This page provides details on the methods and measures used in the NHATS Trends Dashboards and the companion NHATS Chart Book through 2021.
Methods
Data are from the National Health and Aging Trends Study (NHATS). The sample in each round was limited to individuals ages 72 and older. Dashboard results were generated from weighted crosstabulations adjusted for survey design. All dashboard results include individuals living in settings other than nursing homes. Nursing home residents are included in a subset of tabulations for select outcomes and demographic variables. Key findings highlight trends that are statistically significant (p<0.05) based on linear regression models, overall and by age group, gender and race and Hispanic ethnicity groups.
For details on the design of NHATS see Freedman VA, Kasper JD. 2019. Cohort Profile: The National Health and Aging Trends Study. International Journal of Epidemiology 48(4):1044-1045g. doi: 10.1093/ije/dyz109.
Late-life Disability Measures
Self-care and mobility limitations summarizes the ability to perform in the last month the following seven activities – going outside, getting around inside, getting in/out of bed, eating, bathing, toileting, and dressing. Individuals are classified into one of four hierarchical categories: 1) fully able to do all activities (no assistance, difficulty, or device use for any activity); 2) successfully accommodates one or more activities with assistive devices (but no assistance or difficulty); 3) has difficulty when carried out independently (but with devices, if used) with one or more activities (but no assistance); and 4) receives assistance or doesn’t do one or more activities. Individuals missing information on one or more of the activities were assigned the highest value among the non-missing activities.
Household activity limitations summarizes the ability to perform in the last month the following five activities – laundry, shopping for groceries or personal items, making hot meals, handling bills and banking, and keeping track of medications. Individuals are classified onto one of three hierarchical categories: 1) fully able to do all activities (no help for health or functioning reasons or difficulty); 2) has difficulty when carried out independently with one or more activities (but no assistance for health or functioning reasons); and 3) receives assistance or doesn’t do one or more activities for health or functioning reasons. Individuals missing information on one or more of the activities were assigned the highest value among the non-missing activities.
Unmet need, self-care or mobility activities identifies individuals who had a negative consequence because an activity was too difficult to do on their own or because no one was there to help them with the activity. Consequences include: having to stay in bed; not being able to go places in their home or building; not being able to leave their home or building; going without eating; going without showering/ bathing/washing up; accidentally wetting or soiling their clothes; and going without getting dressed. Individuals missing information for a specific activity, or not asked about consequences because they did not report assistance or difficulty, were classified as having no consequence for that activity.
Unmet need, household activities identifies individuals who had a negative consequence because an activity was too difficult to do on their own or because no one was there to help them with the activity. Consequences include: going without clean clothes, going without groceries or personal items, going without a hot meal, going without handling bills and banking matters, and making a mistake in taking their medications. Individuals missing information for a specific activity, or not asked about consequences because they did not report assistance or difficulty, were classified as having no consequence for that activity.
Physical capacity and self-reported physical capacity identify individuals with scores in the highest and lowest quartiles, based on weighted distributions in 2011. Scores for physical capacity are based on a combination of self-reported physical abilities and physical performance tests. Because the performance tests were not conducted in 2020 and peak air flow also not conducted in 2021, we also included a measure consisting of only self-reported measures. Self-reported measures include ability to: walk 6 blocks or 3 blocks; walk up 20 stairs or 10 stairs; carry 20 pounds or 10 pounds; get down on knees or bend over; lift heavy object above head or reach overhead; and open a sealed jar with just hands or grasp small objects. The more difficult action is worth two points and the easier task worth one point. Individuals missing information on a self-reported item are assigned a score of 0 for that item. Performance tests include balance stands, time to walk three meters, time to perform five rapid chair stands, grip strength, and peak air flow. Respondents missing one or two performance tests had scores imputed based on linear regression models including sex, age, self-reported physical capacity, and a physical performance score comprised of scores for non-missing tests. Scores for respondents missing three or more tests were imputed using a linear regression model including age, sex, and self-reported physical capacity. Trends in low scores (based on lowest quartile according to weighted distributions in 2011) for individual performance measures are also reported. Missing values for individual measures were imputed using a linear regression model including age, sex, and self-reported physical capacity. For physical performance test details see: Kasper JD, Freedman VA, Niefeld MR. 2012. Construction of performance-based summary measures of physical capacity in the National Health and Aging Trends Study. NHATS Technical Paper #4. Baltimore: Johns Hopkins University School of Public Health. Available at www.NHATS.org.
