Patient safety: Error analysis tools

A healthcare error is an incorrect or incomplete action that may threaten patient safety. When an error occurs but doesn’t reach the patient, it’s called a near miss. In this case, an error could have caused harm but didn’t, either by chance or because of an intervention. Near misses are valuable because they expose weaknesses in the healthcare system without causing harm, allowing for proactive problem-solving.

Historically, errors were blamed on individuals. Today, we understand that errors typically come from both individual and system failures, such as poor communication or flawed processes. Focusing only on individuals discourages reporting, whereas focusing on systems creates a more supportive environment where healthcare professionals can share concerns and work together to improve patient safety.

Okay, let’s apply these concepts! Mr. Smith, a 68-year-old male, was admitted with community-acquired pneumonia. Because of his limited mobility and risk factors for deep vein thrombosis, or DVT, he required subcutaneous heparin for prophylaxis. The intended heparin order was a prophylactic dose of 5,000 units subcutaneously every 12 hours. However, the physician, Dr. Roberts, accidentally selected 10,000 units of subcutaneous heparin every 12 hours into the electronic health record, or EHR, due to similar looking options in the drop-down menu. The pharmacist, overwhelmed with workload, verified the order without noticing the error. At the patient’s bedside, the nurse noticed the wrong heparin dose, held the medication, and contacted Dr. Roberts. The order was corrected and the patient was not harmed.

This incident is an example of a near miss and the hospital initiated a review to understand how the error occurred despite multiple checks.

Now, there are multiple types of tools we use to investigate near misses and errors. These include root cause analysis, failure mode and effects analysis, barrier analysis, and common cause analysis.

Root cause analysis, also known as event analysis, looks at the events leading up to an error to identify human, technical, and organizational contributing factors. In Mr. Smith’s case, it might reveal the poor EHR design, inadequate pharmacy verification process, and workflow pressures. Identifying these factors is crucial for preventing similar errors.

Root cause analysis uses four tools to retroactively evaluate a near miss or error. The first tool is the “5 Whys” technique which repeatedly asks “why?” at least five times, to dig deeper than surface-level explanations. Back to Mr. Smith, by asking why he almost received 10,000 units of heparin, we can find out that the physician ordered that dose. Next, if we ask why the physician ordered that dose, we discover that they accidentally selected the wrong option from the EHR dropdown menu. We would continue asking why until we’d gone at least five layers deep to get to the sources contributing to the incorrect dose. With this analysis we see the incorrect heparin dose can be traced back to the physician selecting the wrong dose, to confusion with the EHR drop down menu, to the poor interface that did not clearly differentiate between therapeutic and prophylactic doses, and ultimately to the lack of integrated safety alerts.

The second tool in root cause analysis is the cause-and-effect diagram, also known as the fishbone diagram, which organizes contributing factors into categories such as people, processes, technology, communication, environment, and policies. Applying this method to Mr. Smith’s case, we can clearly visualize the relationships between these different factors and their roles in causing this near miss.