RESEARCH PROPOSAL
Universal Versus Selective Risk Factor-Based Screening Strategy For Gestational Diabetes Mellitus.
AUTHOR:
DR. FRANCIS GITHAE MURIITHI, MB.ChB.
RESIDENT,
MASTERS OF MEDICINE IN OBSTETRICS & GYNAECOLOGY,
THE AGA KHAN UNIVERSITY FACULTY OF HEALTH SCIENCES, EAST AFRICA.
SUPERVISORS:
DR. EVAN SEQUEIRA MD, FICOG.
Senior Lecturer, Consultant Obstetrician & Gynaecologist,
The Aga Khan University Faculty of Health Sciences, East Africa.
Dr. NANCY KUNYIHA, MRCP, Diabetology (UK)
Consultant Physician & Diabetologist,
The Aga Khan University Faculty of Health Sciences, East Africa.
METHODOLOGICAL SUPERVISOR:
Professor William Stones MD, FRCOG.
Chair, Department of Obstetrics & Gynaecology,
The Aga Khan University Faculty of Health Sciences, East Africa.
DECLARATION
I declare that this is my original work being done in partial fulfilment of the Master of Medicine programme in Obstetrics and Gynaecology at The Aga Khan University Faculty of Health Sciences, East Africa.
Dr. Francis Githae Muriithi
Resident, Department of Obstetrics and Gynaecology
The Aga Khan University Faculty of Health Sciences, East Africa.
Signature………………………………………..Date…………………………….
Dr. Evan Sequeira,
Senior Lecturer, Department of Obstetrics and Gynaecology
The Aga Khan University Faculty of Health Sciences, East Africa.
Signature………………………………………..Date…………………………….
Dr. Nancy Kunyiha,
Consultant Physician & Diabetologist,
The Aga Khan University Faculty of Health Sciences, East Africa.
Signature………………………………………..Date…………………………….
Professor William Stones,
Chair, Department of Obstetrics & Gynaecology,
The Aga Khan University Faculty of Health Sciences, East Africa.
Signature………………………………………..Date…………………………….
TABLE OF CONTENTSPage
Abbreviations 4
Executive Summary5
Introduction 6
Literature review7
Justification of the study12
Research Question 12
Hypothesis12
Objectives 12
Methodology14
Sample size determination15
Study design16
Procedures16
Statistical analysis17
Study administration18
Timeline18
Ethical considerations19
Application of Results 19
Budget & Budget justification.20
References22
Appendix I consent form25
Appendix II enrolment criteria29
Appendix III Data Collection Form30
Appendix IV Aga Khan Screening Guidelines32
ABBREVIATIONS.
ACOGAmerican Congress of Obstetricians and Gynaecologists
ADAAmerican Diabetes Association
CDACanadian Diabetes Association
Dr.Doctor
FICOGFellow of the Indian College of Obstetrics and Gynaecology
GDMGestational Diabetes Mellitus
HAPOHyperglycaemia & Adverse Pregnancy Outcomes.
IADPSG International Association of Diabetes and Pregnancy Study Groups.
IDFInternational Diabetes Federation
MDDoctor of Medicine
MRCPMember of The Royal College of Physicians
NDDGNational Diabetes Data Group
OGTTOral Glucose Tolerance Test
ORsOdds Ratios
Prof.Professor
RANZCOGRoyal Australian & New Zealand College of Obstetricians and Gynaecologists.
SPSSStatistical package for the social sciences
WHOWorld Health Organization
YrYear
EXECUTIVE SUMMARY.
Background:
Gestational hyperglycaemia is associated with a higher incidence of adverse maternal and foetal outcomes than is seen in normal pregnancy. Untreated gestational diabetes mellitus (GDM) has an increased perinatal morbidity and mortality.
Morbidity related to macrosomia includes shoulder dystocia with birth injury and perinatal asphyxia in the foetus. In the mother macrosomia is a risk factor for genital tract injury, obstructed labour, uterine atony and increased risk of caesarean section.
