SURVEY METHODS
ANALYTICAL APPROACH
The Stanford Center Longevity sponsored an interdisciplinary consensus conference of national experts in January, 2014, to launch THE SIGHTLINES PROJECT. The group identified an extensive list of empirically-validated predictors of longevity and wellbeing, and categorized them by domain. A project team headed by SCL division heads sought out sources of data on each of these topics in nationally representative, high-quality, large-scale data sets which consistently measured the concepts and metrics of interest over the past two decades. Where desirable thresholds were available, analysis compared the percentage of Americans who met the threshold for the most recent year available (typically 2014 or 2013) as well as prior years as long ago as 1995. The key was to compare not just overall trends, but how each age cohort (e.g. 25- to 34-year-olds) scored relative to the same cohort in prior years. Especially where differences emerged, we were able to better understand those differences by looking at subgroups in each time period. For example, to understand changes in home ownership between now and then, we looked at home ownership within each age group who were married versus those that were not.
We honed in on differences between groups OR over time of five percent or more. Given the size of the data sets, and therefore the size of groups being compared, this cut-off reduced the likelihood that differences would be attributable to sampling error. Initial results and successive iterations were shared and reviewed with experts. Alignment with prior research was investigated.
Obviously, the three selected domains and the specific behaviors and conditions discussed in this report do not cover all possible contributors to long life and wellbeing. Specifically, we focused on behaviors that are:
- supported by compelling scientific evidence of improved longevity and wellbeing;
- tracked by existing, authoritative, nationally representative studies of Americans across the age spectrum at multiple points in time over the last 20 years;
- malleable – that is, that individuals and/or society are able to affect.
We were limited by existing measures and samples. Despite the importance of technology-based social engagement, for example, many did not exist 15 to 20 years ago and are not represented in large scale studies. Others were not covered in this report because they have mixed or unknown impact on key areas (e.g. social engagement, financial security) and ultimately wellbeing and longevity. Annual check-ups, for example, are not included in this report because research has failed to support reliable positive impacts on long-term wellbeing.
Regrettably, considerations of race/ethnicity, gender, education and age interactions were often limited by small sample sizes. Further drill downs into specific sub populations will be pursued as we move forward.
DATA
Data were drawn from nationally representative, high-quality, large-scale, multi-year studies.
Domain | Data Source | Provider | Sample Size | Frequency |
Healthy Living | Behavioral Risk Factor Surveillance System (BRFSS) | Centers for Disease Control and Prevention | 350,000 | 2005, 2007, 2009 |
Continuous National Health and Nutrition Examination Survey (NHANES) | Centers for Disease Control and Prevention | 6,000 | Bi-annual | |
Financial Security | Consumer Expenditure Survey (CEX) | U.S. Bureau of Labor Statistics & U.S. Census Bureau | 7,000 | Annual |
Current Population Survey, Annual Social and Economic Supplement (CPS-ASEC) | U.S. Bureau of Labor Statistics & U.S. Census Bureau | 56,000 | Annual | |
Survey of Consumer Finances (SCF) | Federal Reserve | 65,000 | Tri-Annual | |
Social Engagement | Current Population Survey, Annual Social and Economic Supplement (CPS-ASEC) | U.S. Bureau of Labor Statistics & U.S. Census Bureau | 56,000 | Annual |
Current Population Survey Volunteer Supplement (CPSVS) | U.S. Bureau of Labor Statistics & U.S. Census Bureau | 56,000 | Annual | |
Health and Retirement Study (HRS) | University of Michigan & National Institute on Aging | 20,000 | Bi-annual | |
Midlife in the United States (MIDUS) | University of Wisconsin & National Institute on Aging | 1,800 – 3,000 | 1994, 2004, 2012 |
HEALTHY LIVING MEASURES
Category | Variable | Description | Source | Benchmark | Latest |
Healthy Daily Activities | Exercise Moderately | Individual engagement in moderate or vigorous physical activity for at least 150 minutes per week. Includes walking/biking for transport, leisure-time, school, or recreational physical activity but does NOT include work-related physical activity. | NHANES | 1999 (5,448) |
2011 (5,864) |
Low Sedentary Time | Percent of individuals who spend 320 minutes per day or less sitting at work, at home, or at school, including sitting at a desk, sitting with friends, traveling in a car, bus, or train, reading, playing cards, watching television, or using a computer, but NOT sleeping. | NHANES | 2007 (5,448) |
2011 (4,990) |
|
Maintain Healthy BMI | Percent of individuals with a body mass index between 18.5-29.99 (which includes both “normal” and “overweight,” but not underweight or obese). | NHANES | 1999 (3,965) |
2011 (4,713) |
|
Eat 5 Fruits and Vegetables | An individual’s responses to six questions about eating habits were combined to create a composite measure of average daily fruit and vegetable consumption of at least 5 total per day. | BRFSS | 2005 (350,000)* |
2009 (350,000)* |
|
