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AHRQ’s Effective Health Care Program: Applying Existing Evidence to Obstetric Care

Slide Presentation in Text Format

Wednesday, November 10, 2010

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  • On the top of the slide are the logos for the U.S. Department of Health and Human Services and the Agency for Healthcare Research and Quality (AHRQ).

 

Slide 2

Questions

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CALL-IN NUMBER: (888) 632-5061  ACCESS CODE:23727775


Slide 3

Agenda

  • Brief Overview of AHRQ’s Effective Health Care Program - Katherine Griffith, Facilitator
  • Effective Health Care Findings on Gestational Diabetes - Wanda Nicholson, M.D., M.B.A., M.P.H.
  • Q&A from Audience

 

Slide 4

Questions

To submit a question:

  • Press the “Ask Question” button located at the bottom of the screen. 
  • When you click on the button, a box will appear at the bottom of your screen requesting that you enter your question. 
  • Once completed, press the “Submit” button.

 

Slide 5

Patient-Centered Outcomes Research and AHRQ’s Effective Health Care Program

Katherine Griffith
AHRQ’s Office of Communications and Knowledge Transfer


Slide 6

Patient-Centered Outcomes Research

  • Also known as comparative effectiveness research
  • Unbiased and practical, evidence-based information
  • Compares drugs, devices, tests and surgeries, and approaches to health care
    • Benefits and harms
    • What is known and what isn’t
    • Descriptive, not prescriptive


Slide 7

A Framework for Patient-Centered Outcomes Research

This framework outlines the step-by-step process for how the development and implementation of patient-centered outcomes research leads to improvement in health care. Once a topic is nominated, a horizon scan and synthesis of the evidence is completed, followed by evidence generation. Then the research is translated, disseminated and implemented.


Slide 8

Research Focus: 14 Priority Conditions

  • Arthritis and nontraumatic joint disorders
  • Cancer
  • Cardiovascular disease, including stroke and hypertension
  • Dementia, including Alzheimer’s disease
  • Depression and other mental health disorders
  • Developmental delays, ADHD and autism
  • Diabetes mellitus
  • Functional limitations and disability
  • Infectious disease including HIV/AIDS
  • Obesity
  • Peptic ulcer disease and dyspepsia
  • Pregnancy including preterm birth
  • Pulmonary disease/asthma
  • Substance abuse

 

Slide 9

Research Focus: Priority Populations

  • Low-income groups

 

  • Minority groups
  • Women

 

  • Children
  • The elderly

 

  • Individuals with special health care needs, such as those with disabilities, those who need chronic care or end-of-life care, or those who live in inner-city and rural areas.


Slide 10

Effective Health Care Program Translation Products

Multiple images of different products that the Effective Health Care Program creates from the systematic review reports.  These products include: CE Modules, Interactive Case Studies, faculty slides, patient decision aids, policymaker summaries, consumer guides, clinician guides, the Web site, and executive summaries.


Slide 11

Women’s Health Resources

Two images of consumer guides titled, Gestational Diabetes: A Guide for Pregnant Women and Thinking About Having Your Labor Induced: A Guide for Pregnant Women.


Slide 12

Public Involvement

A diagram of the multiple points in the development and dissemination process where stakeholders can get involved. The process includes: Topic Generation, Topic Development, Topic Refinement, Research Review, and Research Needs and Development.  The multiple ways that information is disseminated includes: Web Links, Newsletter Blurbs, Articles or Comment, Web Conferences, and Continuing Education.


Slide 13

Gestational Diabetes: Caring for Women During and After Pregnancy

Wanda Nicholson, M.D., M.P.H., M.B.A.
Departments of Obstetrics and Gynecology
University of North Carolina at Chapel Hill

Slide 14

Outline of Material

  • Background
  • Process for developing the Evidence-Based Review (EBR)
  • Questions addressed in the EBR
  • Results for each question in the review
  • Resources to guide patients and clinicians
  • Complete final report is available online at:  http://www.ahrq.gov/clinic/tp/gestdiabtp.htm#Report

 

Slide 15

Health Impact of Gestational Diabetes Mellitus (GDM)

  • Defined as carbohydrate intolerance first diagnosed in pregnancy
  • Estimated to affect 200,000 (7%) pregnancies each year in the U.S.
  • Maternal outcomes
    • Cesarean delivery, hypoglycemia
  • Neonatal outcomes
    • Neonatal hypoglycemia, birth trauma, NICU admissions

 

Slide 16

GDM: After Delivery

  • Higher risk for developing type 2 diabetes
    • 15%-60% develop type 2 diabetes within 5 to 15 years of delivery

 

  • Postpartum screening can identify women with type 2 diabetes
    • Little information on appropriate screening intervals or test performance


Slide 17

Questions Addressed by Review: Question 1

  • What is the evidence for the risks and benefits of oral diabetes agents (e.g., second-generation sulfonylureas (i.e. glyburide) and metformin), as compared to all types of insulin, for both the mother and neonate in the treatment of women with gestational diabetes?

