The study, published in the journal JMIR Public Health and Surveillance, highlights the importance of adopting a healthy lifestyle in increasing life expectancy and reducing lifetime medical costs.
Study: Impact of healthy lifestyle factors on life expectancy and lifetime medical costs: A nationwide cohort study. Image credit: nadianb / Shutterstock
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The link between unhealthy lifestyle habits and chronic disease and mortality is well documented. Unhealthy lifestyle habits, such as poor diet, lack of exercise, smoking and excessive alcohol consumption, are known to be associated with 60% of premature deaths worldwide.
Increases in life expectancy have been observed worldwide in recent decades. However, it is unclear whether this increase in life expectancy is associated with an overall reduction in health care costs. Several studies have highlighted the association between lifestyle risk factors and health care-related economic burden.
In the study, scientists investigated the individual and combined effects of five healthy lifestyle factors on life expectancy and lifetime medical costs in Taiwan.
Study design
The study included a nationally representative group of over 19,000 Taiwanese adults who participated in the Taiwan National Health Interview Survey (NHIS) in 2001 and 2005.
A rolling extrapolation algorithm was used to estimate lifetime survival functions for the study population. These estimates were used to calculate life expectancy and lifetime medical costs for the study population with and without healthy lifestyle factors.
The study analyzed five components of a healthy lifestyle, including not smoking, avoiding excessive alcohol consumption, getting enough exercise, eating enough fruits and vegetables, and maintaining a healthy weight. Information on these lifestyle components was collected from a survey database.
The study database also contained information on participants’ sociodemographic characteristics and medical history. These factors were adjusted for as potential confounders or covariates in the final analysis.
Important Observations
The study included 19,893 people aged 30 years or older. During the study’s 15-year follow-up period, 3,815 deaths were recorded.
Each of the lifestyle factors analyzed showed a significant association with total mortality risk: increasing healthy lifestyle behaviors was associated with a decreased risk of mortality.
Average life
As adherence to healthy lifestyle behaviors increased, life expectancy was observed to increase: adherence to all five healthy behaviors was found to increase life expectancy by 7.13 years.
In terms of individual healthy lifestyle behaviors, participants who did not smoke and did not consume excessive alcohol had increased life expectancy by 2.31 and 1.62 years, respectively.
Adequate physical activity and adequate intake of fruits and vegetables were associated with an increased life expectancy of 1.85 and 3.25 years, respectively.
Lifetime medical expenses
Adherence to all five healthy lifestyle behaviors was found to reduce the rate of annual health care expenditures per person by 28.12%.
With regard to individual health behaviors, non-smoking and a healthy weight were found to significantly reduce lifetime medical costs: participants who had never smoked and those with a healthy weight reduced annual per capita medical costs by 9.78% and 18.36%, respectively.
Analysis of dose-response effects revealed that being overweight was associated with an increased life expectancy of 0.69 years, but this increase in life expectancy was accompanied by a 21% increase in annual health care costs.
Correlation analysis of life expectancy and lifetime medical costs revealed that adherence to all five healthy behaviors was associated with longer life expectancy and lower annual medical costs.
Among the lifestyle behaviors analyzed, smoking and non-optimal body weight showed significant associations with higher health care costs and lower life expectancy.
Significance of the study
The study revealed that adopting a healthy lifestyle leads to increased life expectancy and reduced medical costs among Taiwanese adults. The findings clearly highlight that non-smoking combined with adequate fruit and vegetable intake is effective in increasing life expectancy.
The study also highlights that optimal body weight is a major determinant of reduced lifetime medical costs.
This study only included baseline data on healthy lifestyle behaviors and therefore could not consider the effects of lifestyle changes over time. Furthermore, the inclusion of self-reported lifestyle behaviors may have led to misclassification.
As the scientists note, people in poor health were less likely to take part in the survey, which may have led to an underestimation of the proportion of people with unhealthy lifestyles.
The scientists also said the study estimated medical costs based on reimbursement data from Taiwan’s National Health Insurance Research Database, which may have underestimated lifetime medical costs.
To gain a more comprehensive understanding, they recommend that future studies should thoroughly investigate the impact of lifestyle factors on composite indicators such as disability-adjusted life years, quality-adjusted life years and health-adjusted life expectancy at the individual level.
Journal References:
Wei-Cheng Lo. 2024. The impact of healthy lifestyle factors on life expectancy and lifetime medical costs: a nationwide cohort study. JMIR Public Health and Surveillance. https://publichealth.jmir.org/2024/1/e57045
