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DOI: https://doi.org/10.15605/jafes.034.01.10


A Randomized Controlled Trial on the Effectiveness of Short Message Service (SMS) Reminders in Improving Postpartum Follow-up among Gestational Diabetes Mellitus Patients
Annie Jane Sarmiento, Diane Carla Bernardo, Iris Thiele Isip-Tan

Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of the Philippines - Philippine General Hospital

Corresponding Author

Annie Jane N. Sarmiento, MD
Section of Endocrinology, Diabetes and Metabolism
University of the Philippines-Philippine General Hospital
Taft Avenue, Ermita, Manila, Philippines 1000
Tel. No.: +632-554-8400 local 2230
E-mail: jayne_nalanga@yahoo.com
ORCiD: https://orcid.org/0000-0001-6207-8848


e-ISSN 2308-118x
Printed in the Philippines
Copyright © 2019 by the JAFES
Received July 10, 2018. Accepted August 14, 2019.
Published Online First: May 3, 2019.

ABSTRACT


Objective. This study assessed whether short message service (SMS) reminders would improve follow-up rate among gestational diabetes mellitus (GDM) patients by 12 weeks postpartum.

Methodology. In this single-center, single-blind randomized controlled trial, we assigned 308 patients with GDM to either of 2 arms, usual care alone versus usual care with SMS reminders. In the usual care group, 154 patients received a 10-minute short lecture on GDM and a 75 g oral glucose tolerance test (OGTT) request prior to discharge. In the SMS group, 154 patients received twice a week SMS reminders at 4 weeks, 8 weeks, and 10 weeks after delivery in addition to usual care. The primary outcome was clinic visit within 6 to 12 weeks postpartum with a 75 g OGTT result.

Results. In our population, the overall follow-up rate was 19.8% (61/308). Follow up rates were 20.1% (31/154) for the usual care group and 19.5% (30/154) for the SMS. The addition of SMS reminders was not associated with an increase in follow-up rate at 12 weeks postpartum (adjusted RR 0.98, 95% CI 0.63-1.52; p=0.932). The use of insulin or metformin for GDM control was associated with increased follow-up (adjusted RR 1.92, 95% CI 1.20-3.07; p=0.006).

Conclusion. SMS reminders did not improve postpartum follow-up rate among GDM patients at 12 weeks postpartum.

Keywords: gestational diabetes, short message service, reminder system

INTRODUCTION

The prevalence of gestational diabetes mellitus is reported to be as high as 14% among Filipinos, based on the ASEAN Federation of Endocrine Societies (AFES) Study Group on Diabetes in Pregnancy.[1] Following GDM, 35 to 60% of women develop type 2 diabetes within 10 years.[2] The incidence of postpartum glucose intolerance among Filipino GDM patients was reported to be as high as 42% (overt diabetes in 7.3% and prediabetes in 34.7%).[3] Subclinical glucose intolerance during pregnancy is also associated with a dose-related increase in cardiovascular disease later in life.[4] Taking into account these long-term implications, early identification of postpartum type 2 diabetes mellitus risk and glucose intolerance is imperative. This can be done by postpartum glucose screening as this presents an opportunity for education and primary diabetes prevention.[5]

The Philippine Clinical Practice Guidelines on the Diagnosis and Management of Diabetes Mellitus recommend that women with GDM be screened for persistent glucose abnormality at 6 to 12 weeks postpartum.[2] However, in our institution, follow-up rates are generally poor, .as most are lost to follow-up after discharge from the hospital. Studies from the United States and Australia also report low postpartum screening, with rates ranging from 19 to 73%.[5],[6] There are efforts to increase awareness focusing mainly on education, as it has been demonstrated that women who are better educated on the importance of postpartum testing are more likely to follow-up.[7],[8],[9] The need to identify simple and innovative strategies to augment current care protocols may serve to improve postpartum glucose testing and follow-up. Among GDM patients, postpartum postal reminders, telephone calls and emails were shown to increase screening rates as reported by other studies.[10],[11] A meta-analysis of postpartum screening practices among Asian women with a known history of GDM showed that postpartum testing rate ranged from 13 to 82% during routine care, as compared to 67 to 95% of women who received SMS or call interventions in the studies.[12] The intention behind putting a reminder system in place provides not only an avenue for continuity of care, but also a continual of awareness of the risk for development of diabetes.[11]

