Is my study a case-control or a retrospective cohort study?

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Hi All.
I'm dipping my toes into medical research and doing an audit of surgical outcomes. I can't work out whether to describe my study as a retrospective cohort or a case-control study.

Here is the study design:
I have a list of all patients in my institution who had free-flap surgery in 2007 and 2008. About 30% of these patients had post-operative complications. I'm looking for any correlation between intra-operative blood transfusion and rates of post-operative complications. Retrospectively, I'm extracting data from clinical notes to look at the rates of complications among patients who had intraoperative blood transfusions versus patients who didn't. I'm also extracting data on other variables that are thought to be associated with psot-operative complications.

All data was entered into the hospital clinical notes at the time and I am now going through those notes and retrospectively extracting the data.

Any help much appreciated.

Thanks,
Jo Earles.

 

[oj2222]

The difference between a retrospective cohort and a case-control study is as follows:

In a case control study we separate groups by disease status and then look backwards for exposures.

In a retrospective cohort we separate groups by exposure and then look at disease status.

From this: "Retrospectively, I'm extracting data from clinical notes to look at the rates of complications among patients who had intraoperative blood transfusions versus patients who didn't."

it sounds to me like you're working with exposure first (the inraoperative blood transfusions) and than looking for complications so I believe retrospective cohort is the study design.

 

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The difference between a retrospective cohort and a case-control study is as follows:

In a case control study we separate groups by disease status and then look backwards for exposures.

In a retrospective cohort we separate groups by exposure and then look at disease status.

From this: "Retrospectively, I'm extracting data from clinical notes to look at the rates of complications among patients who had intraoperative blood transfusions versus patients who didn't."

it sounds to me like you're working with exposure first (the inraoperative blood transfusions) and than looking for complications so I believe retrospective cohort is the study design.

I agree that its retrospective. The classical case-control is the situation where "I have 100 cases of people with intraoperative blood transfusions, and so I went out and looked for 100 people without that. Then I compared the exposure status."