We recommend:

Values up to 20% over ULN are likely to be statistical rather than clinical abnormals

Values < 1.5 times ULN: interval retest in 1-3 months unless clinical suspicion of disease

Values > 1.5 ULN: confirm proportion of indirect (unconjugated) bilirubin

If > 70%, unconjugated, probable Gilbert's syndrome: no further testing needed if non-progessive on interval retesting, unless clinical suspicion of haemolysis. If rising on restesting, consider haemolysis and test haptoglobin, LDH and blood count with reticulocyte count

Values > 3 x ULN: clinical disease probable, further investigation required. Consider ultrasound (conjugated > 50%) or haemolysis (unconjugated > 70%)