Part 1:
1.Choose a paper describing the development or validation of a measure of relevance in health disparities research (please give the full citation and/or upload the paper if that's possible).
Wendy Pechero Bishop, Simon J. Craddock Lee, Celette Sugg Skinner, Tiffany M. Jones, Katharine McCallister, and Jasmin A. Tiro. Validity of Single-Item Screening for Limited Health Literacy in English and Spanish Speakers. American Journal of Public Health: May 2016, Vol. 106, No. 5, pp. 889-892.
2.What was the definition of the construct?
The authors define health literacy as the “ability to obtain, process, and understand basic health information and services needed to make health decisions
3.How did the authors provide evidence on the validity of the measure? Could you think of additional approaches to validating the measure?
The authors compared 3 single item screening questions: (1) How would you rate your ability to read? (2) How confident are you filling out medical forms by yourself? (3) How often do you have someone help you read hospital materials against a previously validated 40 question measure. The administered the single-item questions as well as the longer questionnaire as the gold standard to create AUROC curves for each single item question. The strengths of the author’s validation was that they trialed the measures in primary English speakers and primary Spanish speakers. The population studied to validate the single-question items was primarily younger (<50 years) thus additional validation could be examined in an elderly cohort were health literacy is often a larger issue.
4.How did the authors provide evidence on the reliability of the measure? Could you think of additional approaches to evaluating the reliability of the measure?
The authors did not explicitly measure reliability of the single item questionnaires’. By examining Spanish speaking and English speaking populations separately they actually acknowledge differences in the sensitivity and specificity of the measure depending on the population, indicating that the measure may not be reliable for different populations. The next step in evaluating reliability should be trialing the measures in new cohorts with varied features relevant to health literacy (i.e. age, primary language, safety-net vs other health care setting)
5.Describe the implications of a lack of measurement validity or reliability for future research applications.
The authors note that their single-item screening questionnaires have fairly low sensitivity and specificity compared to the 40 question comparator, thus indicating that the accuracy of the measures are less than ideal. If utilized for future research studies to define low health literacy as a predictor or exposure, these single-item questions would misclassify >30% of participants resulting in misleading results. Future studies might examine a compromised approach between the very quick 1 item questions and the unwieldy 40 item questions, that would have improved AUROC characteristics without being so long as to be unwieldy.
Part 2:
1.Find a paper describing a health disparity (please give the full citation or, even better, upload the paper so everyone else can look at it too)
John Z. Ayanian, MD, MPP; I. Steven Udvarhelyi, MD, MSc; Constantine A. Gatsonis, PhD; Chris L. Pashos, PhD; Arnold M. Epstein, MD, MA. Racial Differences in the Use of Revascularization Procedures After Coronary Angiography. JAMA. 1993;269(20):2642-2646.
2.Summarize the construct and measurement of the dimension of disparity (e.g., racial inequalities?, SES inequalities?) and the outcome measured (e.g., self-rated health).
This was a landmark paper looking at racial differences in coronary artery bypass graft (CABG or bypass surgery) and coronary angioplasty (stenting) after angiography (diagnostic cath which is used to see if arteries are blocked). The dimension of disparity was race and the measure of race was white vs black, which was determined solely from Medicare claims data listing. The outcome measure was receipt of the procedure (CABG or stenting) within 90 days of aniography and the outcome was adjusted by age, sex and geography.
3.What is the evidence for the validity and reliability of the measures?
The authors provide no evidence of validity or reliability of race within their data source of Medicare claims.
4.What is the reference category used for the disparity measure (ie, who is the comparison group)? Why does this reference category make sense (or not) for this research question?
The reference category is white patients. In this instance I think this reference category does make sense as white patients made up the majority of Medicare patients in the 1990s (time of the study) and thus would drive the previously published measures of rates of CABG and stenting after angiography that were not stratified by race.
5.How is the disparity quantified or measured? 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 disparity is measured as:
1) an absolute measure: # of revascularizations procedures per 100 angiograms in white patients vs black patients (Figure 1 and Table 2)
2) A relative measure: “White-to-black odds ratio” of undergoing revascularization shown in Table 4. This measure is adjusted for other patient characteristics (age, gender) and hospital characteristics (teaching status, urban, profit-status).
For this research area I think the relative measure is more important because the value of the outcome is unclear. Revascularization is not always indicated after angiography and it may be that the observed disparity is a result of under-treating black patients, over-treating white patients or difference in patient preferences. Thus revascularization is very different than an outcome like cardiovascular mortality, for which the absolute and relative measures are both important to understanding the racial disparity. If we theorize that revascularization rates should be equal between white and black patients then we still do not know the ideal “rate of revascularization” without additional clinical information such as the results of the angiography so the absolute measure is less important than the relative measure.