Operational Definitions of Treatment Response and Remission in Obsessive-Compulsive Disorder Capture Meaningful Improvements in Everyday Life

INTRODUCTION: The operational definitions of treatment response, partial response, and remission in obsessive-compulsive disorder (OCD) are widely used in clinical trials and regular practice. However, the clinimetric sensitivity of these definitions, that is, whether they identify patients that experience meaningful changes in their everyday life, remains unexplored. OBJECTIVE: The objective was to examine the clinimetric sensitivity of the operational definitions of treatment response, partial response, and remission in children and adults with OCD. METHODS: Pre- and post-treatment data from five clinical trials and three cohort studies of children and adults with OCD (n = 1,528; 55.3% children, 61.1% female) were pooled. We compared (1) responders, partial responders, and non-responders and (2) remitters and non-remitters on self-reported OCD symptoms, clinician-rated general functioning, and self-reported quality of life. Remission was also evaluated against post-treatment diagnostic interviews. RESULTS: Responders and remitters experienced large improvements across validators. Responders had greater improvements than partial responders and non-responders on self-reported OCD symptoms (Cohen's d 0.65–1.13), clinician-rated functioning (Cohen's d 0.53–1.03), and self-reported quality of life (Cohen's d 0.63–0.73). Few meaningful differences emerged between partial responders and non-responders. Remitters had better outcomes across most validators than non-remitters. Remission criteria corresponded well with absence of post-treatment diagnosis (sensitivity/specificity: 93%/83%). Using both the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and the Clinical Global Impression Scale yielded more conservative results and more robust changes across validators, compared to only using the Y-BOCS. CONCLUSIONS: The current definitions of treatment response and remission capture meaningful improvements in the everyday life of individuals with OCD, whereas the concept of partial response has dubious clinimetric sensitivity.