1. What are 3 different ways to account for SES in a analytic models when investigating racial/ethnic health disparities? Briefly discuss the interpretations/implications of each approach as it relates to understanding health disparities by race/ethnicity.
Effect modifier: If SES is an effect modifier on the causal pathway between race/ethnicity as a predictor and a health outcome, then SES will affect the magnitude in which the health outcome is affected by racial/ethnic differences, i.e. the effect of race/ethnicity on a health outcome differs according to level of SES. For example, if African Americans are more affected by diabetes but it differs by income level (i.e. African Americans with high income have low rates of diabetes) then SES would be an effect modifier.
Mediator: SES as a mediator means that the effect of race/ethnicity on health outcomes is partially explained by SES. Excluding the pathway between SES and the health outcome would estimate the sole effect of race/ethnicity on the health outcome whereas including SES would estimate the overall effect of race/ethnicity on the health outcome. In this situation, race/ethnicity determines SES, as it often does in the United States, which in turn determines health outcomes. However, the outcome may also be directly determined by race/ethnicity, meaning that SES is a mediator.
Confounder: If SES is a confounder of race/ethnicity and a health outcome, then it must be included in the model and controlled for in order to estimate the true effect of race/ethnicity on the health outcome because it is affecting both. Without controlling for SES as a confounder, the estimated effect will be biased. SES may determine race/ethnicity in caste societies while also determining specific health outcomes due to poverty, i.e. cholera from lack of access to clean drinking water.
2. Describe a potential effect modifier, mediator, or contextual variable (for definition of contextual variable, see Diez-Roux reading) for an association of interest to you and relevant to health disparities. For example, for investigating the association between education and hypertension, I might be interested in evaluating whether the association between years of education and hypertension is different for Black men than for White men. Describe how you would study whether this relationship exists.
The association that I am interested in is the effect of childhood trauma on anxiety. However, this may be modified by SES as those who have experienced trauma with low or high SES backgrounds may experience greater levels of anxiety. Data for childhood trauma and SES may be gathered using a standardized questionnaire such as the one used in the Adverse Childhood Experiences study by the CDC. Outcomes could be obtained by electronic medical record. To estimate this, I would create a model estimating the effects of childhood trauma on anxiety and stratify by meaningful SES groups.
3. Respond to one other person's post on the forum with a comment or suggestion.
In response to Ashley’s post on the effects of income on birthweight: I agree that prenatal health is likely a mediator on this pathway. Have you also considered if it is actually on the causal pathway? It is hard for me to think of how income could directly affect birth weight without first affecting some other variable. Another question that I have is how prenatal health is related to race/ethnicity in terms of empowerment, nutritional availability, and maternal age. Are you suggesting that the last three vary by race? If so, would race/ethnicity be a confounder for income and birth weight?