How to create a control group based on multiple matching variables?

[Denali]

Dear All,

I am designing a matched case-control study. I have 25 patients diagnosed with COVID and cancer as the case group. I would like to select 50 subjects from a dataset containing 4000 cancer patients as a comparison/control group based on the following matching variables: age (+/-5 years), cance type (8 cancer types: lung, melanoma, sarcoma...etc), gender (male vs. female), year of chemotherapy, race (White vs. Black vs. Others) and survival > 6 months (Yes/No). The priority of the matching variables are listed as the order above.

Can you please advise me on the code? Please let me know if you need further clarifications.Thank you!

[Reeza]

Have you looked into PROC PSMATCH?

https://documentation.sas.com/doc/en/pgmsascdc/9.4_3.4/statug/statug_psmatch_examples04.htm

If you need code examples you will need to provide data examples, specifically both of your input data sets.

[Denali]

@Reeza Thanks for your suggestions. l am not specifically looking for propensity score matching but just the regular matching step. Is there a code for that instead? Do I need to run the Proc Freq first to ensure the frequency of each variable or it does not matter so much?

[Reeza]

Then you're just writing manual SQL code. There isn't a proc for direct matching, but the Mayo clinic used to have a bunch of SAS macros.
I personally thing PSMATCH with the REGION and CALIPERS can be set to do what you want but I've never directly tried it.

I would have assumed that you've ensured that your criteria makes sense already for the matching so not sure what the PROC FREQ will add to the process.