A study showed that treatment with chamomile oil reduces pain levels in patients with Lyme disease. Each session in the study, chamomile oil was inserted in the body at the pain site indicated by the patient. Pain reduction was measured by self-reporting after each session. Another study is being designed to examine whether chamomile oil therapy also reduces pain in patients suffering from pinched nerves in the cervical region of the spine. Four hundred female patients are subjects in the new study.

Part A: What is an appropriate design for the new study? Include treatments used, method of treatment assignment, and variables that should be measured.

Part B: If the study consisted of 200 male and 200 female patients instead of 400 female patients, would you change the study design? If so, how would you modify your design ? If not, why not?

Part C: Could your design be double-blind? Explain.