Effects of age and education on clock-drawing performance by elderly adults in China.

Objective: The Clock Drawing Test (CDT) is widely used as a cognitive screening tool. The purpose of this study was to investigate the influence of gender, age, and education on CDT scores in a sample of elderly, community-dwelling adults in China. Methods: The sample was derived from a cross-sectional survey, "The study on the early screening methods for senile dementia." It included Chinese-speaking persons 65 years of age or older with normal cognitive functioning. All the participants underwent neuropsychological assessments, including the Mini-Mental State Examination (MMSE) and the CDT. The CDT was administered and scored using Shulman's methodology. The effects of gender, age, and education on CDT performance were analyzed. Results: The sample contained 440 males and 445 females, ranging from 65 to 93 years of age, with a mean age of 74.94 +/- 6.17 years old. The mean CDT and MMSE scores were 4.81 +/- 0.54 and 28.79 +/- 1.35, respectively. CDT performance was significantly different among age groups (chi(2) = 22.85, p < .01) and educational levels (chi(2) = 6.94, p = .03). However, there was no significant difference in CDT scores between males and females (t = 0.56, p = .57). The gender difference remained non-significant when the sample was divided according to age group and educational level. Conclusions: The study provides preliminary normative data on the CDT for the older population of China. CDT performance was significantly influenced by age and education, which must be taken into account when using the CDT as a cognitive screening tool in the Chinese population.