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).
Juhn YJ, Beebe TJ, Finnie DM, et al. Development and initial testing of a new socioeconomic status measure based on housing data. J Urban Health. 2011;88(5):933–944. doi:10.1007/s11524-011-9572-7
2. What was the definition of the construct?
The construct, termed “HOUSES,” is a composite index that is derived from size, type, ownership status, and value of housing unit, combined with neighborhood (census tract level) socioeconomic characteristics, with the goal of reflecting one’s SES.
3. How did the authors provide evidence on the validity of the measure? Could you think of additional approaches to validating the measure?
To determine validity, the authors assessed Pearson’s correlation coefficients between HOUSES and more traditional measures of SES as well as variables associated with low SES including low birth weight, overweight children, and household smokers. I think it was valuable for the authors to determine associations not just with measures of SES (income, education, etc) but also with dependent variables that have been shown to be associated with SES in other studies.
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 applied their HOUSES Index (which was developed in Olmsted County, Minnesota) to participants in Jackson County, Missouri. While this was a good start, in order to truly understand the reliability of this measure, it would be important to test it in numerous geographies with residents of widely varying SES.
5. Describe the implications of a lack of measurement validity or reliability for future research applications.
The goal of this measure is to allow researchers to determine SES using address information when other SES variables are missing. Low a lack of validity would lead to inaccurate associations between “presumed SES” and outcomes of interest which could mislead researches and policy makers. Lack of reliability would make the measure less useful for repeated measures and in varying populations.
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)
Arya S, Binney Z, Khakharia A, Brewster LP, Goodney P, Patzer R, Hockenberry J, Wilson PWF. Race and Socioeconomic Status Independently Affect Risk of Major Amputation in Peripheral Artery Disease. J Am Heart Assoc. 2018 Jan 12;7(2). pii:e007425. doi: 10.1161/JAHA.117.007425. PubMed PMID: 29330260; PubMed Central PMCID: PMC5850162.
(sorry couldn't upload file size was too large for some reason)
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 two measured disparities are race and SES. For race, the authors describe using “black, white, and other” but that other race was only 1.3% and was dropped from the analysis. For SES the authors use median household income for the patients’ most recent residential zip code. Sensitivity analysis for SES was performed using neighborhood poverty and area deprivation index.
The outcome measured is major amputation in patients with peripheral vascular disease.
3. What is the evidence for the validity and reliability of the measures?
The race variable is abstracted from the national VA Corporate Data Warehouse without further details. I am concerned about the validity of this measure, as there is limited data on how it is obtained (ie self-reported?). It is also concerning to me that only 1.3% were classified as non-white or non-black.
More detail is provided on how the SES variables were determined and used in analysis. One major concern I have about SES data is that it is all neighborhood based rather than individual based, although this seems to be a common mechanism in large database studies. It also fails to account for important SES indicators such as education.
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?
For race, the comparison on group is white vs black. If the distribution of race is truly as described in the paper, then this comparison makes sense. Although, it is important to note that this study is comprised solely of veterans, and therefor there may be limited generalizability to other populations.
For SES, the authors used a cutoff of median household income >$40,000 for the comparison group. This cutoff was determined based on the crude associations between median household income and amputation risk. I don’t think this cutoff is the best choice, as median income is not an ideal sole determinate of SES, given that income varies greatly with geography and an income of 40,000 in some places may lead to a higher SES overall than in others.
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 in amputation is measured as unadjusted and adjusted hazard ratios (a relative measure). In this case I think hazard ratio is the appropriate measure to report for two reasons. First, hazard difference is not commonly used and may be difficult to interpret. Secondly. The incidence of amputation in this population is not so low that the ratio may be misleading about the magnitude of the problem.