Table 1. Overview of GRADE evaluation.

Outcomes	Study design, n	Study quality	Consistency	Directness	Overall quality
Incidence of hepatotoxicity	Randomised clinical trials, 4 Observational studies, 15	No serious limitations	Important inconsistency in the definition of hepatotoxicity and how it is described	No uncertainty about directness	Moderate
Diagnostic methods	Randomised clinical trials, 2 Observational studies, 8 Case reports, 5	No serious limitations	Important inconsistency in the use of diagnostic modalities across studies	No uncertainty about directness	Moderate
Reduction or truncation of 6TG	Randomised clinical trials, 3 Observational studies, 10 Case reports, 9	No serious limitations	No serious inconsistency	No uncertainty about directness	High