Can I use a "would + was" structure in a conditional that refers to a real situation in the past?

Question

I am trying to describe a protocol in the Methods section of my paper (protocol: refer the patient to hospital X if the test is positive). It is something that happened in the past and I consider it a real situation in the past. So, should I say:

A) The patients would be referred to hospital X if the test was positive;

B) The patients would be referred to hospital X if the test were positive;

or

The patients were referred to hospital X if the test was positive.

Answer 1

The use of "were" is an exception that applies only to unreal conditionals—that is, situations that do not reflect reality. (Hint: unreal conditionals often contain words like “would” or “ought to.”) When you’re talking about a possibility that did happen or might be true, use “was” and “were” as you normally would. For example;

If I were [not was] a rich man, I would make more charitable donations.

If he were [not was] here right now, he would help us.

However;

If I was [not were] rude to you, I apologize.

But;

If I were [not was] rude to you, I would apologize.

For more: “Was” or “Were” in the “If” Clause/Conditional