Difference between clinical significance and statistical significance I am working on a clinical data analysis project and am from IT domain.

While I am analyzing the data, I came to know that though some of the variables are not statistically significant, they are clinically significant.

I also read that difference in median values between case and control group for variables is used as a measure to indicate clinical significance

Can someone help me understand this with a simple example as to why difference in median between groups is considered for clinical significance?
This is non-parametric statistics, the mean requires confirmation to the normal distribution (but there are exceptions), or perhaps better put it requires a fixed relationship between mean and standard deviation. Non-parametric stats always use the median and are distribution free. Wilcoxon test/ Mann-Whitney U test  are used to replace t-test. The Kruscal-Wallace test replaces the 1-way ANOVA 
Finally the Friedman test replaces 2-way ANOVA but has its critiques.  The t- and ANOVA tests require normality, F-max is one approach to determine normality.