To validate the TNI-93 test in illiterate and low-educated subjects by setting cutoff scores to discriminate non-demented and demented subjects in a clinical setting (CESILL) and verifying the adequacy of these cutoff scores in a population-based study (AMI cohort).
We used two study samples. First, a clinical setting (CESILL) comprising normal elderly participants and demented patients, mostly multicultural, low educated, or illiterate, was used to compute the cutoff scores of TNI-93 for the detection of dementia. Second, the AMI cohort, a population-based cohort of retired farmers living in a rural setting, was used as a replication study, to assess the detection properties of the cutoff scores in a different population composed mostly of low-educated older people.
When combining the two scores, that is, free recall <6 or total recall <9, TNI-93 can detect dementia with a high sensitivity (87%) and specificity (96%), in the CESILL setting. These cutoff scores were roughly similar in the AMI cohort with high sensitivity (80% sensitivity) and specificity (81% specificity). In both study samples, the level of education had no effect on performance.
The TNI-93 appears to be a good test to detect dementia. The absence of a significant effect of education level on the performances makes the TNI-93 a tool of choice in the screening of dementia in illiterate/low-educated subjects.