- Compilation of eight reports (Macdonald, 1994). All these early naturalistic follow up studies from different countries, done under the umbrella of EBTA, consistently showed approximately 70% of clients reporting that their goals had been met or that they had improved significantly. (Updated EBTA database here)
- Qualitative review of 15 studies (Gingerich and Eisengart, 2000). This systematic review of bibliographic databases, dissertations, and bibliographies of identified research analyzed 15 studies of which 5 were well controlled studies. All of the 15 studies showed positive outcomes of SFBT.
- Meta-analytics review of 21 studies (Stams, Dekovic, Buist, and De Vries, 2006). In this meta-analysis of 21 published studies and dissertations both strong and weak designs were included (with in total 1,421 participants). The results showed a positive and small to medium size effect of SFBT. The authors noted that this effect was achieved in less time than in other therapies.
- Meta-analytic review of 22 studies (Kim, 2008).For this review studies were grouped into the following three problem-categories: externalizing behavior problems, internalizing behavior problems, and family or relationship problems. Overall, SFBT show small but positive treatment effects but only for internalizing problems was a statistically significant effect found (p<,05). The authors noted that these modest effects might be explained by the fact that on the whole dissertations showed much lower effect sizes than other published studies which. Overall, the intervention fidelity (the degree to which the intervention which is being evaluated is actually and properly delivered to clients as intended) of the dissertation studies seemed to be lower than in the other studies due to the fact that in these studies therapist had received much less training.
Then the chapter describes some recent studies that have been done (Smock et al., 2008; Knekt and Lindfors, 2004; and Knekt et al. 2008a and 2008b), discusses some practical guidelines, some limitations of the research and some implications for future studies. The chapter ends with the following key points to remember:
- Solution-focused brief therapy was first described in the literature in 1986 (by de Shazer et al.) and the first controlled study of SFBT outcomes appeared in 1993 (by Sundstrom).
- More than 48 studies have appeared to date, as well as two independent meta-analytics reviews. The quality of the studies is steadily improving.
- Overall, SFBT has been shown to have a small to moderate effect size and to be the equivalent of other established treatments.