Critical Appraisal is an integral component of Evidence-Based Medicine. Critical appraisal aims to identify methodological flaws in research and provide consumers with the opportunity to make informed decisions about the quality of research evidence. Essentially the appraisal phase requires you to ask critical questions of the research, methodology, validity, and investigators to determine whether or not the evidence is sound. Use the following question guidelines, tools, infographics to help you through the critical appraisal process.
CRITICAL APPRAISAL
Key Questions
Why was the study done?
- A clearly focused question should address population, intervention, and outcomes.
- Was the research question clearly stated?
What type of study was done?
- The study design must match the question asked. Intervention questions are best answered with Randomized Control Trials (RCTs). Utilize the levels of evidence pyramid to help make these determinations.
- Was the study design appropriate?
What are the study characteristics?
- Is it clear how the study population was sampled? Was it representative?
- use PICO question format to help you answer this question.
| P |
Patient, Population, Problem? How were participants recruited? |
| I |
What intervention/test is being studied? |
| C |
Is the intervention/test being compared to no intervention, placebo, another treatment? |
| O |
What outcomes are being assessed- objective/subjective/surrogate? Secondary outcome? |
What was done to address bias?
- Was the assignment of patients to treatments randomized?
- Were patients, health workers, and study personnel 'blind' to treatment allocations?
- Were all of the patients who entered the trial properly accounted for at its conclusion? Look for follow-up tables and whether patients were analyzed in the group to which they were randomized.
- Were the groups similar at the end of the study?
- Aside from experimental intervention, were the groups treated equally?
- Were the researchers' given funds or other favors by stakeholders in the study? Are any biases explicitly states by the researchers within the article?
What are the results and are the results valid?
- How was the data collected?
- Are the outcome measures relevant?
- How large was the treatment effect? How precise was the estimate of the treatment effect?
- Look for confidence limits and p values.
What conclusion can you make?
- Does the data justify the conclusions drawn?
- Does the study add any new or valuable information to the field?
- Are the results generalizable, that is, can the results be applied to your patient? were all clinically important outcomes considered? Are the benefits worth the harms and cost?
- Are the results relevant to your situation? Patient population/ similar definitions/ protocols/ health system similarities.
