyses of the effectiveness of substance abuse treatments across racial/ethnic groups should ensure that outcome measures have the same conceptual meaning (i.e., measurement equivalence) across groups. Because racial groups differ in perceptions and experiences of the therapeutic alliance, this study investigated measurement equivalence properties of the Revised Helping Alliance Questionnaire (HAq-II) across racial groups. The sample included 138 African American and 133 non-Latino White participants, age 18–64 years, who participated in a randomized clinical trial investigating the effectiveness of Motivational Enhancement Therapy in the National Institute on Drug Abuse Clinical Trials Network. Results demonstrated configural invariance and two forms of metric invariance (weak and strong/scalar), suggesting that conceptualizations of therapeutic alliance and overall levels of endorsement of therapeutic alliance are comparable across racial groups. The groups indicated partial, strict metric nonequivalence. No studies to date reported measurement equivalence properties of the HAq-II. Findings support valid measurement and interpretation of HAq-II outcomes.