# A Scale for Older adults’ decisional balance regarding physical ACTIVity (SO-ACTIV): development and validation in a French sample

## TL;DR

This paper introduces a new tool to measure older adults' motivation for physical activity, validated in a French sample.

## Contribution

The SO-ACTIV scale is a novel, theory-based instrument capturing multilevel facilitators and barriers to physical activity in older adults.

## Key findings

- The SO-ACTIV scale has strong psychometric properties, including reliability and validity.
- Facilitators and barriers were structured across four socioecological domains.
- Higher facilitator scores were found in individuals at later stages of physical activity change.

## Abstract

Despite its health benefits, physical activity declines with age. The transtheoretical model posits that individuals’ choice to be active depends on their perceived decisional balance (i.e., facilitators weight against barriers). Some of these factors are age-specific and extend across multiple socioecological levels (intrapersonal, interpersonal, environmental, organizational). Yet, existing decisional balance measures overlook age-related concerns, lack theoretical grounding, or fail to reflect the multilevel socioecological structure. To address these gaps, we developed and validated the Scale for Older adults’ decisional balance regarding physical ACTIVity (SO-ACTIV).

Following established steps for scale development, an online survey was completed by 452 French-speaking older adults. Confirmatory factor analyses tested different models. Reliability was examined through internal consistency and 2-week test–retest. Construct validity was assessed through correlations with motivation toward health-oriented physical activity, a decisional-balance measure for exercise in adults, and a self-reported physical activity level score. Known-groups validity was tested across stages of change.

From an initial pool of 55-item, expert review retained 35-item divided into two overarching factors (facilitators, barriers) and four domains (intrapersonal, interpersonal, environmental, organizational). Confirmatory factor analyses supported a final 26-item instrument structured as a second-order hierarchical model, with two upper-level factors, and four specific domains for each. This model yielded the best fit indices. Internal consistency ranged from acceptable to excellent across domains and factors, and test–retest reliability was mainly demonstrated. Convergent validity was supported: facilitators correlated positively with self-determined forms of motivation and with physical activity, and negatively with amotivation; barriers showed the opposite patterns. Concurrent validity was attested by correlations between facilitators and pros, and between barriers and cons. Known-groups validity was supported by higher facilitator scores and lower barrier scores at action/maintenance stages compared with earlier stages of change.

SO-ACTIV is a brief, theory-based instrument that captures facilitators and barriers to physical activity among French-speaking older adults across intrapersonal, interpersonal, environmental, and organizational levels. Its strong psychometric qualities support its use in future research and to guide targeted counseling and interventions in physical activity.