Predictors of clock drawing test (CDT) performance in elderly patients attending an internal medicine outpatient clinic: a pilot study on sun exposure and physical activity

Abstract

Influence of sun exposure and physical activity on cognition has not been evaluated simultaneously. We aimed to evaluate predictors of clock drawing test (CDT) performance on n=125 patients attending an internal medicine outpatient clinic. Interview data was gathered on sociodemographic, health-related and lifestyle factors referring to the last year. Factors associated with obtaining a score >0 and a full score (10/10) were analyzed by univariate (UVA) and multivariate (MVA) logistic regression analyses. Mean age of the participants was 72 ± 5, 58% were women and 17% were illiterate. Mean CDT score was 4.70 ± 2.27, 61.6% scored >0 and 21.6% scored 10/10. Both duration of walking and summer sun exposure predicted a CDT score >0 in UVA. However only summer sun exposure was an independent predictor (odds ratio=OR=1.73, 95% confidence interval=CI=1.16-2.57). Other factors independently associated with obtaining a score >0 were education level (OR=2.70, 95%CI=1.77-4.12) and cerebrovascular disease (CVD) history (OR=0.08, 95%CI=0.008-0.78). Factors independently associated with obtaining a full score were weight (OR=1.05, 95%CI=1.00-1.10), education level (OR=2.04, 95%CI=1.38-3.00) and visiting the clinic alone (OR=3.92, 95%CI=1.354-11.39). Our study shows that CDT can be utilized to unravel the lifestyle factors associated with cognitive function. To our knowledge, this is the first study to suggest an association between sun exposure and cognition.