2 Clinical Validity and Cut-Off Scores of a Brief Neuropsychological Battery for a Large Rural Population in Community Setting

Abstract

Objective:

There is a dearth of an appropriate standardized tool to assess neuropsychological functions in rural population, which has low literacy rates, are culturally diverse, and have limited access to healthcare resources. The NIREH Neuropsychological Battery for Rural Population (NINB-RP) is a relatively brief and easy-to-administer battery comprising multiple tests that are modified or adopted as per rural community settings to evaluate verbal learning, fine coordination, attention efficiency, executive task, concentration, and visual attention, mental flexibility, and motor coordination in rural populations. The present study aimed to examine the clinical validity and establish cut-off scores for impairment of neuropsychological functions for different age, gender, and education levels of NINB-RP in a rural community in central India.

Participants and Methods:

This was a prospective cross-sectional study conducted in participants aged > 18 years (n=2952, M: F=1407:1545) recruited through a stratified sampling technique from 23 randomly selected villages from central India. The data of nine neuropsychological tests [(Finger and Tweezer dexterity test (FDT, TDT); Digit Forward and Backward test (DFT, DBT); Serial subtraction test (SST); Trail Making-A and B; Finger Tapping test (FTT); and Letter Digit Substitution test, LDST)] from 215 cognitively impaired and 2737 healthy control subjects were analyzed. The tests were performed in a village school/community hall or an outdoor camp. Independent sample t-test, Chi-square test, and Receiver Operating Characteristic (ROC) curve were used to calculate the area under the curve (AUC), cut-off scores, and sensitivity (ST)/specificity (SP) values for seven conditions, i.e., gender (male vs. female), age groups (up to 49 years and above 50 years); and educational levels (illiterate, intermediate and college). For those variables where ST/SP values were lower than 0.70, a unique cut-off score was calculated for the entire sample, adjusting by age and educational levels.

Results:

A significant difference in mean (median) scores between the healthy control and cognitively impaired groups were observed in all tests except Trail Making A and B and LDST. The AUC for most of the tests ranged from 0.70 to 0.81, and the ST/SP values ranged from 69-73% and 65-75%, respectively. The results showed that most tests of NINB-RP reached moderate to good sensitivity and specificity for gender, age and education levels, except for DBT for females, above 50 years, and illiterate and intermediate education groups. FDT for males [AUC: 0.85 (95%CI0.80-0.91], ST/SP=76/82%] and females [(AUC=0.78 (95%CI0.74-0.82), ST/SP=71/70%], TDT for intermediate education group [AUC=0.82 (95%CI0.60-1.00), ST/SP=86/83%] and FTT for less than 49 years age group [AUC=0.75 (95%CI0.67-0.84), ST/SP=71/76%] were the most useful tests to discriminate among healthy control and cognitively impaired rural population.

Conclusions:

The present study is an attempt to establish the cut-off scores of a neuropsychological battery for a large rural population in the community setting. The proposed cut-off values might be helpful in clinical assessment in rural areas where clinical neuropsychology services are not readily available. NINB-RP can be a valuable tool for clinical research studies in rural communities. Further studies on similar samples in other countries need to be undertaken.