In 2015, our National Telehealth Center reported that there were 114.6 million mobile connections in the country.[13] Given the widespread use of texting and mobile phones and the evidence to support their use, numerous text messaging programs for health promotion have been developed.[14] Studies on the use of short message service in health care, particularly among human immunodeficiency virus patients and persons with type 2 diabetes mellitus, showed improved adherence to treatment and increased appointment attendance.[15] Locally, SMS as an adjunct to standard diabetes care has been shown to improve adherence to diet and exercise, supporting disease self-management.[16] An SMS reminder system among postpartum GDM patients in Australia was demonstrated to increase overall postpartum screening rate.[17] In a local study on GDM patients which implemented persistent SMS reminders or calls for scheduled postpartum 75 g oral glucose tolerance test (OGTT), the reported follow-up rate was 71.6%.[3]

Given the prevalent use of mobile phones among Filipinos and the low cost of text messaging (PhP 1.00 equivalent to ~USD 0.020 per standard 160-character SMS), a reminder system through text messaging may prove to be an inexpensive, effective, feasible and culture-appropriate strategy to improve rates of postpartum glucose testing and follow-up.

This study aimed to compare the effectiveness of SMS reminders in addition to usual care in improving follow-up and postpartum glucose testing among GDM patients. We also determined the association of follow-up and socio-demographic and perinatal characteristics, including clinical and neonatal outcomes, and among postpartum GDM patients. We also described self-reported barriers and facilitators for postpartum testing.

METHODOLOGY

Study design and participants

This study was a single-blind randomized controlled trial that was conducted at the Philippine General Hospital, a tertiary teaching hospital in Manila. A concurrent qualitative method approach through survey questions was used to identify self-reported barriers and facilitators for postpartum follow-up. Ethics approval was obtained from the University of the Philippines Manila Research Ethics Board.

Participants were eligible for inclusion if they were diagnosed with GDM during their most recent pregnancy by their physician, or based on criteria from the International Association of Diabetes and Pregnancy Study Group (IADPSG) or the Philippine Obstetric and Gynecology Society (POGS). They should have access to a personal mobile phone (not a shared phone), be able to read and write in Filipino, have normal capillary blood glucose (CBG) upon discharge [fasting blood glucose (FBG) <108 mg/dL and 2-hour postprandial blood glucose (PPBG) <144 mg/dL] and with written informed consent. The diagnosis of GDM based on the IADPSG and POGS criteria is summarized in Table 1.


Table 1. Criteria for diagnosing gestational diabetes mellitus and overt diabetes in pregnancy


The following were excluded from the study: pre-gestational/overt diabetes (type 1 or type 2 diabetes mellitus), history of intake of drugs that can affect glucose metabolism (e.g., steroids, beta agonists), history of long term medical or surgical condition that can affect glucose metabolism (e.g., post-pancreatectomy, acromegaly, Cushing’s syndrome), multiple gestation and perinatal death in the most recent pregnancy (Table 1).

Sample size calculation for 2 independent proportions assumed an estimated baseline follow-up rate of 20%. Stata version 13.0 sample size calculator was used to estimate the sample size. To detect a 15% absolute improvement in follow-up from 20% to 35%, with 80% power, at 95% confidence interval, 5% error, and accounting for 10% data loss inherent in SMS, the sample size needed was computed at 308.

Description of study procedure

All participants admitted for delivery who were referred to the Section of Endocrinology, Diabetes and Metabolism for co-management of GDM, were assessed for eligibility. The primary investigator obtained informed consent if they met the inclusion criteria.

Eligible participants were randomized to either usual care or SMS (in addition to usual care) groups. Randomization was carried out in a 1:1 ratio using a computer-generated random allocation sequence. Allocation of treatment was done by third party personnel, using sequential sealed opaque envelopes. The outcome assessor and primary physician were blinded to treatment allocations. Blinding of the participants was not possible due to the nature of the intervention. Baseline socio-demographic characteristics, GDM status and maternal and fetal outcomes were abstracted from inpatient records and written in data collection forms. Additional information not indicated in the inpatient records was obtained by interview by the primary investigator.

