Decision aid on radioactive iodine treatment for early stage papillary thyroid cancer: update to study protocol with follow-up extension.

BACKGROUND: Patient decision aids (P-DAs) are used to inform patients about healthcare choices, but there is limited knowledge about their longer term effects, beyond the time period of decision-making. METHODS/DESIGN: We developed a computerized P-DA that explains the choice of radioactive iodine (RAI) adjuvant treatment or no RAI, for patients with low risk papillary thyroid cancer after total thyroidectomy. The original protocol for a randomized controlled trial, comparing the use of the P-DA (with usual care) to usual care alone, has been published in Trials http://www.trialsjournal.com/content/11/1/81. We found that P-DA (with usual care) significantly improved patients' medical knowledge at the time of decision-making (primary outcome) compared to usual care alone (control). In this update, we present the protocol for an extended follow-up study (15 to 23 months post-randomization), including qualitative and quantitative methods. The patient outcomes evaluated using quantitative questionnaires include: the degree to which patients feel well-informed about their RAI treatment choice, decision satisfaction, decision regret, cancer-related worry, mood, and trust in the treating physician. The qualitative component explores the experiences of RAI treatment decision-making, treatment satisfaction, and trial participation in a representative subgroup of patients. Extended follow-up study results will be described for the entire study population, and data will be compared between the P-DA and control groups. RESULT AND CONCLUSION: This mixed methods extended follow-up study will provide data on long term outcomes, relating to the use of a computerized P-DA in decision-making about adjuvant RAI treatment in early stage papillary thyroid cancer. DISCUSSION: Our results are intended to inform future research in this area, particularly relating to long term effects of the use of P-DAs in making healthcare choices. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT01083550, registered 24 February 2010 and last updated 5 January 2015.