Consider the study from Example 3.4. Recall that the clinical trial consists of 450 patients. 150 of the patients have stage I cancer and the rest have stages II-IV cancer. In Computation Lab: Generating a Randomized Block Design, we created a balanced treatment assignment for the stage I cancer patients.

a. Create a balanced treatment assignment for the stage II-IV cancer patients.

b. Combine treatment assignments for stage I and stage II-IV. Show that the distribution of stage is balanced in the overall treatment assignment.

Data from Example 3.4

Kim et al. [2017] conducted a randomized clinical trial to evaluate hemoglobin level (an important component of blood) levels after a surgery to remove a cancer. Patients were randomized to receieve a new treatment or placebo. The study was conducted at seven major institutions in the Republic of Korea. Previous research has shown that the amount of cancer in a person’s body, measured by cancer stage (stage I—less cancer, stages II—IV - more cancer), has an effect on hemoglobin. 450 (225 per group) patients were required to detect a significant difference in the main study outcome at the 5% level.