AHEAD Wave 1 Documentation |
The Principal Investigator for the HRS and AHEAD Cooperative Agreement was Thomas Juster. Co-principal investigators on the first wave of the AHEAD project were (in alphabetical order):
The design and content of AHEAD built to a great extent on the very substantial work that went into the planning of the Health and Retirement Study (HRS) during 1990 and 1991. That work was done by six Expert Working Groups (Labor Force Participation and Pensions; Health Conditions and Health Status; Family Structure, Family Support and Mobility; Economic Status; External Record Linkages; and Survey Operations), with a total of 42 individuals from many different universities and academic disciplines.
The first wave of the AHEAD project had a Steering Committee consisting of the following members:
In addition, NIA has its own Data Monitoring and Design Committee for the HRS and AHEAD projects, which forms a second oversight group along with the AHEAD Steering Committee. The NIA committee had the following members representing both academic disciplines and relevant government agencies:
In preparation for the fielding of this first national Computer Assisted Personal Interviewing (CAPI) study conducted by the Survey Research Center, the AHEAD research staff worked closely with SRC Survey Operations Administration, Computing Section, Sampling Section, and National Field Management and Interviewing staff. We wish to acknowledge the contributions of Rhonda Ash, Marcy Breslow, Judy Connors, Marshall Cummings, Steve Heeringa, Barbara Homburg, Kathy LaDronka, Jody Lamkin, Gary Munce, and Glenna Redmond.
A special thanks is extended to study staff members Lynn Dielman and Kathy Terrazas who worked from questionnaire design through data management to help bring this second public release AHEAD data set to completion.
AHEAD used a dual sampling frame for those aged 80 and older (the birth cohorts through 1913). Those in this age range in half of the sampling segments from HRS were dropped and replaced by an approximately equal number of selections from the Master Enrollment File maintained by the Health Care Financing Administration (HCFA) for Medicare enrollees. HCFA provided a tape with all enrollees aged 69 and older in the selected counties. From that list of several million names, the SRC Sampling Section selected samples that parallel the samples dropped from the HRS frame. As with the HRS frame, the sample selected from the HCFA frame was limited to those living in households at the time of the initial interview, thereby excluding those who were living in long-term care facilities or other institutions at baseline.
If more than one age-eligible individual was listed as living in a household, one person was randomly selected. In addition, if that selected individual was married, an interview was sought with the spouse regardless of his or her age. If the sampled individual married or started living with a partner by the time of the request for an interview, an interview was sought with the new spouse or partner. Similarly, if an individual selected from the HCFA Medicare enrollment file was married, an interview was requested with the spouse or partner regardless of age. If the spouse was also cohort-eligible, the spouse was part of the sample in his or her own right; but if the spouse was born in 1924 or later, the interview was conducted to provide additional information about the household of the selected (cohort-eligible) individual.
The long range study design calls for re-interviews with the surviving members of the sample every two years; for those who are deceased, enter nursing homes, or are unable to provide useful information, interviews are to be done by proxy.
Approximately 130 interviewers worked on the data collection. Each interviewer attended one of three training sessions held during October, 1993, at hotels in the Detroit/Ann Arbor area. Each training session lasted for seven days (five days for interviewers who had already had general interviewer training and experience on other SRC studies.) The training involved instruction and experience in the use of the computers as well as training on study objectives, question content, and how to deal with respondent questions and difficulties.
The survey questions and the question-by-question instructions for interview flow were programmed, using the Surveycraft CAI system that SRC utilizes for CAPI and CATI interviewing. In addition to the English language version of the questions, a Spanish translation was incorporated into the computer program. A modification of the interview was prepared for use with proxy informants for those cases where the selected individual was unable to participate.
