Heterogeneity in Healthy Aging - Lowsky D.J et al
Lowsky D.J et al., 2013
https://pmc.ncbi.nlm.nih.gov/articles/PMC4022100/
SUMMARY OF MAIN IDEAS
Chronological age (how old you are in years) isn’t necessarily a good indicator of how healthy or capable you are
No everyone ages in the same way. Two people who are both 80 years old can have vastly different health, independence and quality of life. Some 85 year olds can be just as active and healthy as many 55 year olds - while others may be frail or dependent.
This wide variation is called heterogeneity and authors argue that understanding this diversity is key to good health policy, social planning, and how we think about aging
WHAT THE STUDY DID
Researchers used 2 huge U.S national data sets:
Health and Retirement Study (HRS) - surveys Americans 51+ about their health, income and lifestyle
Medical Expenditure Panel Survey (MEPS) - tracks health care use, costs and quality of life in the general U.S population
They looked at 8 age groups from 51-85+ and then examined 5 indicators of ‘good health’ to see what proportion of each age group was doing well.
THE FIVE EXAMINED MARKERS OF HEALTH
Self rated health
Functional independence - whether help or to what extent help was needed with ADLs (activities of daily living) or IADLs (instrumental activities of daily living)
Work ability - whether there’s limitation to work or housework due to health
Any major chronic diseases - cancer, diabetes, heart disease, lung disease or stroke
High health-related quality of life (HRQoL) - scoring on the EQ-5D, a quiz scoring mobility, self care, pain, mood, and daily activities
KEY FINDINGS
Many Older Adults are Still Healthy
28% of adults over 85 - still rated their health as excellent or very good
56% of adults over 85 - needed no help with daily tasks
56% of adults over 85 - had no limitations in work or housework
32% of adults over 85 - had no major chronic diseases
16% of adults over 85 - had perfect HRQoL scores
This shows even at very old ages, a substantial fraction of people are thriving, independent, and active
Huge Variation (Heterogeneity) Within Every Age Group
Within any given age, health related quality of life scores range widely
The gap between the healthiest and least healthy within a single age group is much larger than the average difference between age groups
This shows being 85 doesn’t tell you everything about someone’s health - some are fit and independent and some are very ill, same goes for all age groups
Women Show Greater Variation
The range of health related quality of life is slightly wider among women, meaning more diversity in health outcomes among older women than men.
Medical Costs Show the Same Pattern
There are people with very high and very low medical expenses at very age
The average cost does rise with age, but the spread is huge so age alone still doesn’t predict medical costs
WHY THIS HAPPENS
This study points out that people age differently due to:
Socioeconomic status (SES): income, education and occupation
Lifestyle: diet, exercise, social engagement, and stress
Psychological Factors: sense of control, mental health
Genetics and environment
POLICY IMPLICATIONS/SO WHAT?
Forecasting Future Dependency
Traditional ‘Old Age Dependency Ratios’ are misleading (saying 65+ means dependent)
Many 65+ are healthy and independent and future predictions should be based on functional health, not age alone
Work and Civiv Roles
Many older people can and want to keep working
Policies like mandatory retirement wastes certain human potential
Eligibility for Entitlement Programs
Current systems assume everyone 65+ need help
Programs should be based on need and functional ability not just age
Understanding What Drives Differences
More research is needed to understand why some people stay healthier longer, which could guide early life interventions to keep people aging healthily
Educating the Public
People should know how much control they have over their long term health
Realising that healthy aging is possible can motivate better lifestyle choices