The Hans Kai trial: study protocol of a mixed methods randomized controlled trial evaluating a peer-led health promotion program for adults with or without noncommunicable diseases

BACKGROUND: A significant proportion of Canadian adults is impacted by chronic noncommunicable diseases. These conditions may be improved by peer-led health promotion interventions that target modifiable risk factors; however, to date, there is mixed evidence on the effectiveness of these interventions. Unlike other health promotion programs, Hans Kai is grounded in a holistic model of health that simultaneously addresses multiple determinants of health at different levels of human ecology. In Hans Kai, a set of informational sessions that are delivered in a group setting by healthcare professionals are followed by regular peer-led group meetings in a self-governed support group setting that is designed to promote implementation of newly learned health competences. The Hans Kai trial described here aims to evaluate the efficacy of the Hans Kai program in promoting the health and wellbeing of its participants and investigate the experiences of the Hans Kai participants and facilitators. METHODS: This research will involve a mixed methods trial combining an experimental component with a qualitative component. The experimental component will involve a 6-month 2-group parallel superiority randomized controlled trial (RCT) in which 105 participants will be randomly assigned to two conditions, an intervention group (n = 70) that will participate in the Hans Kai program and a control group (n = 35) that will have access to standard care using a computer-generated random sequence; blinding will not occur. The RCT will test the impact of the program on several health outcomes and will be followed by a 12–18-month observational follow-up study that will provide data on the long-term durability of the 6-month RCT health outcomes. The qualitative component will investigate the experiences of program participants (n = 30) and facilitators (n = 15) to identify the main strengths and limitations of Hans Kai, uncover potential implementation issues, and elucidate the mechanisms through which the program works. The population of interest will include adults aged 18 + with or without chronic health conditions who self-report an interest in taking control of their own health and improving their lifestyle. In the RCT, all outcomes of interest will be measured using a multi-method approach, involving self-report questionnaires and objective indicators, and within-subject mean changes in outcomes over time between the two groups will be compared to address the RCT aims. Similarly, in the qualitative component, a multi-method approach, involving in-depth individual interviews, photovoice, and online surveys, will be used to reach a deeper and more nuanced understanding of the program strengths, how the program works, and for which people it is more effective. Adaptable components of the program will also be investigated and modified according to the feedback provided by the RCT participants. In the mixed methods integration of evidence, the qualitative findings will be used to explain the quantitative RCT results. DISCUSSION: The RCT findings will help support the further development and use of Hans Kai as well as other peer-led health promotion interventions. TRIAL REGISTRATION: United Stated Clinical Trial Registry ClinicalTrials.gov (registration# NCT03949725; Protocol version 2, June 22nd, 2022). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-023-07708-z.