4:1 matching for case control studies.

[ashraf abugroun]

Which code would work to generate Range match in AGE + Exact match in some cateogrical variables e.g Race, gender. I usually use CCMATCH, however that only generates 1:1 matching. I am looking for 4:1 matching. I appreicate your help.

[Mike Lacy]

-ssc describe calipmatch-

[ashraf abugroun]

Thanks. The help section has no example for how to implement 4:1 matching. Appreciate if you elaborate. Thanks.

[Mike Lacy]

Here's a paste from the help file's description of the -maxmatches()- option.

"maxmatches(#) sets the maximum number of controls to be matched with each case. Setting maxmatches(1) performs a 1:1 matching: calipmatch searches for one matching
control observation for each case observation.

By setting maxmatches(#) greater than 1, calipmatch will proceed in random order through the cases and search for matching control observations until it either
finds the maximum number of matches or runs out of controls. The search is performed greedily: it is possible that some cases end up unmatched because all
possible matching controls have already been matched with another case."