Identifying and Preventing Causes of Lab Errors

By ThinkReliability Staff

A man was mistakenly told he had HIV. A baby who died from a blood disorder that could have been treated during pregnancy, but wasn’t because the routine blood screen came back clear. A little girl who had to receive a second transplant after the test to verify her acceptance of a new organ was run incorrectly. These are just some of the cases mentioned in a watchdog report about how laboratory errors and weak oversight put patients at risk.

There are 7 to 10 billion medical laboratory tests run in the US every year. Lab tests influence about 70% of medical decisions. Having the wrong information from these tests can be deadly, and there is no good data about how many lab tests may be inaccurate, or may be negitively impacting patient safety. Laboratories are generally overseen by accrediting organizations but the results are almost always private, and there have been recent cases where federal regulators have had to step in because serious deficiencies in lab processes were identified.

The risk isn’t just for patients. An employee was infected with HIV and hepatitis C after a machine malfunctioned, splashing contaminated blood product onto her face. The employee had warned her boss previously that the machine was broken and cross-contaminating samples. Patients can also receive wrong information that isn’t harmful to their physical health but causes all sorts of other problems, such as incorrectly run paternity tests that improperly rule out a man as the father of a child.

The process involved in laboratory testing – from taking a specimen from a patient to delivering the results – is complex, and there are potential issues at each step that can lead to inaccurate results. These causes can be visually diagrammed in a Cause Map, or a visual cause-and-effect diagram. (To view the Cause Map, click “Download PDF” above.) In this case, potential causes of lab errors are captured and analyzed for potential solutions. These causes include labeling of samples, time and storage conditions of the samples, use of proper (and non-expired) products to treat the samples, and calibration of the machines used for the testing.

Actions that reduce the risk of inaccurate lab results should be in place at all labs, but even with a well-planned process, mistakes can happen. That makes the addition of checks and oversight into the process incredibly important. Says Michael Baird, the chief science officer and laboratory director at DNA Diagnostics Center, “I will agree that mistakes are something that can happen whatever you do. You just need to have the appropriate controls in place for when a mistake happens, (so) you can catch it before it goes out the door.”

For example, at the lab Baird runs, samples used for DNA checks are run independently by two different technicians and when a man is ruled out as the father of a child, there is a double-check in place. Other labs have incorporated alert systems for time-sensitive specimens and have hired technical directors responsible for overseeing the labs.

There are also steps patients themselves can take to minimize the impact on their safety from potential lab testing errors. First, ensure that any samples taken are labeled immediately and with accurate information. If you’re at all unsure about a test result, get a second opinion at a different lab. Complaints about a lab should be directed to state health officials.

To view the Cause Map addressing potential causes of laboratory errors, click “Download PDF”. To learn more, read the watchdog report.