Please answer the following questions in a paper of at least 6 pages:

1. A researcher is studying the effect of factors that may contribute to a birth defect. The following is a table summarizing the results of bivariate and multivariate analysis.

Table 1. Bivariate versus Multivariate

1. Identify variables from Table 1 that should be further analyzed (to rule out whether they are confounders or effect modifiers). Briefly provide rationale.
2. Stratified analysis was conducted on one of the genes in Table 1 and odds ratios were obtained. What do these results suggest:

Drug A=0: OR=2.2 for birth defect given presence of gene

Drug A=1: OR=1.4 for birth defect given presence of gene

1. Critically review the following controversial paper published (and later retracted) by Wakefield et al, which implicated MMR vaccine as a possible etiologic contributor to Autism, etc. You may use either version for your review. Describe potential sources of bias and other limitations in the study:

Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children A J Wakefield, S H Murch, A Anthony, J Linnell, D M Casson, M Malik, M Berelowitz, A P Dhillon,
M A Thomson, P Harvey, A Valentine, S E Davies, J A Walker-Smith
The Lancet, Volume 351, Number 9103 28 February 1998

Pro 7 Con Arguments: “Should any vaccines be required for children? Retrieved from http://vaccines.procon.org/ on November 5, 2013.