Sufficient Sleep | Individual responses to the question “How much sleep do you usually get at night on weekdays or workdays?” to capture those who answered any number between 7 and 9 hours. | NHANES | 2005 (4,432) |
2011 (5,004) |
|
Avoid Risky Behaviors | Tobacco and Nicotine Use | Percent of individuals who avoided using any tobacco or nicotine products in the past 5 days, including cigarettes, pipes, cigars, chewing tobacco, snuff, nicotine patches, nicotine gum, or any other product containing nicotine. | NHANES | 1999 (3,782) |
2011 (4,224) |
Excessive Alcohol Consumption | Percent of individuals who avoid excess alcohol consumption, which includes men having less than 5 drinks less than 12 times per year, and women less than 4 drinks less than 12 times per year. | NHANES | 1999 (5,448) |
2011 (5,864) |
|
Illicit Drug Use | Percent of individuals who have avoided use of marijuana, cocaine (any form), heroin, and methamphetamine in the past 30 days. | NHANES | 2005 (5,563) |
2011 (5,864) |
*Approximate – sample sizes vary by measure
FINANCIAL SECURITY MEASURES
Category | Variable | Description | Source | Benchmark | Latest |
Cash Flow | Threshold Income | Percent of individuals in households where income is 200+% of the official “Federal Poverty Level,” which is based on the size and composition of households. Thresholds for one- and two-person families headed by someone aged 65+ are lower than those headed by younger individuals. | CPS-ASEC | 2000 (56,000)* |
2014 (56,000*) |
Manageable Debt | Percent of individuals in households in which non-collaterized household debt is less than 20% of household income. | SCF | 2001 (4,500)* |
2013 (4,500)* |
|
Emergency Funds | Percent of individuals in households with access to $3,000 in emergency resources either by ability to borrow from family or friends, or bank account balance of $3,000 above average monthly income. | SCF | 2001 (4,500)* |
2013 (4,500)* |
|
Asset Growth | Investments | Percent of individuals in households with annuities, bonds, brokerage accounts, IRAs, managed investment accounts, mutual funds, savings bonds, stocks, stock options, workplace-based retirement accounts, or whole life insurance plans. | SCF | 2001 (4,500)* |
2013 (4,500)* |
Retirement Savings | Percent of individuals who live in households where household head or spouse has a workplace-based retirement plan or an IRA. | SCF | 2001 (4,500)* |
2013 (4,500)* |
|
Home Ownership | Percent of individuals in households in which home is owner-occupied and is considered either the head of household or the spouse/partner of the head of household. | CPS-ASEC | 2000 (56,000)* |
2014 (56,000)* |
|
Protection | Health Insurance | Percent of individuals with health insurance from any source, including employer/group, private, Medicare, Medicaid, veterans/military, etc. | CPS-ASEC | 2000 (56,000)* |
2014 (56,000*) |
Long-term Disability/Long-term Care | Percent of individuals 25-64 in households with long-term disability insurance or 65+ who have either long-term care insurance, or sufficient assets. | SCF and CEX | 2007 (SCF 4,500)* (CEX 5,000)* |
2013 (SCF 4,500)* (CEX 5,000)* |
|
Life Insurance | Percent of individuals in households with life insurance. | SCF | 2001 (4,500)* |
2013 (4,500)* |
*Approximate – sample sizes vary by measure
SOCIAL ENGAGEMENT MEASURES
Category | Variable | Description | Source | Benchmark | Latest |
Meaningful Relationships | Meaningful Interactions with Spouse/Partner | Percent of individuals who report having a “really good talk about something important” with spouse or partner at least once per week. | MIDUS | 1995 (2,961) |
2012 (2,562) |
Frequent Interactions with Family | Percent of individuals in contact with any family members (brothers, sisters, parents or children) who do not live with them, including visits, phone calls, letters or email, several times per week. | MIDUS | 1995 (2,940) |
2012 (2,569) |
|
Social Support from Family | Percent of individuals who report they can rely “a lot” on family members (brothers, sisters, parents or children) who do not live with them for help with a serious problem. | MIDUS | 1995 (2,960) |
2012 (2,508) |
|
Frequent Interactions with Friends | Percent of individuals who are in contact with any of their friends, including visits, phone calls, letters or email, at least several times per week. | MIDUS | 1995 (2,960) |
2012 (2,569) |
|
Social Support from Friends | Percent of individuals who report they can rely “a lot” on friends for help with a serious problem. | MIDUS | 1995 (2,963) |
2012 (2,563) |
|
Group Involvement | Converse with Neighbor | Percent of individuals who “have a real conversation or get together socially” with any of their neighbors at least once per week. | MIDUS | 1995 (2,970) |
2012 (2,567) |
Volunteer | Percent of individuals who have “done any volunteer activities through or for an organization” since September 1 of the previous year. | CPS-VS | 2002 (82,260) |
2013 (75,593) |
|
Workforce Participation | Percent of individuals who are either employed or in the armed forces; all others are counted as not being employed, whether or not they are considered to be part of the workforce. | CPS-ASEC | 1995 (56,000)* |
2012 (56,000)* |
|
Participate in Community Activities or Attend Religious Services | Percent of individuals who at least once a month either (1) attend meetings of sports, social, or any other groups (that are not required by his/her job) and/or (2) attend religious services. | MIDUS | 1995 (2,835) |
2012 (2,567) |
*Approximate – sample sizes vary by measure