Case Report CAT

This is a draft critical appraisal sheet for case reports. Would be interested in your views.

Critical Appraisal is used to glean scientific evidence from papers. Case reports or case series are not normally considered as part of this process. The reason is that there is usually no hypothesis testing or comparison within a case report and generalising the conclusions to other circumstances is difficult.

However, case reports have value which could be scientific or educational. When reading a case report it is important to be critical and judge the value of the report to the medical literature and to your own clinical practice. This checklist may help.

Checklist Item Comment
Has the case report been peer-reviewed? Is it clear from the publisher what the peer-review process was?

Case reports may be in topic areas, or include topic areas, that are unfamiliar and they should have been reviewed by experts in those topics. You may need to check the publication or the website to understand the peer-review process for their case reports.

Does the case report have a clearly defined focus?

It should be easy to understand if the case reports a rare condition, a novel finding, a reminder of an important clinical lesson, a myth exploded, an unexpected adverse / beneficial outcome of treatment etc. Cases without a focus may not have been properly thought through by the authors.

Are all the necessary facts presented?

Check that there is sufficient detail in the presentation, past medical / drug / social history, examination, investigations and follow-up of the case.

Is the case report linked to the existing literature?

The discussion should highlight if the case is claimed to be unique or if other similar cases have been reported. If unique the authors should describe the search process, terms and synonyms that they used to research the literature. If other cases have been reported then information about how those cases were similar or different to this case report. All cases should be referenced and the authors should again describe the search that they used to find them.

Is the discussion relevant?

The discussion should explore the potential learning points or novel findings from the case but not over-generalise, make recommendations that are not upheld by a single experience, or discuss issues that are not directly involved in the case. The case report should not be a lame excuse for a review of the literature. If there is a call for further research it should be clear in the discussion what this is.

Does the case provide any quantitative evidence?

Are there numbers that could be useful from this case report? It may provide a measure of a physiological variable, a time period or a drug quantity that could help in probability estimates or clinical judgements in future cases. The numbers, if adequately described, could be combined with other published case reports to improve the estimate in a process similar to meta-analysis.

Is the case report important to your clinical practice?

Although interesting and of educational value the paper may be about a condition that you would never be likely to encounter. Judge how relevant the case, the lessons or scientific leads are to your clinical practice. Is it one that your colleagues should read?