The Weigl Colour-Form Sorting Test: A quick and easily administered bedside screen for dementia and executive dysfunction

Abstract

Background: Screening for cognitive impairment in hospital and the community requires a valid, reliable, concise, well tolerated, easily administered instrument. In this investigation, we have studied a non-verbal cognitive screening instrument; Weigl's Colour-Form Sorting Test (WCFT), to determine its utility as a brief cognitive screen in a community based sample of stroke survivors, Parkinson's disease (PD) patients and age/sex matched controls. Methods: A total of 236 subjects consented to participate in this investigation, consisting of 105 stroke survivors, 40 PD and 91 control subjects. The sensitivity and specificity of the WCFT to detect significant cognitive impairment was based upon psychiatric interview, cognitive assessment and application of DSMIV criteria. Results: The optimal cut-point of the WCFT to detect cases of cognitive impairment was 2/4 in all of the groups in this investigation. The sensitivity and specificity of the WCFT at the cut point of 2 in the stroke survivors was 77.8% and 78.3, in the PD patients, it was 78.6% and 85.5% and, in the control group 83.3% and 94.1% respectively. The diagnostic accuracy of the WCFT as calculated by the area under the receiver operating curve was greater than 0.70 in all subject groups, which suggests that it has acceptable psychometric properties to discriminate between case and non-cases of cognitive impairment. Conclusion: The WCFT was able to demonstrate good sensitivity and specificity, at detecting cognitive impairments in all of the subjects. This instrument will prove to be a useful adjunct to existing cognitive screens in clinical practice, due to its excellent psychometric properties, and lack of dependency on language skills. Copyright © 2007 John Wiley & Sons, Ltd.