Smartphone-based Ecological Momentary Assessment (EMA) is increasingly used to collect real-time data on physical activity behaviour. The current study aimed to assess the feasibility and acceptability of activity-triggered EMA in low-income older adults. For 7 days, 39 older adults (76.4 ± 8.5 years; 76% earning below £25,000/year) received EMA surveys, delivered via the movisensXS application (version 1.5.23, movisens GmbH, Karlsruhe, Germany) for Android operating systems, when they surpassed a predefined activity/inactivity threshold, or when two hours elapsed between prompts. Participants wore a Move 4 activity sensor (movisens GmbH, Karlsruhe, Germany) to measure their steps. A post-study questionnaire assessed perceptions of acceptability.

The dataset includes all quantitative data needed to replicate analyses in the article "Feasibility and acceptability of 7-day smartphone-based, activity-triggered Ecological Momentary Assessment among low-income older adults." The "Descriptives" sheet contains a unique participant identifier, demographic information, and responses to the post-study questionnaire. The "EMA" sheet contains a unique participant identifier (Participant_ID), age (Age_years), biological sex (Biological_sex), time of day (Time_of_day), day of week (Weekday), and EMA compliance (EMA_compliance; whether participants completed the EMA prompt or missed the EMA prompt) variables needed to perform the multilevel logistic regression models. It also contains the data necessary to limit the sample to participants with valid activity sensor wear and run Model 2, including the length of time in minutes that participants were not wearing the activity sensor in the 15-minute window before (Nonwear_before) and after (Nonwear_after) the EMA survey, and concurrent physical activity (Concurrent_PA; the number of steps in the ± 15-minute window around the EMA prompt). 

Day of study (day number from 1 to 7), trigger type (whether participants received an activity-triggered, inactivity-triggered, or timeout EMA prompt), trigger time (absolute time of the auditory signal and/or vibration alerting participants that it was time to complete an EMA survey), EMA outcome (whether the EMA prompt was completed, not answered, or answered but incomplete), form start time (absolute time when the EMA survey was answered), form completion time (absolute time when the EMA survey was completed), observation number (variable that assigns the observation number to each row by participant ID), and observation counter (variable that assigns the number of total observations to each row of data for a given participant) variables are also provided to enable researchers to replicate all of the summary statistics presented in the article. A complete description of the variables, including the text of questionnaires (where relevant), is provided in the "Overview" sheet.