What is the role of the PROC FREQ statement?

The PROC FREQ statement in SAS is specifically designed to perform frequency analysis of categorical variables. It generates frequency tables that display the number of occurrences for each category within a variable, allowing researchers to quickly assess the distribution of categorical data. This is particularly useful in clinical trials where understanding the distribution of demographic or categorical outcome variables is important for data interpretation.

These frequency tables can also include percentages and cumulative frequencies, providing a more comprehensive view of how data is distributed across different categories. By identifying the modal category, researchers gain insights into common characteristics within the data set, which can guide further analyses and decision-making in clinical research.

The other options refer to different statistical procedures that are not associated with PROC FREQ. For example, analyzing variance among groups pertains to methods like ANOVA, conducting regression analysis utilizes PROC REG or other similar procedures, and summarizing descriptive statistics often involves PROC MEANS or PROC SUMMARY. Each has its distinct purpose, separate from the frequency analysis offered by PROC FREQ.