Conference Agenda

Purpose: To evaluate the usability of the app-based Global Adolescent and Child Physical Activity Questionnaire (GAC-PAQ) among Spanish caregivers.

Methods: A total of 167 adults enrolled in the GAC-PAQ main study phase (i.e., caregivers of young participants) were invited to complete the questionnaire as proxies. Twenty-six participants completed thequestionnaire during the re-test phase, with a final sample of 25 with complete data. The Spanish version of the 10-item System Usability Scale (SUS) was used. Descriptive statistics were calculated for the overall score and individual items to identify specific usability strengths and barriers. To analyse all individual items the results were standardised to a 0-10 scale.

Results: Almost 15% of caregivers participating in the GAC-PAQ main study phase completed the SUS. The app-based GAC-PAQ usability demonstrated strong internal consistency (Cronbach’s alpha = 0.84). The mean SUS score was 72.8±12.6 (range: 47.5–97.5), classifying the tool's usability as "Good". Item-level analysis revealed high scores for system independence, as participants did not require technical support (item 4 = 8.37 ±2.23) or extensive prior learning (item 10 = 7.98±2.55). The lowest scoring item was the desire for frequent use (item 1 = 5.19±1.86), which is expected given the low rates of responses.

Conclusions: The preliminary results of the app-based GAC-PAQ usability assessment shows that this tool is highly usable for physical activity measurement among caregivers. Its intuitive design minimises technical burden, making it highly feasible for large-scale surveillance in Spanish populations. These findings support the ongoing digital transition of physical activity monitoring policies.