Multisystemic Therapy and Functional Family Therapy Compared on their Effectiveness Using the Propensity Score Method

Multisystemic Therapy (MST) and Functional Family Therapy (FFT) have overlapping target populations and treatment goals. In
this study, these interventions were compared on their effectiveness using a quasi-experimental design. Between October, 2009
and June, 2014, outcome data were collected from 697 adolescents (mean age 15.3 (SD 1.48), 61.9% male) assigned to either
MST or FFT (422 MST; 275 FFT). Data were gathered during Routine Outcome Monitoring. The primary outcome was
externalizing problem behavior (Child Behavior Checklist and Youth Self Report). Secondary outcomes were the proportion
of adolescents living at home, engaged in school or work, and who lacked police contact during treatment. Because of the nonrandom assignment, a propensity score method was used to control for observed pre-treatment differences. Because the riskneed-responsivity (RNR) model guided treatment assignment, effectiveness was also estimated in youth with and without a court
order as an indicator of their risk level. Looking at the whole sample, no difference in effect was found with regard to externalizing problems. For adolescents without a court order, effects on externalizing problems were larger after MST. Because many
more adolescents with a court order were assigned to MST compared to FFT, the propensity score method could not balance the
treatment groups in this subsample. In conclusion, few differences between MST and FFT were found. In line with the RNR
model, higher risk adolescents were assigned to the more intensive treatment, namely MST. In the group with lower risk
adolescents, this more intensive treatment was more effective in reducing externalizing problems.