Multidomain interventions for dementia risk reduction: Can we detect a change in the signal?

Background There is increasing evidence that modifiable lifestyle factors account for around 40% of worldwide dementia cases. Given the multifactorial etiology of dementia, multidomain lifestyle interventions have generated major interest. Results from randomized controlled trials (RCTs) suggest that implementing multidomain interventions in at-risk individuals is an effective strategy to delay disease onset. As per the Obesity-Related Behavioral Intervention Trials (ORBIT) model, to ensure successful interventions, pre-efficacy trials are needed to ascertain that each intervention component can yield a predefined clinically significant change (CSC). Therefore, the main objective of this Proof-of-Concept was to determine if each individual part of an online multidomain dementia risk reduction program can achieve a CSC in the targeted behavioural risk outcome. Method This was a 12-week, within-subject, treatment-only study with three single-domain groups (Diet, Physical Activity [PA] or Cognitive Engagement [CE]) and one multidomain group. The study enrolled cognitively healthy individuals aged 50-70 with at least one risk factor among the targeted domains. The personalized intervention was delivered via a digital, coach-supported application. Primary outcomes were the percentage of participants showing a CSC at study end in each domain. CSCs were defined as a change ≥ 1 point on the Canadian Mediterranean Diet Score, ≥ 300 METs-min/week on the short version of the International Physical Activity Questionnaire, and ≥ 6 points on the Cognitive Activity Questionnaire, respectively. Additional outcomes comprised feasibility indicators. Result Thirty-nine participants (mean age=63.1 [51-68]; 82.1% female) were recruited, with 31 participants enrolled in the single-domain groups (Diet, N=11; PA, N=7; CE, N=13). Within the single-domain groups, participants received 7.9 (6-9) coaching sessions. The number of participants achieving a CSC was 5 (45.5%) in the Diet group, 3 (42.9%) in the PA group and 6 (50.0%) in the CE group. Overall compliance and retention were 93.5% (89.6-98.0) and 97.4% (92.3-100), respectively. Conclusion The results of this study support moving forward to the next ORBIT framework step, which includes refinement of the Luci intervention components and the design of a pilot feasibility trial to test the program in a larger sample of participants.