Marianne Welmers

General Discussion 143 CHAPTER 6 therapist behaviors and characteristics on outcome (e.g., Friedlander et al., 2008a; Muñiz de la Peña et al., 2012), in order to guide providers of family treatment in how to effectively attune their behaviors to family members’ unique behaviors and characteristics. It is also important to note several sample limitations that may hinder the generalizability of results. These limitations indicate the importance of further research on several client characteristics in relation to the alliance in order to well serve the diverse population of families receiving HBFT. First, data on therapists’ cultural background was lacking, and the study sample included only 4 families with parents from a non-western foreign country (5%), whereas approximately 15% of families receiving home-based family treatment in the Netherlands have a non-western cultural background (CBS, 2021). Although the meta- analysis in Chapter 2 did not indicate that the association between alliance and treatment outcome differs between different cultural groups, the body of reviewed studies reveals that cultural background is an under-researched topic in studies on alliance. Notably, a handful of prior qualitative studies in adult psychotherapy does indicate that cultural background may indeed be a relevant factor that affects the process of building alliances during treatment (Asnaani & Hofmann, 2012; Lee et al., 2019; Schonfeld-Ringel, 2001; Vasquez, 2007). A second limitation of the sample is the underrepresentation of families receiving mandated care ( n = 3). In themeta-analysis inChapter 2, the effect of alliance on treatment outcome was significantly stronger for families receiving voluntary treatment than for mandated families, but only few included studies actually identified referral status of the sample. In a recent study on predictors of alliance in home-based family treatment in the Netherlands, 17% of the families included in the sample received court-mandated treatment, and referral status was not related to both therapist- and parent-reported strength of the alliance (DeGreef et al., 2018b). However, a series of studies investigating a Spanish sample of families receiving family therapy showed that alliances withmandated families at the start of treatment were more problematic and did require specific alliance buildings behaviors of the therapist, but a larger evidence base is still lacking (Sotero et al., 2016; 2017; 2018). A final sample limitation is that a rather small number of fathers and male therapists was included. The underrepresentation of fathers and male therapists is a common phenomenon in family treatment studies (e.g., De Greef et al., 2018a/b; Escudero et al., 2021; Friedlander et al., 2019), and seems rather representative of clinical practice. However, this given is in striking contrast with findings of several studies convincingly indicating the importance of father involvement on child development and well-being (Flouri & Buchanan, 2003; Lundahl et al., 2008; Wilson & Prior, 2011). Additionally, findings of this dissertation – in line with other studies – indicate a significant effect of gender