Screening for type 2 diabetes and impaired glucose metabolism: the Australian experience.
OBJECTIVE
To assess the Australian protocol for identifying undiagnosed type 2 diabetes and impaired glucose metabolism.


METHODS
The Australian screening protocol recommends a stepped approach to detecting undiagnosed type 2 diabetes based on assessment of risk status, measurement of fasting plasma glucose (FPG) in individuals at risk, and further testing according to FPG. The performance of and variations to this protocol were assessed in a population-based sample of 10,508 Australians.


RESULTS
The protocol had a sensitivity of 79.9%, specificity of 79.9%, and a positive predictive value (PPV) of 13.7% for detecting undiagnosed type 2 diabetes and sensitivity of 51.9% and specificity of 86.7% for detecting impaired glucose tolerance (IGT) or impaired fasting glucose (IFG). To achieve these diagnostic rates, 20.7% of the Australian adult population would require an oral glucose tolerance test (OGTT). Increasing the FPG cut point to 6.1 mmol/l (110 mg/dl) or using HbA(1c) instead of FPG to determine the need for an OGTT in people with risk factors reduced sensitivity, increased specificity and PPV, and reduced the proportion requiring an OGTT. However, each of these protocol variations substantially reduced the detection of IGT or IFG.


CONCLUSIONS
The Australian screening protocol identified one new case of diabetes for every 32 people screened, with 4 of 10 people screened requiring FPG measurement and 1 in 5 requiring an OGTT. In addition, 1 in 11 people screened had IGT or IFG. Including HbA(1c) measurement substantially reduced both the number requiring an OGTT and the detection of IGT or IFG.
Colagiuri
Stephen
S
Department of Endocrinology, Diabetes and Metabolism, Prince of Wales Hospital, Randwick, NSW, Australia. colagiuris@sesahs.nsw.gov.au
Hussain
Zafirul
Z
Zimmet
Paul
P
Cameron
Adrian
A
Shaw
Jonathan
J
D001315:Australia; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000453:epidemiology*; D018149:Glucose Intolerance / Q000175:diagnosis / Q000453:epidemiology*; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D012307:Risk Factors
D001786:Blood Glucose; D006442:Glycated Hemoglobin