Poor vision identifies individuals who reported being blind or being unable, with glasses or contacts if used, to see well enough to recognize someone across the street; watch television across the room; or read newspaper print. Individuals missing information on vision items are assumed to not have poor vision.
Poor hearing identifies individuals who reported being deaf or being unable, with a hearing aid if used, to hear well enough to use the telephone; carry on a conversation in a room with a radio or TV playing; or carry on a conversation in a quiet room. Individuals missing information on hearing are assumed to not have poor hearing.
Dementia identifies individuals who meet at least one of the following criteria: a report of a doctor’s diagnosis of dementia or Alzheimer’s disease; a score indicating likely dementia on a dementia screening instrument administered to proxy respondents; or impairment based on cognitive tests that evaluate memory, orientation, and executive function (with a score of ≥1.5 standard deviations below the mean in at least two domains). Individuals who recover in the subsequent round are reclassified in the current round as not having dementia. For individuals living in nursing homes in the year they joined NHATS, we assumed 70% had dementia in each year. For details see Kasper JD, Freedman VA, Spillman B. 2013. Classification of Persons by Dementia Status in the National Health and Aging Trends Study. NHATS Technical Paper #5. Baltimore: Johns Hopkins University School of Public Health. Available at www.NHATS.org.
Participation restriction identifies respondents who reported that in the last month their health or functioning kept them from participating in activities that they valued a lot or somewhat. Participation identifies respondents who reported in the last month that they carried out at least one activity that they valued a lot or somewhat. Activities include: visiting in person with friends or family not living with respondents; attending religious services; participating in clubs, classes or other organized activities; going out for enjoyment; working for pay; and volunteering. Value was presumed (because it was not asked) for the latter two activities. Respondents missing information for a specific activity were classified as not having a restriction for that activity.
Late-Life Housing Measures
Residential setting classifies individuals into four groups: living in traditional community settings, retirement communities or senior housing, residential care settings other than nursing homes, and nursing homes.
Housing has five categories reflecting the physical structure of the place where an individual lives: 1) One-level house identifies individuals living in a free-standing or attached house with one level or floor; 2) Accessible, multi-level house identifies individuals living in a free-standing or attached house with two or more levels or floors, including a basement (if present), with an elevator, a stair life/glide, or a kitchen, full bath and bedroom on the same floor; 3) Limited access, multi-level house identifies individuals living in a free-standing or attached house with two or more levels or floors, including a basement (if present), but the home does not have an elevator, a stair lift/glide, or a kitchen, full bath and bedroom on the same floor; 4) Mobile home identifies individuals living in a mobile home or trailer; and 5) Multi-unit building identifies individuals living in buildings with two or more units. Individuals missing all housing information were assumed to live in the most common structure by residential setting (one-level home in the community; multi-unit building in residential care).
Home modifications include: a ramp at the entrance of the building, an elevator inside the home, or a stair lift/glide inside the home (mobility-related); a grab bar in the shower or a bath seat for the shower or tub (bathing-related); and a raised toilet seat or grab bars around the toilet (toileting-related). Individuals missing information for a specific modification are assumed not to have that modification.
Online Activities in Late Life Measures
Email or Texting identifies individuals who communicated by email or texting in the last month. Individuals missing information on email or texting are assumed not to have used email or texting.
Goes online (any reason) identifies individuals who went online in the last month for any reason other than emailing. Individuals missing on any of the online activity questions are assumed not to do the activity.
Goes online for social networking identifies individuals who went online to visit social network sites in the last month. This activity was added in 2013.
Goes online for household activities identifies individuals who went online in the last month to shop for groceries or personal items, to pay bills or do banking, or to order or refill prescriptions.
