Page History

...

2. The lower-case letters "w", "xx", "y", and "zz" that appear in a variable name or label in this document must be replaced in the actual variable name or label using the following conventions:

a. The lower-case letter "w" in a variable name (e.g., PHwSDT, PxxSwSDT) is an index for the wth variable where "w" is replaced with a single digit [1–9].

b. The letters "xx" in a variable name (e.g., TRTxxP, APxxSDT) refer to a specific period where "xx" is replaced with a zero-padded two-digit integer [01–99]. The use of "xx" within a variable name is restricted to the concept of a period, and "xx" is not considered an index.

c. The lower-case letter "y" in a variable name (e.g., SITEGRy) refers to a grouping or other categorization scheme, an analysis criterion, or an analysis range, and is replaced with an integer [1–99, not zero-padded]. Truncation of the original variable name may be necessary in rare situations when a two-digit index is needed and causes the length of the variable name to exceed 8 characters. In these situations, it is recommended that the same truncation be used for both the character and numeric versions of the variables in a variable pair.

d. The lower-case letters "zz" in a variable name (e.g., ANLzzFL) are an index for the zzth variable where "zz" is replaced with a zero-padded two-digit integer [01-99]. Note that the "zz" convention represents a simple counter, while the "xx" convention represents a specific period.

e. If an indexed variable is included in a dataset, there is no requirement that the preceding variable(s) in the sequence be included. For example, a dataset might include ANL02FL but not ANL01FL.

3. Any variable in an ADaM dataset whose name is the same as an SDTM variable must be a copy of the SDTM variable, and its label, meaning, and values must not be modified. ADaM adheres to a principle of harmonization known as "same name, same meaning, same values." However, to optimize file size, it is permissible that the length of the variables differ (e.g., trailing blanks may be removed). In many cases it makes sense to copy over a variable from an SDTM dataset. For example, the SDTM variable --SEQ may be useful for traceability. However, in other cases, it is also perfectly acceptable, and might be much better, to create an ADaM variable with a meaningful variable name and clear and unambiguous metadata. An SDTM variable may be somewhat meaningless when removed from its SDTM context. For example, the meaning of the SDTM variable DSDECOD may depend on other SDTM variables such as DSCAT and DSSCAT, and ultimately on how the data were collected and mapped to SDTM in a particular study; thus it may be better to create a clearly defined ADaM variable. In any case, whenever values are modified in any way, it is mandatory to do so in an ADaM variable, and it is prohibited to do so in a variable whose name is that of an SDTM variable.

4. When

 an an ADaM standard variable name has been defined for a specific concept, the ADaM standard variable name must be used, even if the content of an ADaM variable is a direct copy of the content of an SDTM variable. For example, in the creation of an ADaM dataset based on an SDTM LB dataset, even if AVAL is just a copy of LBSTRESN, the dataset must contain AVAL.

...