We created two videos (A and B) of a physician (LF) seated at a desk describing the availability of a new medication associated with a rare risk of an adverse event relevant to patients with rheumatic diseases: jaw necrosis in Video A and progressive multifocal leukoencephalopathy in Video B. We chose to develop two videos in order to examine willingness to accept risk for primary prevention as well as for symptom control. Scenarios were developed to ensure that patients were not presented with adverse events related to the medications they were currently taking. Video A included a new medication to prevent heart disease and Video B a new medication to treat chronic pain. In both videos the medication was described as being a very effective small pill taken once a day, that does not interfere with any other medications, is completely covered by the subject's insurance, and is very well tolerated except for the extremely rare risk of a serious side effect. Subjects were told that the medications were hypothetical. The scripts for the videos are included in Appendix A
Eligibility criteria for Video A included being 50 years or older and currently taking at least one prescription medication for a chronic disease. Patients with known heart disease, osteoporosis or osteopenia, or currently taking a bisphosphonate were excluded. For Video B subjects had to be 18 years or older and currently taking at least one prescription medication for a chronic painful condition.
Six formats including combinations of quantitative (1 in 100,000), qualitative (extremely rare) and common examples (number of people that can be seated in a major college stadium) were used to describe risk. The risk formats varied for the purpose of a separate study on risk communication and were treated as covariates in the current study. A random number sequence was used to determine which risk format each subject viewed.
Consecutive subjects were approached in a university hospital affiliated outpatient clinic serving general medicine and subspecialties. Following their clinical consultation they were asked to view either Video A or B, depending on their eligibility criteria. Subjects eligible for both were randomly assigned to view one of the videos. After viewing the videos, each subject was exposed to two consecutive sets of instructions. The first set of instructions, designed to minimize volition, contained the following statement: The doctor decides that you should take this medication and she writes you a prescription for it. The second set of instructions was designed to maximize volition: The doctor tells you that it is completely up to you whether or not you take this medication and then asks you to make a decision. After reading each set of instructions, subjects rated (on 11-point numeric scales, ranging from 0=lowest value to 10=maximum value) their willingness to take the medication and their worry about developing the rare complication described on the video. The order of presentation was systematically varied to ensure balance, and order was treated as a covariate. To determine whether this manipulation was successful, we asked subjects to rate, using an 11-point numeric scale, how responsible they would feel if they developed the complication that was described in the respective condition. Mean scores and standard deviations for the high and low volition conditions were 6.6 ± 3.8 and 4.8 ± 3.8, respectively, and the difference was statistically significant (p< 0.001, using a 2-tailed Wilcoxon Signed-Rank test).
We first examined whether there were any significant differences in willingness and worry across both volition conditions using a 2-tailed Wilcoxon Signed-Rank test. We then sought to determine whether the observed difference in willingness across the low and high volition conditions was associated with a corresponding difference in worry after controlling for age, gender, education, and health status, clinical scenario and risk format using a linear regression model. In this model, difference in willingness across both conditions (i.e. willingness to take the medication when the doctor decides that you should take this medication and she writes you a prescription for it – willingness to take the medication when the doctor tells you that it is completely up to you whether or not you take this medication and then asks you to make a decision was treated as the dependent variable. The study protocol was approved by the Human Investigations Committee at our institution.