Psychometric properties of Conversion Disorder Scale- Revised (CDS) for children.

Objective: To revise conversion disorder scale and to establish the psychometric properties of the revised scale.

Methods: This case-control study was conducted from February to June, 2014, at the Government College University, Lahore, Pakistan, and comprised schoolchildren and children with conversion disorder. In order to generate items for revised version of conversion disorder scale, seven practising mental health professionals were consulted. A list of 42 items was finalised for expert ratings. After empirical validation, a scale of 40 items was administered on the participants and factor analysis was conducted.

Results: Of the240 participants, 120(50%) were schoolchildren (controls group) and 120(50%)were children with conversion disorder (clinical group).The results of factor analysis revealed five factors (swallowing and speech symptoms, motor symptoms, sensory symptoms, weakness and fatigue, and mixed symptoms) and retention of all 40 items of revised version of conversion disorder scale. Concurrent validity of the revised scale was found to be 0.81 which was significantly high. Similarly, discriminant validity of the scale was also high as both clinical and control groups had significant difference (p<0.001) in scores. Cronbach's alpha of scale was a=0.91 while item total correlation ranged from 0.50 to 0.80. The sensitivity and specificity analysis indicated that the revised conversion disorder scale was 76% sensitive to predicting conversion disorder while specificity showed that the scale was 73% accurate in specifying participants of the control group.

Conclusions: The revised version of conversion disorder scale was a reliable and valid tool to be used for screening of children with conversion disorder.