The Role of Midlife Obesity in
Late Life Health Outcomes
Brenda C. Spillman
The Urban Institute
Supported by funding from the Office of Disability,
Aging, and Long-Term Care Policy, ASPE/DHHS
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Background
„
Prevalence of overweight and obesity in the U.S.
population is growing
„
Recent studies have found
–
Relative to nonobese elders, obese elders have
similar mortality rates
‹ higher disability rates and have not enjoyed the declines seen
the nonobese population
‹ higher Medicare spending
‹
–
„
Baby boomers have higher rates of obesity in midlife and
earlier than previous age cohorts
Most studies of the elderly population examine only
weight in old age
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Presentation Aims
„
Examine prevalence of current and mid-life
obesity in the 65+ Medicare population
„
Examine the association between
life obesity and late-life health, disability, and
spending outcomes
„
Show how conclusions differ when midlife
obesity can be observed
„
Discuss implications for data collection and
policy
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Data and Sample
„ 1999
–
–
National Long Term Care Survey
Merged Medicare/vital statistics data for a
year follow-up period
Community characteristics from the Area
Resource File and other data merged with
sample
„ Analysis
sample: ~ 5,000 community
residents aged 65+ with and without
disability
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Obesity Measures
„
Current BMI and BMI at age 50 from self-report
height and weight and conventional weight
categories
–
–
–
–
„
Underweight = bmi < 18.5
Normal weight 18.5 - < 25
Overweight 25 - < 30
Obese 30+
“Long-term” weight coded
–
–
–
–
–
Formerly obese, long-term obese, became obese
Long-term under/normal weight
Long term overweight
All other combinations of weight gain/loss not including obesity
Missing current weight/height or weight at age 50
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Outcomes Examined
„ 5-year
mortality (linked vital statistics
„ Self-report
chronic conditions (diabetes,
hypertension, heart disease, arthritis)
„ Chronic
disability (any ADL/IADL
disability, 3+ ADL disabilities)
„ Total
Medicare spending in the 5 years
after interview (linked claims)
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Estimation Models
„
Probit models for 5-year survival, presence of
chronic conditions, and disability
„
Two-part model for Medicare spending
„
Control variables:
–
–
–
Socioeconomic characteristics (age, gender, race,
Hispanic origin, education, income, supplemental
insurance)
Region, urban/rural residence, local health care
market characteristics
Months of follow-up period survived for Medicare
spending models
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Prevalence of Long-term Weight Classes
(at age 50 and at interview)
Currently
obese
Long-term weight
Formerly obese
Long-term obese
Became obese
Long-term under/normal weight*
Long-term overweight
All other weight gain or loss patterns
Missing BMI now and/or at age 50
Percent
4.0
6.5
9.6
29.6
18.7
21.5
10.1
Obese
at
age 50
* Reference group for models
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Long-term weight and health outcomes
Formerly
obese
Long-term
obese
Became
obese
-0.028
-0.050
Five-year mortality
0.144 **
Any chronic disability
0.113 **
0.121 **
0.064 **
Disability in 3 or more ADLs
0.044 **
0.051 **
0.023 **
Diabetes
0.189 **
0.205 **
0.140 **
High blood pressure in the last year
0.143 **
0.197 **
0.224 **
Heart attack/other heart problem in the last year
0.076 **
0.101 **
Arthritis
0.155 **
0.325 **
Any Medicare spending in the next 5 years
Conditional Medicare spending in the next 5 years
0.001
0.416 **
0.006
0.348 **
-0.010
0.208 **
-0.006 *
0.118
Marginal effects for probabilities, percent change for conditional spending
**(*) P-value <= 0.05(0.10) Reference group is long-term under/normal weight
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Disability Rate and Expected Spending
Long-term Weight
Any chronic
disability
3+ ADLs
Per capita
annual
Medicare
spending
All persons age 65+
15.6%
6.8%
$6,307
Long-term under/normal weight
12.4
5.1
5,553
All obese/formerly obese
20.3
8.5
6,963
Formerly obese
28.6
12.9
8,304
Long-term obese
22.3
10.0
7,594
Became obese
15.5
5.7
5,952
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% of Aggregate Disability and Spending
Attributable to Obesity in Midlife or Late Life
Any chronic
disability
3+ ADLs
Medicare
spending
All obese/formerly obese
12.6%
13.6%
4.7%
Formerly obese
3.6%
4.1%
1.6%
Long-term obese
5.4%
6.3%
2.3%
Became obese
3.6%
3.2%
0.8%
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Summary of Findings
„
Midlife obesity is associated with significantly
worse health and disability outcomes and with
higher spending.
„
Former obesity is associated with impaired
survival, but long-term and later onset obesity are
not
„
Becoming obese after midlife appears to be less
harmful, but also is associated with significantly
worse health and disability outcomes and higher
Medicare costs
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Implications
„
Continued upward trends in middle-age obesity, as seen
the Baby Boom generation could
moderate recent downward trends in disability
– increase prevalence of old age chronic disease and Medicare
–
„
Estimates based only on current weight status bias
estimates and understate
Health benefits of stable normal or lower weight
– Detrimental effects of obesity for old age health outcomes
–
„
Results support the importance of initiatives to increase
primary prevention in middle age and earlier.
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