Provisional clinical thresholds for the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) first-edition self-report format

The first‑edition Yale‑Brown Obsessive‑Compulsive Scale (Y‑BOCS) is the most widely used clinician‑administered obsessive‑compulsive disorder (OCD) severity measure, with established thresholds for severity classification, remission, and treatment response, whereas corresponding thresholds for its self‑report format (Y‑BOCS‑SR) are not available. The present study aimed to improve the clinical utility of the Y‑BOCS‑SR by deriving provisional thresholds calibrated to established Y‑BOCS thresholds using meta-analytic methods to aggregate score discrepancies across studies administering both formats to the same participants. Nine independent samples ( N = 485) from Canada, Germany, South Korea, Sweden and the United States were included. Y‑BOCS‑SR scores were on average 2.23 points lower than Y‑BOCS scores (95% CI : −3.31, −1.15; p < .001), with consistent magnitude and direction across countries and languages; discrepancies tended to be larger in samples with higher mean Y‑BOCS scores. Findings support a pragmatic 2‑point downward adjustment of established Y‑BOCS thresholds when interpreting Y‑BOCS‑SR scores, yielding severity benchmarks of 0‑11 (subclinical), 12‑19 (mild), 20‑27 (moderate) and 28‑40 (severe), with a clinical cut‑off of ≥12. Recommendations include applying established Y‑BOCS response criteria unchanged (≥35% reduction; minimal clinically important difference [MCID] of 4.9 points) and using the downward‑shifted Y‑BOCS‑SR severity benchmarks when calculating severity‑stratified MCID thresholds (18% for mild, 26% for moderate and 29% for severe baseline symptoms). The uniform adjustment may not fully account for score‑range dependency, as discrepancies were larger at higher severity. These provisional thresholds may facilitate more accurate classification of OCD severity, remission, and treatment response when using the Y‑BOCS‑SR, pending direct psychometric validation.