For married respondents, interviewers were instructed to divide the reporting task between the two spouses. The interviewers asked which spouse would be the most knowledgeable about the household financial situation (income sources, assets, medical expenditures, and insurance), and that person was designated as the "Financial Respondent;" the other spouse was then designated as the "Non-financial Respondent." In addition, the first respondent interviewed in a household was asked questions about other household members and about all children living elsewhere. To keep the interviews approximately equal in length, the interviewer suggested that the Non-financial Respondent be interviewed first. In practice, this preferred sequence was not always followed, especially when one spouse was in poor health and the other spouse wanted to ease his or her reporting burden.
Data collection began in October, 1993 and continued through July, 1994. The number of individuals in the HRS-based sample was 9854, of whom 1268 were identified as ineligible (i.e., institutionalized or deceased) with 6954 interviewed. A total of 2058 selections were made based on the HCFA frame (including spouses of the original selections), and these were released to the interviewers in February, 1994. Of these selections, 416 were identified as ineligible and 1268 were interviewed. The total number of interviews at the close of the data collection period was 8,222 for a response rate slightly over 80% of the eligible persons.
The following table shows the number of interviews with the various types of respondents.
+---------------------------------------------------+------------------+ | Type of Respondent | Number | +===================================================+==================+ | ONLY Respondent (If sampled person was | 3762 | | not married/partnered and living with | | | spouse/partner) | | +---------------------------------------------------+------------------+ | | | MARRIED OR PARTNER: | +---------------------------------------------------+------------------+ | Lead, Non-Financial Respondent | 1115 | +---------------------------------------------------+------------------+ | Second, Non-Financial Respondent | 1088 | +---------------------------------------------------+------------------+ | Lead, Financial Respondent | 1155 | +---------------------------------------------------+------------------+ | Second, Financial Respondent | 1102 | +---------------------------------------------------+------------------+ | | | | TOTAL | 8222 | +---------------------------------------------------+------------------+
Section A. Demographics; Year of birth, education, education of parents, marital status and history, veteran status. Section B. Health conditions: Whether R has ever seen doctor for each of 12 conditions; assessment of vision and hearing; pain; smoking; drinking; weight; height; depression. Section C. Cognition: Self-assessment of memory; immediate and delayed recall of ten words, plus other questions from the TICS ("Telephone Interview for Cognitive Status"); for proxy respondents, assessments of level and change in cognitive abilities. Section D. Family structure: (asked of Only and Lead Respondents): List of other household members, with details of their age, education, employment status, earnings, whether moved in with Respondent and if so why; list of children and children-in-law living elsewhere with details of their age, relationship to Respondent and spouse, marital status, number of children, education, employment status, home ownership, distance from Respondent, financial situation relative to Respondents; financial help given to children and others. (Asked of all Respondents) Number and marital status of siblings; if parents not living then age when died, if parent(s) living then their current age and whether Respondent has provided help with ADLs. Section E. Section E1. Health care utilization and costs: (For all Respondents) Previous twelve months: hospitalizations, nursing home stays, doctor visits, outpatient surgery, dental care, prescription drugs; bed days; whether covered by Medicare A/B and Medicare number. (For Only and Financial Respondents) Any out-of-pocket costs for each type of health care listed, amount of out-of-pocket expenditure for nursing home stays and other medical expenses for self and spouse; whether a child or anyone else has helped with health care costs. Section E2. For all Respondents: For six ADLs, whether R gets help; uses equipment; and degree of difficulty. Degree of difficulty with several other activities. For each of five IADLs, whether R able to do without help, and difficulty. Section E3. For each helper (accumulated across ADLs and IADLs): gender, frequency, hours, whether paid, out-of-pocket costs, whether anyone helps pay those costs and if so, who. Section F. Housing (asked of Only and Financial Respondents): Type of housing, whether part of a condominium or housing project, whether income limit, whether age limit, whether entry fee or association payments; services offered to residents; number of stories; special features for physically impaired; ownership, mortgage, others on deed; home value (if owner) or rent; amount paid for property