Even studies published in high impact journals can be poorly done. Authors can reach conclusions not supported by the data. Studies can be biased- did the authors do anything to mitigate this?
You need to assess whether the study is relevant to your patients and your context.
Critical appraisal is a systematic way of assessing the quality and relevance of a given research article.
- Focus is on the methodology section instead of abstract/conclusion.
- Is study well conducted/reported?
- What are the limitations? i.e. small sample size, not randomized etc.
- Is bias likely?
- Are the results relevant to your patient(s)/practice/environment?
- Different criteria are used for different study types.