The objective of a study by van Vollenhoven et al. (A-35) was to examine the effectiveness of Etanercept alone and Etanercept in combination with methotrexate in the treatment of rheumatoid arthritis. They performed a retrospective study using data from the STURE database, which collects efficacy and safety data for all patients starting biological treatments at the major hospitals in Stockholm, Sweden. The researchers identified 40 subjects who were prescribed Etanercept only and 57 who were given Etanercept with methotrexate. One of the outcome measures was the number of swollen joints. The following table gives the mean number of swollen joints in the two groups as well as the standard error of the mean. Is there sufficient evidence at the a ¼ :05 level of significance for us to conclude that there is a difference in mean swollen joint counts in the relevant populations?
Treatment Mean Standard Error of Mean Etanercept 5.56 0.84 Etanercept plus methotrexate 4.40 0.57