Preventable laboratory errors occur through all phases of testing process. Unfortunately, 46-68 percent of all laboratory errors occur during the pre-analytics phase of testing due to the complexity and manual processes involved.  Pre-analytic errors occur in a number of different circumstances:

  • At the time of patient assessment and decision to perform an analysis
  • Test order entry
  • Patient identification
  • Specimen collection and transport
  • Specimen receipt and storage in the laboratory
  • Specimen transport to reference laboratory.

An estimated 25 percent of pre-analytical errors result in unnecessary investigation or improper diagnosis, resulting in added costs and negative patient outcomes. Sometimes, errors can even be fatal. This is an outcome most commonly seen with incorrectly identified blood bank specimens.  Luckily, appropriate training and quality management can lead to improvement.

Appropriate Test Selection

To avoid pre-analytic errors in test selection, it is important to provide appropriate test selection guides, and current best-practice information. On line interpretative handbooks can assist the clinician in appropriate test selection. For example, there are 18 different titles of Vitamin D related tests, so clarity in test names is essential as is a complete interpretative handbook to serve as a guide in test ordering..

Ordering the Test

Those individuals ordering the tests must pay close attention to detail to avoid clerical errors such as placing an order on the incorrect patient or for the incorrect test. Whether the test is ordered through paper requisition or computerized patient order entry system, there must be patient identification with two patient identifiers, proper authorization for the individual ordering the study to do so, contact information available so critical results and any questions can be readily resolved.

Collecting & Labeling the Specimen

Prior to specimen collection, the health professional must verify patient with at least two identifiers. When collecting the specimen, the individual should confirm collection pre-requisites. This may include time of last food intake if a fasting blood sugar is being performed, antibiotics being administered if the test is a microbiology analysis and time of drug administration if a drug level is being performed.  Specimen containers (not lids) should be labeled at the time of collection with two patient identifiers.

Special care and attention must be given when labeling specimens because misidentification will follow through the entire testing process ultimately leading to results reported on the incorrect patient.

Specimen Integrity

There are a number of items that can lead to compromised specimen integrity including, for example,  the inappropriate specimen container, incorrect order of phlebotomy draw, inadequate specimen volume, fluid contamination from intravenous infusion etc.

Once the specimen is collected and labeled, it must be properly transported, accessioned and stored.

Conclusion

Because the pre-analytic phase has most steps, most people involved, and most variation in work environment, technique and training, it is the most prone to error. Fortunately, these errors can be avoided with proper training, scheduled competency evaluation, education, and robust Quality Assessment programs. The educational session Pre and Post Analytical Errors at the 2015 CRI® Symposium for Clinical Laboratories will explore these techniques for preventing pre and post analytical errors in more depth and detail.

Resources:

Kaushik N. MD & Green S. PhD. Pre-analytical errors: their impact and how to minimize them. Medical Laboratory Observer; May 2014 http://www.mlo-online.com/articles/201405/pre-analytical-errors-their-impact-and-how-to-minimize-them.php

Plebani M. Errors in clinical laboratories or errors in laboratory medicine. Clin Chem Lab Med. 2006;44(6):750-759; CAP Q-Rrobe 2010  http://www.pathologyinformatics.com/sites/default/files/2012Powerpoints/23AllerWed.pdf