 

  • Is there a threshold value for initiation of therapy?

 

Slide 18

Questions Addressed by Review: Question 2

  • What is the evidence that elective cesarean delivery or choice of timing of induction in women with GDM results in beneficial or harmful maternal or neonatal outcomes?

 

  • How are estimated fetal weight and gestational age related to outcomes of management of GDM with elective cesarean delivery or timing of induction?


Slide 19

Questions Addressed by Review: Questions 3 and 4

  • What risk factors are associated with the development of type 2 diabetes after gestational diabetes?

 

  • What are the performance characteristics of diagnostic tests for type 2 diabetes in women with gestational diabetes?


Slide 20

Evidence-based Review Process

  • We searched MEDLINE® EMBASE® Cochrane Library, and CINAHL from inception through January 2007
    • Augmented with hand searches of 13 relevant journals

 

  • We conducted two independent reviews of titles, abstracts, and full articles
  • Disagreements resolved by consensus

 

 

Slide 21

Evidence Grading

  • High

Further research is very unlikely to change confidence in the present estimated effect

  • Moderate

Further research is likely to have an important impact on confidence in the estimated effect and may change the estimates

  • Low

Further research is very likely to have an important impact on confidence in the estimated effects and is likely to change the estimates

  • Very low

Any estimate of effect is very uncertain

  • Insufficient

Too few studies to grade the comparison


Slide 22

Results of Literature


 

Slide 23

Use of Oral Diabetes Medications Compared to Insulin

  • What is the evidence for the risks and benefits of oral diabetes agents (glyburide, metformin) as compared to all types of insulin for both the mother and neonate in the treatment of women with gestational diabetes?
  •  Is there a difference in outcomes based on glucose level at initiation of medical therapy?

Conclusions:

  •  Unable to draw firm conclusions on any of the comparisons from three RCTs, five observational studies
  •  Limited evidence of no substantial benefit  or harm of glyburide compared to insulin (only small difference in infant birth weight)
  •  No evidence of substantial harms with metformin compared to insulins
  •  No evidence on outcomes based on thresholds for initiation of medications
  •  Overall low grade of evidence


Slide 24

Effect of Oral Diabetes Medications on Maternal Outcomes from RCTs

Authors Glycemic Control Cesarean Delivery Hypoglycemia* Summary of Findings

Anjalakshi, 2006
N=23

Insulin vs. Glyburide

I: FBG:  93 ±  10; 2 hr: 175 ±  32
G:  FBG 95  ±  7; 2hr:  16 ± 7 23

Anjalaski, 2006
N=23

            ---

No difference in maternal glucose levels

Bertini, 2005
N= 51

I: Final-Baseline (F-B):
11.5 ± 3.8
G: 10 ±  5.2

I:  12 (44)
G: 12 (50)

0 (0)
0 (0)
Requiring hospitalization

No difference in glucose control, cesarean delivery, or hypoglycemic episodes

Langer, 2000
N=404

I:  Final FBG:  104± 25;
G: Final FBG: 105± 20

I: 49 (24)
I: 46 (23)

41 (20)
4 (2); p=0.03
FSG < 40 mg/dl

No difference in final average FBG, cesarean delivery. Higher hypoglycemic episodes in insulin group

Rowan, 2008
N= 751

Insulin vs. Metformin

I: FBG: 91.8 ±13
M:  FBG: 93± 11

I:  142 (38)
M: 131 (36)

            ---

No difference in  average FBG or cesarean delivery. Also, no substantial difference in preeclampsia. Substantial less weight gain in metformin group (p < 0.001)

**Limitations: 1) small sample size in 2 of 3 studies;
2) inconsistency in outcomes studied; 3) differences in definitions

 

 

Slide 25

Effect of Oral Diabetes Medications on Neonatal Outcomes from RCTs

Authors Birth weight/macrosomia Congenital abnormalities/ birth trauma Neonatal hypoglycemia /NICU admission Summary of Findings

Anjalaski, 2006
N=23

Insulin vs. Glyburide

I:   2.6 .43
G:  2.7.34

---/---

---/---

No difference in infant birth weight.
No information anomalies, trauma hypoglycemia, or NICU admission

Bertini, 2005
N= 51

I:  3151 407
G:  3396 524/
I: 16%
G: 0%

---/---

I: 1(4)
G: 8(33); p=.006/---

Higher proportion of infants with macrosomia in insulin group. Higher proportion with NICU admissions in glyburide group. No cases of perinatal mortality.

