Reliability and Equivalence of Alternate Forms of the Digital Clock Drawing Test

Randomized crossover trial consisting of two test visits separated by a washout period of 3 to 5 weeks. Subjects are randomized into two equal groups. Group 1 receives the digital pen (DCTclock-pen) version of the test at the first visit, with the tablet version (DCTclock-tablet) given at the second visit; Group 2 receives DCTclock-tablet at the first visit, followed by DCTclock-pen at the second visit. At Visit 1 (day 0), eligibility is assessed and a version of the DCTclock test is administered based on the group allocation. A battery of Linus Platform tests and reference standard tests are also administered. At visit 2 (day 21-35), eligibility is assessed and the alternate version of the DCTclock test is administered based on the group allocation. A battery of Linus Platform tests is also administered, together with reference standard tests. Equivalence of DCTclock-pen and DCTclock-tablet will be tested. Linus Platform test data will also be collected to develop novel measures of cognitive and motor function and assess their accuracy in detecting impairment, construct validity, and test-retest reliability.

Inclusion criteria

• 55-95 years old

Exclusion criteria

• Ineligible for written informed consent
• Impairment of the writing hand that precludes ability to perform the study tasks
• Impaired manual dexterity in the writing hand
• Impaired vision in both eyes
• Under the influence of recreational drugs or alcohol at the time of the visit.
• Current or recent participation in a clinical trial that includes the use of a drug or intervention to alter cognitive function.
• Recent (within the last 6 months) cognitive testing with a Clock Drawing Test.
• Visit 2 Only- Self-reported change (addition or discontinuation) of the following medications between visit 1 and visit 2; Timolol (eye drop), Benadryl, beta blockers, steroids or over the counter medications for sleep (PM varieties).