The validation of the Italian version of the GPCOG (GPCOG-It): a contribution to cross-national implementation of a screening test for dementia in general practice.

BACKGROUND

The General Practitioner Cognitive Assessment of Cognition (GPCOG), a brief, efficient dementia-screening instrument for use by general practitioners (GPs), consists of cognitive test items and historical questions asked of an informant. The validity of instruments across different cultures and languages requires confirmation and so the aim of this study was to validate the Italian version of GPCOG (GPCOG-It).

METHODS

The validity of the GPCOG-It was assessed against standard criteria for diagnosis of dementia (Diagnostic and Statistical Manual of Mental Disorders - 4th edition) as well as the Clinical Dementia Rating scale. The participants comprised 200 community-dwelling patients aged at least 55 years with (patient group) or without memory complaints (control group). Seven general practitioners were involved. Measurements used were the Cambridge Cognitive Assessment, Mini-mental State Examination with standard (24/25) and Italian cut-off (26/27), Alzheimer's Disease Assessment Scale-Cognitive scale and Geriatric Depression Scale.

RESULTS

The GPCOG-It, total score and two-stage method, were at least equivalent in detecting dementia to the MMSE using the standard 24/25 or the Italian 26/27 cut-offs. The two-stage method of administering the GPCOG-It (cognitive testing followed by informant questions if necessary) had a sensitivity of 82%, a specificity of 92%, a misclassification rate of 17.4% and positive predictive value of 95%. Patient interviews took less than 4 minutes to administer and informant interviews less than 2 minutes, half the time needed for MMSE administration.

CONCLUSIONS

GPCOG-It maintains the same psychometric features and time efficiency as the original English version. Despite methodological limitations (i.e. use of defined samples), the GPCOG-It performed well in detecting clear cut and borderline cognitively impaired patients and can be introduced in the daily practice of Italian GPs.