Experiences of being a control group: lessons from a UK-based randomized controlled trial of group singing as a health promotion initiative for older people.

Existing randomized controlled trials within the health field suggest that the concept of randomization is not always well understood and that feelings of disappointment may occur when participants are not placed in their preferred arm. This may affect a study's rigour and ethical integrity if not addressed. We aimed to test whether these issues apply to a healthy volunteer sample within a health promotion trial of singing for older people. Written comments from control group participants at two points during the trial were analysed, together with individual semi-structured interviews with a small sample (n = 11) of this group. We found that motivation to participate in the trial was largely due to the appeal of singing and disappointment resulted from allocation to the control group. Understanding of randomization was generally good and feelings of disappointment lessened over time and with a post-research opportunity to sing. Findings suggest that measures should be put in place to minimize the potential negative impacts of randomized controlled trials in health promotion research.