Blogs: HCAP Comparison

HCAP Comparison

by Codi Young
June 17, 2020
#agingresearch #dementia #cognition #HRS #ELSA #MHAS

In aging research, the Health and Retirement Study (HRS) is probably one of the most well-known longitudinal studies. Surveying a nationally representative sample of people over the age of 50 in the United States, it aims to elicit information on a plethora of topics, such as demographics, health, and economic factors. It’s no wonder that the HRS has since served as a model for a number of sister studies around the world.

The Harmonized Cognitive Assessment Protocol (HCAP) was designed to leverage these HRS-family of studies to assess dementia risk and cognitive function, and has since been used in the USA, India, Mexico, England, and China. All HCAP studies share core elements:

  1. consists of a pair of in-person interviews, one with a target respondent and one with an informant nominated by the respondent and
  2. utilizes a test battery that measures a range of key cognitive domains and asks informants questions about the respondent.

However, because of cross-country differences in literacy and local contexts, study-specific modifications to the tests may be made.

HCAP Comparison Table

blog-graphic-3

Now, if there are study-specific modifications, how are researchers able to determine what’s comparable and what’s not? To answer this, we have created a cross-study comparison table of the HCAP cognitive assessments as part of the Gateway’s initiative to harmonize the HCAP studies. We suggest using this table concurrently with the harmonized datasets and codebooks once available. Thus far, only the HRS-HCAP (USA), LASI-DAD (India), ELSA-HCAP (England), and MHAS Mex-Cog (Mexico) have been included, with more studies to be added in the future.

For each study, we provide the test name, a brief test description, the harmonized variable name, and a breakdown of the questions asked in each test. Because study-specific modifications may be made, we account for the differences of each test in red. For example, in the Orientation to Time test, the MHAS Mex-Cog differs from the other studies in terms of the questions asked in this test. Instead of asking a question on season, Mex-Cog replaces it with a question on time (Figure 1). Greyed boxes indicate that the specific test was not asked in the HCAP study, as seen in the Serial 7’s test for the HRS-HCAP. Here, the Serial 7’s test was asked in the main HRS study, but not in the HRS-HCAP (Figure 2).

blog-graphic-1
Fig 1. Mex-Cog differences in the Orientation to Time test
blog-graphic-2
Fig 2. Serial 7’s test not available in HRS-HCAP

In the coming months, we will be releasing the harmonized codebooks of the HCAP studies on our Gateway website. These files will be available for download for all registered users. Remember to check back often for updates on the Harmonized HCAP studies!


about the author
Codi Young is a Research Programmer at The Program for Global Health, Aging & Policy at CESR.