Association between daily Internet use and intrinsic capacity among middle-aged and older adults: A large Prospective Cohort Study from China (Preprint)

Abstract

Background: Intrinsic capacity, as a comprehensive measure of an individual's functional ability, has gained prominence in the framework for healthy aging introduced by the World Health Organization (WHO). As Internet usage continues to integrate into daily life, it is imperative to scrutinize the association between Internet use and IC to effectively promote healthy aging among middle-aged and older population.

This study aims to investigate the relationship between daily internet usage and intrinsic capacity, an aspect that has not been previously explored.

This study was a secondary analysis that included data from the China Health and Retirement Longitudinal Study (CHARLS) 2011- 2015 including 16,070 participates. First, we evaluated the linear and nonlinear associations of daily internet use with intrinsic capacity using linear regression and regression splines. Subgroup and sensitivity analyses were used to investigate the heterogeneity of intrinsic capacity in specific conditions and the robustness of our results. Mediation effect analysis was utilized to determine how much the effect of daily internet use and intrinsic capacity depended on their social participation proportion.

After adjusting for demographic variables, socioeconomic factors, lifestyle behaviors, and health conditions, and examining the impact of daily internet use and frequency on changes in intrinsic capacity (IC), our findings indicated important associations. Specifically, daily internet use is significantly linked to a slower decline in IC over time (marginal effect: 1.58; 95% CI: 1.03, 2.12, P<0.001). Additionally, individuals with moderate and regular internet use frequency exhibit higher levels of maintenance in IC (marginal effect: 0.74; 95% CI: 0.45, 1.03, P<0.001). Notably, the relationship between IC changes and internet use frequency demonstrated a non-linear inverted U-shaped curve (nonlinear P-value <0.05). Subgroup analysis further revealed that improvements in IC vary based on age and gender. Moreover, mediation analysis denoted that more than 29.06% of the observed association is mediated by social participation.

The results of our study underscore the potential advantages of maintaining a moderate and regular patterns of internet use in promoting and preserving IC, thus preventing a rapid decline in IC, particularly in cognitive capacity, sensory, vitality, and locomotion. The effect may be related to social participation and thus results offer valuable insights for developing interventions to promote healthy aging among the middle-aged and elderly population.

CHARLS was a survey approved by the Ethical Review Committee of Peking University (approval number IRB00001052–11015), and the study data were anonymous. Each participant provided signed informed consent at the time of participation. There was no requirement for additional ethics approval for approved data users.