Yale-Brown Obsessive Compulsive Scale

Goodman, Price, Rasmussen, Mazure, Fleischmann, Hill, Heninger & Charney (1989).

10

1) Severity of obsessions.

2) Severity of compulsions.

Inter-rater reliability estimated to be excellent (obsessions subtotal, r = .97; compulsions subtotal, r = .96; total score, r = .98)—Foa, Kozak, Salkovskis, Coles, Amir (1998).

The total Yale-Brown Scale score was significantly correlated with two of three independent measures of obsessive-compulsive disorder and weakly correlated with measures of depression and of anxiety in patients with obsessive-compulsive disorder with minimal secondary depressive symptoms. Results from a previously reported placebo-controlled trial of fluvoxamine in 42 patients with obsessive-compulsive disorder showed that the Yale-Brown Scale was sensitive to drug-induced changes, and that reductions in Yale-Brown Scale scores specifically reflected improvement in obsessive-compulsive disorder symptoms. Together, these studies indicate that the 10-item Yale-Brown Scale is a reliable and valid instrument for assessing obsessive-compulsive disorder symptom severity, and that it is suitable as an outcome measure in drug trials of obsessive-compulsive disorder—Goodman, Price, Rasmussen, Mazure, Fleischmann, Hill, Heninger & Charney (1989).

Obsessive Compulsive Thoughts Checklist (OCTC)

Bouvard, Mollard, Cottraux, Guerin, (1989)

28

1) Checking

2) Responsibility

3) Washing

The Cronbach coefficient of internal consistency was computed for the 28 items for each group separately. Reliability was satisfactory (OCD patients = .88; agoraphobic patients = .84 and control subjects = .89). Then the Cronbach coefficient of internal consistency was computed for each factor

subscale across the three groups:

- checking subscale (10 items): OCD patients = .87; agoraphobic patients = .88 and control subjects = .79.

- responsibility subscale (11 items): OCD patients = .84; agoraphobic patients = .83 and control subjects = .68.

- washing subscale (7 items): OCD patients = .87; agoraphobic patients = .81 and control subjects = .59— Bouvard, Cottraux, Mollard, Arthus, Lachance, Guerin, Sauteraud & Yao (1997).

Spearman rank correlations were used to compute convergent validity in a sub-group of obsessive compulsive patients (r - 96). The Obsessive Compulsive Thoughts Checklist correlated positively with the Compulsive Activity Checklist (rho - .62; p < .0001). The total score was also positively correlated with the Yale-Brown Obsessive Compulsive Scale (YBOCS total scale: rho - .42; p < .0001; YBOCS obsession scale: rho - .40; p < .0001; YBOCS compulsion scale: rho .37; p = .0002). The factor structure was studied both on the sample which included agoraphobic patients and controls (n - 141) and on the obsessive compulsive patients only (n = 122). In both analyses, three identical factors were found:

- factor 1: checking/ perfectionism-orderliness

- factor 2: responsibility/dread of harming others

- factor 3: washing/contamination.

Results support the validity and the internal consistency of the

Obsessive Compulsive Thoughts Checklist—Bouvard, Cottraux, Mollard, Arthus, Lachance, Guerin, Sauteraud & Yao (1997).