taxes, insurance, utilities. Section G. Job status: Current employment status, whether worked in last two years, whether ever worked for at least 10 years; occupation, earnings and hours last calendar year; most ever earned per year, and at what age that occurred. If widowed or divorced: similar job history questions for former spouse. Section H. Expectations: Chances (on 0 to 100 percent scale) of giving major financial assistance to family members in next ten years; of receiving such help; of leaving an inheritance and amount; of entering a nursing home in next five years; of medical expenses depleting savings in next five years; of income keeping up with inflation; of living to a specified age; of moving in next five years and if so, type of move and which child may move near. Section J. Income (asked of Only and Financial Respondents): Income from each of several sources (Social Security, SSI, food stamps, pensions, veterans benefits, annuities, interest income) for self (and spouse), follow-up questions specific to the various types of sources. Financial assistance from children or from others in last year. Total income of Respondent (and spouse) last calendar year. Whether have a will, and provisions made for children. Section K. Net worth (asked of Only and Financial Respondents): Current value of various assets (if any): Real estate (other than home); automobiles or other means of transportation; family business; IRA or Keogh accounts; shares of stocks or mutual funds; checking, savings, or money market accounts; CDs, government savings bonds; bonds or bond funds. Whether assets were used to pay expenses or additions made to savings or investments last year. Whether any assets are in trusts, and if so, beneficiaries, value of those assets, and whether those assets have already been listed. Other assets and liabilities and lump sum payments in past year (insurance, pension, or inheritance). Section R. Insurance: Current coverage by Medicaid, other government insurance programs, or other health insurance. Any coverage for long term care, and if so, whether have received payments, covers home care, payments increase with inflation. (Asked of Only or Financial Respondents) Life insurance, whole and term: amount, beneficiaries, for Respondent (and spouse).
Module 1. Resiliency: This module was administered as a paper and pencil addition to CAPI Module 4 beginning January 20, 1994. This series of questions is about recent major life events and how much impact those events had on the Respondent. The questions were developed by Robert Kahn and colleagues of the MacArthur Program on Successful Aging. Module 2. Time use: A set of questions on unpaid but economically productive activities (home maintenance, volunteer work, and informal help to others). These questions permit a more balanced assessment of the utilization and provision of human resources by the Respondents than would otherwise be possible. Module 3. ADLs: A set of ADL questions that was planned for the second Longitudinal Study of Aging, by NCHS, so that comparisons can be made with the answers given to the ADL questions asked in the core of AHEAD. Module 4. ADLs: A set of ADL questions from the screener for the National Long Term Care Study. Module 5. Similarities: A measure of abstract reasoning taken from the WAIS. This module also has two ADL questions that were on the 1990 Census long form. Module 6. Quality of life: Quality of life has recently obtained much attention in the medical community as a means of assessing the broad impact of medical treatments and procedures beyond their effect on specific physiologic functions. A focus on the essential quality of life issue -- whether life is still worth living -- underlies the questions in this module, which were adapted from unpublished work by Powell Lawton and from the purpose-in-life subscale of Ryff's Subjective Well-Being Scale. In addition, there are a few items of mastery and personal control taken from work by Pearlin and Schooler. Module 7. In-depth ADLs: Research on cognitive, psychomotor, and psychological functioning has documented an enormous potential for adaptation to and compensation for declining functioning by the elderly. A number of specific mechanisms seem to be involved in such compensation, including a change of specific procedures when performing the activity, increased time allotted for completing the activity, lowered standards, and changes in the immediate environment to ease performance. In order to explore whether such adaptive mechanisms may account for a lack of reported difficulty with bathing and with managing money, questions in this module probe various adaptive strategies that may be involved in carrying out these activities. Module 9. Financial Pressure: Questions in this module ask whether any of several things have happened in the last 12 months because the Respondent was short of money. These include, for example, not paying bills or rent on time, eating less expensive foods, not purchasing prescribed medications, postponing seeing a doctor, skipping a vacation, or skipping needed home repairs. Other questions ask about the perceived fairness of several alternatives proposed with respect to provision of long-term care.
