How many people aged 55-77 years are eligible for lifestyle interventions to prevent cognitive decline?

Background: We analysed data from our online multi-module Maintain Your Brain (MYB) RCT (Heffernan et al, 2019) tailored to reduce dementia risk factors - physical activity, cognitive training, nutrition and depression - to determine how many persons might be eligible for such interventions. Methods: Invitations to participate in MYB were emailed or posted to 96,418 persons aged 55-77 years from the 45 and Up Study, a population based cohort study of about one in ten men and women aged 45 years and older (n = 267,153) from New South Wales, Australia, recruited from Medicare lists between 2006-2009. Baseline assessments included eligibility for four modules of intervention. 1. Physical activity module criteria: obese (waist circumference, BMI), insufficient resistance or aerobic exercise, falls or osteoporosis, current smoker, or history of high cholesterol, high blood pressure, diabetes, cardiovascular disease and no safety exclusion criteria . 2. Cognitive training criteria: 12 years of education, low mental activity during mid-life, or little late-life cognitive engagement. 3) Nutrition criteria: poor adherence to a Mediterranean-type diet, obese or underweight, or history of high cholesterol, high blood pressure, diabetes, alcohol excess or cardiovascular disease. 4) “Peace of Mind” (for depression or anxiety) criteria: a self-reported history of depression or anxiety or high depression (PHQ9 > 9) or anxiety (GAD-7 >9). Results: Of 14,064 who consented, 6,257 completed all baseline assessments (Figure 1). Overall 16% met criteria for all four, 51% for three, 31% for two; and 2% for one module. Twenty-one participants (1 eligibility rule for assigned modules. Conclusions: Nearly all persons aged 55-77 years old who completed the assessment have risk factors for cognitive decline suitable for preventative interventions. Replication in the wider community is needed to confirm these findings. Interventions that are scalable are appropriate for population based digital interventions