NLSY79 health sections are divided into two periods:

• From 1979 to 1996, most of the questions focus on health concerns that restrict or inhibit the respondent's ability to work.
• From 1998 on, as respondents reached middle age, the Health section was expanded to provide a baseline profile of the respondent's overall health as they turn 40, 50, and 60 years old.

40-and over Health Module

Beginning in 1998, because of the aging of the cohort, an extended health module was administered to respondents at the first interview after turning age 40 and general questions on physical activity and exercise were administered to all respondents. While the pre-1998 health questions provide a picture of the respondent's current health restrictions, they offer little insight into chronic health problems that will affect their labor force activity in the future. For example, a serious ailment that slowly develops over time will not be picked up by the regular health questions until the respondent actually drops out of the labor market. This extended health module was created to provide a baseline health profile of the respondent for examining the interrelationship of health and labor market activity in advance of the retirement years. Variables with CCR (Chronic Conditions Roster) in the title have been labeled with this acronym internally for consistent sorting.

To broaden the usefulness of the NLSY79 health data, this extended module, comprising four major parts, is not restricted to work-related health problems, and all questions are asked irrespective of the respondent's labor force status.

1. The first part of the 40-and-over module asks respondents to answer the Center for Epidemiological Studies Depression Scale (CES-D). The 1998 and 2000 surveys collected a reduced set of seven items from the original 20 item CES-D scale (the full 20-item scale was last administered in 1992). The number of items was increased to nine beginning in 2002.
2. The second part of the extended health profile asks respondents when they last saw a health care professional. These questions provide researchers with the date of the respondent's last physical exam and last visit to the doctor for any reason. Information on individuals who never visit a doctor is available as well. This subsection also gathers information about the health and life status of the NLSY79 respondents' biological parents. Questions which ask respondents about their parent's health are designed to improve researchers' understanding of hereditary health problems. Respondents are asked whether their biological parents are alive and if not, their parent's age at death and cause of death. Information is also gathered about any major health problems afflicting either parent.
3. The third section reproduces the SF-12 scale, a 12-question health survey designed by John Ware of the New England Medical Center Hospital. The SF-12 is designed to provide a measure of the respondents' mental and physical health irrespective of their proclivity to use formal health services. Detailed information on the SF-12 is available from QualityMetric. QualityMetric also provides researchers with software and algorithms to score the SF-12. For more information see Appendix 19.
4. The last section of the 40-and-over health module asks respondents if they suffer from an extensive list of health conditions. Respondents with certain major conditions, such as cancer, hypertension, or diabetes, are asked the date at which the condition was first diagnosed and other details relevant to the particular condition.

50-and-over Health Module

This module was included beginning in 2008. The module is administered to progressive two-year birth year cohorts in the survey year during which they would turn at least age 50. NLSY79 respondents were born in 1957-1964. In 2008, the module was administered to respondents born in 1957-1958. In 2010, the module was administered to those born in 1959-1960, and anyone who skipped the 2008 interview, and so on. The 50-and-over Health module contains many of the same questions as the 40-and-over Health module. Some questions provide a second decennial point of reference for general health information. Many others provide updates on previously reported conditions. Questions about diagnosis of skin cancer and other types of cancer, various heart disease-related conditions, and stroke are also asked.

50-and-over respondents are again administered the CES-D items and the SF-12 question series, as well as questions about the life and health status of their parents if they were reported living in the 40-and-over module. In addition, 50-and-over respondents are asked to update information on previously reported conditions such as hypertension/high blood pressure, arthritis, diabetes/high blood sugar, asthma and non-asthma breathing problems, depression, and other emotional/psychiatric problems.

The 50-and-over Health module also contains questions on diagnosis of osteoporosis and the use of special equipment needed to accomplish usual activities, as well as a scale of functionality and the respondent's sleep habits. Finally, respondents are asked for other information about their health that they would like to report.

60-and-over Health Module

This module was included beginning in 2018. Similar to the 50-and-over Health Module, the 60-and-over Health Module is administered to progressive two-year birth year cohorts in the survey year during which they turn at least age 60. NLSY79 respondents were born in 1957-1964. In 2018, the module was administered to respondents born in 1957-1958. In 2020, the module was administered to those born in 1959-1960, and anyone who skipped the 2018 interview. The 60-and-over Health module contains many questions similar to the 40-and-over and 50-and-over modules, providing a third decennial point of reference for general health information for many respondents. Updates on some previously reported conditions are also collected. Questions about diagnosis of skin cancer and other types of cancer, various heart disease-related conditions, and stroke are also asked. Questions about Alzheimer's and other dementia-related conditions are included in the module, as well.

