Question: how to calculate p value from 95 confidence interval?
Answer: If the upper and lower limits of a 95% CI are u and l respectively:
1 calculate the standard error: SE = (u − l)/(2×1.96)
2 calculate the test statistic: z = Est/SE.
3 calculate the P value2: P = exp(−0.717×z − 0.416×z2).