+----+---------------------------+------------------------+------------------+ | SEC| CONTENT: | COMPLETED BY: | AHEAD Class | | | | | FILES: | +====+===========================+========================+==================+ | A | Demographics | All Rs | BR2 (Resp) | +----+---------------------------+------------------------+------------------+ | B | Health Status | All Rs | BR2 (Resp) | +----+---------------------------+------------------------+------------------+ | C | Cognition | All Rs | BR2 (Resp) | +----+---------------------------+------------------------+------------------+ | D | 1. Family Structure | FAMILY R/ONLY R | 1. BHH2 (HH) | | | and Transfers | | | | | | | | | | 2. Parent/Sibling info | All Rs | 2. BR2 (Resp) | | | | | | | | 3. HH member/Child | FAMILY R/ONLY R | 3. BOP2 (Person) | | | Demographics | | | +----+---------------------------+------------------------+------------------+ | E | 1. Health care costs | 1. FINANCIAL R/ONLY R | 1. BHH2 (HH) | | | | | | | | 2. Health care | 2. All Rs | 2. BR2 (Resp) | | | Services/Medicare | | | | | information | | | | | | | | | | 3. ADLs and IADLs | 3. All Rs | 3. BR2 (Resp) | | | | | | | | 4. ADL/IADL Helper info | 4. All Rs | 4. BHP2 (Helper) | +----+---------------------------+------------------------+------------------+ | F | Housing | FINANCIAL R/ONLY R | BHH2 (HH) | +----+---------------------------+------------------------+------------------+ | G | Job Status/Work History | All Rs | BR2 (Resp) | +----+---------------------------+------------------------+------------------+ | H | Expectations | All Rs | BR2 (Resp) | +----+----------------------------------------------------+------------------+ | J | 1. Income | 1. FINANCIAL R/ONLY R | 1. BHH2 (HH) | | | | | | | | 2. Wills | 2. All Rs | 2. BR2 (Resp) | +----+---------------------------+------------------------+------------------+ | K | Net Worth | FINANCIAL R/ONLY R | BHH2 (HH) | +----+---------------------------+------------------------+------------------+ | R | 1. Health Insurance | 1. All Rs | 1. BR2 (Resp) | | | | | | | | 2. Life Insurance | 2. FINANCIAL/ONLY R | 2. BHH2 (HH) | +----+---------------------------+------------------------+------------------+ | MOD| Experimental Modules | All Rs | BR2 (Resp) | |----+---------------------------+------------------------+------------------+ HHIDs for households with no Financial Respondent There are 34 households in which there is no Financial Respondent. The HHID numbers for these households are: 200174, 200237, 200527, 200551, 200817, 201171, 201363, 201625, 201644, 201691, 201737, 201863, 202116, 202183, 202934, 203061, 203623, 204282, 204569, 204645, 204731, 205755, 206030, 206723, 207019, 207174, 207254, 207958, 208202, 208250, 208279, 208287, 208395, 208580 HHIDs for households with no Family Respondent There are 15 households in which there is no Family Respondent. The HHID numbers for these households are: 200072, 200159, 202283, 202709, 203096, 203658, 203752, 204067, 204318, 204883, 206758, 207339, 207958, 208560, 208869
Two types of derived variables have been produced at this point. All components of these derived variables have been left in the dataset and codebook so that users may create their own recodes or imputations if they wish. (Components of the "C variables" have been removed.)
Note that if a specific dollar amount has been imputed, the variable names follow this convention:
V1648 Original dataset variable (family income) V1648C Ranges for DK/RF category followup V1648X All values of the amount including imputation (Use the "X" variable version for analysis if you want to avail yourself of our preliminary imputations.) V1648F Flag indicating the degree of information available for imputation of that variable in a case, or indicating no imputation necessary (0).
