How to Avoid Errors in the Diagnostic Lab

Ensure samples are appropriately identified at reception

For diagnostics labs, samples are obtained from a variety of sources, from clinics and hospitals to biobanks and other repositories. The key to success is to ensure that all samples accrued for testing are already sufficiently identified, ideally using barcode labels. Though RFID can be an effective method of identification for many labs, using RFID tags for shipping is often not a perfect solution, as it depends on the receiver having RFID scanners to process the samples. Instead, it’s best practice to require all sources of samples deliver their packages marked with a standardized barcode. This means that every package received is processed the same way, with less flexibility needed on the part of the diagnostic lab.

One factor to consider is managing label requirements for sites like hospitals. Errors are often made when these requirements are not thoroughly applied. For instance, labels may be placed inside the bag with a sample instead of being affixed to the tube itself, or labels may be placed in the wrong orientation, making the barcode illegible. The challenge is devising strategies to minimize these errors beforehand. Refusing to process a specimen unless it is properly identified represents a good starting point; however, standards for readability and “proper identification” may vary; the more stringent the requirements, the more samples are likely to be refused, costing both the system and patient time, and money. It’s, therefore, critical to clearly communicate the lab’s identification standards and protocols to all potential sources. When possible, it might be beneficial to promote additional training programs to institutions like hospitals to ensure that all labeling SOPs are adequately met across the board.

Use the correct labels

Diagnostic kits come in all shapes and sizes. This means that many different labels may also be necessary during processing. The best example is in histology labs, where diagnostic tests involve harsh chemicals like xylene and other clearing agents that can easily ruin generic labels. Many companies, including LabTAG, manufacture labels for these conditions, which can identify microscope slides, paraffin wax blocks, plastic containers, slide boxes for deep-freeze storage, and resin-embedded samples.

Other diagnostic tests may involve large-scale PCR testing. For these kits, it’s recommended to use PCR-TagTrax, which comprises adhesive-free tags that can slip onto tubes, 8-well strips, and unskirted or semi-skirted plates to give a bird’s-eye view of the printed information. These freezer and thermocycler-safe tags can be printed with barcodes using a thermal-transfer printer, making them adaptable to all thermocyclers and capable of storage in temperatures as low as  -196°C (-321°F).

The Swiss Cheese Model

This model deals with errors in medicine. It stipulates that a “bad apple” approach, where staff is singled out for mistakes, is less effective than systemically changing the workflow itself, making errors less likely.¹ It can help devise a more open lab, where technologists can freely talk about errors; in effect, this prevents them from occurring later through active engagement with the workflow and SOPs and developing strategies to mitigate errors before they happen, such as implementing barcodes or RFID.²

The cost of misidentifying samples can be significant, with estimations of up to $1 million per year for some institutions. Costs associated with redrawing specimens include additional labor, consumables, and supplies—as well as the potential for prolonged hospital stays, all of which can be easily avoided by accurate and consistent identification by the lab analyzing the sample.³