Cultural influence on clock drawing test: A systematic review

Objective: Dementia among migrants is an emerging phenomenon worldwide and the development of neuropsychological tests sensitive to cultural differences is increasingly regarded as a priority. The Clock Drawing Test (CDT) is one of the most used screening tools for the detection of cognitive decline. Nevertheless, there is still a debate about its adoption as a cross-cultural assessment. Methods: To identify cultural variables influencing performance at CDT, we performed a systematic review of literature on three databases of all studies considering the role of at least one of the following: (1) language; (2) education; (3) literacy; (4) acculturation; and (5) ethnicity. Results: We extrapolated 160 analyses from 105 studies. Overall, an influence of cultural determinants on performance at CDT was found in 127 analyses (79.4%). Regarding specific cultural factors, 22 analyses investigated the effect of ethnicity on CDT scores, reporting conflicting results. Only two scoring systems turned out to be sufficiently accurate in a multicultural population. Language influenced performance in only 1 out of 8 analyses. A higher level of education positively influenced test performance in 118 out of 154 analyses (76.6%), and a better quality of education in 1 analysis out of 2. A negative influence of illiteracy on CDT performance emerged in 9 out of 10 analyses. Acculturation affected performances at CDT in 1 out of 2 studies. Conclusions: Based on the present findings, caution is needed when using CDT in a multicultural context, even if it requires limited linguistic competence.