Anti-E has been confirmed with an acceptable probability. There are more than three positive cells and three negative cells (meeting the minimum p value of 0.05).
Online p value calculator
See this online tool for calculating p values - Enter values as follows:
- Change Outcome 1 to negative and Outcome 2 to positive
- Change Group 1 to antigen-neg (e.g., K-) and Group 2 to antigen-pos (e.g., K+)
- The 2 x 2 table would look like this (hypothetical example):
- Choose Fisher's exact test
- Use a one tailed test - A one-tail p value is appropriate only when previous data or common sense tell you that a difference, if any, can only go in one direction. Obviously, with antibody identification, we expect cells that are antigen-positive to react (and vice versa).
- Hit the calculate button.
Caution #1: Statistical calculations do not substitute for carefully examining serologic test results. It is critical to consider p values as just another tool. If acceptable, they provide additional converging evidence to support the conclusion regarding which antibody has been identified.
Caution #2: With complex antibody combinations, some blood banks prefer a minimum p value of 0.01 as an added measure of probability.