Hester van Eeren

| Chapter 6 6 | 142 to answer questions about the effectiveness of interventions. When using available, non-randomized clinical practice data, however, the following considerations should be kept in mind. The treatments evaluated and the results of the analyses should be considered in light of the selected dataset. For example, using data from one institution can complicate the applicability and generalizability of the findings to other institutions, as referral practices and outcome measures may differ between institutions. In addition, characteristics of the selected dataset influence the choice for the analyses, which may influence the results and the conclusions drawn. For instance, when one is interested in a subgroup effect, the definition of this subgroup determines whether it could moderate or mediate the relations between treatment and outcome. Even more, the findings should be interpreted in light of daily clinical practice because clinicians and patients should be able to use these findings in clinical practice. The two issues addressed in this thesis, cost-effectiveness analyses in youth care and treatment evaluation using observational data are related, since effectiveness studies are needed to decide on the necessity and relevance of a cost-effectiveness study. On the other hand, when a cost-effectiveness study is needed, data on the costs and effects of the interventions studied are needed. When data of a randomized trial are not available, alternatives such as clinical practice data gathered within ROM could be useful. Implications for youth care Interventions seem to be most efficiently studied and compared on effectiveness using clinical practice data. Setting up randomized controlled trials (RCT’s) and asking clinicians and adolescents and their parents to fill in questionnaires in addition to the questionnaires that are used to routinely monitor the treatment process can be too expensive and too burdensome for patients and clinicians (Borah, Moriarty, Crown, & Doshi, 2014). Within mental health care, and within youth care, various ROM systems already systematically and repeatedly collect data on patients’ mental health and function as an indicator of the treatment outcome. Not only can these data be used to monitor individual treatment progress, but they can also be used to evaluate interventions on their outcomes. Using such research findings in clinical practice can help youth and their families receive an intervention that is proven to be effective and evidence-based (APA, 2006). To accomplish this, research findings should effectively be communicated to clinical practice and should be translated into clinically relevant actions and policy considerations. Only then, practice-based evidence can lead to evidence-based practice (Veerman, van Yperen, Bijl, Ooms, & Roosma, 2008). Because Dutch budgets available for youth care were reduced and were transferred to local authorities in 2015, these authorities should have insight in which interventions are available and which of them are evidence-based: research findings from clinical practice are needed to gain these insights. When, for example, two interventions have the same target population and the intervention that is more effective is also more costly, it is relevant to evaluate these youth care interventions on their cost-effectiveness as an addition to the effectiveness study. This cost-effectiveness analysis is mostly seen