Were the comparison groups similar with respect to factors which could forseeably influence outcome?The
first question to be answered is:Did you find a systematic overview or meta-analysis? - If you did, click HERE to go to the section on using overviews or meta-analyses.
To appraise a study, there is a series of questions you must answer.
First of all, was the study valid?
Were the comparison groups similar with respect to factors which could forseeably influence outcome?
Were outcomes and exposures measured in the same way in all groups?
Was follow-up sufficiently long and complete?
Did exposure precede the appearance of the symptoms in question?
For medicines, is there a dose-response relationship with respect to the symptoms in question?
After thinking about the above questions, Is there a FATAL flaw in the study?
If there is, then toss this study and go onto the next one. If not, continue the appraisal.
What were the results?
How large is the Relative Risk (RR) or Odds Ratio (OR) of the measured outcomes in the exposed group?
Are confidence intervals given for the Relative risk or Odds ratio?
Are the results applicable to my patients?
Is the magnitude of the risk sufficiently large to obviate the need for work-up of other causes of symptoms?
Is my patient at particular risk for a bad outcome from this exposure?
Do I need to stop the exposure?
If this study is does not answer the original question or if the answer is not meaningful after the above appraisal, then toss out the study and proceed to the next one.
If the answer to the above overall question is YES, then write a C.A.T. so the rest of us don't need to look this up again for a while.
