Application of the Strengths and Difficulties Questionnaire Added Value Score in evaluating the effectiveness of Functional Family Therapy within local authority social work services.

Abstract

As 'Blueprints' evidence-based programmes, such as Functional Family Therapy (FFT), originating from the United States, are increasingly implemented in Social Work services, the importance of assessing their effectiveness in a UK context is crucial. To do this, it is not always practical for services to commission randomised control trials or quasi-experimental control trials. The Strengths and Difficulties Questionnaire (SDQ) Added Value Score has been shown to have utility in the evaluation of intervention programmes by controlling for regression to the mean, attenuation and the shifting nature of most childhood psychopathology. The SDQ Added Value Score was used to assess the effectiveness of FFT in two local authorities in Scotland. One hundred and sixty-four families who had finished FFT completed the Strengths and Difficulties Questionnaire, the Outcome Questionnaire and the Client Outcome Measure at pre- and postintervention. Both parents' and adolescents' average psychosocial distress scores significantly decreased on all measures after FFT and many of the scores postintervention fell to a range equivalent with the general population. Furthermore, calculation of the SDQ Added Value Score indicated that adolescents' mean total difficulties scores were lower following FFT than what would have been expected had this intervention not been received, producing an effect size that compares favourably to other interventions. Functional Family Therapy has been identified as an effective intervention for improving the psychosocial functioning of high-risk adolescents and their families.