Background: Early dementia diagnosis is aided by the use of brief screening tests; scores can be biased by patient and informant characteristics such as age, gender and education.
Objective: To assess whether the General Practitioner's Assessment of Cognition (GPCOG), a brief screening tool for detecting cognitive impairment comprising a patient cognitive test and questions to an informant, is biased by patient and informant characteristics.
Design: Sixty-seven general practitioners recruited consecutive patients (with informants). Patients were subsequently assessed by a research psychologist, and DSM-IV diagnoses assigned following a case-conference.
Setting: Primary Care.
Subjects: Two hundred and eighty three home-dwelling individuals, 11.3% of whom were aged 50-74 years with suspected memory problems and the rest aged 75 or more.
Methods: The GPCOG, Cambridge Mental Disorder of the Elderly Examination cognitive scale (CAMCOG), Geriatric Depression Scale (GDS), and the SF-12 Health Survey (SF-12) were administered and demographic data were collected and consensus DSM-IV diagnoses of dementia made. Relationships between patient and informant characteristics and the GPCOG measure were examined using Pearson correlations and linear regression analyses.
Results: There were correlations in GPCOG-patient scores with age, education and depression scores but on regression analysis only age was associated with the GPCOG-patient section. The GPCOG-informant section was free of bias.
Conclusions: The GPCOG has advantages for use in primary care and is free of many biases common in other scales.