Study intervention

Prior to discharge, the usual care group received a 10-minute lecture on postpartum GDM care and a 75 g OGTT request form. Explicit instructions were given pertaining to the laboratory location and timing of testing at 6 to 12 weeks postpartum. Follow-up visit with test results was also advised.

In addition to the above usual care, the SMS group received twice a week SMS reminders. The SMS were sent at 4, 8 and 10 weeks after delivery: one SMS on a weekday (Wednesday) and one on a weekend (Saturday). The messages in Filipino language contained a short reminder on different aspects of GDM postpartum care and reiteration of written instructions for follow-up (Appendix A). The participants were not required to reply to these reminders. The content of the SMS was derived from a discussion with an endocrinologist who is also a medical informatics specialist. The SMS were sent manually by the study investigators. The overall cost of sending the text messages for the 154 participants in the SMS group was PhP 924.00, equivalent to USD 17.74 to 19.67 based on the current exchange rate during the course of the study. No monetary incentive was given to the participants to avoid any effect on follow-up.


Appendix A. Teaching material and short message service content


An independent outcome assessor evaluated the participants on clinic follow-up. The date and results of the OGTT were recorded. If the OGTT results were abnormal, the participant was referred to her respective endocrinologist for subsequent follow-up and intervention. At the end of the clinic consult, each participant was asked a survey question on why they came for follow-up (Appendix B). If the participant belonged to the SMS group, she was asked the number of SMS reminders received.


Appendix B. Survey questions


All the participants who did not follow-up at 12 weeks postpartum were contacted through voice call to answer the survey questions (Appendix B). Responses were recorded verbatim. If a participant could not be reached on the first call, SMS were sent and she was again contacted on a different day. At least 3 attempts at varied times and on different days were made to reach the participant. The patient was then listed as not contactable if any of the following were encountered: phone number cannot be completed as dialed, subscriber cannot be reached, phone number is unattended or out of coverage area, call ended or dropped, wrong number, or ringing but with no answer on all attempts.

Outcome assessment

The primary outcome was follow-up defined as a clinic visit within 12 weeks postpartum with 75 g OGTT results. The follow-up rate for each group was calculated as the number of participants who followed-up divided by total number of participants in the group multiplied by 100. Participants who did not come for follow-up or came for clinic visit after the 3-month time period were labeled as non-follow-up. Participants who did not bring an OGTT result on clinic visit were considered as follow up, given another OGTT request and advised to come back within the time period.

Responses to survey questions were examined and grouped for emerging themes, and then classified as self-reported barriers and facilitators to postpartum follow-up.

Data analysis

Descriptive analyses were performed and bivariate analyses were run by follow-up status. The percentages across independent variables by follow-up status were calculated. The significance of the main effects of the different independent variables on the follow-up status was determined by bivariate analysis using Mann-Whitney U test for continuous data, while chi-square and Fisher’s exact tests were used to compare categorical data. Bivariate analysis was initially performed to have an idea of the nature of the strength of association of each independent variable and the outcome variable. A bivariate test resulting to a p value ≤0.25 was considered a candidate for the multivariable model. Multivariate logistic regression with backward selection strategy was then performed to determine the factors associated with follow-up, while taking into account all other associated factors. The significance level for removal of a variable in the model was 0.05. Risk ratios (RR), 95% confidence interval (CI), and p values were derived. All statistical analyses were performed using Stata 14 for Windows® (StataCorp LP, College Station, TX, USA). Outcome comparisons were made according to treatment allocation, on an intention-to-treat analysis.

RESULTS

Recruitment and participant flow

Recruitment was performed from April 2017 until March 2018 when the pre-specified sample size was reached. Follow-up of study outcomes was completed by June 2018. Out of the 336 participants assessed for eligibility, 28 were excluded. Twenty-four met different exclusion criteria: 12 had overt diabetes, 2 did not meet postpartum glucose cut-offs and were sent home on diabetes medication, 4 did not have a personal mobile phone, 4 had twin gestation in the index pregnancy, one had required long-term steroid treatment during the postpartum period for idiopathic thrombocytopenia, and one had neonatal death. There were 3 patients who did not give consent to participate, while another was excluded because of poor comprehension of instructions from a speech impediment (Figure 1).


