Driving under the influence (DUI) is not the same as a prescribed concentration of alcohol (PCA) offences.
PCA offences such as low, mid, or high-range drink driving require police to prove that your blood alcohol concentration was not in a normal average. However, DUI charges do not require police to prove that you were contrived by a specific amount of alcohol—only that you were somehow under the influence of an alcohol or drugs.
Rather than a breath test, DUI charges, in general, are based on police observations regarding your driving, actions or demeanour that highlight that you were under the influence of drugs or alcohol.