Hello Everyone! I'm wondering if someone could help me with the code for matching a case-control population or point me in the direction of literature/existing code. We have a 122 cases and 85 controls (recruitment out of a cancer clinic). We would like assess two scenarios for matching to find the best fit for the dataset.

Matching variables:
-gender
-cotinine (+/- 100 pg)
-years_smoked (+/- 5 years) - (desired but likely won't be able to match with the third variable due to sample size).

Scenarios:
1. N 1:1
2. N 1:3 with repeated cases in the pool. We would like to keep the ratio favoring controls because the number of matches will be low to keep the power in check.

​Any help would be much appreciated!​
​Erin​