A joint study led by UBC has identified behavioural and social characteristics that are most closely linked to human death.
Researchers from five universities studied 57 factors for the paper, published on June 22 in the Proceedings of the National Academy of Sciences.
The top three elements of the almost five dozen studied were smoking, divorce, and drinking alcohol. The data analyzed for the study came from information obtained during a 16-year period (1992 to 2008) from 13,611 adults who participated in the U.S. Health and Retirement Survey, with ages ranging from 50 to 104.
Those participants who died during the six years after the survey (2008 to 2014) had their information analyzed to determine which of the 57 factors applied.
Because life expectancy in the U.S. has remained stagnant for the past three decades compared with other industrialized countries, the study attempted to discover which factors contributing to death (other than the medical and biological reasons that always top such lists) were most prevalent. Behavioural, social, psychological, and economic characteristics became the study criteria.
(Canada's life expectancy has risen continuously during the past three decades, according to Statistics Canada.)
The top 10 factors closely associated with death in the study are:
- Current smoker
- History of divorce
- History of alcohol abuse
- Recent financial difficulties
- History of unemployment
- Previous history as a smoker
- Lower life satisfaction
- Never married
- History of food stamps
- Negative affectivity
In a June 22 UBC release, Eli Puterman—the study's lead author and an assistant professor at UBC's school of kinesiology—said that some of the more obscure categories involved in the analysis might provide avenues of investigation to develop initiatives to address life-expectancy issues.
“Smoking has been understood as one of the greatest predictors of mortality for 40 years, if not more," Puterman said, "but by identifying a factor like negative affectivity—this idea that you tend to see and feel more negative things in your life—we can see that we might need to start targeting this with interventions.
"Can we shift it and have an impact on mortality rates? Similarly, can we target interventions for the unemployed and those with financial difficulties to reduce their risk?”
Puterman noted: "“If we’re going to put money and effort into interventions or policy changes, these areas could potentially provide the greatest return on that investment."
The researcher was aided by UBC kinesiology masters student Benjamin Hives.
Puterman added that the study's lifespan methodology was clearly essential compared with a "snapshot" approach that might offer insight into only a brief period in someone's life.
“It shows that a lifespan approach is needed to really understand health and mortality. For example, instead of just asking whether people are unemployed, we looked at their history of unemployment over 16 years. If they were unemployed at any time, was that a predictor of mortality?
"It’s more than just a one-time snapshot in people’s lives, where something might be missed because it did not occur. Our approach provides a look at potential long-term impacts through a lifespan lens.”
The U.S. researchers involved in the study came from the University of California San Francisco, the University of Pennsylvania, Stanford University, and Johns Hopkins University.