Usefulness of clock-drawing test in Indian older adults with diabetes mellitus

Clock-drawing test (CDT) is a simple, quick, and bedside cognitive screening test which measures different cognitive domains but has some limitations. The aim of this study was to examine the usefulness of CDT for Indian older adult based on a part of an ICMR-funded research project, New Delhi, India.

Sample comprised seventy participants (38 controls and 32 cases) aged 60 years and above included according to the inclusion/exclusion criteria in a consecutive series. Participants, who gave written informed consent, residing permanently in the area of Chowk, Lucknow, constituted the study sample. Semistructured sociodemographic details and medical history pro forma, socioeconomic status scale, General Health Questionnaire-12 (GHQ-12), CDT, and Hindi cognitive screening test (HCST) were administered. Biochemical investigations were carried out, and blood glucose level (fasting ≤100 mg/dl and postprandial ≤140 mg/dl) was considered for having diabetes mellitus (DM). The participants were categorized into two groups: (1) case: participants with DM only and (2) control: participants without discernible abnormality of physical illness and GHQ negative. Data were analyzed using percentages, t-test, the Chi-square test, sensitivity, and specificity.

About 71.05% participants in control and 81.25% in the case group have cognitive impairment on CDT. Significantly higher illiterates (P < 0.05) were found to be significantly more cognitively impaired on HCST. CDT has a high level of sensitivity (0.71) and low specificity (0.23) when compared with HCST.

CDT had screening bias to Indian older adults as a higher number of literates (almost double) and illiterates (four times) were found to be cognitively impaired compared to on HCST. Usefulness of CDT to screen Indian older adults for cognitive impairment is debatable.