Part 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).
Hager ER, et al. Development and validity of a 2-item screen to identify families at risk for food insecurity. Pediatrics 2010;126:e26–e32
What was the definition of the construct?
Food insecurity was defined as being unable to obtain adequate food because of constrained resources at some time during the year. The authors sought to develop a food insecurity screen to identify families at risk of FI from the widely utilized 18-item US Household Food Security Scale (HFSS), which can be time consuming to perform. They sought to develop a food security screen from the characteristics of the HFSS with 5 specific characteristics: (1) applicable to families with young children, (2) brief, (3) highly sensitive (> 90%), highly specific (> 80%) and valid (convergent validity).
How did the authors provide evidence on the validity of the measure? Could you think of additional approaches to validating the measure?
The authors had 30,098 families (23% food insecure) complete the 18-item HFSS. A food insecurity screen was developed on the basis of affirmative HFSS responses among food insecure families. Sensitivity and specificity were then evaluated.
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 convergent validity (correspondence between FI screen and theoretically related values) which was assessed with logistic regression, adjusting for covariates including the study site, caregivers’ race/ethnicity, US born vs immigrant status, marital status, education, employment, history of breastfeeding, child’s gender, and child’s low birth weight status. An additional, and much needed, approach to evaluate the reliability of the measure is to assess this in other populations.
Describe the implications of a lack of measurement validity or reliability for future research applications.
If the 2 item food security screener is not valid or reliable and then was utilized in future studies, this would have the potential to worsen health disparities. Currently, this specific 2 item FS screener has yet to be tested in populations of varying socioeconomic status, in rural populations, or in families without young children.
Part 2:
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)
Randall L, et al. Recurrent diabetic ketoacidosis in inner-city minority patients: behavioral, socioeconomic, and psychosocial factors. Diabetes Care. 2011;34:1891–1896.
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 paper seeks to determine reasons for why individuals living in inner-cities develop diabetic ketoacidosis (DKA) through bedside surveys and laboratory assessment. As opposed to the other articles attempting to describe predictors for the development of DKA, where the number one reason listed is “insulin omission,” this is the ONLY publication to take the concept of “insulin omission” a step further by trying to uncover the reasons behind insulin omission in a specific population. This study was conducted with 164 adults who were admitted with DKA to Grady Hospital (Atlanta) between 2007 and 2010. The authors obtained demographic, diabetes treatment, education, mental illness history, depression history, and quality of life measures, in addition to laboratory data.
What is the evidence for the validity and reliability of the measures?
There is validity in some of the specific measurements that were assessed in this population (e.g. lab results, PHQ-9 to assess for depression, SF-36 to assess quality of life). However, as this is the first such study of its kind (first generation research) and was performed in a specific population (100% were inner city dwellers, 96% identified as African American), there is currently no external validity of the results. Such a study should definitely be replicated in other populations in order to assess for external validity.
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 study compared patients presenting with first time DKA with those presenting with recurrent DKA, with first time DKA being the reference category. Compared with first-time DKA, those with recurrent episodes had longer durations of diabetes, were younger at the onset of diabetes, had higher rates of depression, alcohol, and drug abuse, as well as higher rates of homelessness. Comparing first-time DKA (as a reference category) with recurrent DKA does make sense for this study given that the authors were also trying to find additional risk factors to predict recurrent DKA (given the high cost and elevated comorbidities associated with this).
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.
In this study, the disparity is quantified in terms of prevalence (e.g. prevalence of alcohol abuse, drug abuse, history of homelessness), which is an absolute measure. Insulin discontinuation was the leading precipitating cause in this study (68%). Of those who discontinued insulin, 32% gave no reason for stopping, 27% lack of money to buy insulin, 19% felt sick, 15% were away from their supply, and 5% were stretching insulin. Given the first generation nature of this research, I actually believe that further qualitative studies (qualitative measures) are needed. Through qualitative measures, one may be able to further parse out WHY so many individuals had a lack of money to buy insulin, WHY some people were away from their supply, and WHY some individuals had to stretch supplies.