The importance of diagnosis of GDM relates not only to potential immediate morbidities at the time of birth but long term sequelae for the child. Obesity, development of type 2 diabetes mellitus, intellectual and neurological development and mental problems are known long term sequelae. For the mother, GDM is a very strong risk factor for the development of type 2 diabetes later in life. Published studies show that after GDM, 35-60% of women develop type 2 diabetes within 10 years. Mendeley Citation{cc0cd935-3a53-408f-850e-8fab0bf68766};{77f3bad0-4128-45f9-8af9-8a4adacb83e1}(1; 2)
Therefore it is prudent that gestational diabetes is diagnosed and appropriate treatment and monitoring instituted. Diagnosis begins with screening. However, a Cochrane review published in 2011 found insufficient evidence on the best type of screening that would improve maternal and fetal health outcomes.Mendeley Citation{6635ba6c-10a0-4245-8f50-a993646625b1}(3)
Objectives: To compare detection rates of the universal to the selective risk factor-based screening strategy for gestational diabetes mellitus
Methodology: A prospective cross-sectional study involving 185 subjects at or less than 28 weeks gestation attending antenatal care at The Aga Khan University Hospital, Nairobi.
Recruitment of study subjects shall be consecutive as they present for booking to the antenatal clinic until a sample size of 185 is achieved.
All subjects shall have their risk factors for gestational diabetes identified and recorded at the beginning of the study.
All subjects recruited shall then undergo the 50g O’Sullivan Screening test.
At the end of the study, the detection rate of the universal screening strategy will include all participants irrespective of risk factors. The detection rate of the selective risk factor strategy will only include those identified to have risk factors for gestational diabetes mellitus.
The detection rates for both screening strategies shall then be compared.
INTRODUCTION
Gestational diabetes is carbohydrate intolerance resulting in hyperglycaemia of variable severity with onset or first recognition during pregnancy. The definition applies irrespective of whether or not insulin is used for treatment or the condition persists after pregnancy. It does not exclude the possibility that the glucose intolerance may
antedate pregnancy but has been previously unrecognized.
Women who become pregnant and who are known to have diabetes mellitus which antedates pregnancy do not have gestational diabetes but have ‘diabetes mellitus and pregnancy’ and should be treated accordingly before, during, and after the pregnancy.Mendeley Citation{7b04ad86-8a82-4989-8836-e333a3c434e1}(4)
Approximately 7% of all pregnancies are complicated by GDM. The prevalence may range from 1 to 14% of all pregnancies, depending on the population studied and the diagnostic tests employed.Mendeley Citation{e62f8f15-0d24-488a-bfd2-01c4d1673c5c};{b2803bc6-8881-4299-93d0-30ea44382e29}(5; 6)
There is, however, a paucity of data on the prevalence of GDM in Sub-Saharan Africa. The few published studies reported a prevalence of between 0 in Tanzania to 9.2% in Ethiopia.Mendeley Citation{ff91f5fe-8fa1-458e-9605-551c15a009ee}(7)
There are no published studies on screening or prevalence of gestational diabetes from Kenya.
