Evidence-Based Practice

1. Is the study valid?

This is the determination of the quality of the design and analysis, as well as the extent to which you can be confident in the study’s findings. Various scales can be used to assess the methodological quality of a study.

• Is the research question important, and is it based on a theoretical rationale? Is the study design appropriate for the research question?

• Was the study sample selected appropriately? Was the sample size large enough to demonstrate meaningful effects? Were subjects followed for a long enough time to document outcomes?

• Was bias sufficiently controlled? For an intervention trial, was randomization and blinding used? For observational studies, was there control of potential confounders?

• Was the sample size large enough to demonstrate treatment effects?

• What were the outcome measures? Were they valid and reliable? Were they operationally defined? Were they appropriate to the research question?

• Were data analysis procedures applied and interpreted appropriately? Do data support conclusions?

2. Are the results meaningful?

Results must be interpreted in terms of their impact on patient responses and outcomes. They may be related to primary and secondary outcomes.

• Is the sample sufficiently representative of the target population so that results can be generalized?

• How large was the effect of intervention, the accuracy of the diagnostic test, or the degree of risk associated with prognostic factors?

• Is the effect large enough to be clinically meaningful?

3. Are the results relevant to my patient?

Finally, you must determine whether the findings will be applicable to your patient and clinical decisions.

• Were the subjects in the study sufficiently similar to my patient?

• Can I apply these results to my patient’s problem? What are the potential benefits or harms?

• Is the approach feasible in my setting and will it be acceptable to my patient?

• Is this approach worth the effort to incorporate it into my treatment plan?