Evidence-based assessment of treatment outcomes for late-life generalized anxiety disorder using the Penn State Worry Questionnaire (PSWQ) and Penn State Worry Questionnaire - Abbreviated (PSWQ-A).

Objective: The Penn State Worry Questionnaire (PSWQ) is a commonly used measure of treatment outcome for late-life generalized anxiety disorder (GAD). However, there is considerable variability in the definitions used to define treatment response and remission. This study aimed to provide empirically derived guidelines for assessing treatment response and remission among older adults with GAD using the PSWQ and the abbreviated PSWQ (PSWQ-A).

Design: Longitudinal assessment of GAD symptoms pre- and posttreatment.

Participants: Participants were 259 older adults aged 60-86 years with a diagnosis of GAD who were assessed before and after treatment.

Intervention: Participants were randomly assigned to cognitive behavioral therapy or control (waitlist, discussion group, or supportive therapy) conditions.

Measurements: Signal-detection analyses using receiver operating characteristic (ROC) methods were used to determine optimal agreement between structured diagnostic interviews and scores on the PSWQ and PSWQ-A.

Results: Results suggest that a score of ≤51 was optimal for defining diagnostic remission status on the PSWQ, and a score of ≤24 was optimal on the PSWQ-A. A 9% reduction or ≥4-point reduction was optimal for assessing treatment response on the PSWQ. The PSWQ-A was poor at identifying treatment response status.

Conclusions: Findings suggest that most of the previously used definitions have underestimated the treatment effects for late-life GAD. However overall, the PSWQ and PSWQ-A are suboptimal for assessing treatment outcome for late-life GAD. The standardization of response and remission criteria has implications for comparison between treatment trials, and for the benchmarking of outcomes in clinical practice.