Adherence to lifestyle intervention activities in the SINgapore GERiatric to reduce cognitive decline and physical frailty (SINGER) study: A one-year preliminary analysis of process evaluation

Objectives: To evaluate adherence to lifestyle intervention activities in the SINgapore GERiatric Intervention Study to Reduce Cognitive Decline and Physical Frailty (SINGER) study's intensive intervention arm over one year, as part of ongoing process evaluation. The analysis identifies sociodemographic, psychosocial, and vascular risk factors associated with adherence to optimize intervention strategies and improve participant engagement. Methods: Adherence was categorised as non-adherent, low, moderate and high adherence based on participants' attendance. Total adherence was assessed in two ways, i) a composite of all attendance and ii) Latent Class Analysis (LCA) to identify distinct participant subgroups based on adherence to the SINGER study activities. Regression models assessed associations between individual factors with adherence to each type of intervention component and adherence profiles derived from LCA. Results: More than 70 % of participants achieving moderate to high adherence. LCA identified three distinct adherence profiles: Low, Moderate and High adherence. Participants showed higher adherence to vascular and diet components, followed by exercise components, and lower adherence to cognitive components. Factors such as being female and having higher education were associated with higher adherence while living alone was associated with lower adherence. Participants with hypertension had higher overall adherence but lower adherence to vascular management sessions. The complexity, delivery mode and frequency of the activities influenced adherence, with more complex and frequent activities showing lower adherence. Conclusion: The intensive intervention arm showed satisfactory adherence. A comprehensive analysis highlighted the relationship between adherence, sociodemographic factors, and vascular risks, emphasizing the need for targeted strategies to support subgroups with lower adherence and optimize engagement. Practice implications: The study team should enhance participant engagement by simplifying complex activities and tailoring strategies for subgroups with lower adherence. Ongoing monitoring of adherence patterns and participant feedback will be crucial for making timely adjustments to the intervention.