60-and-over respondents are again administered the CES-D items and the SF-12 question series, as well as questions about the life and health status of their parents if they were reported living in the most recent health module administered to the respondent. In addition, 60-and-over respondents are asked to update information on previously reported conditions such as hypertension/high blood pressure, arthritis, diabetes/high blood sugar, asthma and non-asthma breathing problems, depression, and other emotional/psychiatric problems. The 60-and-over module also contains several other attitudinal scales, including the Satisfaction With Life Scale/SWLS (Deiner, et. al.) and General Anxiety Disorder/GAD scale (Spitzer, et. al.). In 2018, 4 items on the Brief Resilience Scale/BRS (Smith, et. al.) were administered. In 2020, the intention was to ask BRS questions again, but the questions were dropped partway through the round due to time constraints.

The 60-and-over Health module also contains questions on the diagnosis of osteoporosis and the use of special equipment needed to accomplish usual activities, as well as a scale of functionality and the respondent's sleep habits. Finally, respondents are asked for other information about their health that they would like to report.

General health

Questions about general health practices and visits to health care professionals have been asked of respondents since the 2002 interview. Respondents are asked about levels and frequency of activity, whether they have had routine tests, whether they have discussed general health issues with their doctors, if they take certain kinds of medications, and usual eating habits.

Cognition module

Beginning in 2006, the survey included a battery of exercises designed to capture cognitive capabilities. Similar to the 50-and-over Health module, the Cognition module was administered to two birth-year cohorts in the survey year during which they would turn at least age 48. In 2006, the module was administered to respondents born in 1957-1958; in 2008, the module was administered to those born in 1959-1960 and age-eligible respondents who skipped the 2006 interview, and so on.

Respondents were first asked for their own assessment of the current quality of their memory. They were then given a word recall exercise using four randomly assigned sets of 10 words. The numbers of correctly and incorrectly recalled words were recorded. Respondents were next asked to count backwards from 20, then from 86. Following this, they were given the starting point of 100 and asked to subtract 7; the process was continued five times (e.g., until the final subtraction answer should have been 65). Finally, respondents were asked to recall the same list of 10 words that they were given at the beginning of the cognition battery.

The vast majority of respondents completed the Cognition module by the 2012 interview. A relatively small but not insignificant number of respondents, who missed the interview at their first eligible year for the Cognition module and missed multiple interviews after that, took the battery in the 2014 or 2016 interview.

The 48+ cognition data from round 22 through round 27 (2006-2016) has been compiled into a single set of variables. Variable names for this set of items begin with "COGNITION" and are contained in the COGNITION area of interest. These items are assigned to the XRND survey year and do not identify non-interviewed cases for specific survey years. The variable COGNITION_SOURCEYR (Reference #X00311.00) contains the survey year in which each respondent's data was collected.

The 2018 interview included several independent cognition questions. To test verbal fluency, respondents were asked to name as many animals as they could in 60 seconds. Additionally all respondents were asked to evaluate their own memory.

Users should note that a questionnaire malfunction in survey year 2008 caused all respondents to be skipped around the second set of Word Recall questions. Respondents who were inadvertently not administered those questions can be identified by using the COGNITION_SOURCEYR variable in the COGNITION area of interest.

Depression Scale (CES-D)

The Center for Epidemiologic Studies Depression Scale (CES-D) measures symptoms of depression, discriminates between clinically depressed individuals and others, and is highly correlated with other depression rating scales (see Radloff 1977; Ross and Mirowsky 1989). First administered to NLYS79 respondents in 1992 (R38949.- R38968), the CES-D is a 20-item instrument. Sixteen of the items ask about negative symptoms (e.g., feeling sad, depressed, poor appetite, etc.). Four items (R38952., R38956., R38960., & R38964.) ask about positive symptoms (e.g., feeling happy). Symptom severity is measured by asking the frequency of occurrence of each item over the preceding week. Responses range from 0 (rarely or none of the time/1 day) to 3 (most or all of the time/5-7 days). The four positive symptom items are reverse- scored, and responses to all items are then summed, resulting in a maximum score of 60. Most studies have used a cutoff of 16 as an indicator of depression.

Based on research by Ross and Mirowsky (1989) and others, the number of CES-D items included in the 1994 NLSY79 was reduced to seven (R49783. - R49789.). However, only 5 items of the 7-item Mirowsky and Ross scale were used and the item response choices in the NLSY79 were kept consistent with the 1992 NLSY79 (and original Radloff) responses to the full CES-D: 0 (rarely or none of the time/1 day) to 3 (most or all of the time/5-7 days). (Mirowsky and Ross used the following response set in their 7-item administration: # days in the past week, 0-7.)  The CES-D scale was NOT administered in the 1996 NLSY79 survey round. Beginning in 1998 the CES-D was moved to the HEALTH section and is asked only of respondents once when they turn age 40 and again when they turn age 50.

