Trial Information

Decision Aid on Radioactive Iodine Treatment for Early Stage Papillary Thyroid Cancer (Randomized Controlled Trial)

A. Primary research question

In patients with early stage papillary thyroid cancer, does the administration of a
computerized decision aid improve the score on a test of knowledge about early stage PTC and
adjuvant RAI treatment, when compared to usual care? (The knowledge score is a sum of
positive responses from a total of 10 true/false questions in a self-administered
questionnaire, to be administered at the study visit, Q2A).

B. Secondary research questions

1. In patients with early stage PTC, does the administration of a computerized decision
aid reduce overall decisional conflict (as well as the following respective subscales -
informed subscale, uncertainty subscale, and effective decision subscale), when
compared to usual care? (Decisional Conflict questionnaire, DCS).

2. In patients with early stage PTC, does the administration of a computerized decision
aid, improve reduce decisional regret relating to RAI decision making after the final
decision has been made? (Decision Regret Questionnaire, DRQ)

3. In patients with early stage PTC, does the administration of a computerized decision
aid, reduce the number of participants receiving adjuvant radioactive iodine treatment
(analysis for all participants, as well as those who are not already on a waiting list
for radioactive iodine treatment at the time of recruitment, respectively)?

4. Do the respective monitoring or blunting scores on the Miller Behavioral Style Scale
(MBSS) correlate with the number of clicks for information performed by participants
reviewing the decision aid? (subgroup analysis in the decision aid intervention group)

5. Do the respective monitoring or blunting scores on the Miller Behavioral Style Scale
(MBSS) correlate with the score on a test of knowledge about early stage PTC and
adjuvant RAI treatment? (Respective analyses planned for entire study population, as
well as the intervention and control groups)

6. What are the main reasons why RAI treatment is selected or not selected (after the
decision has been finalized), grouping descriptions according to exposure or
non-exposure to a computerized decision aid? (See Follow-up questionnaire
[administered by telephone], question 2, qualitative description, with reasons to be
coded and quantified using mixed methods).

NOTE: In the original design of this study, we hoped to utilize a modified Client
Satisfaction Questionnaire for assessment of satisfaction of patient participants and
physicians as secondary trial outcomes. However, we are unable to utilize any modified
Client Satisfaction Questionnaires in this study, because of lack of permission from the
original developer of the Client Satisfaction Questionnaire-8, who has copyrighted and
trademarked the questionnaire and prohibits such modifications. No modified client
satisfaction questionnaire results have been analyzed in this study and will not be
analyzed.

Study design The project design will be a single-centre randomized controlled trial
conducted at University Health Network. The participants will be randomized to a) the
decision aid group (in addition to usual care [counseling by his or her physician, called
usual care]) or b) usual care. The DA will be available only to participants during the
study (not the public or treating physicians). The decision aid testing will be performed
at the Toronto General Hospital.