The Norwegian Mother and Child Cohort Discussion
All of the following questions are in relation to the following journal article which is available on Moodle: Parr CL, Magnus MC, Karlstad O, Holvik K, Lund-Blix NA, Jaugen M, et al. Vitamin A and D intake in pregnancy, infant supplementation and asthma development: the Norwegian Mother and Child Cohort. Am J Clin Nutr 2018;107:789-798.
QUESTIONS: Questions 1-4 pertain to the crude and adjusted relative risk estimates in table 5. (Note: use the second crude RR called RR3).
- Do the confounding factors attenuate the increased risk for asthma by daily multivitamin supplementation by infants?
- Calculate the amount of confounding for daily intake of multivitamins.
- Do the confounding factors attenuate the protective effect of daily vitamin D only supplementation?
- Are any of the effect estimates in table 5 unaffected by the confounding factors? If so, which ones?
- Do the authors consider the same potential founders in table 3 as they do in table 5?
- Do you draw a different conclusion from the adjusted RR for total vitamin D intake on risk of asthma than you do from the crude results in Table 3?
- How might the investigators have used restriction to control for the confounding of birthweight in this study? How would this decision effect the validity of the study sample?