Special Variables

Variables with xx, y, and zz Parameters

Overview: Variables with xx, y, and zz Parameters

Some ADaM variables contain embedded parameters that require values. These parameters can be a single digit (denoted by y in the name of the variable) or two digits (denoted by xx or zz in the name of the variable). Example names of such variables are CRITy, TRTxxP, and ANLzzFL. Some variables contain multiple parameters, such as TRxxPGy.

If you include a variable with a parameter in an ADaM data set, you must select the value (or values) to use for the parameter. The values of the parameters become part of the variable’s name.

For example, if the variable TRxxPGy is used, and you select values 01 and 02 for xx, and 3 and 4 for y, these variables are created: TR01PG3, TR01PG4, TR02PG3, and TR02PG4.

Note: An ADaM data set might contain only a subset of the values that are associated with the xx, y, and zz parameters.

xx Parameter

The xx parameter represents a two-digit period. Single digits are padded with a leading zero. Valid values are 01–99.

When planning to create an ADaM data set, consider the periods to include in the analysis. Then, assign a unique two-digit number to each period.

y Parameter

The y parameter represents a single-digit grouping or category, an analysis criterion, or an analysis range. Valid values are 1–9.

When planning to create an ADaM data set, consider the groups or categories, analysis criteria, and ranges to include in the analysis. Then, assign a unique single-digit number to each.

These tables indicate how the y parameter is used in various variables.

ADSL Grouping Variables
Variable	Description of y
SITEGRy, SITEGRyN	The index of a site-grouping algorithm
RACEGRy, RACEGRyN	Denotes the index for a particular pooling or grouping of race
TRxxPGy, TRxxPGyN	The index for a particular planned pooled treatment
TRxxAGy, TRxxAGyN	The index for a particular actual pooled treatment

BDS Grouping Variables
Variable	Description of y
TRTPGy, TRTPGyN	The planned pooled treatment scheme
TRTAGy, TRTAGyN	The actual pooled treatment scheme
PARCATy, PARCATyN	A parameter category
AVALCATy	An analysis category
BASECATy, CHGCATy, PCHGCATy	A baseline category
R2AyLO, R2AyHI, AyLO, AyHI	An analysis range
SHIFTY, SHIFTyN	A group
CRITy, CRITyFL, CRITyFN	An analysis criterion

zz Parameter

The zz parameter represents a two-digit index for the zzth record selection algorithm. Single digits are padded with a leading zero. Valid values are 01–99.

When planning to create an ADaM data set, consider the record-selection algorithms to use. Then, assign a two-digit number to each algorithm.

Wildcard Variables

Some ADaM variables contain a wildcard character that requires a value. A wildcard is denoted by an underscore (_) in the name of the variable. Example names of such variables are _DTF, _STM, and _SDTM.

If you include a variable with a wildcard in an ADaM data set, you must select the value to substitute for the wildcard and a value to substitute for the ellipsis (…) in the variable description.

Note: The variable name is limited to no more that eight characters.

Note: Part of the variable description is automatically generated. You cannot change this text.

For example, here is the wildcard variable _STM:

In this example, the value for Name prefix replaces the underscore in the name _STM. And, the value for Description suffix replaces the ellipsis. The generated variable name becomes prefSTM. The generated description becomes Start Time of descSuffix.