Checklist for Habitual Physical Activity (CHaPA) for adults 75years and older: tool development and content and face validation

BackgroundPhysical activity significantly contributes to older adults' physical and mental health, suggesting that physical activity could enhance healthy life expectancy. Despite its importance for adults aged 75 and older, activity levels among a large proportion of individuals aged 75 and older in Japan do not meet the recommended levels of physical activity, indicating a need for specific strategies tailored to this age group. This study aimed to develop a screening tool that measures daily activities promoting physical activity among older adults and assessed its content and face validity.MethodsIn Stage 1, we derived constructs pertinent to physical activity from previous literature and formulated an item list based on a prior qualitative study we undertook in Japan that evaluated daily behaviours facilitating physical activity among older adults. During Stage 2, we assessed the content and face validity of the list utilising the Nominal Group Technique (NGT), involving eight experts. The content validity was confirmed through two scoring evaluation rounds, while the face validity was verified through the NGT discussion, focusing on the comprehensibility and appropriateness of the tool.ResultsWe created a tool with 22 items consisting of three constructs. The NGT participants modified eight of these items for the final assessment, resulting in a finalised tool comprising 22 items that satisfied the adaptation criteria. The content validity of these items was affirmed by median adequacy (>5.0 points) and interquartile range (