2.3. Procedures
After screening out the ineligible caregiver applicants, we used a computer program to randomly assign the participants to arm 1 (MBFPE) or arm 2 (ordinary FPE). All caregivers were blinded to the allocation. To reduce the potential expectancy effect, the participants were told that they would be involved in a “family psychoeducation program” without mentioning the term “mindfulness,” even if they were randomly assigned to MBFPE.The themes and content of arms 1 and 2 were reported as a study protocol [In arm 1, the first hour was spent on mindfulness training. Qualified mindfulness-based instructors introduced mindfulness exercises, including body scanning, mindful stretching, mindful walking, mindful sitting, mindfulness with difficult moments, and befriending, according to the sequences in a typical eight-week mindfulness program [The caregivers who completed the data collection were given HKD 100 (around USD 12) cash coupons at T2 and T3 and the YAIR were given HKD 100 (around USD 12) coupons when they completed the assessments at T1, T2, and T3. A cash remuneration coupon is a commonly used incentive in research to promote engagement [The caregivers were told that the study was independent from the healthcare service and they were able to withdraw from the study at any time without any negative consequences. This project was registered with the United States Clinical Trials Registry (NCT03688009).