Gestational hyperglycaemia is associated with a higher incidence of adverse maternal and foetal outcomes than is seen in normal pregnancy. Untreated GDM has an increased perinatal morbidity and mortality. Morbidity related to macrosomia includes shoulder dystocia with birth injury and perinatal asphyxia in the foetus. In the mother it causes more genital tract injury, obstructed labour, uterine atony and increased risk of caesarean section. The importance of diagnosis of GDM relates not only to potential immediate morbidities at the time of birth but long term sequelae for the child. Obesity, development of type 2 diabetes mellitus, intellectual and neurological development and mental problems are known long term sequelae. For the mother, GDM is a very strong risk factor for the development of type 2 diabetes later in life. Published studies show that after GDM, 35-60% of women develop type 2 diabetes within 10 years.Mendeley Citation{cc0cd935-3a53-408f-850e-8fab0bf68766};{cf3d2084-f4b0-4e28-bfc1-13ba7963f267}(1; 8) Therefore it is prudent that gestational diabetes is diagnosed and appropriate treatment
and monitoring instituted. Diagnosis begins with screening. However, best screening strategy and test is not universally agreed upon.Mendeley Citation{802baf0a-ccca-4286-9644-27c3329b0e1b};{322a8dc2-3608-4507-be2f-76363c9ee35c}(9; 10)
LITERATURE REVIEW
The first study to provide solid evidence of a direct association between maternal glucose levels and pregnancy outcome, irrespective of the diagnosis of GDM, was the HAPO study Mendeley Citation{cc0cd935-3a53-408f-850e-8fab0bf68766};{77f3bad0-4128-45f9-8af9-8a4adacb83e1};{cf3d2084-f4b0-4e28-bfc1-13ba7963f267}(1; 2; 8)
The HAPO study was a large multinational prospective study that included 25505 women. The participants underwent a two-hour OGTT with 75 g of glucose between 24 and 32 weeks of gestation and their glycaemic levels were investigated in relation to predefined adverse pregnancy outcomes. The four predefined primary outcomes were primary caesarean delivery, clinical neonatal hypoglycaemia, and birth weight and cord serum C-peptide above the 90th percentile. Premature delivery, shoulder dystocia or birth injury, intensive neonatal care, hyperbilirubinemia, and preeclampsia were chosen as secondary outcomes. In respect to secondary outcomes, glucose levels were analyzed only as a continuous variable.
For the primary outcomes, glucose concentration was also analyzed as a categorical variable, after stratifying the women into seven categories according to the glucose values obtained during the two-hour OGTT. The frequency of the primary outcomes increased in parallel with increasing maternal glucose levels and odds ratios (ORs) were calculated for all seven glycemic categories, using as reference (OR=1) the category with the lowest glucose concentration ranges. The Odds ratios increased across the categories of maternal glycaemia and these results were statistically significant for all primary outcomes, with the exception of neonatal hypoglycaemia. Similarly, when glucose concentration was analyzed as a continuous variable, a continuous association of maternal glucose with primary and secondary outcomes was observed. Notably, these associations were detected even for low glucose levels and did not differ among the 15 centers in nine countries that participated in the study.
Even though the HAPO study indicated the need to revise the diagnostic criteria of GDM, it did not deduce any threshold glucose values that can be used in clinical practice. Therefore, even after completion of the study, screening and diagnostic methods of GDM still differ among various associations and practice guidelines.
Screening recommendations
A systematic review comparing different guidelines showed large differences between the recommendations made, mainly by international bodies, from ‘screening when clinically indicated’ to ‘universal screening’. These differences translate into a large variation in number of screening tests, costs and translation of these guidelines into practice. Mendeley Citation{7eee92c0-3796-4070-96fc-6ed4a7eea16c}(11) These disparity has persisted over time.
The American Diabetes Association (ADA) in its 2011 position statement on Standards of Medical Care in Diabetes ,Mendeley Citation{2a408b14-7503-400f-8769-5ddc67b305f0}(12) recommends for all pregnant women not known to have diabetes, universal screening for GDM at 24 –28 weeks of gestation, using a 75-g 2-h OGTT and the diagnostic cut points as The diagnosis of GDM is made when any of
the following plasma glucose values are
exceeded:
• Fasting _92 mg/dl (5.1 mmol/l)
• 1 h _180 mg/dl (10.0 mmol/l)
• 2 h _153 mg/dl (8.5 mmol/l)
The American Congress of Obstetricians and Gynecologists
(ACOG) in its practice guideline number 30 to obstetricians recommends selective risk factor led screening of all women at between 24 and 28 weeks gestation using the 50g OGTT screening test. Mendeley Citation{e62f8f15-0d24-488a-bfd2-01c4d1673c5c}(5)
The World Health Organization (WHO) recommends selective screening using the 75 g two-hour OGTT and the diagnostic thresholds of 126 mg/dl (7mmol/dl) and 140 mg/dl (7.77mmol/dl) for fasting and 2-hour glucose concentrations, respectively.Mendeley Citation{c97fc7d2-15e7-4ded-9eb6-2eec977e5fb0}(13) .
