Statistical significance as seen in an investigator-initiated trial is used to determine whether the results of a treatment group are different than that of a control group. This is done by selecting the appropriate statistical tests based on a sample and then calculating the corresponding P-values. Another way of looking at statistical significance is that the difference seen in the sample also exists in the population. It is simply the relationship between two variables. For example, a researcher would want to know whether changing the sound of a car horn will result in more people buying it. Clinical significance on the other hand, measures the extent that a change can create a significant impact for a patient. Clinical significance, unlike in statistical significance has no set guidelines to determine clinical importance of a response. Subjective judgment is relied upon in identifying the clinical relevance of results. It also means that the difference between effectiveness of treatments is clinically relevant (Sedgwick, 2015).
It is important to note that statistical significance is very valuable in research because it is used to depict the reliability of the study results, while clinical significance shows its relevance to clinical practice. Clinical significance should be able to tell how much change it has impacted, whether the change makes an actual difference on the lives of the subjects, sustainability of the change, its cost-effectiveness, and how easy it is to implement (Ranganathan, 2015). Both statistical and clinical significance play an essential role in a DPI project, in the sense that the validity and viability, and reliability will give credibility to the project which will positively impact the practice improvement in all aspects.
Ranganathan, P., Pramesh, C. S., & Buyse, M. (2015). Common pitfalls in statistical analysis: Clinical versus statistical significance. Perspectives in clinical research, 6(3), 169.
Sedgwick, P. (2014). Statistical Significance vs Clinical Significancehttps://sengiclinical.com/research-tips/105-statistical-clinical-significance