Motivation | Doctor status | |||
---|---|---|---|---|
Responses (n (%)) | Direct personal benefit n=54* | Altruism/dual n=35* | Own doctor n=39* | Other n=49* |
How is it decided who will receive the experimental treatment vs sham surgery? | ||||
Random assignment | 39 (75.0) | 29 (82.9) | 31 (81.6) | 35 (74.5) |
Subject mentions some method other than random assignment | 4 (7.7) | 3 (8.6) | 2 (5.3) | 5 (10.6) |
Subject not sure | 9 (17.3) | 3 (8.6) | 5 (13.2) | 7 (14.9) |
What were the chances of a subject being assigned to the sham surgery group? | ||||
Correct answer | 43 (82.7) | 30 (90.9) | 33 (86.8) | 39 (84.8) |
Incorrect answer | 4 (7.7) | 2 (6.1) | 2 (5.3) | 4 (8.7) |
Subject not sure | 5 (9.6) | 1 (3.0) | 3 (7.9) | 3 (6.5) |
What is the purpose of having a sham surgery group? Why do researchers need to have a sham condition? | ||||
Mentions or describes need to control for placebo effect | 36 (67.9) | 19 (54.3) | 23 (60.5) | 30 (61.2) |
Mentions to make study legitimate/rigorous (no mention or description of placebo effect) | 10 (18.9) | 14 (40.0) | 10 (26.3) | 15 (30.6) |
Mentions that FDA requires it | 1 (1.9) | 1 (2.9) | 1 (2.6) | 1 (2.0) |
Can't determine from text if subject understands purpose of sham surgery (response unclear) | 2 (3.8) | 1 (2.9) | 1 (2.6) | 2 (4.1) |
Subject not sure | 2 (3.8) | 0 (0) | 1 (2.6) | 1 (2.0) |
Other | 2 (3.8) | 0 (0) | 2 (5.3) | 0 (0) |
Describe the difference in procedures between those who receive sham surgery and those who receive the experimental intervention. | ||||
Correct answer (describes difference between two arms accurately) | 42 (89.4) | 25 (80.6) | 25 (80.6) | 40 (88.9) |
Incorrect answer | 2 (4.3) | 2 (6.5) | 2 (6.5) | 2 (4.4) |
Not sure | 3 (6.4) | 3 (9.7) | 3 (9.7) | 3 (6.7) |
Other | 0 (0) | 1 (3.2) | 1 (3.2) | 0 (0) |
Fisher's exact tests did not show differences in the responses for any of the four questions for understanding of research procedures by motivation or by doctor status.
*Denominator varies because of missing data for some questions.
FDA, Food and Drug Administration.