Classify Results and Catch Two Invalid Applications

The case set includes ordinary threshold examples and two invalid applications. Use the current criteria card and attached method notes to classify the ordinary examples, then flag any result that cannot be used the way it is being requested before signing off on a disposition.

The two invalid applications are not simple threshold lookups. One is the triage point-of-care glucose already discussed: 142 mg/dL, nonfasting, drawn on a meter validated for monitoring, not diagnosis. Using it to support or exclude a diabetes diagnosis is an invalid application regardless of the number itself. The other is an A1c of 5.9% charted on a patient with documented sickle cell trait, carrying a lab comment that reads variant interference possible, method-dependent. A value inside the 5.7-6.4% prediabetes band does not settle the question when the assay's reliability for this patient has not been checked; the correct action is to verify interference against the specific analyzer before treating 5.9% as this patient's true glycemic status.

The ordinary threshold examples are ordinary threshold applications: a fasting glucose, a 2-hour OGTT value, and a same-day A1c and fasting-glucose pair, each read straight against the criteria card from the focused-instruction section. The discipline is the same one used in the guided example: identify which category each result belongs to, apply the correct threshold, and decide whether one abnormal result is sufficient or whether the two-abnormal-result rule needs a second confirming test.

Classifying a result correctly means checking both the number against the threshold and the test against its validated role; a number that looks fine can still be the wrong tool for the question being asked.