Aurelie Lange

150 | Appendices Summary Therapist adherence (the degree to which a clinician delivers the specified components of a treatment), is a quality indicator in routine clinical care when evaluating the success of the implementation of an intervention. Implementing evidence-based interventions into clinical practice with high adherence has proven challenging. Therefore, the first aim of this dissertation was to evaluate what factors affect therapist adherence scores when disseminating evidence-based interventions. This first aim is described in Chapter 1 and is subsequently addressed in Chapter 2 and 3. A focus on adherence presupposes that the specific techniques of the intervention are important for achieving good outcomes. Some scholars, however, have stated that common factors play a much larger role. Common factors are factors common to all psychotherapy, such as the working relationship with the client (alliance). The second aim of this dissertation was to study how adherence and alliance interact and uniquely and jointly contribute to treatment outcomes. This second aim is described in Chapter 1 and subsequently addressed in Chapter 4 through 6. Both aims were addressed using the Dutch Therapist Adherence Measure Revised (TAM-R), developed to asses therapist adherence to the treatment model of Multisystemic Therapy (MST). MST is an evidence-based family- and community-based intervention for antisocial adolescents aged 12 to 18 years. It focuses on addressing all environmental systems that impact the adolescent and works intensively with caregivers to achieve this. The TAM-R is routinely collected in clinical practice as part of the quality-assurance system of MST and is used to monitor and improve adherent delivery of MST worldwide. It is a 28- item questionnaire that is assessed through monthly phone interviews with the primary caregiver during treatment. Chapter 2 compared the Dutch TAM-R to the original TAM-R from the United States (US) to evaluate equivalence of Dutch and US adherence scores. International implementation of the TAM-R assumes cross-national equivalence, even though this assumption had never been investigated. In Study 1 Rasch analysis was applied to 1,875 Dutch TAM-R reports and the frequency distributions of 1,875 US TAM-R reports. Several items showed differences in their level of difficulty. This means that some Dutch items were very ‘easy’ to score (most Dutch therapists had a high score on these items), whereas high scores on the same items proved very difficult to achieve in the US (few US therapists had a high score on them). For scores on other items, it was just the other way around. Furthermore, response frequencies were more heavily skewed in the US compared to the Netherlands, meaning that the upper response categories were used more frequently by US respondents than by Dutch respondents for almost all items. Study 2 investigatedwhether adaptations to the translation of the items and response categories could improve equivalence. For this purpose, 237