Hans van den Heuvel

6 Data collection Baseline and outcome characteristics Patient records were used for data collection on baseline characteristics and maternal and fetal/neonatal outcomes of pregnancy and delivery in both groups. Hypertensive disorders of pregnancy were defined according to criteria of the International Society for the Study of Hypertension in Pregnancy (ISSHP). 10 Healthcare consumption of hospital visits, fetal ultrasound assessments, blood/urine analysis, use of medication and all admissions were extracted from the hospital system of participants. Cost Analysis This cost analysis used the results of healthcare consumption from one university hospital (2500 deliveries annually, both secondary and tertiary care) that participated in the SAFE@HOME study. Costs were analysed from the perspective of direct healthcare costs, as well as from a societal perspective taking into account work absence and travel costs of study participants and companioning partners. Timeframe of our cost analysis was restricted to antenatal care from the first visit until the admission of delivery, excluding delivery and postpartum care. For the direct healthcare cost comparison, all procedures regarding antenatal care were obtained from the electronic health records and categorised. The category of outpatient visits included scheduled and unscheduled visits, not followed by hospital admission and performed by hospital midwives or gynaecologist (in training). The ultrasound category included appointments for viability scan and nuchal scan in first trimester, anomaly scan(s) and fetal biometry scans. Number and length of antenatal admissions were also recorded, including reason for admission. The category “Other healthcare costs” included numbers and costs of each individual order for blood and/or urinary analysis, followed by the total costs of all tests performed. Additionally, other diagnostics (such as MRI in pregnancy) were recorded. The last subcategory involved usage of allied health services such as physiotherapists or dieticians. Dutch national tariffs and the Netherlands Healthcare Institute costing manual were used to assign costs to corresponding procedures. 11,12 All costs were converted to 2018 Euros using consumer price indices of Statistics Netherlands. Procedures and costs related to the delivery, postpartum admission and cost of medication use were not included since the scope of this cost analysis was restricted to antenatal care. Costs associated with the digital health platform were calculated based on time invested by healthcare staff for monitoring purposes, device cost and subscription cost. For the analysis involving societal costs, data on productivity of study participants and partners were calculated according to Netherlands Healthcare Institute guidelines and were based on figures available from Statistics Netherlands. 13 For travel costs it was assumed that patients lived, on average, 36 km from University Medical Center Utrecht. 14 In the calculations it was assumed that each ultrasound appointment or laboratory test took place on the same day as an outpatient visit or during an admission. For each outpatient visit, the SAFE@HOME: COST ANALYSIS 89