Hester van Eeren

Comparative effectiveness of MST and FFT | 5 111 | future research could focus on the applicability and validity of a checklist based on the RNR model, for example, to support stepped care when applicable, and assigning adolescents directly to more intensive interventions when needed (Krugten et al., 2016). In addition to the effectiveness and assignment procedures of the interventions, and with stringent health care budgets, the costs of an intervention should be taken into account. If costs of a more effective intervention are higher than the costs of its alternative, it can beworthwhile to compare the interventions and their cost-effectiveness. Earlier studies in the US and UK have shown MST to be cost-effective compared with alternatives like individual therapy (Cary, Butler, Baruch, Hickey, & Byford, 2013; Klietz, Borduin, & Schaeffer, 2010). The cost-benefit ratio of FFT compared to MST in the US has been shown to be in favor of FFT (Lee et al., 2012). In the Netherlands, Vermeulen and colleagues (2016) compared MST to treatment as usual, including FFT, and found MST to be more cost-effective. Thus, cost-effectiveness depends on the context of the study, e.g. sample or country. With regard to the current study, it would for example be beneficial to implement a cost-effectiveness analysis in the subsample of adolescents without a court order. In this subsample, MST was more effective at reducing externalizing problems than FFT. Although it is unknown what the precise costs of MST and FFT are in the Netherlands, it is expected that MST is more expensive due to the intensity of the intervention. Cost-effectiveness analysis could reveal whether additional costs for MST are worth the higher effects. Future research must focus on estimating the exact costs of MST and FFT in the Netherlands and estimating health services use of this population to indeed estimate the cost-effectiveness. Moreover, it is of additional interest to determine the cost-effectiveness of intervention options when following a stepped care procedure, i.e. should youth with a lower risk be assigned to MST directly, or should a less intensive option be the first choice. Comparing evidence-based interventions within overlapping target populations could eventually result in greater knowledge about which interventions work best for whom (Yirmiya, 2010). Therefore, it is important to examine treatment through client interactions and understand and study the assignment procedure based on the RNR model in greater detail. However, it is likely even more necessary—given the broad range of interventions currently available—to study practice elements or program elements of interventions to determine overlapping, effective elements (Chorpita & Daleiden, 2009; Evenboer, Huyghen, Tuinstra, Knorth, & Reijneveld, 2012; Lee et al., 2014). Furthermore, it would be of interest to compare the long-term effects of MST and FFT to find out whether their comparative effectiveness changes over time. This study also shows that using clinical practice data, like ROM data, is worthwhile for evaluating treatments. It increases both the external validity of the study and the clinical utility because data was gathered in regular clinical practice and sample selection bias is less present (Hodgson, Bushe, & Hunter, 2007). The current study shows that the PS method is a useful and important method for using these data (West et al., 2014). It is, however, relevant to evaluate the chosen treatment outcomes in light of the selected dataset. The current study selected data from the Viersprong and not from other youth care institutions. Moreover, of the data selected, a sample was selected for which there was an outcome measure after treatment. The study sample — within