Subtle Changes in Medication-Taking Are Associated with Incident Mild Cognitive Impairment

Introduction: Medication-Taking is a routine instrumental activity of daily living affected by mild cognitive impairment (MCI) but difficult to measure with clinical tools. This prospective longitudinal study examined in-home medication-Taking and transition from normative aging to MCI. Methods: Daily, weekly, and monthly medication-Taking metrics derived from an instrumented pillbox were examined in 64 healthy cognitively intact older adults (M^age=85.5 y) followed for a mean of 2.3 years; 9 transitioned to MCI during study follow-up. Results: In the time up to and after MCI diagnosis, incident MCI participants opened their pillbox later in the day (by 19 min/mo; β=0.46, P<0.001) and had increased day-To-day variability in the first pillbox opening over time (by 4 min/mo) as compared with stable cognitively intact participants (β=4.0, P=0.003). Discussion: Individuals who transitioned to MCI opened their pillboxes later in the day and were more variable in their medication-Taking habits. These differences increased in the time up to and after diagnosis of MCI. Unobtrusive medication-Taking monitoring is an ecologically valid approach for identifying early activity of daily living changes that signal transition to MCI.