JMIR Publications

ABSTRACT

Background:

Cognitive decline poses one of the greatest global challenges for health and social care, particularly in China, where the burden on the elderly population is most pronounced. At present, there is a limited understanding of the long-term cognitive impacts of internet usage among middle-aged and elderly individuals.

Objective:

This study aims to explore the association between internet usage and age-related cognitive decline among middle- and old-aged Chinese.

Methods:

We analyzed data based on 12,770 dementia-free participants aged ≥ 45 years from the China Health and Retirement Longitudinal Study. We employed a fixed-effects model to measure the relationship between internet usage and cognitive decline and further validated it using multiple linear regression, generalized estimating equations (GEE), propensity score matching (PSM), inverse probability of treatment weighting (IPTM), and overlap weighting (OW). It also focused on the varying effects that internet devices and usage frequency have on cognitive function. The Karlson-Holm-Breen (KHB) method was used to estimate the mediating role of internet usage in the urban-rural cognitive gap.

Results:

After adjusting for demographic and health risk factors, there is a positive correlation between internet use and cognitive function (β=0.551, 95% CI 0.391 to 0.710). The negative impact of age on cognitive function was consistently more minor among internet users compared to non-users after the age of 50. With the increase in internet usage frequency, the cognitive benefits for middle-aged and elderly individuals become more evident (rs = 0.378, P<.001). As digital devices for internet access, cellphones (β=0.398, 95% CI 0.283 to 0.495) seem to have a higher level of cognitive protection compared to computers (β=0.147, 95% CI 0.091 to 0.204). The urban-rural disparity in cognitive function was partially attributed to the disparity in internet use (34.18% of the total effects, P<0.001).

Conclusions:

This study reveals that the use of internet by individuals aged 45 years and older is associated with a reduced risk of cognitive decline. Internet usage has the potential to be a viable, cost-effective, non-pharmacological intervention for cognitive decline among middle-aged and elderly individuals.