Stay Active: a smartphone application to support the delivery of a physical activity intervention in women with gestational diabetes

Current primary outcome measures as of 15/08/2022:
The feasibility and acceptability of the intervention to inform a decision on whether a randomised controlled trial is warranted:
1. Recruitment rates measured as a percentage of women with GDM who are eligible for the study at first contact with potential recruit:
1.1. The percentage of eligible participants at the Gestational Diabetes Clinic, Women Centre, John Radcliffe Hospital
1.2. The percentage of women who fulfil the eligibility criteria and accept the invitation to participate
2. Retention rate measured by assessing the proportion of women that completed the study at visit 3 - 36 week gestation (number)
3. Participant engagement with the intervention measured using:
3.1. Participant adherence rates to wrist-worn accelerometer at baseline visit and at baseline and visit 3 between 36 and 38 weeks pregnant (number of days worn over 7 days period, average daily wear, portion of wear (hours); availability of data for Physical Activity (PA) outcome measures)
3.2. Attendance rate at follow-up sessions
3.3. Completion rates of self-reported PA questionnaires (both at baseline and follow-up visit 3)
3.4. Proportion of participants who set goals on Stay-Active (%) during the study period
3.5. Proportion of participants who recorded PA on Stay-Active (%) during the study period
4. Acceptability of the interview with Completion of the Oxford Maternity Diabetes Treatment Satisfaction Questionnaire (OMDTSQ) by participants at baseline and between 36 and 38 weeks pregnant.
5. Fidelity of the motivational interviewing component of the intervention measured in 10% of participants' MI interviews one week after study enrolment
5.1. Whether all Motivational Interviews are audio recorded
5.2. 10% of motivational interviews will be coded using the Motivational Interviewing Treatment Integrity Code (MITI 4.2.1) to assess the fidelity of sessions

Previous primary outcome measures:
1. Participant adherence measured by hours of wearing the wrist-worn accelerometer (hours) for first week after baseline appointment, for the week after first MI session and for one week between 36 and 38 weeks pregnant.
2. Acceptability measured using Oxford Maternity Diabetes Treatment Satisfaction Questionnaire (OMDTSQ) at baseline and between 36 and 38 weeks pregnant
3. Physical activity measured by average daily minutes of Total PA (>40 mg) and Moderate to Vigorous PA (≥ 93.2 mg) using the acceleromter at recruitment and at 36-38 weeks pregnant
4. Recruitment rates measured as a percentage of women with GDM who are eligible for the study at first contact with potential recruit

Current secondary outcome measures as of 15/08/2022:
1. Physical activity (PA) levels assessed using information on physical activity time, type, intensity, and frequency assessed from baseline and follow-up visits:
1.1. Device-specific (accelerometer) data: Total PA average per measured day in moderate to vigorous (defined as any movement with a measured acceleration value ≥93.2 mg). PA and average accelerations in g (the standard SI unit of acceleration)
1.2. Pregnancy Physical Activity Questionnaire (PPAQ) – outcome: Energy expenditure (units measure of average weekly energy expenditure (MET-h·week-1) in both moderate (activities >3.0 and <6.0 METs) and vigorous activity (activity >6.0 METs)
1.3. Exercise Vital Sign – total weekly minutes of Moderate to Vigorous PA
2. Usage and participant attitudes to +Stay Active:
2.1. Stay-Active usage during the study period from enrolment and activation of the App to completion:
2.1.1. Average time spent on app per week (seconds and minutes)
2.1.2. Average time per session (seconds and minutes)
2.1.3. Frequency of app opened and duration per session (seconds)
2.1.4. Number of participants logging activity per week
2.2. Participants' attitudes to +Stay-Active (5 questions rating) on the usefulness of motivational interviewing, goal setting, tracking your goals via the app, automated motivational messages, personalised messages and an open comments section at approximately 36 weeks pregnant
3. Blood glucose control and medication prescribed assessed using:
3.1. Difference in glycaemic control measured as mean blood glucose (mmol/L) at recruitment and at 36-38 weeks (using blood glucose taken in the week that the accelerometer is worn), adjusted for number and timing of measurements
3.2. Participant’s prescribed medication (generic name and dose) from enrolment to end of the study
4. Maternal and neonatal outcomes measured using collected from medical records within 6 weeks after birth
4.1. Maternal outcomes (weight gain (kg), pharmacological medication (initiation, timing and doses in relation to meals and blood glucose readings), hypertensive disorders of pregnancy (gestational hypertension and pre-eclampsia), gestation at delivery (weeks), mode of delivery
4.2. Neonatal outcomes (birth weight (grams), neonatal hypoglycaemia (number of cases requiring IV glucose treatment for hypoglycaemia), neonatal hyperbilirubinaemia (number of cases requiring phototherapy), admission to SCBU for >24 h (number of cases), shoulder dystocia (number of cases)
5. Health costs: number of additional visits, contacts made by research midwife (both text message and telephone call) and time spent delivering the intervention (minutes) measured using collected from medical records and study SOP during the study period

Previous secondary outcome measures:
1. Blood glucose (BG) measured using a blood glucose monitor weekly from baseline until birth
2. Information on physical activity time, type, intensity and frequency assessed from accelerometer data throughout the study
3. Participants attitudes to Stay Active (with 5 questions, pushed by the app) measured 2 weeks after visit 2 and 36-38 week gestation, rating the usefulness of:
3.1. Motivational interviewing
3.2. Goal setting
3.3. Tracking your goals via the app
3.4. The automated motivational messages you receive
3.5. The personalised messages about your physical activity via the app
4. Maternal outcomes measured using patient records after birth:
4.1. Weight (kg) at baseline and at birth
4.2. Pharmacological medication (initiation, timing and doses in relation to meals and BG readings) throughout gestation
4.3. Hypertensive disorders of pregnancy (gestational hypertension and pre-eclampsia) throughout gestation
4.4. Gestation at delivery (weeks)
4.5. Mode of delivery
5. Neonatal outcomes measured using patient records after birth:
5.1. Birth weight (kg)
5.2. Neonatal hypoglycaemia (yes/no)
5.3. Neonatal hyperbilirubinaemia (yes/no)
5.4. Admission to SCBU for >24 hrs
5.5. Shoulder dystocia (yes/no)
6. Health economic information measured using patient records after birth:
6.1. Number of clinic visits throughout gestation
6.2. Time spent by clinical midwife delivering the intervention (minutes)