biostudies-literatureMaher JPNHLBI NIH HHSjmpb.2023-0035https://www.ebi.ac.uk/biostudies/studies/S-EPMC12922600biostudies-literatureUnknown7(1)Measurement reactivity has implications for behavioral science, as it is crucial to determine whether changes in constructs of interest represent true change or are an artifact of assessment. This study investigated whether measurement reactivity occurs for movement-related behaviors, motivational antecedents of behavior, and associations between them. Data from ecological momentary assessment studies of older adults (<i>n</i> = 195) and women in midlife (<i>n</i> = 75) lasting 8-10 days with 5-6 prompts/day and ambulatory monitoring of movement were used for this secondary data analysis. To examine potential drop-off patterns indicative of measurement reactivity, multilevel models tested whether behavior, antecedents, and associations changed after the first or first 2 prompts compared wiJournal for the measurement of physical behaviourMeasurement Reactivity in Ecological Momentary Assessment Studies of Movement-Related Behaviors.PMC12922600K23 HL136657R03 HL160602Arigo DBaga KSalvatore GMMaher JPHudgins BLPasko KKonig LMfalseMeasurement Reactivity in Ecological Momentary Assessment Studies of Movement-Related Behaviors.Measurement reactivity has implications for behavioral science, as it is crucial to determine whether changes in constructs of interest represent true change or are an artifact of assessment. This study investigated whether measurement reactivity occurs for movement-related behaviors, motivational antecedents of behavior, and associations between them. Data from ecological momentary assessment studies of older adults (<i>n</i> = 195) and women in midlife (<i>n</i> = 75) lasting 8-10 days with 5-6 prompts/day and ambulatory monitoring of movement were used for this secondary data analysis. To examine potential drop-off patterns indicative of measurement reactivity, multilevel models tested whether behavior, antecedents, and associations changed after the first or first 2 prompts compared wi2024-01-01T00:00:00Z20242026-07-16T18:36:50.061Z2026-07-09T11:15:17.202ZS-EPMC129226004172604310.1123/jmpb.2023-0035