The International Diabetes Federation (IDF) global guidelines recommend that women who are at high risk (history of previous GDM) should undergo an OGTT as soon as possible. For all other women the OGTT should be performed between the 26th and 28th week of gestation. In both cases, a one-stage procedure with the 75 g OGTT is preferred.Mendeley Citation{322a8dc2-3608-4507-be2f-76363c9ee35c}(10)
The CDA (Canadian Diabetes Association) guideline recommends universal screening of all pregnant women between 24-28 weeks using the 50g GCT. The CDA also recommends that women with multiple risk factors undergo first trimester screening using the 50g GCT and reassessment in the subsequent trimesters if initial results are negative. It further suggests that in populations at high risk of GDM, a single 75 g OGTT can be used as a definitive screen.Mendeley Citation{4d9615e5-a50e-47b1-a81e-ceb480a3f138}(14)
UK NICE guidelines recommend that screening for gestational diabetes using fasting plasma glucose, random blood glucose, glucose challenge test and urinalysis for glucose should not be undertaken. The 2 hr 75g oral glucose tolerance test (OGTT) should be used to test for gestational diabetes and diagnosis made using the criteria defined by the World Health Organization.Mendeley Citation{ed563252-da45-46ea-8af5-552df92cabae}(15)
The RCOG in a 2011 opinion paper has recommended a review of the current selective screening by NICE following the HAPO study findings and the IADPSG recommendations.Mendeley Citation{3084b161-d57c-4c26-8e41-16d9409fca39}(16)
The Scottish Intercollegiate Guidelines Network (SIGN) recommend a selective screening approach using the 75g OGTT. Mendeley Citation{3084b161-d57c-4c26-8e41-16d9409fca39}(16)
The RANZCOG guidelines recommend Universal Screening at 26 to 28 weeks. Choice of 50g GCT or 75g OGTT is left to the attending clinician.Mendeley Citation{12fa34cc-d26e-49fa-b2e4-948b44918cc6}(17)
Due to the lack of uniform diagnostic criteria for more than 40 years, there has been no global consensus about the appropriate screening or diagnostic test, whether it should be applied selectively or to all pregnant women and about the diagnostic thresholds. There has been both short term and long term benefits of screening and treating maternal hyperglycemia in the HAPO study and the Australian Carbohydrate Intolerance Study in Pregnant Women (ACHOIS). Mendeley Citation{e0e77d26-5310-4e1f-9f85-c7803f2ae142}(18) IADPSG has hence offered recommendations.Mendeley Citation{988afc0d-58ed-49a9-b2f8-08f50eeb2861}(19)
IADPSG recommendations
The IADPSG was formed “as an umbrella organization to facilitate collaboration between the various regional and national groups that have a primary or significant focus on diabetes and pregnancy” In 2010, the IADPSG proposed a new set of diagnostic criteria for GDM, The overall strategy recommended by the IADPSG Consensus
Panel for detection and diagnosis of hyperglycemic
disorders in pregnancy is in two discrete phases. The first is detection of women with overt diabetes not previously diagnosed or treated outside of pregnancy. Universal early testing in populations with a high prevalence of type 2 diabetes is recommended, especially if metabolic testing in this age-group is not commonly performed outside of pregnancy. The second phase is a 75-g OGTT at 24–28 weeks’ gestation in all women not previously found to have overt diabetes or GDM. Mendeley Citation{988afc0d-58ed-49a9-b2f8-08f50eeb2861}(19)
Universal vs. Selective Screening Strategy
The two main strategies to screening are ‘universal’ where all pregnant women undergo a screening test for GDM; and a selective approach where only those women at high risk are screened. The main risk factors are maternal age, high body mass index, family history and cigarette smoking. The different screening strategies used around the world to identify women with GDM include identifying women based on their risk factors then conducting a urinalysis for glycosuria, a random blood sugar, fasting blood sugar, oral glycemic challenge or oral glucose tolerance tests. Mendeley Citation{afbc34be-c860-4bbf-8ac1-75a62a8c59b3};{3f08f104-4dc0-4f7d-85e9-c21c80a50129}(20; 21)
