Table 10 Influencing factors of brand substitution
Type | Factors | Explanation | Variable Type and Assignment | References |
|---|---|---|---|---|
Policy effect | Round of NCDP | Which round of the NCDP did the drug belong to | Categorical variable, the first to the fifth round were assigned as 1–5 respectively | Jiang Y(2019)[15] Wang J(2022)[16] |
Drug market condition | Price reduction of bid-winning brands | Price reduction = -(bid-winning price -retail price before policy intervention)/retail price | Continuous variable | Huang S(2019)[17], Yang X(2019)[18] |
Average price reduction of bid-non-winning brands | Price reductiona = -(average price before policy intervention—average price after policy intervention)/average price before policy intervention | Continuous variable | ||
Indication type | Indication type of the policy-related drug | Categorical variable, detailed assignment shown in Table 12 | Hu S(2021)[19], Han J(2021)[20], Zhen D(2022)[21] | |
Number of drugs of the same indication selected before | Number of policy-related drugs of the same indication selected into the NCDP before the target drug | Continuous variable | ||
Number of drugs of the same indication selected after | Number of policy-related drugs of the same indication selected into the NCDP after (or together with) the target drug | Continuous variable | ||
Previous drug utilization of the medical institution | Whether bid-winning brands were used before policy intervention | Whether bid-winning brands were used in the medical institution before policy intervention | Binary variable | Han J(2021)[20] |
Whether brand-name drugs were used before policy intervention | Whether brand-name drugs were used in the medical institution before policy intervention | Binary variable | ||
Number of prescriptions | Number of prescriptions from 2019 to 2021 | Continuous variable | Actual situation of the medical institution |