JMIR Publications

ABSTRACT

Background:

Various digital biomarkers have been explored to detect cognitive impairment in community-dwelling older individuals, among which electricity consumption (EC) obtained from smart meters is novel and promising because of no burden for the individuals.

Objective:

We aimed to explore the potential of EC as a digital biomarker to screen cognitively impaired older individuals living alone.

Methods:

We recruited 40 older individuals living alone and recorded their one-year daily household EC data. We used the Japanese version of the Montreal Cognitive Assessment to categorize participants into healthy and cognitively impaired groups. As the pattern of daily household EC is different between lower and higher temperature ranges because of the usage of heating and cooling equipment, we divided the daily household EC into three temperature ranges. Using a linear mixed model, we evaluated the relationship between daily household EC, daily outside temperature, and the groups.

Results:

After excluding 12 participants, 18 and 10 were categorized into healthy and cognitively impaired groups, respectively. The daily household EC data consisting of 9,391 points showed two characteristics: 1) interaction between the daily outside temperature and groups in the high-temperature range (P<.001), and a less increase in daily household EC with increasing daily outside temperature in the cognitively impaired group indicated by subgroup analysis (0.635 kWh/°C for the cognitively impaired group; P<.001, 0.835 kWh/°C for the healthy group; P<.001), and 2) a tendency for low daily household EC in the cognitively impaired group in the moderate-temperature range (-1.523 kWh; P=.074).

Conclusions:

The cognitively impaired group might use less cooling equipment in the high-temperature range and few home appliances in the moderate-temperature range. Daily household EC might be useful in screening cognitive impairment in older individuals living alone.