2
$\begingroup$

Suppose we have identified $20$ cases from a population of $1000$ people. $15$ of these cases are male. We want to use one-to-one matching to choose the control group. We would match on gender. So would we just randomly choose $15$ males from the population that are not cases and then arbitrarily match them to the $15$ cases? There are $\binom{15}{2}$ matchings possible.

$\endgroup$
2
$\begingroup$

That's right, although of course there are plenty of other things you could match on as well as gender. And I didn't get your calculation of the number of matchings possible: there are $\frac{n!}{(n-15)!}$ ways to match the male cases, where $n$ is the number of males in the population that are not cases.

| cite | improve this answer | |
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.