Figure 1. Participant flow diagram


Participants were randomized to either usual care (n=154) or SMS (n=154) groups. It was presumed that 151 participants received their text reminders. Three participants reported that no text reminders were received due to change of phone number, subscriber identity module (SIM) card malfunction and inability of mobile unit to receive SMS. A total of 81 (26.3%) participants could not be contacted at the end of the follow-up period [34 (22%) from the usual care group and 46 (30%) from the SMS group]. At the end of the study, these participants were considered as non follow-up, in accordance with an intention-to-treat analysis. During the follow up period, one participant died due to eclampsia in the immediate postpartum period.

Socio-demographic characteristics of included women

There were no significant differences in socio-demographic characteristics between the 2 groups. The mean age for both groups was 31 years. Approximately 60% of participants have college level education. The distribution of other demographic (monthly household income, employment status and parental status) and anthropometric characteristics [pre-pregnant weight and body mass index (BMI)] were similar in both groups (Table 2).


Table 2. . Socio-demographic and anthropometric characteristics at trial entry


Perinatal factors

There were no significant differences in maternal factors between the groups. Antenatal 75 g OGTT results were available for 295 participants. The 13 patients without actual OGTT results on admission were physician-diagnosed and on active outpatient follow-up with an endocrinologist during their current pregnancy (Table 3).


Table 3. Maternal factors at trial entry


More participants in the SMS group had a history of preterm delivery (3.9% in the usual care, 9.1% in the SMS groups). On the other hand, more participants in the usual care group delivered pre-term in the index pregnancy (19.5% in the usual care, 7.1% in the SMS groups). Consequently, a higher rate of neonatal hypoglycemia was recorded in the usual care compared to the SMS group (22.1% versus 13.6%, p=0.053) but this difference did not reach statistical significance. Birth weights and neonatal ICU admissions were similar in both groups (Table 3).

Postpartum follow-up and glucose status

A total of 66 participants came for postpartum visit, resulting to an overall follow-up rate of 19.8%. Five participants (3 from the usual care and 2 from the SMS groups) came after the prescribed 6 to 12 week postpartum period and were then considered as non-follow-up. The difference in follow-up rates between groups was not statistically significant (Table 4).


Table 4. Postpartum follow-up rates and glucose status


Among those who were able to return for follow-up, 42 (63.6%) had normal glucose status. Nineteen (28.8%) had pre-diabetes, with impaired fasting glucose (IFG) as the most common condition (11 participants, 16.7%). Type 2 DM was newly diagnosed in 3 (4.6%) participants. Two (3%) had unknown glycemic status because the postpartum OGTT was not done at that time of clinic visit (Table 4).

The study was only powered to detect a difference in the follow-up rates between the usual care and SMS groups. The factors associated with follow-up were explored nonetheless to better characterize our population of GDM patients. A bivariate analysis was done to determine the association of demographic and maternal characteristics, including clinical and neonatal outcomes and follow-up (Appendix C). Participants were more likely to come for postpartum follow up if they were older, had a monthly household income at or above minimum wage, and used insulin or metformin for glycemic control during pregnancy. After adjusting for these factors, the addition of SMS to usual care did not increase follow up after 12 weeks postpartum (adjusted RR 0.98, 95% CI 0.63-1.52; p=0.932). Patients who used insulin or metformin during pregnancy were twice more likely to follow-up after delivery (adjusted RR 1.92, 95% CI 1.20-3.07; p=0.006) (Table 5).


Appendix C. Bivariate analysis of factors associated with follow-up



Table 5. Logistic regression analysis of factors associated with follow-up


Because of the significant number of participants who did not follow-up, a post hoc per protocol analysis was performed, excluding 34 patients from the usual care group and 47 from the SMS group who were unreachable at the end of 12 weeks (Appendix D). The results were similar in both intention-to-treat and per-protocol analyses.


