Do postal reminders increase postpartum screening
of diabetes mellitus in women with gestational
diabetes mellitus? A randomized controlled trial
Heather D. Clark, MD, MSc; Ian D. Graham, PhD; Alan Karovitch, MD, MEd; Erin J. Keely, MD
OBJECTIVE: Women with previous gestational diabetes mellitus rarely re-
ceive the recommended 2-hour oral glucose tolerance test (OGTT) after
delivery. We sought to determine whether postal reminders to be sent after
STUDY DESIGN: Patients were assigned randomly to 4 groups: re-
minders sent to both physician and patient, to physician but not pa-
tient, or to patient but not physician or no reminders were sent. The
primary outcome was the proportion of patients who underwent an
OGTT within 1 year after delivery. The secondary outcome was the
performance of other postpartum screening tests.
RESULTS: OGTT rates were significantly increased in the physician/
patient reminder group (49/81 women; 60.5%), in the patient-only re-
minder group (42/76 women; 55.3%), and in the physician-only re-
minder group (16/31 women; 51.6%) compared with the no reminder
group (5/35 women; 14.3%; P ? .05).
CONCLUSION: Postpartum reminders greatly increased screening rates
for women with gestational diabetes mellitus.
Key words: gestational diabetes mellitus, glucose tolerance test,
postpartum testing, reminder
Cite this article as: Clark HD, Graham ID, Karovitch A, Keely EJ. Do postal reminders increase postpartum screening of diabetes mellitus in women with gestational
diabetes mellitus? A randomized controlled trial. Am J Obstet Gynecol 2009;200:634.e1-634.e7.
drate intolerance in pregnancy, affects ap-
proximately 3% of nonaboriginal preg-
nant women in Canada.1,2Although the
focus on the detection and treatment of
high risk of the development of diabetes
estational diabetes mellitus (GDM),
the onset or recognition of carbohy-
tion health reason for screening in preg-
nancy.3Most of these women will experi-
ence type 2 diabetes mellitus, with rates
continuing to rise dramatically the first 5
factors for insulin resistance.4A smaller
Most expert committees, which in-
cludes the Canadian Diabetes Associa-
tion (CDA), recommend screening for
diabetes mellitus in all women who have
had GDM 6 weeks to 6 months after de-
livery with an oral glucose tolerance test
(OGTT) as the preferred screening
test.3,6-8The use of a fasting plasma
abetes mellitus after delivery will miss
detection of impaired glucose tolerance,
which is a strong predictor of cardiovas-
cular disease and progression to type 2
All studies have demonstrated a very
low adherence to postpartum screening
recommendations.12-14There are nu-
merous reasons that women may not be
screened in the postpartum period, in-
cluding fragmentation of care, poor
competing demands for time, transient
population, and limited knowledge of
in other clinical areas (eg, cancer screen-
ing) may increase adherence with
physician-directed, patient-specific de-
cision support systems may improve the
management of chronic health condi-
tions.17Patient-specific reminders for
women with GDM have not been stud-
ied previously. Given our previous find-
ing that women are not being screened
after delivery as part of usual care, we
sought to determine whether postal re-
minders that are sent after delivery to a
patient, to her physician, or to both
would increase postpartum screening,
according to the CDA guidelines.
MATERIALS AND METHODS
This 2 ? 2 factorial randomized con-
Hospital, a university-affiliated tertiary
center in Ottawa, Ontario, Canada, that
provides services to a catchment area of
Presented at the 10th Annual Meeting of the
Canadian Diabetes Association, Toronto, ON,
Canada, Oct. 18-21, 2006.
Received June 4, 2008; revised Oct. 15, 2008;
accepted Jan. 12, 2009.
Reprints: Heather D. Clark, MD, MSc, 1053
Carling Ave., Ottawa, ON K1Y 4E9, Canada.
Funding was provided by the Canadian
Institute of Health Research, Knowledge
Translation and Exchange (CIHR-KTE), Grant
© 2009 Mosby, Inc. All rights reserved.
American Journal of Obstetrics & Gynecology JUNE 2009
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American Journal of Obstetrics & Gynecology JUNE 2009