Eligible studies were those that used either the Clock Drawing Test or a variant to assess cognitive function in participants aged 65 years or more who had no diagnosis of dementia at baseline, no additional psychiatric disorders that may have affected performance on cognitive testing, a Clock Drawing Test score at baseline and longitudinal follow-up.
Screening tools for dementia in addition to the Clock Drawing Test included the Mini-Mental State Exam (MMSE), Dementia rating scale, neuropsychological battery and the depression and functional impairment screen.
Two reviewers independently selected the studies for inclusion in the review.