JMIR Publications

ABSTRACT

Background:

Physical inactivity increases dementia risk, and for middle-aged and older adults with co-occurring cognitive concerns and mental health symptoms, dementia risk increases further. Despite clinical trials showing lower adherence to physical activity (PA) interventions in high-risk groups, there is a sparsity of interventions tailored to support unique behavior change needs. In EXCEL Phase 1 we developed a model to understand the needs of this population and identified tailoring requirements to enhance engagement (see Curran et al. 2023). Here we report the findings of a pilot online intervention designed to support middle-aged and older adults with Subjective Cognitive Decline (SCD) or Mild Cognitive Impairment (MCI) and mild to moderate symptoms of depression or anxiety to adopt and maintain PA.

Objective:

We aimed to measure 1) efficacy of the intervention in promoting adoption of PA in line with Australian guidelines, 2) acceptability, feasibility and safety of the intervention, 3) changes to dementia risk, stages of change, and mental health symptoms, and 4) changes in potential cognitive mechanisms of change.

Methods:

A pilot online individual 12-week home-based PA intervention. Participants aged 45-80 years, experiencing both cognitive (SCD or MCI) and mild-moderate anxiety and depression symptoms (measured by the Depression Anxiety and Stress Scale - DASS-21), were prescribed individually tailored PA programs combining aerobic and strength PA, plus balance training as indicated, with fortnightly online coaching.

Results:

Fifty-five participants were enrolled (46 females/9 males; mean age=62.2 years). Retention rates were high (95% completion rate), and feedback indicated 98% found the program useful. Safety was successfully monitored by a clinical panel via email, using a system of alerts. The intervention led to significant improvements in PA levels. At baseline, only 3.8% of participants met all applicable PA guidelines, compared to 46.2% post-intervention (P<0.001), with participants at least eight times more likely to meet the age-appropriate guidelines for aerobic, strength, and balance activities after the intervention. Changes in secondary outcomes were mixed. Effect sizes for reductions in depression, anxiety, and stress scores were large and clinically meaningful (d=-1.31, d=-0.89, and d=-1.18, respectively; all P<0.001), with dementia risk also reduced (d=-0.32, P=0.008). Over half (51.9%) transitioned to a higher stage of change at post-intervention. Improvements in action planning (d=0.66, P<0.001) and positive outcome expectancies (d=0.33, P=0.012) indicate potential cognitive mechanisms of change.

Conclusions:

Our findings showed this home-based online intervention to be feasible, acceptable and safe, and to successfully support an at-risk cohort of aging adults to adopt PA in line with Australian guidelines. The intervention also led to significant reductions in mental health symptoms and dementia risk. Reflecting the COM-B model underlying the intervention design, improvements in action planning and outcome expectancy appeared to play a role in bridging the PA intention-behavior gap. Clinical Trial: Australian New Zealand Trials Clinical Registry (ANZCTR), ACTRN12621001152819