Appendix D. Logistic regression analysis of factors associated with follow-up, per protocol analysis, n=227


Self-reported barriers and facilitators for postpartum follow-up

The participants who came for postpartum reassessment were asked about their reasons for follow-up. The most common reason cited by the responders (n=66) was the need to know their glucose status after pregnancy. Among those who did not follow-up, most reported child care difficulties as the reason for not returning for clinic visit. Table 6 cites the themes identified as facilitators and barriers for follow-up based on open-ended responses.


Table 6. Identified barriers and facilitators to follow-up


DISCUSSION

The results indicate that SMS reminders in addition to usual care did not improve follow-up among GDM patients at 12 weeks postpartum in our center. In addition, the postpartum testing rates were suboptimal (<50%) for both groups. We found that the use of insulin or metformin for GDM control was significantly associated with higher follow-up rate, among the various factors examined. Identification of self-reported facilitators and barriers to follow-up gave us an overall context of the suboptimal outcome of postpartum follow-up in our setting.

Our findings are similar to the results of the DIAMIND study. The investigators reported that SMS reminders did not increase postpartum OGTT, fasting plasma glucose or HbA1c completion, despite a higher overall screening rate of 82%. This was attributed to the concurrent receipt of postal reminders under the national reminder scheme and an OGTT recommendation in the follow-up treatment plan.[17] The findings of a study done in an Asian population reported a better follow-up rate in contrast to our study, at 66.6 to 94.9%, after being recalled by SMS reminder, phone call or invitation to join in studies.[12] A high follow-up rate was reported by Malong in a similar Filipino cohort, possibly attributable not only to persistent SMS or call reminders, but also because the cost of OGTT was free for the patients.[3] While employing a reminder system similar to the aforementioned studies, we investigated the effect of SMS reminders alone, without any concurrent reminder system or monetary incentives that may have affected the rate of follow-up. Another difference is that all of the studies had considerably longer follow-up duration of up to a mean of 22.8 months.[3],[12],[17] Our trial specified follow-up within the recommended 6 to 12 weeks postpartum. This may possibly coincide with the period of adjustment to new parenting roles, which took precedence over postpartum follow-up, regardless of an SMS reminder. This was also observed in a study on a South Asian population in Australia. Although majority of the women were aware of the importance of OGTT screening, they struggled with the lack of support in the immediate postpartum period, and many were unable to attend for routine OGTT screening at 6 weeks postpartum leading to postponement of testing.[18] While SMS may seem like a simple platform to employ behavioral intervention, it may not be the case for this particular subset of patients.

The open-ended responses to the survey questions provided insight into the reasons for lack of follow-up. Logistics such as child care difficulties, work and transfer of residence were identified by the participants as the most common reasons for non-follow-up. From those who were unable to return for follow-up, 5 patients had attended postpartum consult in a center within closer proximity to their home or workplace. Financial limitation was cited as the fourth most common reason for non-follow-up based on the survey. Postpartum follow-up is not covered by PhilHealth, our national social insurance program, making it an out-of-pocket expense. Follow-up visits possibly take a low priority in resource allocation for some individuals. These concerns come into play in any behavioral outcome and may have played a major role in the low overall follow-up rates. These barriers to follow-up cannot be addressed by any reminder system alone.

Another technology-based consideration is that about 26.3% of our participants were deemed not reachable by the end of the study period. Our pre-specified data loss at 10% may have underestimated real life attrition among those receiving SMS intervention in our setting.

The use of insulin or metformin for GDM control was significantly associated with higher follow-up in our trial. Apart from the additional intervention of medication use, these women are compelled to come for more regular antepartum follow-up particularly for medication adjustment and monitoring. This may have allowed for more physician-patient interaction and more opportunities to make the patients aware of their condition and the implications on their health, as opposed to their diet-only counterparts. This factor, along with older age, nulliparity and higher income or education, were identified to be predictors of higher follow-up rates in a review by Tovar.[6] With the exception of nulliparity, we also found the same factors to be associated with higher follow-up based on bivariate analysis.

Identification and description of self-reported facilitators and barriers to postpartum follow-up gave us an overall context of the low rate of follow up in our setting. We observed that follow-up was not mechanistic, in that the addition of reminders does not necessarily result to better rates of postpartum follow-up.

