Digital Clock Assessment in South Asian Setting: Pilot study

As cognitive impairment becomes a growing burden in low- and middle-income countries, scalable tools for early detection are urgently needed. This pilot study evaluated the feasibility and performance of a tablet-based digital Clock Drawing Test (DCTclock) among 303 adults aged 50 years and older 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 (≤ 2 vs. ≥3). DCTclock administration required less than four minutes, and 99.3% of tests yielded analyzable outputs. 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). Using established FDA thresholds, participants scoring below 60 had 3.35-fold greater odds of impairment compared with those scoring 75 or higher, and those scoring 60-74 had 1.93-fold increased odds. In sensitivity analyses, the ROC-derived Youden cut point of 38 identified impaired participants with 3.95-fold greater odds of Mini-Cog impairment. These findings demonstrate the feasibility and potential utility of digital clock drawing for cognitive screening in diverse, resource-limited settings, supporting its broader application in aging surveillance and dementia risk stratification.