Effectiveness of screening for diabetes.

Area of Science:

• Endocrinology
• Preventive Medicine
• Clinical Diagnostics

Background:

• Diabetes mellitus is a growing public health concern.
• Effective screening strategies are crucial for early diagnosis and management.
• Current screening methods for diabetes mellitus have varying diagnostic yields.

Purpose of the Study:

• To evaluate the diagnostic yield of screening for diabetes mellitus using fasting serum glucose and hemoglobin A1c.
• To compare the effectiveness and cost of different confirmatory testing methods.

Main Methods:

• Analysis of patient records from 6445 visits to an executive health surveillance program.
• Measurement of fasting serum glucose and hemoglobin A1c for screening.
• Confirmatory testing using oral glucose tolerance tests (OGTT) and repeated fasting glucose determination.

Main Results:

• Increased fasting serum glucose (≥ 6.6 mmol/L) was found in 3% of patients, with only half receiving confirmatory testing.
• Confirmatory OGTT revealed a 70% incidence of diabetes mellitus and impaired glucose tolerance in those with elevated screening glucose.
• OGTT was equivalent in cost and superior in diagnostic yield to repeated fasting glucose determination.
• Hemoglobin A1c was unreliable for predicting impaired or diabetic glucose tolerance.

Conclusions:

• Obligatory confirmatory oral glucose tolerance testing is essential for maximizing the value of diabetes mellitus screening.
• Clinician preference for repeated glucose determination contributes to underdiagnosis.
• Current screening protocols may not be fully optimizing diabetes detection.