Goes online for health-related reasons identifies individuals who went online in the last year to contact a medical provider, handle Medicare or other health insurance matters, or get information about a health condition.
Quality of End of Life Measures
End-of-life experiences are reported by proxies for NHATS participants who died between survey rounds.
Location of death identifies the type of place where the individual passed away: at home, in a hospital, in a nursing home, or somewhere else. The last category includes someone else’s home, a hospice residence, in transit, and missing information on location.
Hospice care identifies individuals who used hospice services in the last month of their life. Individuals who died in a hospice residence, in the inpatient hospice unit of a hospital, in the hospice unit of a nursing home, or received hospice care at home in the last month of life are included. Since hospice at home was added in 2013, this measure is shown beginning in that year. Missing items are coded as not receiving hospice care.
Quality of end-of-life care indicates whether a proxy felt that the care the respondent received in the last month of life was excellent or very good vs. good, fair, poor or did not receive care in the last month of life. Individuals missing information on quality of end-of-life care are assigned to the most common answer for a given year.
Late-Life Demographic Measures
Age reflects an individual’s age group at the time of the interview.
Gender is categorized into men and women.
Race/ethnicity categorizes individuals into four groups according to their primary reported race/ethnicity: White, non-Hispanic; Black, non-Hispanic; Hispanic; and Other race/ethnicity. Individuals reporting missing information about race/ethnicity were imputed to be non-Hispanic White or Black based on a logistic regression model with the base weight, five-year age group and sampling strata or were assigned to a race/ethnic group based on race/ethnic distribution within strata or interview language.
Education reflects highest completed level of education: less than high school; high school graduate; some college; bachelor’s degree; or a graduate degree. Individuals missing completed education were assigned to the most common level for their age group for a given year.
Region is a four-category variable reflecting where the individual lives, as defined by the Census: Northeast, Midwest, South, and West. All individuals have information on region.
Assistance with activities classifies individuals into three groups: receives no assistance, receives assistance with only household activities (laundry; shopping for groceries or personal items; making hot meals; handling bills and banking; and keeping track of medications) for health and function reasons, and receives assistance with self-care or mobility activities (going outside, getting around inside, getting in/out of bed, dressing, bathing, eating, using the toilet).
Dementia identifies individuals who meet at least one of the following criteria: a report of a doctor’s diagnosis of dementia or Alzheimer’s disease; a score indicating likely dementia on a dementia screening instrument administered to proxy respondents; or impairment based on cognitive tests that evaluate memory, orientation, and executive function (with a score of ≥1.5 standard deviations below the mean in at least two domains). Individuals who recover in the subsequent round are reclassified in the current round as not having dementia. For individuals living in nursing homes in the year they joined NHATS, we assumed 70% had dementia in each year. For details see Kasper JD, Freedman VA, Spillman B. 2013. Classification of Persons by Dementia Status in the National Health and Aging Trends Study. NHATS Technical Paper #5. Baltimore: Johns Hopkins University School of Public Health. Available at www.NHATS.org.
Marital status classifies individuals as to their status at the time of the interview: married/partnered, separated/divorced, widowed, or never married. For individuals missing marital status, we assumed the most common group by age group and gender for a given year.
Number of children indicates the number of living children an individual had at the time of the interview: 0, 1, or 2 or more.
Living arrangement classifies individuals into four categories: whether the individual lives alone, lives only with a spouse or partner, lives with a spouse or partner and other people, and lives only with people other than a spouse or partner. Individuals missing living arrangement (only in Round 1) were assumed to live alone if they were not married and had no children.
Residential setting classifies individuals into four groups: living in traditional community settings, retirement communities or senior housing, residential care settings other than nursing homes, and nursing homes.
Acknowledgments
The NHATS dashboards were prepared with funding from the National Institute on Aging (U01AG032947 and P30AG012846).
Recommended citation: Freedman VA, Cornman JC. 2023. National Health and Aging Trends Study: Trends Dashboards. Available at www.micda.isr.umich.edu/research/nhats-trends-dashboards.