Langer, 2000
N=404

I: 3194 578
G: 3256 543/
I: 4%
G: 7%

I:  4 (2)
G:  5 (2)/---

I: 12 (6)
G: 18 (9)/
I:14 (17)
G: 12 (6)

No difference in infant birth weight, congenital anomalies, neonatal hypoglycemia, or NICU admissions. Two cases of mortality in both groups.

Rowan, 2008
N= 751

Insulin vs. Metformin

I:  3372 573
M: 3413 569

I:  18 (3)
M: 11 (5)/
I:  17 (4.6)
M: 16 (4.4)

I: 8.%
M: 3.%; p=0.008/
I*:  45 (12.2)
M: 46 (12.7)

No difference in congenital anomalies, birth trauma, or NICU admissions. Higher proportion of hypoglycemia in insulin group.

**Limitations: 1) small sample size in 2 of 3 studies; 2) inconsistency in outcomes studied; 3) differences in definitions ; *admission greater than 24 hrs.  

 

Slide 26

Five Observational Studies of Glyburide Compared to Insulin, N=911

  • Jacobson, retrospective study, N=504
    • Findings: Higher FBG, 1 & 2 hr PPG in insulin vs. glyburide  group
    • Higher number of maternal hypoglycemia in glyburide vs. insulin group
    • *Glyburide not associated with neonatal hypoglycemia, hyperbilirubinemia, macrosomia, LGA or SGA infants,  compared to insulin
  • Conway, prospective study; N=75
    • 63 women on glyburide compared 12 women who required addition of insulin or transitioned to insulin alone
    • No difference in macrosomia or birth weight
  • Yogev: prospective study, N=82
    • Diet: 27, glyburide: 25, insulin: 30
    • Findings: Insulin  group had higher likelihood of asymptomatic hypoglycemia vs. glyburide group (OR 4.4; 95% CI: 1.4 13.9)
    • No neonatal outcomes evaluated

 

*Adjusted for race/ethnicity, FBG on OGTT, BMI, and gestational age


Slide 27

Five Observational Studies, Cont’d

  • Chmait: prospective study, N= 72
    • 59 on glybride alone compared to 13 who required addition of insulin or transitioned from glyburide to insulin
    • Findings: 1-hr and 2-hr PPG levels higher in glybride versus insulin group
    • No difference in CD, macrosomia, birth weight or hyperbilirubinemia
  • Rochon, retrospective study; N= 101
    • Identify factors to predict “success” or “failure”
    • 80 maintained on glyburide compared to 21 who required addition of insulin or transitioned from glyburide to insulin
    • No differences in infant birth weight, cesarean or shoulder dystocia

 

Slide 28

Conclusions and Limitations

  • RCTs show no substantial differences in maternal or neonatal outcomes with glyburide compared to insulin

 

  • Only one RCT with appropriate sample size
    • Inability to detect small differences
  • Observational studies suggest no adverse effects of glyburide, but there are glyburide failures (require addition or transition to insulin)
    • Only one observation study included a multivariate analysis with adjustment for confounders

 

Slide 29

Effect of Elective Cesarean Delivery, Timing of Induction, and Estimated Fetal Weight on Outcomes

  • What is the evidence that elective cesarean delivery or the choice of timing of induction in women with gestational diabetes results in beneficial or harmful maternal and neonatal outcomes?
  •  How are estimated few weight and gestational age related to outcomes of management of GDM with elective cesarean delivery or timing of induction?

Conclusions

  •  Little evidence exists
  •  One RCT compared effect of two labor induction protocols on maternal and
  • perinatal outcomes
  •  Four observational studies examined effect of EFW and/or gestational age on
  • delivery management and outcomes
  •  Unable to draw firm conclusions
  •  Insufficient evidence


Slide 30

1 RCT Comparing Two Labor Induction Protocols

Author, yr Control group Intervention group Key conclusion Limitations

Kjos, 1993
RCT
GDMA2, pre-gestational (6.5%)

Expectant management

Induced at 38 wks

Decrease in macrosomia and
birth weight in study group

High rate of induction in control group; randomization process not described


Slide 31

Effect of EFW and/or GA on Delivery Management and Outcomes

Author, yr; design, GDM group Control group Intervention
group
Key conclusion Limitations

Conway, 1998
Prospective cohort with historical controls (HC); protocol-based;
GDMA1 and A2

