Comparative study reveals mortality due to health risk factors changes over time

06 Jul 2023 --- A long-term US survey found that over 97% of individuals had at least one of 19 investigated health risk factors and the prevalence of these factors have changed over time.

Using survey data from 28,279 adults over 20, researchers compared how the prevalence of risk factors in 1988-1994 changed in 1999-2014 and how these factors impacted mortality risk five years after these periods. 

“We’re more likely to have a lifestyle health-risk factor now than in the ‘80s and that’s associated with even greater mortality risk now than before,” says lead author Jennifer Kuk, Faculty of Health associate professor at York University, Canada. 

“What we discovered is that the relationship between risk factors and mortality changes over time, which could be explained by factors such as evolution in treatments and changes in social stigma.”  

Highlights of the paper found that more people had increased health risks due to lifestyle, social, mental or physical factors in 2014 than 20 years earlier, while rates of physiological risks – e.g., cardiovascular disease or high cholesterol – decreased by 6.5%. 

Having any lifestyle, social or mental risk factor in 1999-2014 was associated with a higher mortality risk than in 1988-1994. Physical risk factors and poor self-rated health were linked to mortality risk throughout the study. 

Study set up 
Using publicly available data from the US National Health and Nutrition Examination Surveys, the researchers compared samples from 1988-94 with the same groups in 1999-2014, with a five-year mortality follow-up for each group. They also analyzed self-reported health by the study participants. 

More people had increased health risks due to lifestyle, social, mental or physical factors in 2014 than 20 years earlier.Lifestyle and physiological risk factors were the most common among the participants, which included no physical activity, high-fat diet, smoking, alcohol consumption, high blood pressure, hyperglycemia, dyslipidemia, cardiovascular disease, cancer and lung problems.  

Figures fluctuate over time and differ among men and women. Between 2011-14, 83.6% of men and 86.2% of women had a lifestyle risk factor, while physiological risk factors affected 78.6% of men and 79.3% of women. 

Physical and social/mental risk factors affected 50-60% of individuals between 2011-2014. These include lack of health insurance, low education, food insecurity, low income, use of mental health or pain medication, obesity and daily living limitations (in the case of people over 60).  

Health trends 
Kuk notes that while the prevalence of obesity went up – one of the sub-indicators for lifestyle risk – mortality risks associated with obesity decreased.

“Even though there are more and more people with obesity, it’s actually not resulting in more deaths over time. And so I think that that’s another clear thing we need to recognize, that we’re very good at treating the outcomes associated with obesity. And regardless of our body weight, most of us have something we can probably work on.”

Similarly, while rates of diabetes and hypertension increased, mortality risk decreased. Fewer people exercise when compared to the 1988-94 survey, which is now related to worse outcomes than before. 

“You can take this as a good or a bad news story, depending on how you want to look at these numbers,” sees Kuk. 

Though being on medications for mental health was not a significant risk factor in the ‘80s, the researchers found it was associated with increased mortality in the last dataset. 

Not finishing high school is associated with health risks in the second dataset, but not in the ‘80s. 

Excessive alcohol consumption and insufficient physical activity increased, while smoking and consuming high-fat diets decreased between 1988 and 2014. Moreover, more people had high blood pressure, glucose or cancer and fewer experienced cardiovascular diseases or high lipids.

Fewer people had health insurance, while rates of food insecurity and use of mental health medication increased. 

While the prevalence of obesity went up mortality risks associated with obesity decreased.Overcoming health issues 
The study, published in Plos One, finds room for improvement in health for nearly all people surveyed, especially in terms of diet, exercise, smoking, alcohol and drug intake. 

“Given that nearly 90% of us have some healthy lifestyle factor that we can improve upon, I think it's important for us to all try better,” says Kuk, “and this is true regardless of your body weight status.”

At the same time, she cautions that some factors are out of many people’s control. 

“When we look at things like food insecurity, low education – as a society, we’re making it so that health might not be an easy choice for many people. We need to be sensitive to that when we look at these risk factors.”

Previous research also documented these risk factors, but Kuk notes that their relationships with mortality risk must be better understood. She explains that these associations can be paradoxical. 

For example, rates of smoking decreased overall due to solid public-health campaigns. At the same time, the mortality risk of being a smoker increased over time, which Kuk suggests could be explained by an increased stigma as addiction becomes less common. Awareness of smoking risks grows, which could be reflected in research funding. 

She adds: “If you look at cancer research, there’s a lot of funding overall, but specifically for lung cancer, it seems to be associated with moral fault and, as a consequence, lower funding.” 

“When you look at the mortality risk associated with having lung cancer relative to all the other common cancers, it’s extremely high. So I think that this lack of push is detrimental.”

By Jolanda van Hal