TABLE 4-10 Westgard quality control
Note: standard deviation rules and (s) interpretation: Control Rule Designations Interpretation
Cre control may be used by observing exceeding the mean 12s-this up warning rule that initiates testing of the control data by the other control rules.
One control observation exceeding the mean 13s- recommend rejecting patient results and this rule is sensitive to random error;
Two consecutive control observations exceeding the same mean plus 28 or mean minus 2s limit recommend rejecting patient results; this rule is sensitive to systematic error.
One observation exceeding the mean plus 2s and another exceeding the mean minus 2s recommend rejecting patient results; this rule is sensitive to random error.
Four consecutive observations exceeding the mean plus 18 or the mean minus 1s recommend rejecting patient results; this rule is sensitive to systematic error.
Ten consecutive control observations falling on one side of the mean (above or below) with no other requirement on size of the deviations recommend rejecting patient results; this rule is sensitive to systematic error.