S0016 [Source: Sandgren & McCaul (2007). Psycho-Oncology 16:38-47.]
There were three groups of breast cancer patients.
Group 1 (n=76) received breast cancer health education. Group 2 (n=89) received emotional expression therapy. Group 3 (n=49) received standard care.
Interventions in Groups 1 and 2 were made by certified oncology nurses. At the 13-month follow-up assessment, patients in the two interventional groups were asked if they would have liked to talk to their nurses again. Forty-eight percent of health education women said "yes" while 32% of the emotional expression women said "yes". Note that one patient from each of Groups 1 and 2 drop-out at 13-month.
Q1. What statistical method would you use to compare the percentage of women who would have liked to talk with their nurse again between Group 1 and Group 2? Do you need to make any assumptions? If yes, list them all.
Q2. Perform the test you suggested in Q1.
Q3. What conclusion could you make from your results obtained in Q2?
Q4. How were the two percentages different?