Table 1 Therapeutic regimen of this study

Pirfenidone

The initial dosage is 200 mg/time, 3 times/day; and then add the dose to 600 mg/time by 200 mg/day. Finally, the dose is 600 mg/time, 3 times/day for 12 months

Take it half an hour after breakfast, lunch and dinner, respectively

Drug must be used for each participant

Acetylcysteine

200 mg/time, 3 times/day for 12 months

Take it half an hour after breakfast, lunch and dinner, respectively

Selective use for all subjects

Glucocorticoid

0.5 mg × kg⁻¹ × day⁻¹ for 1 month, and then 0.25 mg × kg⁻¹ × day⁻¹ for 2 months, and then the dose decline to 0.125 mg × kg⁻¹ × day⁻¹ for 12 months

Take it half an hour after breakfast, lunch and dinner, respectively

Selective use for all subjects

Chinese medicine granules 1

8 g/bag, 2 bags/ time, 3 times/day for 12 months

Take this granula after mixing it with water, take it half an hour after breakfast, lunch and dinner, respectively

Drug must be used for each individual in treatment group

Chinese medicine granules 2

8 g/bag, 2 bags/time, 3 times/day for 12 months

Take this granula after mixing it with water, take it half an hour after breakfast, lunch and dinner, respectively

Drug must be used for each volunteer in control group