Screening for dementia in elderly Nigerians: results of the pilot test of a new instrument.

ABSTRACT

We developed a new instrument for the assessment of cognitive functions in elderly Nigerians as a preliminary step towards the determination of the burden of dementia in Nigerian Communities. The instrument was pilot tested on 250 cognitively-normal Nigerians and their scores compared with those of 15 subjects with clinically-diagnosed dementia. The cognitively normal subjects had a mean score of 24 (SD 2.3) while the cognitively-impaired subjects had a mean of 35 (SD 3.0) and p less than 0.01). Of those with normal cognition, subjects with at least 6 years of education had significantly lower mean scores than illiterates (p less than 0.005). The instrument was completed in 4 minutes in normal subjects as against 7 minutes in those with cognitive impairment. The 19 item instrument had a sensitivity of 80% and a specificity of 72% at a cut-off value of 27. With the elimination of 3 items related to information, the sensitivity and specificity increased to 93% and 83% respectively. We conclude that the 16 item version is adequate for a 2 stage study of dementia in this environment, its main role being that of screening in the first stage.