Creating cognitive normative data for rural Indian population
Nilima Nilima1, Hina Narzari1, Shubham Gupta1
1All India Institute of Medical Sciences, New Delhi, India.
Frontiers in Aging Neuroscience
|August 8, 2026
Summary
This study generated education-stratified cognitive norms for older adults in rural India using the ICMR-NCTB. These new norms aid in detecting early cognitive impairment in diverse, low-literacy populations.
Area of Science:
- Neuroscience
- Gerontology
- Public Health
Background:
- Accurate interpretation of cognitive tests requires population-specific normative data, especially in low-resource settings with low literacy.
- Normative values for the Indian Council of Medical Research-Neurocognitive Tool Box (ICMR-NCTB) in rural Indian older adults are scarce.
- Early detection of cognitive impairment is crucial for timely intervention.
Purpose of the Study:
- To generate education-stratified normative values for the ICMR-NCTB cognitive domains in rural Indian older adults.
- To evaluate the classification ability of these norms for identifying early cognitive impairment.
- To address the need for culturally relevant cognitive assessment tools in India.
Main Methods:
- Utilized baseline data from the SMRUTHI cohort (n=3,175) of adults aged 55+ in rural India.
- Estimated normative centiles using quantile regression and the Box-Cox power exponential (BCPE) method.
- Employed Receiver Operating Characteristic (ROC) analyses to assess classification accuracy for cognitive impairment.
Main Results:
- Generated age- and education-stratified normative data for the ICMR-NCTB.
- Found education to be a significant factor, while age and gender had minimal associations.
- ROC analyses showed good classification performance for episodic memory and composite scores (AUC up to 0.84).
Conclusions:
- The study provides essential, population-specific normative data for the ICMR-NCTB in rural Indian older adults.
- Highlights the importance of percentile-based norms for detecting cognitive impairment in low-literacy, diverse settings.
- Suggests empirically derived cutoffs approximating the 25th percentile for screening balance sensitivity and specificity.
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