A Cochrane review in 2010 reviewed four trials involving 3972 women recommended further research to determine the most appropriate screening strategy for GDM.Mendeley Citation{fba4f160-e1c2-4f7b-835f-13e2b7847bab}(22)
Gaps in the screening of gestational diabetes and postpartum follow up have been identified. This was in a study that estimated the screening rate and prevalence of gestational diabetes mellitus (GDM) and the
screening rate and prevalence of postpartum diabetes, in a large, national sample of pregnant women. It concluded that many women may not be receiving GDM screening during pregnancy and postpartum diabetes screening rates after pregnancy remain low.Mendeley Citation{89c7e391-f0a3-4418-bfbc-f234da92522f}(23)
Various studies have demonstrated benefits of universal screening over selective screening. The HAPO and ACHOIS studies are the most recent and are expected to greatly influence screening strategies around the world.Mendeley Citation{802baf0a-ccca-4286-9644-27c3329b0e1b};{cc0cd935-3a53-408f-850e-8fab0bf68766};{e0e77d26-5310-4e1f-9f85-c7803f2ae142}(1; 9; 18)
An observational study at the University of Michigan assessing suitability of Selective screening over universal screening found that 10 to 11 % of women with risk factors and 4% of women with GDM would be missed by the selective strategy.Mendeley Citation{2c23bf2b-b393-4157-bbd1-956810f59050}(24)
An audit of pregnancies complicated by diabetes from a centre in United Arab Emirates five years apart with selective versus Universal screening, confirmed the influence of ethnic background on the prevalence of gestational diabetes in a multiethnic and multicultural society. Universal screening was shown to a be a better screening policy in that set up that had a high prevalence of Type II diabetes with 66.7% increase in prevalence over 5 years.Mendeley Citation{82ece845-c9eb-4963-80e6-23935ca1d2e3}(25)
A study in Argentina in 2008 involving 1702 women comparing selective versus universal screening concluded in favour of universal screening. Selective screening yielded 4% prevalence while universal screening 9% .Due this disparity, universal screening was recommended in their population. Thus, all non-hyperglycaemic 24–28-week pregnant women should be tested for GDM with an OGTT, and particular attention must be paid to MG women with risk factors for GDM: if negative at 24–28 weeks, they may be retested at 32 weeks.’Mendeley Citation{e150be1d-e6ca-4869-99fb-0711b79dc7b6}(26)
A randomized study conducted at The National Maternity Hospital, Dublin Ireland showed a GDM prevalence of 2.7% using universal screening compared to 1.45% in the risk factor group. Universal screening also facilitated earlier diagnosis and an improved pregnancy outcome.Mendeley Citation{d39d3503-f127-4672-8041-b8cead755767}(27)
A comparative analysis in Australia showed benefits of universal screening over selective screening.Mendeley Citation{7dc5114a-e287-4136-90f4-151374d2e02d}(28)
A French observational study with end points of fetal and maternal outcomes demonstrated better outcomes with universal rather than selective screening.Mendeley Citation{40dec4f1-fe24-4f3d-be83-629e5b5fac47}(29)
JUSTIFICATION OF THE STUDY
Current practice at The Aga Khan University Hospital Clinic is Selective. Patient’s risk factors are assessed at the booking clinic and clients found to have two or more risk factors are subjected to the 50g O’ Sullivan test with a follow up 75g OGTT for clients with an abnormal O’ Sullivan test. Mendeley Citation{96a3771c-cb00-47eb-886d-1a81f67c7cdf}(30)
The prevalence of type II diabetes in Kenya is estimated at between 4.2% and 12% Mendeley Citation{886326eb-3008-4bbe-ad1a-1278afa3d036}(31) There are no publications to shows estimates of the prevalence of gestational diabetes. It is expected to mirror that of type II diabetes in a population.
