Best Tests DIABETES
There has been a marked improvement in diabetes detection in New Zealand over the last few years, but there remains a small section of people who prove difficult to reach. While many of the barriers faced by GPs are common to most practices, there will be other barriers unique to each practice. Methods for identifying and overcoming barriers can not be prescriptive, ideas and solutions need to be as individual as the issues each practice faces.
The recent bpac resource “Detecting Diabetes: Tools for better care” provided a range of tools for identifying and overcoming barriers that will be applicable to many practices. The key questions asked were:
- Is diabetes testing available: Does the practice have the knowledge and tools to provide testing?
- Is diabetes testing appropriate: Are the right people getting the right tests at the right time?
- Is diabetes testing accessible: Are the people that need testing able to access the service?
- Is diabetes testing acceptable: Is testing culturally acceptable to your practice population?
A number of tools are available below to help address each of these questions:
- Tool a: Diabetes Action Plan
- Tool b: Testing guide
- Tool c: Practice poster
- Tool d: How to set up PMS system alert
- Tool e: Patient recall letter
- Tool f: Patient information “Why test me for diabetes”
- Tool g: Peer review group activity
Tool A: Practice Action plan
Plan for targeted testing:
Goal: To create an environment in the practice in which all staff acknowledge and recognise the importance of identifying people with risk factors for diabetes.
Who to test...
|There is currently no recommendation for population wide screening in New Zealand. This is consistent with international recommendations.|
- People with symptoms of diabetes
- People at high risk of diabetes*
- People having CVD risk assessment
What test to use...
Fasting plasma glucose is recommended as the best initial test for the diagnosis of diabetes.
Note: non-fasting glucose has a role in opportunistic testing. A non-fasting glucose of <5.5 doesn’t require further testing while a result of ≥11.1 in symptomatic people is diagnostic of diabetes.
No further testing
|5.5 – 6.0
GTT for those with
|6.1 – 6.9
GTT for all
Asymptomatic: repeat fasting glucose
Symptomatic: diagnostic of diabetes
The following are diagnostic of diabetes
Role of other tests for diagnosis...
HbA1c is now the recommended test for diagnosis of Type 2 Diabetes. For more information, see "When to use fasting glucose to diagnose people with type II diabetes", BT 17 (December, 2012).
What to test...
HbA1c is the best test of glycaemic control in diabetes. Test six monthly in stable diabetics, and three monthly following changes in treatment. The goal is to achieve an HbA1c as low as possible, preferably less than 7.0%, without causing unacceptable hypoglycaemia.
Self monitoring blood glucose
*For further information see BPJ issue 14
- For people with non-insulin treated type 2 diabetes, self-monitoring of blood glucose (SMBG) appears to have little or no effect on glycaemic control.
- SMBG is associated with higher costs and lower quality of life.
- HbA1c remains the most useful tool for assessing glycaemic control in people with non-insulin treated type 2 diabetes.
Fasting lipid levels are measured three monthly until stable and then 6 – 12 monthly thereafter.
Diabetic renal disease
Urinary albumin:creatinine ratio (ACR) and serum creatinine with estimated glomerular filtration rate (eGFR) should be performed on everyone with diabetes at diagnosis and repeated at least annually – more frequently if there is proteinuria, microalbuminuria or reduced eGFR.
Self Monitoring of Blood Glucose – not for everyone
This report looks at your prescribing of glucose testing strips for patients with diabetes.
Historically, self monitoring of blood glucose (SMBG) has been considered an important component for the management of most people with diabetes. New evidence suggests SMBG is not of benefit for patients with diabetes not using insulin.
People on insulin and performing SMBG
For people on insulin, SMBG remains an essential component of maintaining glycaemic control. It is interesting to note that nationally, approximately 10% of all people receiving insulin are not receiving test strips. Data shows there is considerable variation between PHOs with the percentage of people receiving both insulin and SMBG ranging from 71% to 95%.
People with diabetes not using insulin and performing SMBG
Up until recently, the diagnosis of diabetes was accompanied by education of SMBG. This graph* demonstrates that nationally approximately 60% of all people receiving oral hypoglycaemics are performing SMBG. This varies between PHOs, with between 42% and 83% of people on oral hypoglycaemics (but not on insulin), performing SMBG.
For type 2 diabetes patients not using insulin, evidence shows SMBG does not lead to lower HbA1c levels. SMBG is associated with increased cost and lower quality of life, therefore SMBG for this group is not recommended.