Part 1:
1) Choose a paper describing the development or validation of a measure of relevance in health disparities research (give full citation)
Weiss et. al. Quick assessment of literacy in primary care: The Newest Vital Sign. Ann Fam Med. 2005 Nov; 3(6): 514–522.
2) What was the definition of the construct?
The Newest Vital Sign (NVS) tool is a nutrition label accompanied by a 6 questions that takes 3 minutes to administer. The NVS was developed to measure health literacy and in this study was tested in English and Spanish speaking patients in primary care practices. The length of time required for administration of the TOFHLA (18 to 22 minutes for the full version and 7 to10 minutes for a short version) is a barrier, so the NVS was developed to be shorter and easier to use in actual practice environments.
3) How did the authors provide evidence on the validity of the measure? Could you think of additional approaches to validating the measure?
The performance of the NVS was compared to the Test of Functional Health Literacy in Adults (TOFHLA), the most widely accepted test. This is a good approach in terms of proving equivalence to a current standard but offering the added benefit of being a shorter test to administer. Alternative approaches to have considered for validation may have included extensive and thorough testing of health literacy using both quantitative and qualitative methods. Ultimately the goal is to demonstrate health literacy and not prove non-inferiority to another test which may are may not be accurate.
4) How did the authors provide evidence of reliability of the measure? Could you think of additional approaches to evaluating the reliability of the measure?
For reliability, the performed the test in three different practices, but all were affiliated with the same university. A better way to demonstrate reliability would have been to use the tool in a wider variety of practice settings. The sample size of 500 patients was large which likely improved reliability.
5) Describe the implications of a lack of measurement validity or reliability for future research applications.
In this case, this was the first study of NVS, and so failure to demonstrate measurement validity or reliability may not have been profound if providers agree that it is not a replacement of the TOFHLA. HOWEVER, those looking for a shorter test may still go ahead and use the NVS and that may be harmful in that patients with low health literacy may not be detected by the test and may slip through the cracks. It is less of an issue if patients with good health literacy are thought to have low health literacy. So we are most concerned with false negatives.
Part 2:
1) Find a paper describing a health disparity (give full citation)
Kanaya AM, et al. Comparing coronary artery calcium among U.S. South Asians with four racial/ethnic groups: The MASALA and MESA studies. Atherosclerosis. 234 (2014) 102-107.
2) Summarize the construct and measurement of the dimension of disparity (e.g. race, SES) and the outcome measured (ex: self-rated health)
Relative to other race/ethnic groups, South Asians have a high burden of coronary heart disease and several traditional cardiovascular risk factors such as diabetes, hyperlipidemia, lack of physical activity, and hypertension. Coronary artery calcium (CAC) is a subclinical measure of atherosclerosis. More aggressive cardiovascular screening and preventative care is recommended for certain individuals with high CAC scores. The study sought to identify if there were disparities in subclinical CAC presence and severity relative to other race/ethnic groups. Explicitly, the outcome measured was the coronary artery calcium (CAC) score from cardiac computed tomography. The dimension of the disparity measured was race/ethnic group: South Asians, Chinese Americans, Latinos, African Americans and Whites.
3) What is the evidence for the validity and reliability of the measures?
The method used to measure CAC in this study is strong and serves as the gold standard in many ways. However, the collection of race/ethnicity is always challenging. For example, the term “South Asian” reflects a wide array of genetic variation and people ranging from many disparate geographies like Bangladesh, Sri Lanka, India, Nepal and Pakistan. We have discussed the challenges of the race/ethnic variable in class quite extensively.
4) What is the reference category used for the disparity measure? Why does this reference category make sense (or not) for this research question?
The reference category is the White race/ethnic group. With respect to the evidence base for cardiovascular disease and CAC burdens, the most has been published about Whites. In part this is due to the Framingham cohort, which generated some of the seminal work on CAC. The Multiethnic Study of Atherosclerosis (MESA) has also generated a lot of the CAC literature and does include four race/ethnic groups: Whites, Chinese Americans, African Americans and Latinos. Nevertheless, since so little is known about South Asians, it makes sense to draw a primary reference to Whites, from which most of the data and current guidelines are based with respect to CAC.
5) How is the disparity quantified? Is this an absolute or relative measure or are both provided? Describe which type of measure you would prefer for this research area, or, if both, why?
The CAC disparity is quantified in both absolute and relative terms in this manuscript. Relative risk is calculated in multivariable models and absolute CAC scores after adjustment are also compared between race/ethnic groups. I think in this case, the relative measures are more useful given that there are many zero-CAC scores (close to 50%) in each race/ethnic group. Interpreting absolute values may prove challenging when looking at the entire cohorts. However, if we exclude the zero scores, I would prefer absolute comparisons instead. The relevant clinical CAC cutpoints are 0,