C4A and systemic lupus erythematosus: Meta-analysis showed that the additional use of Qinghao Biejia decoction superior to chemical medicine alone in people with SLE in improving the overall response rate (RR = 1.30, 95% CI [1.19, 1.41], p < 0.00001, heterogeneity p = 0.61, I2 = 0%), and can decrease SLE Disease Activity Index (SLEDAI) and TCM symptom scores, improve immunological indexes (C3, C4, IgG, IgA, IFN-γ, IL-4, Th1/Th2), reduce the occurrence of adverse events in treatment (P ≤ 0.05).