We also noted that the results of early postpartum glucose profiles in our study are similar to the rate of early postpartum glucose status in Asian countries. These studies observed incidences of 3.9 to 41.8% for prediabetes, and 2.8 to 20.6% for overt diabetes within 12 weeks postpartum.[3],[11] Postpartum glucose abnormalities in our trial may have been under-reported, given a follow-up rate of only 19.8%.

Limitations and Recommendations

As a public tertiary referral center, the patients seen in our institution belong mostly to lower income brackets. Majority of our referrals came from service consults in the Department of Obstetrics and Gynecology. Fewer than 10% of patients came from the private wards, making higher income brackets less represented in our cohort. Future studies may look into better income bracket representation, especially because follow-up is an out-of-pocket expense for our patients.

Improved SMS intervention design aimed at making messages more engaging and persuasive should be a consideration for similar projects in the future. Personalized messages and a two-way versus a one-way SMS design may be more effective, as this allows for more interaction and versatility.[19][20] Quantification of the actual effect of the SMS intervention is difficult to ascertain and remains a limitation of technology-based intervention.

We were not able to contact 26.3% of the participants by the end of the study period. Although no difference in results were seen statistically when this group was excluded from analysis, this remains a significant percentage of the study population. Because we had no control over data loss, a higher attrition rate may be considered in future study designs involving SMS interventions. In addition, other social media platforms which may be more engaging and persuasive, such as a closed Facebook group for GDM patients, can be explored in future studies. Apart from looking for adjunctive methods to increase follow-up, we recommend expanding the sample size to better delineate socio-cultural-economic factors that affect follow-up in our setting, as these were some of the self-reported barriers and facilitators to follow-up. This is the first study in our setting which aimed to identify possible predictors of postpartum follow-up.

The postpartum stage is indeed a challenging period, as can be surmised from the survey responses of the participants. Strategies to make postpartum follow-up universal, more accessible, more affordable and closer to local hospitals and health centers may serve to improve overall follow-up rates. Simplifying postpartum follow-up by incorporating pediatric, obstetric and medical follow up in a single clinic within the same schedule may be a viable option for future healthcare systems planning.

CONCLUSION

SMS reminders did not improve postpartum follow-up rate among GDM patients at 12 weeks postpartum in our setting. Among the factors examined, the use of insulin or metformin was independently associated with increased follow-up rate. Strategies addressing accessibility and affordability of postpartum care may serve to improve overall follow-up rates.

Acknowledgments

The authors are grateful to Prof. Olivia Sison from the Department of Clinical Epidemiology, University of the Philippines Manila and Dr. Anna Angelica Macalalad-Josue for their invaluable help and assistance with the statistical analysis.

They are also grateful to our fellows-in-training from the Section of Endocrinology, Diabetes and Metabolism and our colleagues from the Department of Obstetrics and Gynecology of the Philippine General Hospital who have assisted us in the recruitment process.

They would also like to acknowledge Dr. Raymond Francis Sarmiento, Director of the National Telehealth Center, National Institutes of Health, for sharing his expertise; and Dr. Henry Medina for his assistance in data checking and encoding.

Statement of Authorship

All authors certified fulfillment of ICMJE authorship criteria.

Author Disclosure

The authors declared no conflict of interest.

Funding Source

The study was supported by a research grant from the Philippine Society of Endocrinology, Diabetes and Metabolism. The funding agency had no role in the study design, data collection and analysis, and preparation of the manuscript.

References

[1] Litonjua A, Waspadji S, Pheng CS. AFES Study Group on Diabetes in Pregnancy: Preliminary data on prevalence. Philipp J Intern Med. 1996;34(2):67-8.

