Controlled before-and-after study (Intervention study): Sample size: Use the formula to determine the difference o between the two pre - and post-intervention rates: Type 1 error, select α = 0.05 (95% confidence) Z1-α/2 = 1, 96; β: type 2 error, select β = 0, 1 (study power 90%) Zβ = 1, 28; p1: The proportion of drug use according to FHI evaluation was 12%; p2: The proportion of patients using the drug after the intervention was reduced to 5%.