April, 2026
Older adults are more likely to experience frailty and cognitive decline. Frailty affects how
well someone can recover from illness and can lead to reduced mobility, muscle weakness, and
social isolation. It also raises the risk of falls, disability, and hospitalisation. Cognitive
decline sits between normal cognition and dementia and includes conditions such as subjective
cognitive decline (SCD), mild cognitive impairment (MCI), and mild behavioural impairment (MBI).
There is some evidence that people with SCD are more likely to be prefrail or frail..
While frailty and cognitive decline are generally not reversible, understanding how loneliness
and day-to-day social interactions relate to frailty in people experiencing cognitive decline
could help identify people at higher risk earlier, giving more time for support and
interventions.
In this month’s Tap into Research, we summarise a study exploring how the number of social
interactions and levels of loneliness relate to frailty in older adults with SCD and MCI.
How were smartphones used in the study?
A smartphone app was used to collect information on social interactions and loneliness over two
weeks.
Four times a day – upon waking, breakfast, lunch, and dinner – participants received an alert
and answered two questions. The first asked how many social encounters they had since the
previous prompt (including face-to-face and phone or video calls). The second asked how lonely
they felt at the moment. Both were scored from 0 to 5, and average daily scores were calculated.
To improve data quality, participants received training sessions on how to use the app, an
instruction manual, and access to phone and in-person help during the follow-up period.
Frailty and cognitive decline were measured using questionnaires completed outside the app.
What did the study find?
A total of 145 adults aged over 65 with SCD or MCI were recruited in Seoul, South Korea. Of
these, 101 completed all the required tasks and were included in the analysis. Thirteen
participants were classified as frail, 30 as prefrail, and 58 robust (not experiencing prefrail
or frailty symptoms).
Participants who reported being more social (having a higher average daily social interaction
score) were less likely to be frail compared with the participants classified as robust. There
was no evidence that daily social interactions were related to frailty when comparing the
prefrail group with the robust group. Loneliness levels were not associated with frailty status.
Frail older adults also showed more severe MBI symptoms than the prefrail or robust groups.
Why does this matter?
This study highlights the relationship between social interaction and frailty in people with cognitive decline, suggesting that interventions that support social interactions could help reduce frailty and promote healthy ageing. Using smartphones allowed researchers to capture day-to-day variations in social interactions without relying on memory, which is particularly useful in populations with cognitive difficulties. Future studies could explore whether the type or quality of social interactions matters for frailty risk.