Get to Know the Gateway: Physical Functional Health User Guide
Written by: Codi Young and Peifeng Hu
Published on: Mar 17, 2022
The Health and Retirement Study (HRS) family of surveys is expanding globally, conducting more rounds of interviews and collecting new information in 44 countries. With this growth, it can be difficult for researchers to find the information they need. As users of these rich datasets, we understand how overwhelming it can be to find comparable measures across surveys for cross-country comparisons. The Gateway is here to help! In addition to the concordance tables that the Gateway creates, summarizing comparable measures in an easy-to-read format, we also publish working papers that dive deeper into the similarities and differences of different domains across the surveys and waves.
We recently released a user guide on the physical functional health measures (the concordance table can be found here and in this blog post) that are available in the harmonized studies on the Gateway: the US HRS, the Mexican Health & Aging Study (MHAS), the English Longitudinal Study of Ageing (ELSA), the Survey of Health, Ageing, and Retirement in Europe (SHARE), the Costa Rican Longevity and Healthy Aging Study (CRELES), the Korean Longitudinal Study of Aging (KLoSA), the Japanese Study on Aging and Retirement (JSTAR), the Irish Longitudinal Study on Ageing (TILDA), the Chinese Health and Retirement Longitudinal Study (CHARLS), and the Longitudinal Aging Study in India (LASI).
Now, more importantly, what are physical functional health measures? These encompass items characterized as activities of daily living (ADLs), instrumental activities of daily living (IADLs), and other functional activities that are not in the purview of either ADLs or IADLs. While the above surveys all collect information on physical functional health, they vary across the spectrum in terms of response scales and details asked. The Gateway has taken these variations into account when harmonizing and has listed the assumptions and differences in each study codebook, but it can be time-consuming parsing through each one for cross-country comparisons. This is why we’ve summarized this host of information into one central document.
The first section of the user guide provides an inventory of the harmonized measures available in each study. It summarizes coverage of the three broad categories of physical functional limitations and includes the assumptions made when converting different response scales to indicate whether the respondent experiences any difficulty with the activity in the harmonized variables. For example, in section 1.1.1., we note that starting in Wave 3 of the HRS, respondents were asked to respond with “yes”, “no”, “can’t do”, or “don’t do”. In the harmonized measures, a score of 1 was assigned if the responses were “yes” or “can’t do”. In addition, we also compare measures from the other studies with the HRS and highlight any differences seen. Concordance tables, like Figure 1, are included at the end to summarize the measures seen across the surveys.
We’ve also derived ADL, IADL, and other functional limitation summary measures that are perfect for both longitudinal and cross-study analyses. These measures typically capture the activities that are most commonly asked across studies, and are the focal point of Section 2 of the user guide. Each subsection categorizes the summary measures by the number of items used to derive it, lists the studies that construct the same harmonized variable, and indicates any differences across studies. For example, in section 2.2, we constructed a 3-item IADL summary measure, RwIADLA, that sums any difficulty with using the phone, managing money, and taking medications. This harmonized measure is derived for the HRS, ELSA, SHARE, KLoSA, TILDA, CHARLS, and LASI, and is comparable across these studies. As in Section 1, this breadth of information is also summarized into easy-to-read tables, as shown in Figure 2.
Wrapping up the user guide is the question concordance in Section 3, which lists out the question numbers and texts asked in the latest wave (as of this blog post!) of each survey. The harmonized measures we’ve created are derived based on these questions and are included for the user’s convenience. As a reminder, these questions can also be found through our survey search function on the Gateway website! We hope our user guides and concordance tables prove useful in understanding this wealth of data and for your research. If there is another topic that you’d be interested in having a user guide written, feel free to send us your suggestions at firstname.lastname@example.org!
- Codi Young is a Programmer at the University of Southern California.
- Peifeng Hu is a Professor of Geriatric Medicine at the UCLA School of Medicine.