Re-Examining the Role of Engaging in Activities: Does Its Effect on Mortality Change by Age among the Elderly?

Objectives:  This study examined how the effect of engaging in activities on mortality changes by age among the elderly.  Engaging in activities has been found, overall, beneficial to individual’s well-being.  What has not been systemically tested with large sample data is whether such benefits diminish at old ages.  The selectivity theory suggests that reduction in certain activities when people reach very old ages may be an adaptive strategy to optimize their survival or well-being.

Data and Methods: This study used the Chinese Longitudinal Health Longevity Survey (CLHLS) between 2002 and 2008.  There were 16,064 peopled aged 65 or above interviewed in 2002 and 8,066 died within the six-year period.  Two types of activities were examined:  customary physical activities, such as such as doing housework and gardening; and social activities, such as playing cards and attending organized activities.  The Cox model was applied to analyze the hazards of mortality and its association with these two types of activities and how these effects change by age.

Results: Both physical and social activities reduced the hazards of mortality for the whole sample and both activities showed a negative interaction effect with age.  As age increases, their beneficial effects decrease.  These patterns are also evident in the sub-sample analysis by age.

Conclusion: Although many studies have shown the beneficial effect of engaging in activities for individuals’ well-being and it is well reported in the media, this study suggests a diminishing effect at old ages.  A rigorous re-examination of its effect seems warranted.