[The revised version of the Y-BOCS: responsivity and other psychometric properties]

BACKGROUND

The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) is a widely used semi structured clinician-rated interview to assess the presence and severity of obsessive-compulsive disorder (OCD). The scale is revised (Y-BOCS-II) to overcome several psychometric limitations, for example by extending the scoring for better discrimination within higher severity levels.

AIM

To examine the responsiveness and other psychometric properties of the Y-BOCS-II in a Dutch clinical sample.

METHOD

The Y-BOCS-II was translated into Dutch (Y-BOCS-II) and administered to 110 patients seeking therapy for OCD. This was done twice, before and after treatment. The original Y-BOCS was simultaneously rated. Self-report measures regarding depression, symptom severity and OCD symptoms were assessed.

RESULTS

The Y-BOCS-II had a good internal consistency (Cronbach’s α = 0.84), test-retest (ICC = 0.81) and inter-rater reliability (ICC = 0.94). The construct validity proved to be modest to good. The responsiveness over time was in favour of the Y-BOCS-II, compared with the YBOCS-I, particularly in the severely affected OCD patients.

CONCLUSION

The Y-BOCS-II severity scale is a reliable and valid instrument for accurately assessing the severity of OCD symptoms and for measuring treatment-induced change. This second version also has clinical and psychometric advantages over the YBOCS-I. When these findings are sufficiently replicated, use of the YBOCS-II as the new common standard seems recommendable.

Responsiveness and other psychometric properties of the Y-BOCS Severity Scale-Second Edition (Y-BOCS-II) in a Dutch clinical sample

The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) is a widely used clinician-rated interview to assess the presence and severity of obsessive-compulsive disorder (OCD). The scale is revised (Y-BOCS-II) to overcome several psychometric limitations, for example by extending the scoring for better discrimination within higher severity levels. The aim of the present study was to examine the responsiveness and other psychometric properties of the Y-BOCS-II Severity Scale in a Dutch clinical sample. The Y-BOCS-II is translated into Dutch (Y-BOCS-II) and administered to 110 patients seeking therapy for OCD. This was done twice, before and after treatment. The original Y-BOCS was simultaneously rated. Self-report measures regarding depression, symptom severity and OCD symptoms were assessed. The Y-BOCS-II has a good internal consistency (Cronbach's α=0.84), test-retest (ICC=0.89) and inter-rater reliability (ICC=0.98). The construct validity proved to be modest to good. The responsiveness over time was in favour of the Y-BOCS-II, compared with the YBOCS-I, particularly in the moderate-severely affected OCD patients. The Y-BOCS-II severity scale is a reliable and valid instrument for accurately assessing the severity of OCD symptoms and for measuring treatment-induced change. This second version also has clinical and psychometric advantages over the YBOCS-I. When these findings are sufficiently replicated, use of the YBOCS-II as the new common standard seems recommendable.

Proof of Principle: Is a Pre-treatment Behavior Approach Test a Potential Predictor for Response to Intensive Residential Treatment in Patients With Treatment Refractory Obsessive Compulsive Disorder?

Patients with severe and treatment refractory obsessive compulsive disorder (OCD) are usually referred to a specialized center for intensive residential treatment (IRT), consisting of exposure and response prevention (EX/RP), pharmacotherapy and additional therapies. About 50% of the patients does not respond to IRT. Currently we are not able to predict treatment response. If we were to have predictive tools, we could personify treatment at an earlier stage. Recent studies show that early adherence and willingness to EX/RP and low avoidance during EX/RP measured during treatment were associated with treatment response. In this observational study willingness and ability of patients with severe and treatment refractory OCD (N = 58) is conceptualized by a behavioral measurement, measured before the start of 12 weeks of IRT, using a Behavior Approach Test (BAT), as opposed to relying on self-report measurements. A medium or strong association between pre-treatment performance on the BAT and treatment response would justify next steps to test the BAT as a predictive tool for IRT. Results of regression analyses showed that there is a significant association between the performance on the BAT and change in OCD symptom severity after IRT. However, the effect-size is too small to use the BAT in its current form as predictor in clinical practice. The principle of the association between pre-treatment behaviorally measured willingness and ability to fully engage in EX/RP, and treatment response has now been proven. To ultimately design a predictive tool, future research is needed to refine a behavioral measurement of pre-treatment willingness and ability.