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At least 1 product variable is required in a BDS dataset. This requirement is satisfied by any of the subject-level product variables (e.g., TRTxxP) or record- level product variables (e.g., TRTP). All product variables defined in Table 3.3.2.1 are record level, meaning that the values contained in the variable may vary by record within a subject. Subject-level product variables are described in Section 2.9.5.4 Product Variables for ADSL Datasets.

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