Deciphering PROC COMPARE Codes: The Use of the bAND Function

The COMPARE procedure is very useful for validating SAS® data sets in clinical studies. One particularly useful feature is its SYSINFO system macro variable by which numerical codes are issued following the comparison of data sets. These codes represent up to 16 messages that describe the outcome of the comparisons. Thus, interpreting SYSINFO codes can provide a very concise PROC COMPARE report, especially when many pairs of data sets are involved. In this paper, we demonstrate a novel approach for decoding SYSINFO values using the SAS function bAND (bitwise logical AND). With this function, one can quickly determine which of the 16 PROC COMPARE output messages a SYSINFO code contains.