[2] Jimeno CA, for the Technical Review Committee of the UNITE for DM Clinical Practice Guidelines on the Diagnosis and Management of Diabetes. A summary of the Philippines UNITE for diabetes clinical practice guidelines for the diagnosis and management of diabetes. Part I: Screening and diagnosis of DM. J ASEAN Fed Endocr Soc. 2011;26(1):26-30. CrossRef

[3] Malong CL, Sia-Anastacio A, Andag-Silva A, Cunanan E. Incidence of postpartum diabetes and glucose intolerance among Filipino patients with gestational diabetes mellitus seen at a tertiary hospital. J ASEAN Fed Endocr Soc. 2013;28(1):56-63. CrossRef

[4] Dawson SI. Glucose tolerance in pregnancy and the long-term risk of cardiovascular disease. Diabetes Res Clin Pract. 2009;85(1):14-9. PubMed CrossRef

[5] Nielsen KK, Kapur A, Damm P, de Courten M, Bygbjerg IC. From screening to postpartum follow-up – the determinants and barriers for gestational diabetes mellitus (GDM) services, a systematic review. BMC Pregnancy and Childbirth. 2014;14:41. PubMed PubMed Central CrossRef

[6] Tovar A, Chasan-Taber L, Eggleston E, Oken E. Postpartum screening for diabetes among women with a history of gestational diabetes mellitus. Prev Chronic Dis. 2011;8(6):A124. PubMed PubMed Central

[7] Stasenko, M, Liddell J, Cheng YW, Sparks TN, Killion M, Caughey AB. Patient counseling increases postpartum follow-up in women with gestational diabetes mellitus. Am J Obstet Gynecol. 2011;204(6):522.e1-6. PubMed PubMed Central CrossRef

[8] Hunt KJ, Conway DL. Who returns for postpartum glucose screening following gestational diabetes mellitus? Am J Obstet Gynecol. 2008;198(4):404.e1-6. PubMed PubMed Central CrossRef

[9] Kim C, McEwen NL, Kerr EA, et al. Preventive counseling among women with histories of gestational diabetes mellitus. Diabetes Care. 2007;30(10):2489-95. PubMed CrossRef

[10] 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(6):634.e1-7. PubMed CRossRef

[11]Jeppesen C, Kristensen JK, Ovesen P, Maindal HT. The forgotten risk? A systematic review of the effect of reminder systems for postpartum screening for type 2 diabetes in women with previous gestational diabetes. BMC Res Notes. 2015;8:373. PubMed PubMed Central CrossRef

[12] Nouhjah S, Shahbazian H, Amoori N, et al. Postpartum screening practices, progression to abnormal glucose tolerance and its related risk factors in Asian women with a known history of gestational diabetes: A systematic review and meta-analysis. Diabetes Metab Syndr. 2017;11(Suppl 2):S703-12. PubMed CrossRef

[14] Abroms LC, Whittaker R, Free C, Van Alstyne JM, Schindler-Ruwisch JM. Developing and pretesting a text messaging program for health behavior change: Recommended steps. JMIR MHealth UHealth. 2015;3(4):e107. PubMed PubMed Central CrossRef

[15] Kannisto KA, Koivunen MH, Välimäki MA. Use of mobile phone text message reminders in health care services: A narrative literature review. J Med Internet Res. 2014;16(10):e222. PubMed PubMed Central CrossRef

[16] Tamban C, Isip-Tan IT, Jimeno C. Use of short message services (SMS) for the management of type 2 diabetes mellitus: A randomized controlled trial. J ASEAN Fed Endocr Soc. 2013;28(2):143-9. CrossRef

[17] Van Ryswyk EM, Middleton PF, Hague WM, Crowther CA. Postpartum SMS reminders to women who have experienced gestational diabetes to test for type 2 diabetes: The DIAMIND randomized trial. Diabet Med. 2015;32(10):1368-76. PubMed CrossRef

[18] Bandyopadhyay M, Small R, Davey MA. Attendance for postpartum glucose tolerance testing following gestational diabetes among South Asian women in Australia: A qualitative study. J Womens Health Issues Care. 2015;4:1. CrossRef

[19] Suffoletto B. Text message behavioral interventions: From here to where? Curr Opin Psychol. 2016;9:16-21. PubMed NIHMSID: NIHMS725153. PubMed Central CrossRef

[20] Webb TL, Joseph J, Yardley L, Michie S. Using the internet to promote health behavior change: A systematic review and meta-analysis of the impact of theoretical basis, use of behavior change techniques, and mode of delivery on efficacy. J Med Internet Res. 2010;12(1):e4. PubMed PubMed Central CrossRef

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