5.X2 (uses the same data as 5.X1)

The paper, "Serum beta-2-microglobulin (SB2M) in patients with multiple myeloma treated with alpha-interferon" [Journal of Medicine (1997) 28:311-318] reports on the influence of alpha-interferon administration in the treatment of patients with multiple myeloma (MM). Twenty newly diagnosed patients with MM were entered into the study. The researchers randomly assigned the 20 patients into the two groups. Ten patients were treated with both intermittent melphalan and alpha-interferon (treatment group), whereas the remaining 10 patients were treated only with intermittent melphalan (control group). Measurement of SB2M was performed using a radioimmune assay method 1, 3, and 6 months from the start of therapy. The measurements at one month can be accessed using the R code below.

  file <- "http://www.uvm.edu/~rsingle/stat211/data/extra/ch5_6-14.txt"
  dat<-read.table(file, header=T, na.strings=c("NA",".")) 

a) Using the appropriate non-parametric test in R (without correction for continuity), determine if the level of SB2M is LOWERED due to alpha-interferon. Provide a p-value and conclusion at the 0.05 level.

b) Write the null and alternative hypotheses for the test in part (a), using greek letters to represent the population parameters being tested.

c) Comment on any differences between the tests and conclusions in 5.X1 and 5.X2.