Shared decision-making (SDM) requires that individuals are correctly and smoothly supported to make decisions. However, in Japan, development of decision aids (DAs) to support implementation of SDM is lagging behind Western countries, and there are few reports focused on breast reconstruction. Thus, it is unclear if SDM using a DA in the context of the unique national character and medical culture in Japan is useful in decision-making for breast reconstruction, including whether or not to undergo reconstruction. The aim of this multicentre collaborative study is to investigate the clinical effectiveness of SDM using a DA for patients with breast cancer considering reconstruction, from the perspectives of decisional conflict and postoperative quality of life.

A multisite trial will be conducted at 12 facilities certified by the Japanese Society of Breast Oncoplastic Surgery. A cluster-randomised controlled trial is planned at centres that have implemented SDM with DAs and those that have not implemented SDM, but use a conventional surgical explanation and informed consent to make decisions about reconstruction methods. The study participants will be female patients aged ≥20 years with newly diagnosed stage 0–III breast cancer who are interested in breast reconstruction. Data collection includes baseline and follow-up patient surveys and medical record review. The effectiveness of the DA at reducing conflict and regret in decision-making (primary outcome) will be evaluated using the decision conflict scale.

This protocol has been approved by the Kyoto University Central Institutional Review Board, and permission for performance of the study has been obtained from the Ethics Review Board at each participating centre. We plan to disseminate the findings through journal publications and national meetings, including a presentation of the research results at the Japanese Society of Breast Oncoplastic Surgery. Our findings will advance the science of medical decision-making and have the potential to reduce socioeconomic health disparities.

UMIN000052161.

Temperature control is a fundamental intervention for neuroprotection following resuscitation from cardiac arrest. However, evidence regarding the efficacy of hypothermia in post-cardiac arrest syndrome (PCAS) remains unclear. Retrospective studies suggest that the clinical effectiveness of hypothermia may depend on the severity of PCAS. The R-CAST OHCA trial aims to compare the efficacy of hypothermia versus normothermia in improving 30-day neurological outcomes in patients with moderately severe PCAS following out-of-hospital cardiac arrest.

The multicentre, single-blind, parallel-group, superiority, randomised controlled trial (RCT) is conducted with the participation of 35 emergency and critical care centres and/or intensive care units at academic and non-academic hospitals. The study enrols moderately severe PCAS patients, defined as those with a revised post-Cardiac Arrest Syndrome for induced Therapeutic Hypothermia score of 5.5–15.5. A target number of 380 participants will be enrolled. Participants are randomised to undergo either hypothermia or normothermia within 3 hours after return of spontaneous circulation. Patients in the hypothermia group are cooled and maintained at 34°C until 28 hours post-randomisation, followed by rewarming to 37°C at a rate of 0.25°C/hour. Patients in the normothermia group are maintained at normothermia (36.5°C–37.7°C). Total periods of intervention, including the cooling, maintenance and rewarming phases, will occur 40 hours after randomisation. Other treatments for PCAS can be determined by the treating physicians. The primary outcome is a favourable neurological outcome, defined as Cerebral Performance Category 1 or 2 at 30 days after randomisation and compared using an intention-to-treat analysis.

This study has been approved by the Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and Okayama University Hospital, Ethics Committee (approval number: R2201-001). Written informed consent is obtained from all participants or their authorised surrogates. Results will be disseminated via publications and presentations.

jRCT1062220035.