4.1 Trial design
B2B&Me is a multicentre single-blind randomised controlled implementation trial with the aim of testing the innovation of a mHealth app and personalized health coaching with integrated health service screening for high-risk women in pregnancy, until one year postpartum. The details of the trial are reported elsewhere (26) but are briefly accounted for here. The study will aim to recruit around 800 women across four hospital sites, National Maternity Hospital Dublin, Ireland, San Cecilio University Hospital Granada, Spain, Southmead Hospital Bristol, England, Monash Medical Centre, Melbourne, Australia. The intervention will be implemented at each hospital site with pregnant women aged 18 and older attending maternity services screened for risk of developing GDM using the validated Monash GDM Screening Tool around their first antenatal visit. Individuals scoring 3 or higher on the tool will be invited to participate if they meet the inclusion and exclusion criteria below.
The inclusion criteria are: women attending a participating maternity service for maternity care, scoring of 3 or higher on the Monash GDM screening tool, smartphone owner, and not currently in a health behaviour change clinical trial. The exclusion criteria are: previously diagnosed diabetes (type 1 or type 2), greater than 24 weeks gestation, current multiple pregnancy (e.g. twin, triplets), cancer (not in remission), severe mental illness, substance abuse or myocardial infarction in the last three months, difficulty with using the English language for the Irish, English and Australian sites and Spanish for the Spanish site, and not owning a smartphone capable of hosting the intervention app.
At the baseline visit demographics will be collected via questionnaire including maternal age, ethnicity, gravidity, parity, relationship status, educational attainment, employment status (of the participant and relevant partner), housing status, childcare responsibilities and prior medical history. Maternal height (cm) and weight (kg) will be extracted from medical records and participants will be invited to weigh themselves weekly on a Bluetooth-enabled scales provided by the study. Blood pressure will be measured during the baseline visit. Online questionnaires will be completed within one week of the baseline visit. The questionnaires will collect data on diet, physical activity, breastfeeding attitudes, health status (EQ-5DL), psychological health, sleep quality, health literacy and willpower. The questionnaireswill be completed within a week of final study visit (12 months postpartum). Additional questionnaires on infant development, health status, diet and physical activity as well as anthropometry on infant length (cm), weight (kg), and head circumference (cm) will be completed at the final visit. At 3, 6, 9 months a questionnaire will be completed on healthcare visits and out-of-pocket costs postpartum.
4.2 Effect outcomes
The two main health outcomes for the economic evaluation will be health-related quality of life measured using the quality-adjusted life years (QALY) approach and maternal body weight (kg) 12 months postpartum. QALYs are a summary health outcome measure routinely utilised for economic evaluation integrating quantity and quality of life into a single index (27). QALYs will be calculated based on responses from the EQ-5D-L questionnaire sent out to patients in the clinical trial and country-specific value sets will be applied (28-31).
Effects (QALYs and weight) for the economic evaluation will be measured on individual patient level at baseline and 12 months postpartum. Additional effect outcomes (maternal and infant) can be employed if necessary, depending upon the analysis of the trial clinical effects.
4.3 Cost outcomes
The cost-effectiveness analyses will be performed from a health sector perspective. Cost categories for the economic evaluation include the value of all antenatal healthcare consumption, postpartum healthcare consumption related to diet, activity and weight for both baby and mother, costs of pharmaceuticals in pregnancy, and the cost of the intervention itself.
Information on utilisation of health services and utilisation of pharmaceuticals will be collected at the individual level. The antenatal services will be captured from the electronic case report forms (eCRFs) maintained by hospital sites. If participants visited hospitals or health providers other than the trial sites, the number of diagnostic and treatment procedures will be obtained based on self-report. Information on type of visit, frequency and out-of-pocket postpartum healthcare visit costs relating to diet, physical activity and weight management for the participant and their infant will be collected through online questionnaires at 3 months, 6 months, 9 months and 12 months postpartum. Valuation of the resources identified and measured will be done using country-specific unit costs for healthcare services. Each contact (face-to-face visit, phone contact etc.) will be assigned a unit cost based on type of visit and type of healthcare professional. Costs for the intervention itself will be collected by the company providing the smartphone application (Liva Healthcare) and will contain costs related to the implementation of the application in participating countries healthcare systems. Costs will be presented in 2023 Euros.