Understanding Goal Setting and Behavior Change Mechanics in an Older Adult Sitting Reduction Intervention.

Purpose: We explored intervention fidelity, participant satisfaction, and the goals and reminder strategies participants chose to reduce sitting.

Approach: Mixed methods approach leveraging data collected during study coaching and fidelity monitoring.

Setting: A successful 6-month randomized controlled trial of a sedentary behavior (SB) intervention for adults ≥60 years in Washington, USA.

Participants: N = 283 (140 intervention, 143 attention control); mean age 69, 66% women, 69% Non-Hispanic White.

Intervention: Theory-based SB reduction intervention structured around phone-based health coaching and goal setting. Attention control received equal coaching on non-SB health topics.

Method: Coaches tracked all participant goals, and 8% of visits were randomly observed and fidelity coded using a structured template. Participants completed a satisfaction questionnaire at study end. Goals data were qualitatively grouped by reminder strategy and topic. Fidelity and satisfaction data were summarized and compared by study arm using two-sided paired t-tests.

Results: Both participants' satisfaction (>90% satisfied, between-group = .195) and coach fidelity to intervention content and techniques were high (96% sessions set SMART goals, = .343) across both arms. Intervention participants primarily set goals leveraging outward (e.g., fitness band prompts) and habit (e.g., adding standing to a daily meal) reminder strategies highly tailored to individual preferences and lifestyle.

Conclusion: Participants' SB-related goals varied widely, suggesting tailored intervention approaches are important to change sitting behavior, particularly for older adults with chronic conditions.