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).
Telomere Length as Biological Marker in Malignancy
Svenson, Ulrika, and Göran Roos. "Telomere Length as a Biological Marker in Malignancy." Biochimica Et Biophysica Acta (BBA) - Molecular Basis of Disease 1792.4 (2009): 317-23. Web.
Telomere length can be used as a clinical marker of risk and prognosis predictor. Other papers have explored the effects of telomere lengths in the past, and now this paper is able to confirm that shorter telomere lengths are associated with a higher risk of cancer.
2.What was the definition of the construct?
The construct is defined as the accurate measurement of telomere length in the clinical setting. It has been noted that telomere length in leucocytes declines with increasing age. “Subsequently, it was speculated that telomere length could be a biomarker of biological cell age and thus indicate the risk of age-related disease such as cancer, cardiovascular diseases, pulmonary disease, diabetes and others.” (Bojesen 402) (upload paper)
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 used a multitude of previously published papers that had established the techniques used to measure telomere length in order to set up their experiment. There has been decades of research conducted around telomere lengths. I believe this paper did a good job of validating their measure before conducting their own research.
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 used a few techniques in order to quantify telomere lengths. They compared results between the southern blot, Q-FISH and flow FISH assays, and quantitative PCR methods. They were able to validate their measurements and found the most accurate method for telomere measurements. The paper covered all available techniques for measuring telomere lengths in great detail, at this time I do not have any additional approaches.
5. Describe the implications of a lack of measurement validity or reliability for future research applications.
If there was an issue with the validity of measurements that would not only create problems for the papers that have already been published using this approach, but would also limit the use of this technique going forward. If telomere measurements were not found to be reliable, decades of research would need to be changed.
Part 2:
1.Find a paper describing a health disparity (please give the full citation or upload the paper)
Do US Black Women Experience Stress-Related Accelerated Biological Aging?
Geronimus, Arline T., Margaret T. Hicken, Jay A. Pearson, Sarah J. Seashols, Kelly L. Brown, and Tracey Dawson Cruz. "Do US Black Women Experience Stress-Related Accelerated Biological Aging?" Hum Nat Human Nature 21.1 (2010): 19-38. Web.
2.Summarize the construct and measurement of the dimension of disparity (e.g., race, SES) and the outcome measured (e.g., self-rated health).
This study examines race as a dimension of disparity and measures telomere length as a health outcome. In this paper, even after controlling for unhealthy behaviors, estradiol, and other factors effecting telomere length, there was a significant shortening of African American women’s telomeres.
3.What is the evidence for the validity and reliability of the measures?
The evidence for the validity of these measures was founded in previous research and verified by the authors before conducting the research for this paper. Evidence of the reliability of this measure is also provided in the methodology of quantitative PCR. QPCR requires established standards before one can run any actual samples, and it requires there to be a multiple samples per subject. In order for the results to be validated, the coefficient of variation in between the samples cannot be greater than 5%.
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 main reference category for this measure is race. However, the authors of this paper did also use perceived stress, poverty, smoking, and WHR (a measure of central adiposity) as reference categories for the measure. For the final results, black women’s telomere lengths were referenced to a white female counterpart in the SWAN cohort.
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 disparity is quantified through a relative measure. The measure of telomere lengths is not provided, only the length relative to the reference groups. After reading the Harper and Lynch paper, I would prefer to have access to both absolute and relative measures. However, I believe that the absolute measures would need data from longer periods of time in order to be as relevant as the relative measure. Right now the relative measure reflects a huge racial disparity, but overtime an absolute measure could show the changes in health disparities as measured by health outcome.