1. State your health outcome of interest. (It could be the one you used for week #2 or another one.) Pick two key behaviors that are important factors leading to your health outcome. Explain the importance of these behaviors either for etiology, prevention, or intervention. (If none of the behaviors in the readings are important for your health outcome, suggest another behavior that is.)
My health outcome of interest is listing for lung transplantation. Two key behaviors that are important factors leading to this outcome are smoking and exercise. Since smoking is a cause of end-stage lung disease, patients who smoke are not considered candidates for transplantation. As such, smoking is a very key behavior in the outcome of interest. Another important behavior is exercise. As patients get sicker prior to transplantation they become more frail and have less ability to exercise. However, the more frail a patient is prior to transplantation the less likely they are to survive the operation and the post-operative period. Thus, exercise is an important factor in determining if a patient is a candidate. This behavior is complicated because some of the limitation in this behavior may be due to the patient and some may be due to the lung disease.
2. Describe how you would study the role of one of the behaviors described for question #1 and your health outcome of interest. Incorporate a social factor (e.g. race/ethnicity, social exclusion, stress) in the study approach.
The behavior I believe would be most interested to look at in relation to listing for transplantation is exercise. As I alluded to in the prior question, teasing out exercise tolerance from exercise desire is critical here. A patient will not be a candidate if they do not exercise. While some patients do not exercise because they cannot due to the lung disease itself, this is often not felt to be a sufficient excuse by our team unless the patient is hospitalized. One way to study this outcome of interest is to pair a questionnaire on exercise with an actual physical activity. You could have a patient fill out a survey asking about their exercise habits and why they do or do not exercise, and at the same visit, you could have them do a six minute walk test to test their exercise capacity. This would be a key way to differentiate what constitutes exercise limitation vs desire. It is also possible that some social factors may be intertwined here. Patients with more social support and more income will be more likely to have access to a gym to exercise or to exercise equipment in their household. As such, the interplay between income and support network could be assessed as well to determine if it mediates better exercise.
3. If key health behaviors (e.g. smoking, exercise, nutritious diet) are strongly influenced by neighborhood, income, and/or education, do we need to continue to study how these behaviors influence health outcomes? Why or why not?
It is very important to study how behaviors influence health outcomes independently of the things that influence them. Just because an individual lives in a neighborhood that has a lot of smokers it is not enough to assume that this person will be a smoker. In fact, there is some informativeness to the variability within the neighborhood. It is important to study the behaviors and the influencers in parallel to determine which are most important and to elucidate the causal pathway in our outcome of interest.