Normative cognitive scores in western India, stratified by age, rurality, cognitive domains, and psychiatric comorbidity

Abstract

AbstractBackground and objectivesIndian ethnic and educational diversities necessitate obtaining normative cognitive data in different populations. We aimed to evaluate cognitive scores using a Marathi translation of the Kolkata Cognitive Battery (KCB), and to study the association of KCB components with depression and socio-demographic variables.MethodologyWe studied 2651 individuals aged ≥40 years, without pre-existing neuropsychiatric conditions, from urban (Mumbai) and rural districts of Maharashtra. For each component of KCB, the lowest 10th percentile score was used to define cognitive impairment.ResultsWe studied 1435 (54%) rural and 1216 (46%) urban residents equally divided by gender (1316 women, 1335 men), average age 54 years. KCB scores were significantly lower with female sex, older age, illiteracy and depression. The largest effect sizes attributable to these factors were in the domains of calculation (gender), visuo-constructional ability (VCA; rurality) and verbal fluency (VF; depression). Scores remained significantly lower in rural residents after controlling for age, sex and education, particularly for VCA, immediate recall and calculation.ConclusionThis Marathi KCB having been validated on large urban as well as rural samples, may be used to study cognition in Marathi speaking populations with appropriate cut-offs tailored to the degree of urbanization of the population.