Table 2 Incidence of hepatic injury.

	Hepatic injury	Person‐years under observation	Incidence rate (95% CI)	Incidence rate ratio (95% CI)
Exposure classification 1*
High exposure group	22	86.7	0.25	9.6 (3.8–28.9)
Low exposure group	6	226.6	0.03
Exposure classification 2†
High exposure group	19	75.0	0.25	6.7 (2.9–16.8)
Low exposure group	9	238.4	0.04
All subjects	28	313.3	0.09 (0.06–0.13)

*The cut‐off for exposure classification 1 was 20 mg/g creat.

†The cut‐off for exposure classification 2 was 30 mg/g creat.