Maternity Unit, Southern General Hospital, Glasgow
Audit title
Local Audit of Referrals for Oral Glucose Tolerance Testing (OGTT) according to SIGN Guideline 116.
Specialty/service
Obstetrics and Gynaecology
Division
Southern General Hospital, Glasgow
Project teamProject Lead: Caroline Toye / Medical Student
Dr Judith Roberts / Consultant Obstetrician
Sandy Cameron / Ward Sister
Data Period: June-July 2011
Clinical audit report
Project title
Local audit of referrals for Oral Glucose Tolerance Testing (OGTT) according to SIGN guideline 116.
Specialty/service/operational area (locality)
Maternity Unit Southern General Hospital, Glasgow
Disciplines involved
Obstetrics and Gynaecology, Midwifery, Medical Students.
Project lead
Caroline Toye, 4th year medical student, University of Glasgow – data collection and audit report writing
Other staff members involved
Dr J Roberts, Consultant Obstetrician and Gynaecologist, Southern General Hospital
S Cameron, Sister, Southern General Hospital
Background/rationale
It is still unclear which characteristics should be considered as risk factors for gestational diabetes and which of these indicate the need for referral for oral glucose tolerance testing (OGTT) (SIGN 2010). Although there are a few risk factors identified in clinical guidelines, other features of pregnancy may warrant the physician or midwife to consider referral of this patient, such as persistent glycosuria or polycystic ovary syndrome (Impey and Child, 2008).
As well as indications for referral, the time frame in which patients are tested is also very important. Those diagnosed with gestational diabetes should be diagnosed at an early stage of their pregnancy so that through appropriate management (dietary advice, blood glucose monitoring and insulin therapy) they can reduce the risk of macrosomia and perinatal complications such as shoulder dystocia, bone fractures and nerve palsies (Crowther et al, 2005).
For these reasons this audit investigates which features are indicated in the referral of patients with suspected gestational diabetes, the stage of their pregnancy in which they are tested and whether these adhere to current clinical guidelines.
Aim
To be able to evaluate if patients are referred for oral glucose tolerance testing within the gestational time period recommended by national clinical guideline SIGN 116.
To be able to evaluate the extent of which indications for referral of patients for oral glucose tolerance testing comply with SIGN 116 guidelines.
Objectives
To ensure that referrals for oral glucose tolerance testing comply with SIGN guidelines.
Standards/guidelines/evidence base
SIGN (March 2010) clinical guideline 116: Management of Diabetes. Section 7: Management of Diabetes in Pregnancy.
Sample
Patients referred to Daycare for OGTT (oral glucose tolerance testing) in a 4 week period from 27th June to 21st July are included in the audit.
There were a total of 42 patients referred for OGTT during this period. The health records of 33/42 patients were obtained; 9 health records were unavailable to be retrieved as they were used for other clinical purposes whilst this data was collected. Of the 33 case notes reviewed, 3 patients were tested for postnatal diabetes and so the total number of case notes which could be included in this audit was 30, thus N=30.
Data source
The daycare clinic midwives use pink forms which are placed inside patients’medical records. On the day of assessment, information regarding indication for testing and the stage of gestation of the pregnancy are noted on these forms by the midwives in the clinic. The following day the results of OGTT from the laboratory were recorded on a clipboard and on patients’ pink forms, with a statement as to what management is appropriate regarding their results.
Information written by the midwives on the pink forms regarding the stage of gestation and the indication for referral for OGTT provided the information required for this clinical audit.
Audit type
Information from completed pink forms regarding indications for referral and gestation were retrieved retrospectively.
Methodology
This clinical audit took place at a local level at the Southern General Hospital in July 2011.
The planning of this audit was discussed between a medical student, an Obstetrics Consultant and Daycare Sister. The Daycare Sister gave consent for the medical student to access medical records and informed the midwives of their presence during the course of the month whilst they collected the necessary data required for the audit.
Data was obtained by manually checking patients’ referral forms (pink forms), completed by the midwives 1 day prior to the appointment. The midwives note the stage of gestation of the patient and the indications for which the patient was referred for OGTT. Data was collected using a notepad but personal details were omitted so that patients remained anonymous. Microsoft Excel was used to analyse the data.
This report was written by Caroline Sarah Toye, a fourth year medical student at the University of Glasgow.
Caveat
The pink forms provided all the information regarding the gestation at which the women were referred to the clinic for OGTT and the indications which prompted the referral; medical notes from previous antenatal appointments or from the community midwife referrals were not used. There therefore may be discrepancies between what the midwives and consultants would consider as indications for referral.
Findings
30 patient cases were considered suitable for inclusion in this audit (3 of 33 patients were post-natal patients and could therefore not be included) thus N=30.
1. Standard: “All women with risk factors should have 75g OGTT at 24-28 weeks”(SIGN)
“All women with risk factors should have 75g OGTT at 24-28 weeks” SIGN (n=30)Weeks gestation / <23+6 weeks / 24-28+6 weeks / 29+ weeks
No. of patients (n=30) / 3 (10%) / 13 (43%) / 14 (47%)
2. Standard: According to SIGN guidelines, the following risk factors are associated with an increased risk of gestational diabetes:
· BMI >30kg/m2
· Previous macrosomic baby
· Previous gestational diabetes
· Family history of diabetes
· Family origin associated with a high prevalence of diabetes:
- South Asian: India, Pakistan or Bangladesh
- Black Caribbean
- Middle Eastern: Saudi Arabia, United Arab Emirates, Iraq, Jordan, Syria, Oman, Qatar, Kuwait, Lebanon or Egypt
The table below shows the indications which were stated on patient’s pink forms. Please note that the total number of indicators is greater than the number of patients as more than one reason may have been stated for the referral for OGTT, hence n=42.
