Table 2.

Summary of usability and feasibility studies and RCT^a protocols.

Author, year, reference	Country	App or system name	Focus and study design	Target audience and sample	Key results and outcome variables
Peleg, 2017 [34]	Spain	MobiGuide	Feasibility Quasi-experimental	Intervention: GDMb patients (n=20) Control: historical cohort GDM patients (n=247) Duration: <34th gestational week to delivery (5-11 weeks)	Intervention vs control: BGc measurement complianced (1.01±0.10 vs 0.87±0.28; P=.03), BP control (98.6/64.7 vs 119.3/72.8 mmHg; P<.001). Patient compliancee: BG measures (0.87±0.11), ketonuria (0.98±0.03), BP (0.82±0.24), responded to message “High BG (2 abnormal per week), did you eat more than you should?” (0.31). Patient satisfaction (rated positive): system increased confidence (12/17), liked system’s adaptability to daily life (12/17), system did not complicate life (15/17); would recommend to others (16/17). Clinician satisfaction (rated positive): system helped identify priorities (6/6), increased patient safety (5/6), easier to manage patients (4/6).
Bromuri, 2016 [28]	Switzerland	PHSf	Development, usability, feasibility RCT	Intervention (telemedicine): GDM patients (n=12) Control (standard protocol): GDM patients (n=12) Duration: 24th-32nd gestational week to delivery (2-4 months)	Intervention vs control: number of BG measures (2749 vs 1616; P<.001); BG control (5.4 vs 5.7 mmol/L or 98 vs 102.4 mg/dL; P<.001). Intervention group satisfaction: 12/12 satisfied with the care by PHS and perceived the system easy to use. Caregiver satisfaction: perceived the system as appropriate, reduced reaction time, provided possibility of daily consultation, and saved time through automated alerts.
Garnweidner-Holme, 2015 [29]	Norway	Pregnant+	Development, usability	Women with GDM (N=22) Duration: 1-time use of the app	Perceived ease to register and control BG levels. Participants had success performing given tasks: finding information on healthy eating (10/11), physical activities (10/11), GDM (10/11), finding where to register BG levels (11/11), entering appointments for medical consultations (9/11), and finding how to register body weight (5/11).
Borgen, 2017 [35]	Norway	Pregnant+	RCT protocol (ongoing)	Women with a 2-hour OGTTg ≥9 mmol/L (N=230) Intervention: app + standard care Control: standard care Duration: <33rd gestational week to 3 months postpartum	BG level measured at 2-hour OGTT 3 months postpartum. Change in health behavior and knowledge about GDM, quality of life, birth weight, mode of delivery, and complications for mother and child.
Jo, 2016 [32]	South Korea		Development, usability, feasibility	Usability: GDM patients (n=5) User acceptance test: GDM patients (n=60) Duration: 1 week	Average usability score: 69.5 out of 100. User acceptance score with behavioral intention to use 5.5, intrinsic motivation score 4.3, perceived ease of use score 4.6, and perceived usefulness score 5.0, out of 7 for all measures.
Mackillop, 2014 [33]	United Kingdom	GDm-Health	Development	Beta testing phase: GDM patients (n=7) Service development phase: GDM patients (n=50) Duration: diagnosis to delivery	Women used the system for 13.1 weeks on average. 46/54 women submitted the minimum of 18 BG readings per week. 19,410/19,686 (98.6%) of BG readings were manually tagged with additional information (time of measurement and comments) by patients.
Hirst, 2015 [30]	United Kingdom	GDm-Health	Usability	See row above	Satisfaction: women were satisfied with the care (45/49), and agreed the equipment was convenient (47/49), reliable (43/49), and fit into their lifestyle (42/49).
Hirst, 2016 [31]	United Kingdom	GDm-Health	Feasibility	See 2 rows above	12/41 (29%) women delivered LGAh babies. Mother’s BG (LGA vs non-LGA babies): mean BG (6.3 vs 5.6 mmol/L; P=.004), fasting BG (5.8 vs 5.1 mmol/L; P=.004), and 2-hour postprandial BG (6.9 vs 6.0 mmol/L; P=.001). Odds of delivering an LGA baby increased with every 1-SD increase (0.7 mmol/l) in mean BG (ORi 5.5, 95% CI 1.4-21.2) and mean postprandial BG (OR 6.1, 95% CI 1.6-23.4).
Mackillop, 2016 [37]	United Kingdom	GDm-Health	RCT protocol (ongoing)	N=200 pregnant women with abnormal glucose tolerance Intervention: use GDm-Health system (app), attend the clinic every 4-8 weeks Control: standard care, self-record BG diary at home, attend the clinic every 2-4 weeks Duration: 14-34 weeks to delivery	Efficacy of GDm-Health; BG control and management intensity; maternal and fetal outcomes.
Kennelly, 2016 [36]	Ireland	Pears	RCT protocol (ongoing)	N=506 pregnant women, 10-15 weeks’ gestation, body mass index 25-39.9 kg/m2 Intervention: targeted low GIj, nutritional advice, and a daily exercise prescription (in-person education session) with a smartphone app as support, and biweekly follow-up emails Control: standard obstetric care Duration: 2nd to 3rd trimester	Incidence of GDM at 29 weeks. Gestational weight gain, maternal physical activity levels in the 3rd trimester, and GI and glycemic loading of maternal diet in the 3rd trimester.
Skau, 2016 [38]	Malaysia	Jom Mama	RCT protocol (ongoing)	N=660 newly registered married or engaged couples. Female not pregnant, diabetes-free at baseline Intervention: contact with community health promoter: 3 face-to-face meetings, 3 phone calls, communication through WhatsApp group chat, and use of the eHealth platform Control: standard care Duration: 8 months	Change in abdominal fat content. Change in body mass index, waist-to-height ratio, waist-to-hip ratio, weight, hemoglobin A1c, fasting lipid profile, blood pressure, health literacy, dietary intake, physical activity and sedentary behavior, and stress level. Incidence of GDM.

^aRCT: randomized controlled trial.

^bGDM: gestational diabetes mellitus.

^cBG: blood glucose.

^dNumber of days measured ≥4 BGs/number of days prescribed to measure BG.

^eProportion of performed/recommended measurements.

^fPHS: personal health system.

^gOGTT: oral glucose tolerance test.

^hLGA: large for gestational age.

ⁱOR: odds ratio.

^jGI: glycemic index.