The XbarM alarm is in theory an
absolutely brilliant idea. Given that the population with which we are dealing
remains constant then the average result of any given blood parameter will also
remain constant. And so any serious change in the average of the measurements
of that parameter will tell us (me!) that there’s something causing that
result to change.
However there is one big assumption in
there… if we take the day’s workload and compare it to yesterday’s or tomorrow’s
then the population with which we are dealing probably does remain constant.
However we aren’t comparing on a daily basis. We are comparing batches of
twenty patients. And bearing in mind that the various clinics batch up their
work and sent it to us in job lots, XbarM analysis effectively ends up
comparing twenty ante-natal patients with twenty oncology patients.
And so the alarm goes off.
There’s an interesting
article from Sysmex on the matter which you can read
by clicking here.
