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).
The following paper evaluates cardiovascular disease risk awareness in patients visiting their primary care doctor.
Woringer M, Nielsen JJ, Zibarras L, Evason J, Kassianos AP, Harris M, Majeed A, Soljak M. Development of a questionnaire to evaluate patients’ awareness of cardiovascular disease risk in England’s National Health Service Health Check preventive cardiovascular programme. BMJ Open. 2017 Sep 25;7(9):e014413. PMCID: PMC5623403
2. What was the definition of the construct?
Construction in this study is health knowledge with specific focus on cardiovascular disease risk awareness.
3. How did the authors provide evidence on the validity of the measure? Could you think of additional approaches to validating the measure?
This study begins with developing an 85-question questionnaire by review of the literature.
Then it has two phases of questionnaire modification to improve validity:
The first phase was modification of questionnaire by expert panel to obtain satisfactory content validity. In this phase an expert panel assessed content validity of the questionnaire by examining whether the items were representative of the content they were intended to measure. Items were examined for representatives of the scale domain, appropriateness and relevance. The content validity index (CVI), a widely used technique in scale development determined item and questionnaire clarity, homogeneity and relevance on a 4-point Likert scale (ranging from 1=an irrelevant item to 4=an extremely relevant item). A CVI of ≥0.80 is recommended. The expert panel concluded that out of the 85 items that were evaluated, 69 met the CVI≥0.80 criterion and were retained.
The second phase was modification of questionnaire by patient focus group to obtain satisfactory face validity of the 69-item questionnaire resulting from the expert review. Face validity is assessed by end users deciding whether the questionnaire appears to measure what the researchers who developed it claim. Participants were asked to complete the 69-item questionnaire as well as to provide feedback on whether the items correctly measured the intended scales, appropriately stated the intent of the questionnaire and matched the individual’s situations. In addition, participants were asked to respond to questions about clarity, content, appropriateness, format, biases of questions and presentation of information. As a result of the focus group review of the 69-item questionnaire, 6 items were removed, 2 items were added, and several items were modified leaving a final total of 65 items with satisfactory face validity.
I think the authors did a great job validating the questionnaire by an expert panel for content validity and by a patient panel for face validity.
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?
65-item questionnaire was administered to 110 NHS Health Check attendees immediately after their visit in a cross-sectional study in England to determine the reliability of the resulting questionnaire. The reliability of factors constituting particular scales was assessed using Cronbach’s α coefficient. In this phase, the questionnaire was reduced from 65 to 26 items. The 26-item questionnaire constitutes four scales: Knowledge of CVD Risk and Prevention, Perceived Risk of Heart Attack/Stroke, Perceived Benefits and Intention to Change Behavior and Healthy Eating Intentions. Perceived Risk had Cronbach’s α=0.85 and Perceived Benefits and Intention to Change Behavior had (Cronbach’s α=0.82) indicating satisfactory reliability (Cronbach’s α≥0.70). Healthy Eating Intentions (Cronbach’s α=0.56) had minimum threshold for reliability. One additional way to evaluate the reliability could be repeating the test one month later in the same group and evaluate the correlation between first and second tests.
5. Describe the implications of a lack of measurement validity or reliability for future research applications.
The results obtained from the questionnaires like the one in this study that evaluate the cardiovascular disease knowledge and risk awareness will be used to identify educational gaps and to develop educational programs to enhance the cardiovascular disease knowledge in high risk groups with poor knowledge. If there is lack of measurement validity and reliability in these questionnaires, this would result in mischaracterization of knowledge gaps and decreasing efficiency of any possible educational interventional program that gets developed accordingly.
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)
Ku E, Lee BK, McCulloch CE, Roll GR, Grimes B, Adey D, Johansen KL. Racial and Ethnic Disparities in Kidney Transplant Access within a Theoretical Context of Medical Eligibility. Transplantation. 2019 Sep 13; PMID: 31568216
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).
The construct is racial and ethnic disparities and the measured outcome is access to transplant.
3. What is the evidence for the validity and reliability of the measures?
The authors used USRDS which is a dataset that has the information about all end-stage kidney disease patients on dialysis that are potentially eligible for kidney transplant and based on characteristics of these patients including their comorbidities, they determined their medical eligibility for kidney transplant by race/ethnicity. To evaluate the face validity of this approach to determining medical eligibility for transplantation by race/ethnicity, the authors used the CMS data that has a form that asks providers to indicate whether patients were informed of the option of transplantation and if not, to list the reasons for not doing so. I didn’t specifically find an evidence for reliability of the measures in this paper’s methodology.
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 for the disparity measure was non-Hispanic white patients and they were compared with Hispanic and non-Hispanic blacks. I think this reference category makes sense for this question because prior studies have shown non-Hispanic whites have better access to overall kidney care and specifically kidney transplant even when controlled for sociodemographic factors.
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 authors examined the association between race/ethnicity and access to a living or deceased donor transplant (as a composite outcome) using unadjusted Fine-Gray models (accounting for the competing risk of death) to determine the extent to which race/ethnicity itself was associated with differential access to transplant. They determined the sub-hazard ratio for transplantation by one-year intervals and compared it between non-Hispanic whites and Hispanics and non-Hispanic blacks. This is a relative measure; I prefer this relative measure because we are comparing the hazard ratio for kidney transplant between different ethnicities.