Expectant management

US at 37-38 wks
CD if EFW > 4, 250g; Induced if LGA and EFW < 4,250g

Increase in  CD; decrease in macrsomia; Shoulder dystocia in study group

No adjustment for confounders or stratified analysis

Lurie, 1996
Prospective cohort study with HC; protocol-based
GDMA1/GDMA2

Induced if EFW > 4,000g; CD if EFW > 4,500g

Induced at 38 weeks
CD if EFW > 4,500g

Decrease in  macrosomia, shoulder dystocia (only if compared to controls delivered after 40 wks)

No adjustment for confounders or stratified analysis

Lurie, 1992
Retrospective cohort; groups based on GA
at delivery
GDMA1/GDMA2

Induced if EFW > 4,000g; CD if EFW > 4,500g,  delivery > 40 wks

Induced if EFW > 4,000g
CD if EFW  > 4,500g,
delivery < 40 wks

Increase in Birth weight in GDMA2 patients delivering before 40 wks

No adjustment and outcomes not clearly defined

Peled, 2004
Retrospective cohort; groups based on gestational age at delivery
GDMA1/GDMA2

HC A: induced at 42 wks. CD if EFW > 4,500g; HC B:  Induced at 40 wks if LGA; CD if EFW > 4,000g; HC C:  Induced at 40 wks if LGA; CD if EFW > 4,000g

Period D:  Induced at 38 wks if LGA
CD if EFW > 4,000g

Decreasing rates of macrosomia and shoulder dystocia with  level of intervention

No adjustment for confounders, limited information on baseline characteristics, long study period (19 years)

Slide 32

Conclusions and Limitations

  • Heterogeneity in the severity of GDM
  • Observational studies conducted over wide time frame
    • Difficult to account for change in prevalence of GDM during timeframe
    • Modifications in physician practice patterns and obstetrical technology
  • No adjustment for confounders, so findings may not be entirely valid

 

Slide 33

Predicting Type 2 Diabetes After GDM

What risk factors are associated with short-term and long-term development of type 2 diabetes following a pregnancy with gestational diabetes?
Conclusions

  •  Consistent evidence
    • Adiposity (weight, BMI, waist circumference) before pregnancy and at ante/postpartum periods
  •  16 observational studies
    • Metabolic risk factors (↑FBG at diagnosis, insulin-requiring GDM, and glucose AUC at ante-partum testing)
  •  No evidence
    • Lifestyle factors (e.g. physical activity)

 

Slide 34

Ante/intrapartum Obesity Associated with Type 2 Diabetes After GDM

The graph shows antepartum as well intrapartum maternal obesity associated with GDM. There are several measures across several studies. By looking at the graph across the x-axis, any estimates of risks that are to the right of one show an increased risk; any point to the left basically show no increased risk. It’s fairly consistent across these six studies, that an increase in pre-pregnancy at adiposity measures including weight and BMI are associated with the development of type 2 diabetes after gestational diabetes.


Slide 35

Postpartum Obesity Associated with Type 2 diabetes After GDM

The graph looks at postpartum obesity and found the same results as slide 34.  One of the premier studies in this area is a study by Cho published in 2005 who looked at a variety of measures of adiposity ranging from BMI to weight to measures of skin-fold thickness.  The graph shows that each of those point estimates are to the right of one suggesting an increase in the odds of developing type 2 diabetes ranging from two up to 3.3.


Slide 36

FBG and Glucose AUC Associated with Type 2 Diabetes After GDM

The graph briefly looks at the metabolic factors that could be associated or predictive of the development of type 2 diabetes. Several studies looked at the fasting blood glucose during the three hour OGTT.   Each of these studies showed an increase with the development of type 2 diabetes. 

And at the bottom of the slide, it is shown that the overall OGTT response during pregnancy is also highly predictive of development of type 2 diabetes. 

 

Slide 37

Diagnosing Type 2 Diabetes After GDM

What are the performance characteristics (sensitivity, specificity, and reproducibility) of tests for diagnosing type 2 diabetes after pregnancy in patients with a history of gestational diabetes? Are there differences in the performance characteristics of the test results in different subgroups?
Conclusions

  •  Eight observational studies
  •  Unable to draw firm conclusions on accuracy of fasting blood glucose (FBG) compared with gold standard of 75g 2-hr OGTT
    • 2-hr OGTT values different from current standards
    • High specificity, but variable sensitivity
  •  No studies on reproducibility


Slide 38

10 Comparisons of FBG with 75g OGTT to Diagnose Type 2 Diabetes

No. Studies Ref. Test Criteria Comp. Test Criteria

2

OGTT

WHO 1985

OGTT

WHO 1999

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