Errors in patient specimen collection: application of statistical process control.
BACKGROUND
Errors in the collection and labeling of blood samples for pretransfusion testing increase the risk of transfusion-associated patient morbidity and mortality. Statistical process control (SPC) is a recognized method to monitor the performance of a critical process. An easy-to-use SPC method was tested to determine its feasibility as a tool for monitoring quality in transfusion medicine.


METHODS
SPC control charts were adapted to a spreadsheet presentation. Data tabulating the frequency of mislabeled and miscollected blood samples from 10 hospitals in five countries from 2004 to 2006 were used to demonstrate the method. Control charts were produced to monitor process stability.


RESULTS
The participating hospitals found the SPC spreadsheet very suitable to monitor the performance of the sample labeling and collection and applied SPC charts to suit their specific needs. One hospital monitored subcategories of sample error in detail. A large hospital monitored the number of wrong-blood-in-tube (WBIT) events. Four smaller-sized facilities, each following the same policy for sample collection, combined their data on WBIT samples into a single control chart. One hospital used the control chart to monitor the effect of an educational intervention.


CONCLUSIONS
A simple SPC method is described that can monitor the process of sample collection and labeling in any hospital. SPC could be applied to other critical steps in the transfusion processes as a tool for biovigilance and could be used to develop regional or national performance standards for pretransfusion sample collection. A link is provided to download the spreadsheet for free.
Dzik
Walter Sunny
WS
Blood Transfusion Service, Massachusetts General Hospital, Boston, Massachusetts 02114, USA. sdzik@partners.org
Beckman
Neil
N
Selleng
Kathleen
K
Heddle
Nancy
N
Szczepiorkowski
Zbigniew
Z
Wendel
Silvano
S
Murphy
Michael
M
D001771:Blood Banks / Q000592:standards* / Q000706:statistics & numerical data; D001787:Blood Group Incompatibility / Q000453:epidemiology / Q000517:prevention & control*; D001800:Blood Specimen Collection / Q000592:standards* / Q000706:statistics & numerical data*; D001803:Blood Transfusion / Q000592:standards*; D003627:Data Interpretation, Statistical; D006801:Humans; D007391:International Cooperation; D019300:Medical Errors / Q000517:prevention & control* / Q000706:statistics & numerical data; D008499:Medical Records / Q000706:statistics & numerical data; D040242:Risk Reduction Behavior; D012984:Software