The gold standard of evidence gathering in evidence-based practice is:

• A. Clinical knowledge and judgment
• B. Expert opinions
• C. Randomized clinical trials
• D. Theories of practice

Answer: (C)

Randomized clinical trials are the strongest form of evidence in evidence-based practice because their design minimizes bias and clarifies cause-and-effect. Random assignment helps balance known and unknown confounding factors between groups, so differences in outcomes are more likely due to the intervention itself rather than other variables. A control group provides a direct comparison to what would happen without the intervention, and prospective planning with standardized protocols reduces measurement error. When possible, blinding lowers bias in how outcomes are assessed and how participants behave. Together, these features give high internal validity, making it easier to determine whether the intervention truly works. Other sources like clinical judgment, expert opinion, or theories are valuable for generating ideas and guiding initial decisions, but they don’t offer the same level of rigorous evidence about effectiveness.