Also note that components of income received in the last calendar year have usually NOT been imputed as yet (although the single family income question in J52. has been imputed). Further, derived variables ending in "Y" do contain recodes of the amount of each source received in the last calendar year which still contain unimputed DK or Refused codes.
Money amount variables which did not have follow-up unfolding questions have also been imputed. For these variables, the hot deck method was used for all imputations. This method uses a "donor" case with real (non-missing) data for a variable to impute data for a case with missing data for the variable. Prior to imputation, the data set was sorted by characteristics of the respondents which were expected to be related to the variable being imputed - such as marital status, age group, years of education, or household income category. A case with missing data will then receive imputed data from a donor who is similar on characteristics thought to be related to the variable being imputed.
V... Actual answers. (Amount given .D, .R, INAP=.) V...C Categories of unfolding if DK/RF (0=R gave amount) V...F Flag, 0=not imputed, 1-9=imputed, or degree of information available V...X Total answers: original answer or imputed answer V...H Holding variable [whether have asset] (including imputed) V...R Monthy amount derived for some variables, missing data not imputed
On the Respondent-level file this number identifies the respondent.
On the Helper-level file this number identifies the respondent who reported getting the help; if both spouses reported getting help from the same individual, there are two records for that helper, but with different respondent identification numbers.
libname ahead 'c:\xxx'; data tempr; set ahead.ahcr(keep=hhid id sex age v435 adlany iadlany); by hhid; *This next statement captures both records of a couple and renames spouse variables; if not first.hhid and last.hhid then do; newid=lag(id); newsex=lag(sex); newage=lag(age); new435=lag(v435); nadlany=lag(adlany); niadlay=lag(iadlany); output; end; *This statement captures single records and leaves the lag variables as INAP (.); if first.hhid and last.hhid then output; run; *Sort the temporary dataset by HHID; proc sort data=tempr out=temprs; by hhid; run; *The merge; data ahead.flat; merge ahead.ahchh(keep=hhid v1648x networth) temprs; by hhid; run;You have created a small temporary dataset from the Respondent file which keeps only selected variables, and you have renamed the spouse variables which are to be added with the R variables to the selected variables from the household level file. You have merged the temporary data set to the selected household data, creating a new dataset which has been sorted by HHID.
A disclaimer is appropriate, however. We do not claim to be experts at SAS programming; for the AHEAD research staff, this is the first major study in which we have used SAS. So while we have tried to check and double check the example setups for the accuracy with which they do what we intended, we do not guarantee them to be the most "elegant" way to merge.
For each of the following examples of setups, there is a copy of the setup file, called EXAMPLEn.SAS, and of the output from running that setup, called EXAMPLEn.OUT, in the subdirectory /PUB/AHEAD/DOCS. These are stored as a single, compressed ASCII file, named EXAMTXT.ZIP.
Example 1: This adds household-level variables to the respondent-level record. By the way, this and the other examples may look more complicated than they really are, partly because they include a lot of "comment lines" to explain the setup, and some additional setup lines to print frequencies if you want to check that the merge has done what you expected it to do. The basic merge in this example is accomplished by the following few lines: libname ahead 'c:\ahead\xxxx'; %let hhvars=V407 V435 V466; %let rvars=V559 V562 V565 V576; data RSPFILE1; merge AHEAD.AHDHH(keep=HHID &hhvars) AHEAD.AHDR(keep=HHID HHIDPN &rvars); by HHID; run; Example 2: This adds household-level variables, plus information from the spouse (if the respondent is married to another respondent) to the respondent-level record. (example not available) Example 3: This takes information from the one or two respondents in a household and adds variables to the household-level record. In the example, the variables from respondents are distinguished as coming from either a male or a female respondent. (example not available) Example 4: This counts and aggregates across records from the Child/other household member-level file and adds these to the household-level records. (example not available)
Two types of data management were performed on household member and non-resident child variables in this data set. The first type was simple editing from interviewer notes, comments or other sources. Duplicate household member and non-resident child records were eliminated and full or partial records were added when information was missing because of data transmission problems or if child records had to be entered by hand from the Coversheet Roster (only 10 children could be entered into the CAPI application). Edited records are not flagged in HHMEMADD/NRCHDADD in the PERSONS file as imputed.
