Validity and reliability of the Persian version of general practitioner assessment of cognition (P-GPCOG)

Objectives: The study aimed to examine the validity, reliability, and practicality of the Persian version of the General Practitioner Assessment of Cognition (P-GPCOG) as a brief, efficient cognitive assessment instrument in Iranian older adults. Method: The sample comprised 151 community-dwelling older adults and 79 nursing home residents (aged ≥60 years). The English GPCOG was translated, back-translated, and revised to prepare the final P-GPCOG. The Abbreviated Mental Test score (AMTs) and the Depression in Old Age Scale (DIA-S) were administered to the two different samples to establish the convergent and discriminant validity of the P-GPCOG. Results: The mean age of the sample was 70.67 (SD = 9.51); 57.4% were male. The mean P-GPCOG scores for the total, cognitive and informant subscales were 7.67 (SD = 4.59), 4.18 (SD = 2.73), and 3.49 (SD = 2.24), respectively. Cognitive (P < 0.001), informant (P < 0.001) and total scores (P < 0.001) differed significantly between community-dwelling participants and nursing home residents. Worse cognitive performance on the P-GPCOG correlated significantly with worse scores on the AMTs (r = 0.61, P < 0.001) and less so with depressive symptoms as measured with the DIA-S (r = -0.20, P < 0.05). Cronbach's alpha for the P-GPCOG cognitive and informant subscales were 0.90 and 0.83 respectively, indicating a high degree of internal consistency and homogeneity between items. The test-retest correlation for the total P-GPCOG score was 0.82 in 30 participants after 19 days. P-GPCOG cognitive scores correlated significantly with education. Conclusion: The P-GPCOG displayed strong psychometric properties, offering healthcare professionals a quick and efficient cognitive instrument for older Persian speakers. As with other cognitive assessment tools, the P-GPCOG cognitive score is affected by a person's level of education.