At the Aga Khan University Hospital, we still find a number of women at term and the immediate post partum who are diabetic, have impaired glucose tolerance or have foetal macrosomia. The effects of missed diagnosis are likely to be associated with increased morbidity. This raises the possibility that the practice of selective screening of gestational diabetes in the antenatal period based on risk factors identified by history taking does not always diagnose all cases of gestational diabetes.
There is therefore a need to estimate the prevalence of a positive screening test, the prevalence of gestational diabetes, the most significant risk factors in the patients attending our clinic, the most appropriate screening practice for our population.
This study shall aim to provide answers to the questions above. This may influence policies and screening guidelines.
Research Question
Is the detection rate of an abnormal 50g oral glucose challenge test higher with universal screening strategy compared to selective screening strategy?
Null Hypothesis
Detection rates of an abnormal 50g OGTT are higher with Universal screening strategy compared to selective screening strategy.
Broad Objective
To compare the detection rate of universal screening of gestational diabetes using the 50g Glucose Challenge Test to that of selective screening based on risk factors.
Specific Objectives
To compare detection rates of Universal versus Selective risk factor based screening strategy for gestational diabetes mellitus in the local population.
To determine the prevalence of an abnormal screening test for gestational diabetes mellitus.
To identify risk factors most predictive of gestational diabetes in our population.
METHODOLOGY
STUDY SETTING
The study will be based at the Aga Khan University Hospital, Nairobi, which is a 254-bed private tertiary institution under the Aga Khan Health Services. It is located in the North-Western part of Nairobi.
The hospital serves residents of Nairobi and is a referral centre whose catchment includes other parts of the country and the entire East and Central Africa region. It is a teaching hospital offering courses in post graduate medical education and advanced nursing. Patients who attend for antenatal follow-up are a heterogeneous representation from a cosmopolitan population.
The department of Obstetrics and Gynaecology runs several specialized outpatient clinics including antenatal clinics. On average there are forty new antenatal bookings per week.
STUDY POPULATION
Reference population
The target population will include all pregnant women attending the antenatal clinic at the Aga Khan university Hospital, Nairobi over the study period.
Sample population
The sample population will comprise pregnant women booking for antenatal follow-up at or before 28 weeks gestation during the study period
Study population
This will comprise all the pregnant women eligible and recruited for the study.
SAMPLING
Consecutive recruitment as women enrol into the antenatal clinic for booking and regular follow-up. Recruitment shall be conducted after the antenatal consultation is completed.
SAMPLE SIZE DETERMINATION
In Limpopo province of South Africa and using the 2hr OGTT, The prevalence of gestational impaired glucose tolerance (GIGT) and gestational diabetes mellitus (GDM) was 8.8% (7.3% GIGT; 1.5% GDM)Mendeley Citation{ff91f5fe-8fa1-458e-9605-551c15a009ee}(7) The prevalence of gestational diabetes in the low risk population is between 0.1 and 2.8%.Mendeley Citation{7861d51a-f99c-4338-813f-7bff2b2849f3}(32) Mendeley Citation{7861d51a-f99c-4338-813f-7bff2b2849f3}) Studies comparing the two screening strategies show an approximate doubling of prevalence with Universal compared to Selective screening strategy. Mendeley Citation{82ece845-c9eb-4963-80e6-23935ca1d2e3};{d39d3503-f127-4672-8041-b8cead755767}(25; 27)
A sample size of 185 will be required to achieve a 5% alpha error with a 10% width of the confidence interval.
The formula illustrated below will be used to determine the sample size that will enable a comparison between 2 proportions.
