Table 1.

Included intervention and observational studies for postpartum follow-up after gestational diabetes. (N = 6)

Author (year) country	Design	Setting	Reminder targeted participants and study location	Outcome and Follow-up	Description of intervention	Results
Chittleborough et al. (2010) Australia	Intervention using letter	Secondary The Diabetes Center at The Queen Elizabeth Hospital	Intervention target group: Patient and physicians 429 Postpartum women and their GPs in the GDM Recall Register receiving reminders for postpartum OGTT testing	Outcomes 1. Rate of returned update forms that was included in the reminder letter 2. The range of women reporting they had attended an OGTT test the previous year	Two times reminder letter to both patients and GPs. First time 15 months after delivery Second time every 12 months thereafter	Of the 429 women receiving a reminder letter 46 % returned an update form and 56 % had an OGTT in the previous 12 months Second reminder letter resulted in 45 % return of which 75 % had OGTT the previous 12 months
Clark et al. (2009) Canada	Intervention using letters	Secondary Ottawa Hospital, Ontario	Intervention target group: Patient and physicians 256 Patients and their physicians assigned randomly to 4 groups according to reminder intervention	Outcomes 1. Percentage of women who underwent OGTT 2. Performance of postpartum screening test	Patients assigned randomly to 4 groups: 1. Reminders both to physicians and patient 2. Reminders to patients only 3. Reminders to physician only 4 No reminders sent	OGTT rates 1. Both patient and physician reminders: 60.5 % 2. Patient only: 55.3 % Physician only: 51.6 % No reminders: 14.3 %
Korpo-Hyövälti et al. (2012) Finland	Intervention using telephone calls	Primary South Ostrobothnia, Finland	Intervention target group: Patient and physicians Counselling during pregnancy and lifestyle intervention for GDM patients. From this population a postpartum intervention was carried out among 266 high-risk-for-GDM women and their physicians in four municipalities	Outcome: the prevalence of high-risk-for-GDM women who underwent an OGTT in the postpartum period	Postpartum intervention was offered to the high-risk-for-GDM women who were included in lifestyle interventions Nurses received a list of patients and were advices to call the women for reminding them of glucose test. Reminder was sent out to the patients from the central hospital nurses or from the central hospital to the health care provider of the patient	A telephone reminder from the central hospital to the women or to their health care provider vs. no reminder: OR: 13.4, 95 % CI (2.1; 12.2), p < 0.0001
Lega et al. (2011) Canada	Register-based observational study	Secondary Toronto, Canada	Intervention target group: Patients Retrospective study of 314 women from an endocrine clinic, 173 had a checklist for the physician at their record which resulted in a reminder follow-up visit	Outcomes: OGTT Follow-up visit: The effect of a reminder system in the database on screening rates on outpatient postpartum women	No direct intervention Retrospective recording of checklist on patients in database	Intervention-group: OR (95 % CI) 2.99 (1.84; 4.85) for completion of OGTT. Intervention-group OR (95 % CI) 3.71 (2.26; 6.11) for follow-up visit
Shea et al. (2011) Canada	Intervention using mailed reminders	Secondary Ontario, Canada	Intervention group: Patients in screening sites. Three clinical sites providing screening tests with 262 patients in total: two sites received reminder (A and B), one did not (C)	Outcome: Percentage of women who received an OGTT test within 6 months after delivery	Intervention targeted patients Clinical site A received mailed reminders with a laboratory requisition for OGTT Clinical site B were sent a laboratory requisition for OGTT, phoned for appointment, or both Clinical site C: no reminders	Prediction of postpartum glucose screening: reminder site A vs site C: OR (95 % CI): 1.57 (0.66; 3.70) reminder site B vs. site C: OR (95 % CI): 3.10 (1.35; 7.14)
Vesco et al. (2012) US	Intervention using combined telephone calls/emails and staff education	Secondary Oregon and Washington	Intervention target group: Patients 200 Women for the pre-implementation (no intervention group) 179 Women for the post-implementation (intervention group)	Two-fold outcome 1. Outcome among providers was the rates of women for whom a screening test was ordered 2. Patient outcome measured by postpartum screening rates among previous GDM patients	Implementation of a process improvement program consisting of 1. Staff education sessions 2. Revised GDM protocols 3. Implementation of system-based reminders to call in women for glucose screening send out within 3 months of delivery and after 3 months of delivery	With implementation of program the rate of women receiving order for OGTT increased from 77.5 to 88.8 % Final screening rate with completion of OGTT increased from 59.5 to 71.5 % (p = 0.004), (HR (95 % CI) 1.37 (1.07; 1.75)