Question

Question 3 (Essay Worth 10 points) (03.02, 03.04 HC) A study showed that low-intensity shock therapy reduces pain levels in patients with lupus. During each session, electrodes were placed on the pain site indicated by the patient. Pain reduction was measured through self-reporting after each session. Another study is being designed to examine whether low-intensity shock therapy also reduces pain in patients suffering from bulging disks in the thoracic region of the back. Two 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. (4 points) Part B: If the study consisted of 100 male and 100 female patients instead of 200 female patients, would you change the study design? If so, how would you modify your design? If not, why not? (4 points) Part C: Could your design be double-blind? Explain. (2 points)

Answer 1

Part-A : Here the type of experimental design can be completely randomized design experiment where experimental units of 200 female subjects which are allocated randomly to say 4 treatment groups with each treatment group consist of 50 female patients.Here the treatment used is low-intensity shock therapy which is also factor or explanatory variable.After administrating above treatment for a period of say 2-3 weeks (duration of treatment can be decided by the doctor or lab technician),the response in pain reduction (response variable here) can be measured among all patients in 4 treatment groups by comparing their earlier pain level for reduction in pain.

Part-B : If the study consist of 100 Male and 100 Female Patients,the experimental design can be changed into randomized block design by blocking subjects by gender first,say by assigning 100 Male and 100 Female subjects in Block#1 and Block#2 respectively.Here again,we can have two treatment groups in each Block where 50-50 patients can be assigned randomly to each two treatment groups in each block of gender by covering all 200 Patients and then measuring their reduction in pain level for each treatment groups under each block.This way,experiment can be effective by eliminating certain extraneous variables like gender among the subjects.

Part-C : The above design can be double blinded by not letting know either the patients or lab technicians aware about which treatment groups,each of these subjects are experimented against to keep the data confidential.