1012825165100Formula
where n = the sample size required
p1 = outcome at baseline
p2 = estimated proportion after intervention
Z1-α=critical value for level of significance
Zb =critical value for desired power
P1=9%, P2=19% (Considering an increase of 10% in prevalence as significant)
N= (1.96+0.84)2 (0.09(1-0.09) + 0.19(1-0.19)
(0.09-0.19)2
= ( 2.82) (0.09(0.91)) + 0.19(0.81)
-0.12
= (7.84) (0.0819 + 0.1539)
0.01
=7.84 x 0.2358
0.01
=1.848672
0.01
= 184.8672
N = 185
STUDY DESIGN
The study will be of a cross sectional design.
PROCEDURES
The study will be undertaken at the Aga Khan University Hospital antenatal clinic during the booking visits on Tuesday, Thursday and Friday every week for the period of the study. Patients shall be informed of the study and their consent requested after they have completed their clinic consultation.
Enrolled women will be booked for the 50g Oral Glucose Tolerance Test between 24 and 28 Weeks. The Cost of the screening test shall be met by the study budget.
All subjects shall have their risk factors for gestational diabetes identified and recorded at the beginning of the study.
All subjects recruited shall then undergo the 50g O’Sullivan Screening test. Those subjects found to have an abnormal screening test shall be referred for a diagnostic test, the 75g OGTT for which they shall meet the cost of the test. Those diagnosed as having gestational diabetes shall be followed up at the Combined Physician-Obstetrician-Dietician clinic, the One Stop Medical-ANC Clinic.
At the end of the study, the detection rate of the universal screening strategy will include all participants. The detection rate of the selective risk factor strategy will only include those identified to have risk factors for gestational diabetes mellitus.
The detection rates for both screening strategies shall then be compared.
Inclusion
All pregnant women attending the antenatal clinic at the Aga Khan University Hospital, Nairobi and;
Willing to participate in the study having completed a fully signed informed consent form (appendix I)
Those at or less than 28 weeks gestational age at booking.
Exclusion
Clients who decline to give consent to participate in the study.
Clients who are found at the booking visit to have a gestational age above 28 weeks
Clients with chronic illnesses or medication that may influence glucose metabolism.
Women known to have diabetes mellitus
STATISTICAL ANALYSIS
FLOW CHART: Statistical analysis shall constitute the whole recruited sample and a subgroup of patients identified to be at risk as per the Aga Khan Screening Guidelines.
1733550102870 ALL SUBJECTS
ALL SUBJECTS
7334255080With Risk Factors for GDM
With Risk Factors for GDM
333883043180With No Risk Factors for GDM
With No Risk Factors for GDM
Calculation of detection rates:
For All Subjects (Universal Screening Strategy)
For The At Risk Group (Selective Screening Strategy)
Data management and analysis
Data generated from the study will be stored in a departmental computer under password protection and backed up on an external hard drive. The hard drive will be under the safe custody of the principal investigator. Each entry shall be under the enrolment study number so as to protect the privacy of the study participants. The data collection questionnaires will be filed and stored in a safe cabinet where verification of results can be done whenever necessary.
The primary data will be captured as MS Excel spreadsheets SPSS version 17.0 will be used for data analysis and the statistics presented as proportions and in graphical and tabular format as appropriate.
For continuous variables of normal distribution, the Student’s t-test shall be used to compare the groups and discrete data shall be compared using chi-square analysis and Fischer’s exact test where applicable. A probability < 0.05 shall be considered statistically significant. The Sensitivity, Specificity, NPV and PPV of both screening strategies shall be calculated & compared with each other.
The statistician will offer guidance during data entry, analysis and presentation of the final statistics.
STUDY ADMINISTRATION
The principal investigator will have the sole responsibility to brief the target population about the study, recruit those who will be willing to participate in the study and take their consent. He will further collect the blood samples or liaise with the laboratory to have samples collected and have them clearly labelled and delivered for analysis within 24 hours from the time of collection. The principal investigator will ensure all forms in the study are fully filled by entering both laboratory data and patient information. All data entered shall be checked for completeness and accuracy by the principal investigator as soon as is practically possible.
The supervisor will offer guidance to the principal investigator as the study proceeds as appropriate.
TIME LINE
Proposal develop
