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).
I chose the attached paper:
The paper evaluates the validation of three separate scales in the assessment of levels of opioid withdrawal in a cohort of 46 patients.
2. What was the definition of the construct?
Clinical opioid withdrawal is defined as a clinical syndrome in which a patient who has opioid dependence goes through a period of abstinence which precipitates several symptoms associated including nausea, vomiting, diarrhea, sweating, anxiety, restlessness, among other symptoms. The COWS assessment is a clinician-administered scale assessing a patient's severity of withdrawal by assessing the degree of severity of several symptoms associated with opioid withdrawal. The scale varies from no active withdrawal (score <5), mild withdrawal (5-12), moderate withdrawal (13-24), moderate severe (25-36), severe withdrawal (>36). The COWS is most commonly used in the setting of buprenorphine induction, a medication to treat opioid use disorder which requires the patient to be in a period of at least mild withdrawal before initiating the medication.
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 validated COWS by comparing to two other validated clinical assessments of withdrawal, the CINA (Clinical Institute Narcotic Assessment) and the VAS Index (visual analog scale) in a cohort of 46 patients with known opioid dependence. They administered each patient the same dose of morphine and then administered naloxone, an opioid antagonist which is displaces the opioid from the opioid receptors in the patient precipitating withdrawal. They measured at least two scales in all patients and measured the cross validation and concordance of the COWS with CINA. Additional evidence supporting COWS was the comparison with VAS, where COWS scores correlated with peak VAS scores.
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?
Additional evidence supporting COWS was the comparison with VAS, where COWS scores correlated with peak VAS scores. The reliability of the measure was also in how the results were repeatable in most individuals in this cohort.
5. Describe the implications of a lack of measurement validity or reliability for future research applications.
COWS is considered a valid measure of clinical opioid withdrawal syndrome; it is sometimes criticized for the subjective nature of the clinical scale (e.g., a clinician may rate someone's restlessness as a "3" or "frequent shifting in seat" while another would rate it as a "5" or "Unable to sit still") which can affect the interpretation of the score. If using the COWS in a research study, it's important to ensure standardization among the clinicians providing the clinical scale to make sure that there is measurement agreement among all researchers in the study.
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)
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 a self-reported measure of health literacy using three validated questions: problems due to reading, understanding, and filling out forms, not due to poor vision. The questions are ‘‘How often do you have problems learning about your medical condition because of difficulty understanding written information?’’; ‘‘How confident are you filling out medical forms by yourself?’’; and ‘‘How often do you have someone like a family member, friend, hospital or clinic worker or caregiver, help you read health plan materials (such as written information about your health or care you are offered)?’’
The outcome measured was whether or not the patient used the Internet-Based Patient Portal to help manage their medical conditions.
3. What is the evidence for the validity and reliability of the measures?
The evidence and validity supported by use of these measures is summarized in this paper: "Chew LD, Griffin JM, Partin MR, et al. Validation of screening questions
for limited health literacy in a large VA outpatient population. J Gen Intern Med. 2008;23(5):561–566. doi:10.1007/s11606-008-0520-5" in which they validated all three measures in a large VA population of over 1,400 patients in 4 large VA medical centers across the US and compared their answers to these questions on health literacy to 2 validated health literacy measures, the Short Test of Functional Health Literacy in Adults (S-TOFHLA) and Rapid Estimate of Adult Literacy in Medicine (REALM).
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 comparison group for this measure is those with "adequate" literacy levels, or those considered with high scores, do not report having problems obtaining/understanding medical information about their conditions, and feel confident about filling out forms by themselves.
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.