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).
Please see attached (MacCarthy, 2019).
2. What was the definition of the construct?
MacCarthy et. al. define Sexual Minority Women (SMW) as “lesbian and bisexual women.”
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 followed previously established guidelines on how to phrase a survey question pertaining to sexual orientation (“which of the following best represents how you think of yourself?”). Possible responses were, “straight, that is, not lesbian or gay,” “gay or lesbian,” “bisexual,” “something else,” and “I don’t know.”
However, their “integrated approach” is unique in how they aggregate subgroups of sexual minority women followed by testing for subgroup heterogeneity. They classified “straight, that is, not lesbian or gay,” as heterosexual and “bisexual,” “gay or lesbian,” and “something else” as sexual minority women. They then constructed statistical models related to their outcome, access to care, using SMW as a predictor. They found a statistically significant difference in outcomes based on SMW status and few differences in outcome when they repeated the same modlels with separate indicators for SMW subgroups. They contend that this supports their integrated approach as without aggregation of subgroups, studies may understate disparities for SMW or overstate disparities for SMW subgroups.
Their study underscores the need for larger sample sizes and the trade-off between statistical power and understanding the particularities of smaller subgroups. As such, this study did not address the validity of their measurement, which might have been improved had they more precisely defined SMW, perhaps as a percentage of non-hetersexual encounters, and added survey questions pertaining to the number of sexual encounters (also to be defined) with non-men.
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?
Reliability was demonstrated by repeating the models with various outcomes. This approach could be strengthened by examining additional outcomes besides access to care, such as health outcomes or asking variations of the same question with regards to sexual orientation.
5. Describe the implications of a lack of measurement validity or reliability for future research applications.
Lack of measurement validity would imply that there are differences between how one responds to the sexual orientation question on the survey and whether one is truly lesbian or bisexual according to the construct of sexual orientation. Assuming that SMW are a minority, this would reduce statistical power if it is underreported or vice versa. Lack of reliability would add noise to the results but this is addressed by aggregating data in ways that are more clearly defined, i.e. hetersexual vs. sexual minority or by repeating the same question in different ways.
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)
Please see attached (Campbell, 2019).
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 Adverse Childhood Experiences (ACE), which characterizes a broad range of negative events or unequal life experiences in children (ages 0-18). This study aims to study the effect of ACEs on mortality as mediated by diabetes.
3. What is the evidence for the validity and reliability of the measures?
Unfortunately, there is little evidence supporting the validity or reliability of this measure (Felitti, 1998). However, one can estimate that ACEs may be underreported due to stigma, undermining its validity. One can also expect that recall bias is an important factor that affects the validity of this instrument.
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 are those without any adverse childhood experiences.
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.
This is an absolute measure where a higher score indicates greater risk for diabetes and mortality. The authors also calculated the absolute risk increase of mortality. I would prefer to have both relative and absolute measures because a relative measure for the predictor and outcome because it would inform us of the magnitude and allow for easier comparison across time, geographic locations, and other indicators.
Part 3:
1. Read someone else's response to part 1 above (identifying a construct) and comment, specifically noting whether you can see any additional implications of measurement quality for future research or whether you agree with those noted by your classmate.
I read Ignacio Farina’s response regarding the REALD-30 tool to measure the construct of health literacy in dentistry. I agree with his assessment that validity could have been improved by providing more context for the participant, i.e. reading abstract phrases may not be the best measure of literacy since retention generally improves with added context. However, I thought that reliability might be improved if more questions were added to the assessment and/or the instrument was administered at multiple time points to gain a better sense of one’s true health literacy.