Additional information on NLSY79 CES-D variables can be found in Appendix 25 and Appendix 27.

Respondent characteristics

Height and weight

A respondent's height and weight are natural indicators of health. Height questions were asked in 1981, 1982, 1983 (only to females who were ever pregnant), 1985, and 2006-2016. Exercise caution because the height questions have been collected in a variety of formats. The 1981 question combines feet and inches into a single number. Hence, respondents range from 400 (four feet and zero inches) to 611 (six feet and eleven inches). The 1982 and 1985 questions convert all answers into just inches. The 1983 height questions are found under two different reference numbers: female height in feet is provided in R09989., while height in inches is provided in R09990. 

Since weight fluctuates more than height, questions on weight are asked more frequently. Weight questions appear in the 1981, 1982, 1985, 1986, 1988-90, and 1992-2016 surveys. Weight in all years is recorded in pounds. The weight data are normally distributed from 50 to 400 pounds in all years except 1989. In 1989, there are 11 individuals marked as weighing 996 pounds. This number is not a true weight but rather an out-of-range code. Users are advised to examine height and weight distributions prior to analysis in order to make informed decisions as to how to handle outliers.

Hair and eye color

Respondent hair and eye colors were collected during the 1985 interview and information on whether they were left or right handed was collected in the 1993 interview.

Asthma

In 2004 a series of questions about asthma were added to the survey. These included the onset and diagnosis of asthma, whether the respondent missed work, when they had an attack and methods of prescribed treatment. Also included were questions regarding onset in the children of female respondents. A reduced set of asthma questions were included beginning with the 2006 survey.

Heart medication

Beginning in 2008 respondents were asked if they were taking any statin drugs or heart medications.

Childhood health

In 2012, all respondents were asked a series of new questions on childhood health including overall health, major hospitalizations, or long periods of home recovery. Adversity questions included family mental health, alcohol abuse, physical abuse, and amount of parental affection. Researchers believe that questions such as these are predictive of adult obesity and other health-related outcomes. This question series was asked in 2014 or 2016 for those who were not interviewed in 2012.

Head injury

Also introduced in 2012 was a module on traumatic head injury. All respondents were asked if they have experienced a serious head injury or loss of smell. Because traumatic head injury and loss of smell have been found in numerous studies to be linked to subsequent dementia, these questions were added to augment ongoing efforts to track respondents' cognitive function as they advance into middle age and beyond. This module was repeated in 2014 or 2016 for those not interviewed in 2012.

Health insurance

The NLSY79 provides researchers with a variety of insurance information. Almost every survey asked working respondents if their current or most recent job provided health insurance benefits. Table 2 is taken from the employee benefits series and shows that, over time, an increasing number of NLSY79 respondents work in jobs that are covered by health insurance benefits. While only 39.3 percent were working in covered jobs in 1979, by 2020 81.6 percent had employee health insurance available.

There are a number of problems with using the employee benefits question series in the CPS and ES section to understand and track health insurance coverage. First, respondents who are not working are excluded from these questions. Second, not all health insurance is employer provided. Some individuals pay directly for health insurance, while others are covered by their spouse's or partner's plans. Lastly, while an employer may offer this benefit, workers might not participate in the plan and therefore may not be aware of its availability. To overcome these limitations, the "Health" section of the NLSY79 was expanded beginning in 1989 to directly ask about sources of health insurance coverage.

The "Health" section of the questionnaire in 1989, 1990, and 1992-2018 asks respondents if they are covered by a health plan. If the respondent answers "yes," the interviewer asks who pays for the plan. Responses include current employer, previous employer, spouse's employer, purchased directly, and Medicaid or welfare source. If the respondent is married, the same set of questions on medical coverage are asked about the wife or husband (and beginning in 1994, about the nonmarital, opposite-sex partner, (the term opposite-sex was excluded in 2002) if any). Additionally, if the respondent has any children, the same questions are asked about the children's health insurance coverage.

National Death Index (NDI) data

The round 29 (2020) release includes data from the National Death Index for deceased respondents for whom a death certificate could be matched. Respondent records were reviewed individually to establish matches between NLSY79 respondents and death certificate data returned from an NDI search. The created variables above are included on the public and progressively restricted geocode and zipcode releases. See NLSY79 Attachment 8: Health Codes for more information related to NDI data.