Adherence timescale impacts completion rates of high-frequency mobile cognitive assessments among older adults

Mobile technology enables frequent, remote cognitive assessments, introducing new methodological opportunities and challenges. The study evaluated the feasibility of a high-frequency cognitive assessment schedule among older adults, in terms of total assessments and adherence to a prescribed schedule.

Thirty-three older adults were recruited from the Boston University Alzheimer's Disease Research Center (mean age = 73.5 years; 27.3% cognitively impaired; 57.6% female; 81.8% White, 18.2% Black). Participants downloaded the DANA Brain Vital mobile application on their own mobile devices during a remote study visit, and were provided a schedule with seventeen assessments to complete over one year at varying frequencies. The first segment contained three subsegments to be completed within one week, the second segment consisted of weekly subsegments spanning three weeks, and the third and fourth segments consisted of monthly subsegments spanning five and six months, respectively. Three adherence types were defined to reflect incrementally broader adherence timescales: subsegment adherence (strict adherence to each prescribed assessment period), segment adherence (completing the required number of assessments within each broader segment), and cumulative adherence (completing the total number of assessments irrespective of timing).

Completion rates differed depending on the adherence timescale and corresponding adherence type. Using the strictest adherence definition (subsegment adherence), completion rates declined (from 93.9% to 72.7%, p = 0.05) during the fourth segment. However, when a broader adherence timescale was applied, completion rates did not decline. Overall completion rates increased as adherence timescale parameters were broadened from subsegment adherence (60.6%) to segment adherence (78.8%), to cumulative adherence (90.9%).

Older adults, including those with cognitive impairment, are able to complete remote cognitive assessments at a high-frequency, but may not necessarily adhere to prescribed schedules. Future high-frequency studies should consider adherence as a potential behavioral variable to complement cognitive test data, while recognizing the potential influence of adherence timescale on interpreting completion rates.