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.)
Health outcome of interest: progression of chronic kidney disease (CKD) to end-stage renal disease (ESRD)
1. Poor diet - diabetes is the leading cause of ESRD, and poor glycemic control is associated with faster decline in renal function. Thus, patients with renal dysfunction due to diabetes who make poor dietary choices develop ESRD more quickly, and dietary counseling to improve blood glucose control can slow CKD progression. In addition, patients with advanced CKD can develop metabolic derangements such as hyperkalemia and hyperphosphatemia as a direct result of poor dietary choices. Adherence to a low-potassium, low-phosphorous diet is an intervention that can be used to stave off dialysis needs (i.e., the transition to ESRD).
2. Exercise - poorly controlled hypertension is the second-leading cause of ESRD and contributes to CKD progression. Maintaining a regular aerobic exercise regimen can improve blood pressure control and therefore slow CKD progression. In addition, regular exercise can help diabetic patients who are also obese lose weight, which can improve insulin sensitivity and therefore improve glycemic control, which again (as discussed above) slows CKD progression. Finally, CKD patients are at high risk for cardiovascular disease, cardiovascular events can cause acute kidney injury (e.g., heart failure exacerbation leading to acute cardiorenal syndrome, acute coronary syndrome resulting in poor renal perfusion and acute tubular necrosis), and acute kidney injury (especially when recurrent) causes CKD and exacerbates renal function decline. Therefore, a regular exercise regimen can help prevent cardiovascular disease burden that could accelerate CKD progression as well.
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.
One example would be to study the impact of race/ethnicity on dietary counseling as a behavioral intervention to slow renal function decline among diabetic CKD patients. We could enroll diabetic CKD patients to participate in an individualized dietary counseling program (that helps create a personalized plan for achieving a diabetic renal diet using a “baseline” understanding of the patient’s dietary patterns) vs. usual care (e.g., giving patients general informational brochures describing foods to choose or avoid) and assess hemoglobin A1c trends and changes in estimated glomerular filtration rate over time. Since dietary patterns are closely linked to cultural backgrounds, people of different races/ethnicities may find general informational brochures (usual care group) more or less helpful: e.g., many informational brochures only discuss foods common to the Western diet, but these may not be particularly relevant or helpful for a patient who doesn’t consume a Western diet. We might therefore hypothesize that the intervention (individualized counseling) may have a greater effect on non-Caucasian racial/ethnic groups. We would want to enroll patients stratified by race/ethnicity, assess and monitor dietary patterns (e.g., self-report via a questionnaire), and then assess for interaction between race/ethnicity and the intervention effect.
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?
Yes, an accurate understanding of how behaviors influence health outcomes is still very important because behavioral change represents an opportunity for therapeutic intervention. That is, while addressing broader issues such as neighborhood, income, and/or education is important at a policy or community level, behaviors can and should be tailored at the individual level to maximize health outcomes. Treatment approaches for all kinds of disease should target all levels of patient’s well-being - from population-level issues down to more proximal factors on outcomes such as behaviors. Also, because behavior is more “proximal” to the patient, the benefits of addressing broader social issues like neighborhood and income will be lost or attenuated if patients still make poor behavioral choices. Lastly, I think use of behavioral change to impact outcomes can also be used to motivate patients and to assert their self-efficacy (i.e., show them that they have control over their own health).