Tag Archives: lab errors

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.

Medical Laboratory Errors

By ThinkReliability Staff

Surprisingly, many of what are considered laboratory errors do not actually occur in the lab.  But errors related to laboratory testing can negatively impact patient care.  We can look at the impacts and causes of errors related to diagnostic testing in a Cause Map, which allows us to visually diagram cause-and-effect relationships.

We begin this type of root cause analysis by determining the impacts to the organization’s goals.  In this case, because we want to consider all possible sources of diagnostic errors in a proactive analysis, we will look at the generic goals for an organization that provides healthcare.  Diagnostic errors can cause an impact to the patient safety goal because of the risk of impact to patient treatment.  Employees’ abilities to do their job is impacted because they may be receiving incorrect information from lab testing. There is a risk of impact to the patient’s treatment, which is an impact to the patient services goal.  Additionally, there is a risk of performing unnecessary treatment as a result of incorrect testing results, which could impact both the property and labor goals.

Once we have determined the impacts to the organization’s goals (and there may be more impacts for specific incidents involving diagnostic testing errors), we can ask “Why” questions to determine the causes that result in these impacts.  We will begin with the patient safety goal impact.  The patient safety goal is impacted because of the risk of an impact to a patient’s treatment.  This includes the possibilities of a risk of delayed treatment, risk of not receiving needed treatment, and a risk of unnecessary treatment.  Delayed treatment can occur from a delayed diagnosis, which could result from either delayed or incorrect testing results.

Delay of testing results can be caused by delayed reporting of results, potentially due to a lack of time requirement for reporting results and/or a lack of tracking these results.  A possible solution to delayed reporting of results can be to implement a standardized process for reporting results, which may include time limits or guidelines for reporting results.

Incorrect treatment – whether that is not getting needed treatment or receiving unneeded treatment – can result from an incorrect diagnosis.  An incorrect diagnosis can result from  an incorrect assessment of diagnostic testing.  An incorrect assessment can result from either an incorrect interpretation of laboratory test data or incorrect data from the lab testing.

Incorrect interpretation of lab testing can result from reports that are difficult to interpret, either due to a confusing layout or illegibility.  A solution to this is to have a standardized reporting form.   Other potential causes of incorrect interpretation include confusion of verbal reporting (such as over the phone) or results not being interpreted by a specialist.  Solutions that can reduce this confusion include providing reports electronically when available or repeating results when provided verbally, and making lab experts available for interpretation.

Three main reasons that incorrect data is provided as a result of lab testing is that the specimen is associated with the wrong person, possibly because a patient is misidentified, a specimen is mislabeled, or information is entered incorrectly into the computer.  Possible solutions are to use two patient identifiers and label the specimen in the presence of the patient.

Contaminated specimens can also cause incorrect testing results.  Specimens can be contaminated at collection, handling, or testing.  Any of these issues can be caused by insufficient quality control.  The risk of contamination can be minimized by a standardized quality control procedure.

Lastly, incorrect diagnostic data can result from the wrong test being performed.   This could occur due to equipment failure, an incorrect entry into the computer, or the wrong test being ordered.  More details about any specific incident can be added to the Cause Map based on evidence gathered in the course of an investigation.

To view the Outline and Cause Map, please click “Download PDF” above.  Or click here to read more.