Predicting psychotherapy benefit: a probabilistic and individualized approach

We describe the development of the probability of treatment benefit (PTB) chart that incorporates, integrates, and extends more recent approaches to describing treatment effects, such as the Reliable Change Index (Jacobson & Truax, 1991) and normative comparisons (Kendall, Marrs-Garcia, Nath, & Sheldrick, 1999), by including parameters that are simultaneously probabilistic and individualized. To illustrate the PTB chart, data are taken from an effectiveness trial (N=139) of a modular treatment for disruptive behavior disorders. The results highlight both individual variability and the probabilistic nature of psychotherapy benefit. Finally, we discuss the utility of the PTB chart in terms of research, policy, and practice implications. Probability tables, such as the PTB chart, have the potential to be used as simple clinical tools to supplement traditional effect sizes and help patients make truly informed decisions about treatment participation.