AN AUDIT OF ORAL GLUCOSE-TOLERANCE TEST REQUESTS

Requests for 1862 randomly selected oral glucose tolerance tests (OGTT) were reviewed in a general pathology practice. In non-pregnant patients, only 76% of OGTT requests were for the standard 2-hour OGTT. In pregnant patients, 21% of referrals were for the standard 2-hour OGTT, 75% were for a 1-hour screening test following a 50-g oral glucose load, 1% were for a 3-hour OGTT following a 100-g oral glucose load, and 3% were for other variants. Of 922 standardized 2-hour OGTTs performed, 70% may not have been medically necessary and a further 10% resulted in an uninterpretable outcome. Considerable misunderstanding appears to remain within the medical community as to when an OGTT is indicated. There also appears to be little standardization on the tests performed for the detection and diagnosis of gestational diabetes.