- STRESC will be populated in the following way when --ORRES is populated:
- By conversion of values in --ORRES to values in standard units
When --ORRES is populated, --STRESC must also be populated, regardless of whether the data values are character or numeric. The variable --STRESC is populated either by the conversion of values in --ORRES to values with standard units, or by the assignment of the value of --ORRES, as in the Physical Examination (PE) domain, where --STRESC could contain a dictionary-derived term. A further step is necessary when --STRESC contains numeric values. These are converted to numeric type and written to --STRESN. Because --STRESC may contain a mixture of numeric and character values, --STRESN may contain null values, as shown in the following figure.
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Figure. Original to Standardized Results
When the original measurement or finding is a selection from a defined codelist, in general, the --ORRES and --STRESC variables contain results in decoded format (i.e., the textual interpretation of whichever code was selected from the codelist). In some cases where the code values in the codelist are statistically meaningful standardized values or scores, which are defined by sponsors or by valid methodologies such as SF36 questionnaires, the --ORRES variables will contain the decoded format, whereas the --STRESC variables as well as the --STRESN variables will contain the standardized values or scores.
Occasionally data that are intended to be numeric are collected with characters attached that cause the character-to-numeric conversion to fail. For example, numeric cell counts in the source data may be specified with a greater than (>) or less than (<) sign attached (e.g., >10,000, <1). In these cases, the value with the greater than (>) or less than (<) sign attached should be moved to the --STRESC variable, and --STRESN should be null. The rules for modifying the value for analysis purposes should be defined in the analysis plan and a numeric value should only be imputed in the ADaM datasets. If the value in --STRESC has different units, the greater than (>) or less than (<) sign should be maintained. See Example 1, Rows 11 and 12