A nurse reads a study about a new intervention with a small sample size. What is the best criterion to evaluate before implementing it?

• A. Look at the study's popularity with colleagues
• B. Examine the study design, methodology, sample size, biases, and applicability to practice; favor higher-quality evidence
• C. The size of the institution
• D. The color of the publication

Answer: (B)

Evaluating a new intervention for practice hinges on the quality and relevance of the evidence, not on popularity or superficial details. The best criterion is to examine how the study was designed and carried out, including the rigor of its methods, the adequacy of the sample size, the potential biases, and whether the findings can be applied to your patient population and setting. A well-designed randomized trial or a thorough systematic review with transparent methods provides more reliable guidance than a small, uncontrolled study.

Look for a clear description of who was studied and how they were selected, how the intervention was implemented and compared, what outcomes were measured, and how the data were analyzed. Adequate sample size matters because small studies can yield imprecise results with wide confidence intervals and may be underpowered to detect meaningful effects or may overestimate effects by chance. Consider biases that could distort results, such as selection bias, measurement bias, or loss to follow-up, and assess whether the study addressed confounding factors. The applicability to practice is crucial: are the participants similar to the patients you care for, is the setting similar, and are the resources and procedures feasible in your environment? If the evidence is weak—due to a small sample, methodological flaws, or limited generalizability—you’d want to seek stronger evidence or guidelines before implementing the intervention.

Why the other options aren’t suitable: popularity among colleagues doesn’t guarantee quality or applicability; the size of the institution doesn’t reflect the validity or rigor of the study; and the color of the publication has no bearing on the credibility or usefulness of the findings.