Responsive regulation of treatment duration in routine practice in United Kingdom primary care settings: Replication in a larger sample

Replicating a previous study (M. Barkham et al., 2006), the authors examined rates of improvement in psychotherapy in United Kingdom primary care settings as a function of the number of sessions attended. Included in the study were adult clients who returned valid assessments at the beginning and the end of their treatment, had planned endings, began treatment above the clinical cutoff score, and were seen for 20 or fewer sessions (N = 9,703; 72.4% female; 87.7% Caucasian; average age = 40.9 years). Clients' average assessment scores improved substantially across treatment, with a pretreatment-posttreatment effect size of 1.96; 62.0% achieved reliable and clinically significant improvement (RCSI). Clients' mean pretreatment-posttreatment change was approximately constant regardless of treatment duration (in the range of 0 to 20 sessions); the RCSI rate decreased slightly with treatment duration, as fewer clients fell below the cutoff at longer durations. Results were interpreted as suggesting that therapists and clients tend to make appropriately responsive decisions about treatment duration.