We select 2SD value to plot LJ curves because?
a. They are easy to calculate,
b. They cover 97.5% of normal population,
c. Patient value rarely go beyond these limits.
(c) QC results follow a Gaussian distribution, thus 95% of these results normally fall within ±5% of the mean. Therefore, 2.5 out of 100 (1:40) are acceptable to be above +2s and 2.5 our of 100 are acceptable below -2s.
a. They are easy to calculate,
b. They cover 97.5% of normal population,
c. Patient value rarely go beyond these limits.
(c) QC results follow a Gaussian distribution, thus 95% of these results normally fall within ±5% of the mean. Therefore, 2.5 out of 100 (1:40) are acceptable to be above +2s and 2.5 our of 100 are acceptable below -2s.