Counting Subjects by Treatment Group

The script creates a demo dataset `sample_adsl` containing information on subjects and their treatment groups (`trta`, `trtan`). A macro `%count` is then defined, which takes as parameters the input dataset, variables to consider for sorting and counting, and the numerical range of treatment groups. The macro uses `PROC SQL` to count distinct subjects (`usubjid`) for each treatment group within the specified range and stores these counts in global macro variables (e.g., `bign0`, `bign1`, etc.). Finally, the macro is called with the appropriate parameters for the `sample_adsl` dataset and treatment groups 0 to 3.

Data Analysis

Type : CREATION_INTERNE

The `sample_adsl` dataset is created directly within the script using a DATA step. It does not depend on unmanaged external data sources or SASHELP libraries.

1 Code Block

DATA STEP Data

Explanation :
This DATA step creates the `sample_adsl` dataset. It is populated with five observations, each representing a subject (`usubjid`) assigned to a treatment group (`trta` with its numerical version `trtan`). This dataset serves as a test basis for subject counting.

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1	DATA sample_adsl;
2	trta="Placebo";trtan=0;usubjid="A1";OUTPUT;
3	trta="Drug A";trtan=1;usubjid="B2";OUTPUT;
4	trta="Drug B";trtan=2;usubjid="C3";OUTPUT;
5	trta="Placebo";trtan=0;usubjid="D4";OUTPUT;
6	trta="Drug A";trtan=1;usubjid="E5";OUTPUT;
7	RUN;

2 Code Block

MACRO %COUNT

Explanation :
This macro named `%count` is designed to count distinct subjects. It supports an input dataset (`data`), counting and sorting variables (`var`), and a range of treatment groups (`trts` to `trte`). Inside the macro, `PROC SQL` is used to create a temporary table `count` and then, through a `%do` loop, iterate over each treatment group. For each group, it counts unique subjects (`usubjid`) and stores the result in a dynamic global macro variable (e.g., `bign0`, `bign1`). The results are displayed in the SAS log via `%put`.

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1	%macro count(DATA=,var=,trts=,trte=);
2	PROC SQL noprint;
3	create TABLE count as select &var. from &DATA. order BY &var.;
4	%DO i=&trts. %to &trte.;
5	%global bign&i.;
6	select count(distinct usubjid) into: bign&i. from count where trtan=&i;
7	%put bign&i. &&bign&i.;
8	%END;
9	QUIT;
10	%mend count;

3 Code Block

MACRO %COUNT CALL

Explanation :
This call executes the `%count` macro. It provides the previously created `sample_adsl` dataset, specifies the variables `trtan`, `trta`, and `usubjid` for the operation, and requests counting for treatment groups ranging from 0 to 3. This will generate global macro variables such as `bign0`, `bign1`, `bign2`, `bign3` containing the subject counts for each respective group.

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1	%count(
2	DATA=sample_adsl,var=%str(trtan,trta,usubjid),trts=0,trte=3);
3

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Copyright Info : Program Name : Bign_counter.sas * Author : Balaji.M * SAS Version : SAS 9.4 or higher * Description : This SAS program is use to generate subject counts from adsl dataset with dummy treatment groups in below example Drug C is counted with dummy values for testing purpose. *Macro variable : data:- Input Dataset var:- Variables used for counting and sorting purpose should be included trts:- treatment group start numeric value trte:- treatment group end numeric value

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