Barb, If your lab is doing standardized diagnostic tests then a 7 percent
repeat rate is far too high. I would start with a study into why the repeats
are necessary. Is it bad antibodies, forgetful techs (forget to put a
solution on), poor tissue sections, wrong controls used, etc. The answers to
questions like those would determine your course of action. For instance, in
our lab we very rarely do repeats and when we do it is usually because a
control is inadequate or there is high background or a human error will be
made (wrong reagent, forget a control, slides switched in position, etc). I
would say we repeat about 100 out of 5000 diagnotic slides stained in a
year, or 2.0 percent.  That is probably as good as we can get considering
you will always have random mistakes in any system. Certain procedures may
be able to improve on that (ie, double checks by a second person, barcoded
reagents and slides).  I think automated stainers help reduce mistakes, but
they still creep in here and there. BTW, we don't count any developmental
work in that repeat rate. 

Tim Morken
CDC, Atlanta



-----Original Message-----
From: Barbara.Davies@memhospcs.org [mailto:Barbara.Davies@memhospcs.org]
Sent: Wednesday, December 05, 2001 4:29 PM
To: histonet@pathology.swmed.edu
Subject: repeat rates on IHC


We are doing a performance improvement project at our lab trying to reduce
the rate of  Immunos that need repeated.  Our present repeat rate is 7% of
the slides/antibodies need to be repeated (this rate varies with techs from
2% to 12%.)    Is anyone willing to share with me their repeat rates, so
that I can make a more informed goal for this improvement project of ours.

Thanks in advance,

Barb Davies
Memorial Hospital
Colorado Springs, CO