Effect of age and education on the Trail Making Test and determination of normative data for Japanese elderly people: The Tajiri Project

• Published in: Psychiatry and clinical neurosciences 2006-08, Vol.60 (4), p.422-428
• Main Authors: HASHIMOTO, RYUSAKU, MEGURO, KENICHI, LEE, EUNJOO, KASAI, MARI, ISHII, HIROSHI, YAMAGUCHI, SATOSHI
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Aging - psychology; aging effect; Biological and medical sciences; Education; educational effect; Female; Humans; Japan; Male; Medical sciences; Neuropsychological Tests; normal aging; Psychology. Psychoanalysis. Psychiatry; Psychometrics. Diagnostic aid systems; Psychomotor Performance - physiology; Psychopathology. Psychiatry; Reference Values; Techniques and methods; Trail Making Test
• ISSN: 1323-1316; 1440-1819
• DOI: 10.1111/j.1440-1819.2006.01526.x

The Trail Making Test (TMT) is a common two‐part neuropsychological test, in which visuospatial ability (TMT‐A) and executive function (TMT‐B) are evaluated. Normative data for this test have not been reported for Japanese subjects; therefore, the purpose of the present paper was to investigate the effect of age and education on the TMT in 155 healthy elderly adults with clinical dementia rating 0 (healthy). The participants were classified into three groups based on age (70–74 years, 75–84 years and ≥85 years), and also into three groups based on educational level (6 years, 8 years and ≥10 years). The time to complete TMT‐A and TMT‐B were measured, and the difference in score between TMT‐A and TMT‐B (B–A) and the ratio of the score (B/A) were calculated as indices of executive function. The time for completion of both parts of the TMT increased markedly in the ≥85‐years group. For TMT‐A, there was a significant difference between the 6‐years and 8‐years groups, and between the 6‐years and ≥10‐years groups, and for TMT‐B, there was a significant difference between the 6‐years and ≥10‐years groups, and between the 8‐years and ≥10‐years groups. The difference and ratio scores increased in the ≥85‐years group, but the educational level did not significantly influence these scores. Our data suggest that cognitive functions evaluated by TMT‐A and TMT‐B are not affected by aging until the subjects are ≥85 years old. For TMT‐A, an educational effect becomes apparent when the population includes poorly educated subjects, but this part of the test is not affected by educational level provided that the subjects have some education (>6 years). The time to complete TMT‐B is affected by educational level, consistent with previous reports. However, when adjusted using the results for TMT‐A [(B‐A) or (B/A)], the educational effect on executive function disappeared. Thus, the effect of educational level on executive function was unclear in normal elderly subjects.