Content Validation and Perceived Value of Text Messages to Promote Physical Activity Among U.S. Older Adults and Care Partners

Background: Motivational text messages can encourage increased physical activity. This study aimed to assess the content validity and perceived motivational value of text messages to encourage physical activity among older adults and care partners. Methods: We designed nine motivational text messages to capture nine distinct physical activity scenarios. Using a cross-sectional design, we enrolled 14 content experts, 310 older adults, and 305 care partners. Content experts assessed the relevance, while the older adults and care partners assessed the perceived motivational value of each text message on a 5-point Likert scale. We computed the item content validity index and assessed differences in perceived motivational value among older adults and care partners using quantile regression, while adjusting for sociodemographic and health characteristics. Results: The item content validity index ranged from 0.86 to 1.00. The median (interquartile range) perceived motivational values for each text message were 4.0 (3.0–5.0), and there were no statistically significant differences in the reported motivational values between older adults and care partners. Conclusion: We present nine content-validated text messages with high motivational value for older adults and care partners, which can be integrated into technology-based intervention studies and may improve physical activity behavior among both groups.