Digital clock assessment in South Asian setting: pilot study

Abstract As cognitive impairment increasingly burdens low- and middle-income countries, scalable tools for early detection are pivotal. This pilot study evaluated the feasibility and performance of a tablet-based digital Clock Drawing Test (DCTclock) in 303 adults aged ≥ 50 years from the population-based CARRS cohort in urban India. Participants completed both the tablet-based DCTclock and the paper-based Mini-Cog, which was used to classify cognitive status (impaired: ≤2 vs. unimpaired: ≥3). The DCTclock required under four minutes to administer, and 99.3% of tests yielded analyzable data. Compared with cognitively unimpaired participants (n = 252), those classified as impaired (n = 51) scored significantly lower on the DCTclock total score and subdomains, particularly spatial reasoning and information processing. Performance was lower with older age and lower educational attainment (both p < 0.001) but did not differ by sex. The DCTclock demonstrated moderate discriminative accuracy for Mini-Cog-defined impairment (AUC = 0.669), and each interquartile range higher total score was associated with 52% lower odds of impairment (OR = 0.48; 95% CI, 0.32–0.70). Similar patterns were observed using FDA-recommended thresholds, while in this cohort, a ROC-derived cut point of 38 yielded slightly stronger discrimination (3.95-fold greater odds). These findings support the DCTclock’s feasibility and potential as a scalable digital tool for community-based cognitive screening.