Wearables provide useful data on dementia patients

Wearable devices can reliably capture activity patterns, circadian rhythm, and changes in sleep in patients with dementia, according to a new study. In the aggregate, these gadgets show that patients are less active and have disturbed sleep compared with healthy controls.

“[T]his systematic review and meta-analysis has shown that the wearable devices studied demonstrate differences in those with dementia,” the researchers said. “To our knowledge, this study is the first systematic review and meta-analysis of wearable device testing in participants with dementia.”

Forty-eight studies, totaling 2,516 dementia patients and 1,224 healthy controls, were eligible, of which 19 were included in at least one meta-analysis. Only those that employed wearable technologies and with a mean sample age ≥50 years were eligible; using direct interventions, such as drugs or supplements, was a ground for ineligibility. Studies were retrieved from the database of IEEE, Embase, PubMed, PsycInfo, and the Cochrane Database.

In a pooled analysis of 23 studies, dementia patients engaged in significantly lower mean daytime activity counts than healthy controls (mean difference, –1.60, 95 percent confidence interval [CI], –2.66 to –0.55). [Front Med 2021;doi:10.3389/fmed.2020.501104]

“[D]efinitions of physical activity differ significantly between studies and daily activity counts measured by wearable devices are not definite indicators of beneficial exercise, but merely of movement,” the researchers pointed out, adding that future studies in this area are needed.

Thirty-one studies had available data regarding sleep measures and found that patients were significantly more disadvantaged than controls, particularly in terms of sleep efficiency (mean difference, –0.52, 95 percent CI, –0.89 to –0.16). Average total sleep time was comparable between groups (mean difference, 0.46, 95 percent CI, –0.21 to 1.12).

In terms of circadian rhythm, dementia patients showed significantly worse interdaily stability (mean difference, –0.47, 95 percent CI, –0.81 to –0.14) and relative amplitude (mean difference, –0.53, 95 percent CI, –0.76 to –0.30) than healthy controls. Activity in the most active 10 hours was also significantly lowered in dementia patients (mean difference, –0.61, 95 percent CI, –1.16 to –0.06).

On the other hand, interdaily variability (mean difference, 0.46, 95 percent CI, 0.27–0.65) and activity in the least active 5 hours (mean difference, 0.38, 95 percent CI, 0.15–0.61) were both significantly higher in patients vs controls. The pooled analysis for the nonparametric measures of circadian rhythm involved 16 studies.

However, “a high level of heterogeneity between studies was observed for this outcome measure. Despite evidence of the utility of wearable actigraphy in sleep monitoring, consistent outcome measures and methods of analyzing sleep data and circadian rhythm have not been universally agreed upon,” the researchers said.

“In order for actigraphy to become routinely used in clinical and drug treatment trials, consistent outcome measures are needed and, as shown in this meta-analysis, may provide a useful endpoint for patients with dementia,” they added.

The present meta-analysis highlights the potential for future efforts to link device-obtained parameters to clinical markers, such as loss of mobility or neuropsychiatric manifestations.