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CHAPTER 4 100 rated from “not at all severe” to “very severe”) on 0-100 visual analogue scales (VAS). The overall CCS score was calculated by averaging ratings across all 21 items (cf. Deacon & Maack, 2008). Even though importance of checking, likelihood of threat and severity of threat ratings were moderately to highly correlated (see Table 2), subscales were calculated by averaging ratings across the seven items of each subscale to gain insight in the separate constructs of the CCS. The CCS had excellent internal consistency at both time points (α’s = .89 and .93), and high test-retest reliability ( r = .87; calculated using the pre- and post-test of the control group). Subscales showed very good internal consistency too, with importance of checking α’s = .80 and .88, likelihood of threat α’s = .78 and .88, and severity of threat α’s = .81 and .86. Obsessive beliefs questionnaire-44 (OBQ-44) responsibility and threat estimation (RT) scale A Dutch translation of the 16-item RT-subscale of the OBQ-44 (Obsessive Compulsive Cognitions Working Group [OCCWG], 2005) assessed participants’ beliefs about preventing harm from happening to oneself or others, beliefs about the consequences of inaction, and responsibility for bad things happening, and was used as a dependent variable. This scale accounts for more variance in OCD-related beliefs than the other belief domains of the OBQ (OCCWG, 2005). Participants rate their agreement with each statement on a 7-point Likert scale (e.g., ‘‘Harmful events will happen unless I am very careful’’, 1 = disagree very much, 7 = agree very much). Internal consistency was excellent at both time point (α’s = .84, and .90). Obsessive-compulsive inventory-revised (OCI-R) The Dutch translation (Cordova-Middelbrink, Dek, & Engelbarts, 2007) of the OCI-R (Foa et al., 2002) was used to check for pre-test differences in obsessive compulsive tendencies. The OCI-R contains 18 items concerning OCD characteristics, each measured on a 4-point Likert scale (e.g., “I check things more often than necessary”, 0 = not at all, 4 = extremely). The OCI-R has good test-retest reliability and validity in