Another type of management involved the addition of padded records. If the Respondent indicated the number of household members or non-resident children but refused to answer questions about them, we added a partial record. Padded records contain PN, NRCHDADD/HHMEMADD, V417/V461. Sometimes records were added where no explicit interviewer comment or refusal response explained the inconsistency, but other related responses pointed to the existence of other household members or non-resident children. When records were imputed in this manner, the flag variables HHMEMADD/NRCHDADD have a value of '1'.
Other cleaning included reconciling relationship to Respondent and/or Spouse when children were coded as 7, "Other Relationship". Relationship was recoded to "Child or Step-Child" only when interviewer comments indicated that the child was adopted. When the interviewer comments indicated that the child was a foster child or a non-biological child raised as a child, or if no information was available, values of 7 were left as is. Please note that a code of 7 in these variables means "other relationship", not NO relationship,
Masking: For this second Public Release we have stripped the datasets of all names, Medicare, Medicaid, and Social Security numbers; we have removed or collapsed code values wherever these responses may violate confidentiality or allow the possibility of individual respondent identification. Variables which have been omitted are: Sample ID (PSU and Segment), month and day of Respondent birth, and state or country of birth. We have, in addition, collapsed occupation codes to broad categories.
Variables are presented in the order of the questionnaire, except where noted. (B) (C) (D) V325 [RESP] PC2a. HOW MEMORY CHG (E) PC2a. Is (his/her) memory better or worse than two years ago? ----------------------------------------------------------------------------- 20 BETTER............................. 1 (F) 437 WORSE.............................. 2 PC2c (H) 2 DK................................. .D PC3 (G) 1 RF................................. .R PC3 7763 INAP, NOT PROXY [PROXY=1]; NO CHANGE IN (H) MEMORY (DK/RF) [V324 NE 1] B. Most variable names are Vnum in sequential order of their appearance in the questionnaire. Exceptions are some demographic variables such as SEX or MODE, and the derived variables. C. The dataset in which the variable appears is indicated in brackets, i.e., [HH] [RESP] [PERSONS] [HELPER]. D. The variable label appears above each question. E. Question number and full question wording and interviewer instructions appear for each variable. F. Unweighted marginals (frequencies) for all cases (including age-ineligible) appear to the left of the code descriptions for most variables. For continuous variables, the unweighted n, mean, s.d., minimum and maximum are provided as well as frequencies of missing data. G. Missing data conventions in the dataset and codebook are as follows: 1. Don't know (DK) .D 2. Refused by R (RF) .R 3. Question Inappropriate (INAP) . All three of these missing data codes are less than 0 and will not be used by SAS analyses unless deliberately requested. They can be addressed globally with: IF Vxxx lt 0 or individually: IF Vxxx = .D Please note that CAPITAL .D and .R should be used in your setups. H. Skip patterns may be followed either from the "go-to indicators" (GO TO PC3), or from the INAP context description. Category follow-up variables have been created for each series of unfolding bracketed range questions following missing data on an amount question. The original unfolding bracketed range variables have been removed. (A) If J46. = DK,RF go to J46a. Would the total be $5,000 or more? (B) If YES go to J46b. $10,000 or more? (C) If YES go to J46c. $50,000 or more? ALL go to J47-1. [END SEQUENCE] (C) If NO,DK,RF go to J47-1. [END SEQUENCE] (B) If NO go to J46d. $1,000 or more? (C) ALL go to J47-1. [END SEQUENCE] (B) If DK,RF go to J47-1. [END SEQUENCE] A. First unfolding bracketed range question. B. Response to the first unfolding bracketed range question followed by the next unfolding bracketed range question. C. Response to the second unfolding bracketed range question followed by the next unfolding bracketed range question, if any.
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