Indications Stated on Pink Forms in the Referral of Patients for OGTT (the guideline approved indications are shown in bold)Indications / BMI >30kg/m2 / Previous macrosomic baby / Previous GDM / Family history DM / Polyhydramnios / Abdominal circumference >95th centile / Glycosuria / OGTT tested in previous pregnancy / Thirst
Frequency of indication written in notes (n=42) / 5 (12%) / 4 (10%) / 2 (5%) / 6 (14%) / 9 (21%) / 8 (19%) / 6 (14%) / 1 (2%) / 1 (2%)
Compliance / Non-compliance
Indications for referral are those approved by SIGN guidelines (n=42) / 17/42 (40%) / 25/42 (60%)
Unfortunately as the pink forms did not state the family origin of patients, it was not possible to discern those who may be from an area with a high prevalence of diabetes.
Summary of audit findings:
No. / Standard / N 2011 / Compliance 20111. / All women with risk factors should have 75g OGTT at 24-28 weeks (SIGN) / 30 / 43%
2. / Indications for referral for OGTT are those approved by SIGN guidelines / 42 / 40%
Observations
Timeframe for Oral Glucose Tolerance Testing
1. Less than half of all the patients referred for testing were referred at the recommended gestation period stated by the SIGN guidelines.
This is surprising to discover as there is much emphasis on testing women who have a previous history of gestational diabetes. In the 30 patient cases, two patients were diagnosed with gestational diabetes. It is significant to note that both these patients were referred for testing out with the recommended gestational testing period.
There may be several reasons as to why many of these patients did not meet the recommended target for referral for OGTT:
- Failed to attend previous daycare appointment for OGTT which was within the appropriate timeframe
- Transportation – patient may have found it difficult to travel to the hospital. They may therefore have had their OGTT to coincide on the same day as their antenatal clinic appointment, which may have led to a delay in OGTT.
- Patients referred for OGTT at a later stage of their pregnancy to investigate the cause of unexplained macrosomia.
Indications for Referral
2. Polyhydramnios and “abdominal circumference >95th centile” were the most commonly written indicators for referral for OGTT.
Polyhydramnios and abdominal circumference >95th centile are characteristics of macrosomia. According to SIGN guidelines these do not qualify as suitable indicators to warrant testing for gestational diabetes. However, “previous macrosomic baby” is an indication for referral and so it would make sense to also consider polyhydramnios and an abdominal circumference of the foetus as > 95th centile as risk factors. As features of macrosomia cannot be identified at the first booking appointment, patients with polyhydramnios or “abdominal circumference >95th centile” written in their notes must have been those referred to the daycare clinic at a later stage of their pregnancy (which may explain why there was such a high incidence of patients referred for OGTT beyond 28 weeks gestation). It seems that these referrals for OGTT were more likely to identify whether gestational diabetes is the cause of the macrosomia and to prepare for potential complications at birth rather than identifying at an earlier gestational stage those with gestational diabetes, in the hope of controlling the diabetes and reducing the risk of macrosomia.
3. “Previous OGTT in previous pregnancy” is also not considered an indicator according to guidelines.
This was quite a vague description and so it required further investigation in the patient’s notes. There was no evidence of previous gestational diabetes in this patient’s notes.
4. Glycosuria is not strictly an indicator of gestational diabetes.
However, many recognise the importance of persistent glycouria as an indicator of type 1 or type 2 diabetes mellitus (Impey and Child, 2008). The majority of these patients had other risk factors written in their notes so it is difficult to evaluate the importance of including glycosuria as an indicator for OGTT referral.
5. The indication of “thirst” is not currently recognised as an indication to warrant referral for OGTT.
This patient had no other risk factors to suggest an increased risk of gestational diabetes. They were referred by a community midwife. It is therefore significant to question whether it was necessary for this patient to have this referral.
The main issue regarding the referral of patients for OGTT is identifying at the first booking appointment (12 weeks) those with guideline-approved risk factors of increased risk of gestational diabetes.
Presentation/Discussion
This audit is yet to be presented and discussed.
Recommendations
1. This audit should be repeated but with a greater size of data and for a longer duration of time to improve reliability of results.
2. Medical professionals should try to schedule antenatal appointments and OGTT testing for the same day so that OGTT lies within the 24-28 weeks gestation period in the hope of improving attendance.
3. Forms which contain all the suitable indications for referral for OGTT should be provided to all medical professionals responsible for referring patients. Those who refer patients for OGTT should need to complete this form by showing which of these applies to the patient eg ticking boxes. In particular, it should be noted which patients originate from a country with a high prevalence of gestational diabetes, as this was not noted on any of the pink forms and is a recognised indicator for OGTT referral in accordance with guidelines.
4. Once these changes have been implemented, a re-audit is required to note any improvement in compliance to guidance.
Learning points
In hindsight, it would have been worthwhile to compare the patients’ medical notes to the pink forms to note any differences with regards to indications for referral. It would also help to establish whether the delay of OGTT could be due to failure to attend these appointments.
References
Crowther, C.A., Hiller, J.E., Moss, J.R., McPhee, A.J., Jeffries, W.S., Robinson, J.S. Effect of Treatment of Gestational Diabetes Mellitus on Pregnancy Outcomes. N Engl J Med 2005; 352:2477-86
Impey, L., Child, T. Diabetes and Gestational Diabetes in: Obstetrics and Gynaecology. 3rd edition. Published 2008. Blackwell Publishing. ISBN: 978-1-4051-6095-7.
NICE (March 2008) clinical guideline 63: Diabetes in Pregnancy.