Purpose: Using evidence from Qualitative or Quantitative studies that can be used to guide to bring a change in the practice, evaluate a program or initiate or revise a health policy
Knowledge: By completing this assignment you will begin to understand how appraise research studies and the contributions these studies make to address specific current practice issues. You will find theories are generated (Qualitative Research) or tested (Quantitative Research). Middle range theories are more specific and used more frequently in clinical practice. Sometimes one theory alone will not address a clinical issue or practice situation and nurses will use more than one theory to manage a clinical situation. Critical appraisal of Quantitative studies focus on three important steps:
1. Is the study valid?
The first step is to decide whether the study was unbiased by evaluating its methodological quality. Different criteria for validity of articles are used for different types of questions on: treatment, diagnosis, prognosis and economic evaluation. Depending on the validity of an article we can classify it within a scale of levels of evidence and degrees of recommendation.
2. What are the results?
If we decide that the study is valid, we can go on to look at the results. At this step we consider whether the study’s results are clinically important. For example, did the experimental group show a significantly better outcome compared with the control group? We also consider how much uncertainty there is about the results, as expressed in the form of p values, confidence intervals, and sensitivity analysis.
3. Are the results useful?
Once you have decided that your evidence is valid and important, you need to think about how it applies to your question. It is likely, for example, that your patient or population may have different characteristics to those in the study. Critical appraisal skills provide a framework within which to consider these issues in an explicit, transparent way.