There are 2 types of reserved variable fragments described in ADaM: those that are reserved as variable suffix fragments and those that may used in naming ADaM variables. The suffix variables must be used as listed; if they appear at the end of a variable name, then the variable must match the fragment definition. The other fragments listed should be used in variable naming if possible but this does not preclude these fragments appearing in a variable name that has a different meaning.
Required Suffix Fragments for Use in Naming ADaM Variables
The following table lists standard suffix fragments (i.e., variable name fragments used as the last part of a variable name) that are required when naming variables in ADaM datasets, as defined in Section 2.9.5, Predefined Standard Variables for ADSL; Section 2.9.6, Predefined Standard Variables for BDS; and Section 2.9.7, Predefined Standard Variables for OCCDS. For these fragments, it is a requirement that the appropriate fragment be used whenever the concept applies and that the fragment is reserved to be used only for the corresponding concept. For example, a variable whose name ends in DT must contain a numeric date, and a variable created to contain a numeric date must have a name ending in DT.
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Num | Fragment | CDISC Notes | 1 | GRy | Suffix used in names of grouping variables, where "y" refers to the grouping scheme or algorithm (not the category within the grouping). Note that GRy can be abbreviated to Gy when necessary to comply with the variable name length limit of 8 characters. The corresponding numeric version of the variable will use the suffix GRyN (or GyN if the Gy abbreviation is used). For more information on grouping variables see Section 2.9.3.1, General Variable Conventions. | 2 | FL | Suffix used in names of character flag variables, when the valid values of the variable are Y/null or Y/N/null. The corresponding numeric version of the variable will use the suffix FN. For more information on flag variables, see Section 2.9.3.1, General Variable Conventions, and Section 2.9.3.4, Flag Variable Conventions | 3 | DT | Suffix used in names of numeric date variables. For more information on timing variables, see Section 2.9.3.2, Timing Variable Conventions, and Section 2.9.6.3, Timing Variables for BDS Datasets | 4 | TM | Suffix used in names of numeric time variables. For more information on timing variables, see Section 2.9.3.2, Timing Variable Conventions, and Section 2.9.6.3, Timing Variables for BDS Datasets, for examples of timing variables. Note that although ADaM variable ARELTM ends in TM, it is an exception, and is not a numeric time variable. In addition, the SDTM variables -- ELTM are not numeric time variables. | 5 | DTM | Suffix used in names of numeric datetime variables. For more information on timing variables, see Section 2.9.3.2, Timing Variable Conventions, and Section 2.9.6.3, Timing Variables for BDS Datasets, for examples of timing variables. | 6 | DTF | Suffix used in names of date imputation flag variables. Note that DTF can be abbreviated to DF to comply with the variable name length limit of 8 characters. For more information, see Section 2.9.6.3, Timing Variables for BDS Datasets, for examples of timing imputation variables. | 7 | TMF | Suffix used in names of time imputation flag variables. Note that TMF can be abbreviated to TF to comply with the variable name length limit of 8 characters. For more information, see Section 2.9.6.3, Timing Variables for BDS Datasets, for examples of timing imputation variables. | 8 | DY | Suffix used in names of relative day variables that do not include day 0. For more information on timing variables, see Section 2.9.3.2, Timing Variable Conventions, and Section 2.9.6.3, Timing Variables for BDS Datasets. | |
Additional Fragments that May Be Used in Naming ADaM Variables
The following table lists additional standard reserved fragments to use as a guide when naming variables in ADaM datasets. This list should be used in addition to the list of timing fragments defined in Section 2.9.3.5, Variable Naming Fragments, and the fragments defined in the CDISC Non-Standard Variables Registry. It should be noted that some concepts have slightly different fragments in ADaM than in the TIG; the ADaM fragment takes precedence when creating an ADaM variable. When using fragments, the general rule is to use the fragment(s) that best conveys the meaning of the variable within the 8-character limit. This list of fragments is provided as a guideline, not as a requirement.
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Num | Fragment | CDISC Notes | 1 | BL | Baseline. As described below, the position of this fragment within the variable name is dependent on the purpose of the variable. Not to be used to support more than 1 baseline definition for AVAL in BDS datasets. See paragraph immediately following this table. | 2 | CHG | Change. As described below, the position of this fragment within the variable name is dependent on the purpose of the variable. Not to be used to support change from more than one baseline for AVAL in BDS datasets. See paragraph immediately following this table. | 3 | FU | Follow-up. As described below, the position of this fragment within the variable name is dependent on the purpose of the variable. | 4 | OT | On treatment. As described below, the position of this fragment within the variable name is dependent on the purpose of the variable. | 5 | RU | Run-in. As described below, the position of this fragment within the variable name is dependent on the purpose of the variable. | 6 | SC | Screening. As described below, the position of this fragment within the variable name is dependent on the purpose of the variable. | 7 | TA | Taper. As described below, the position of this fragment within the variable name is dependent on the purpose of the variable. | 8 | TI | Titer. As described below, the position of this fragment within the variable name is dependent on the purpose of the variable. | 9 | U | Units. The position of this fragment is at the end of the variable, as a suffix. To identify the units for a variable, a separate variable can be created, using the name of the original variable with a "U" suffix added. To keep within the 8-character variable name length limit, some truncation may be necessary prior to appending the U. In situations where the units do not vary within the ADaM dataset, it may be preferable to simply include the units in the variable's label and metadata. The approach taken will be determined by the producer, based on the requirements of the analysis and review of the dataset. Note that there is no separate units variable for BDS variables PARAM or AVAL, since the units of AVAL will be included in the value of PARAM. | 10 | WA | Washout. As described below, the position of this fragment within the variable name is dependent on the purpose of the variable. | |