Patient Safety Focus: More on Latent Errors in Laboratory Services

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More on Latent Errors in Laboratory Services
By Bonnie Messinger and Peggy Ahlin

While latent errors in the lab are not always readily apparent to an outside observer, active errors are usually quite apparent and occur during lab workers’ interactions with some important aspect of his or her work environment. For example, interactions with instruments, computers, pneumatic tube systems, storage containers, collection devices, test requisitions, and even patients are all potential points where active errors can occur. It’s important to remember that one latent error, such as a poorly designed computerized form, can lead to many active errors in data entry. Therefore, to maximize the impact of quality improvement efforts, laboratorians should focus on sources of latent errors, which can help eliminate many active errors.

Table 1
Examples of Latent Errors in Lab Testing




  • The patient is abusive and the staff member wants to minimize face time.
  • The patient is passive and does not correct an obvious identification error.
  • The patient intentionally misrepresents him/herself in order to obtain insured medical care.
  • The phlebotomist did not know that the patient did not speak/hear English.


  • There is no standard for how work is done.
  • The time allotted to the task is unrealistic.
  • A required task is unnecessary, but time-consuming.
  • Reports for final review are in multiple locations or formats.


  • Chronic understaffing on evening shift leads to high error rate as staff rush to complete the high volume of work before the shift ends.
  • Training for new employees was abbreviated in order to get them on the bench as soon as possible.
  • Employees work through breaks due to understaffing/high workload.
  • Professional skill levels are not matched to work/expectations, leading to under utilization for some and poor performance for others.
  • A supervisor is not available on the night shift for decision making.
  • Physical health is affected by high workload.

IT /

  • Lack of instrument interface with LIS leads to many active data entry errors.
  • Poor formatting of lab results in electronic medical record leads to the frequent misinterpretation of lab results by physicians.
  • Font choice is poor (italics, size, etc.) and is easily misread.
  • A programming error causes additional work.
  • The workload exceeds the capacity of the IT support structure to facilitate work; there is a mismatch between the selected IT solution and the work performed.
  • Alert flags are set incorrectly.


  • Old error-prone analyzers are held together by duct tape and covered in post-it notes.
  • Main chemistry analyzer is overloaded and has no backup leading to long delays when the instrument is down.
  • The instrument readouts are very small and difficult to read.
  • In order to work productively, an important safety feature on the instrument is surreptitiously disabled.


  • Culture of multitasking leads to error-prone environment as techs try to answer phones and analyze specimens at the same time.
  • Long term remodeling project leads to excessive noise that distracts technologists.
  • Convoluted physical layout of lab creates an environment where specimens are more likely to be misplaced.
  • Disconnection of lab staff from the patient experience tends to decrease motivation to improve quality.
  • Tools, aids and supplies are not close or readily available, due to poor workstation design, leading to creative substitutions in order to keep production high.
  • The lighting is not even over the work area and some areas are darker. Employees have to continually adjust their eye sight.
  • The temperature is not controlled—too hot or too cold.

Policy and

  • Policy allowing relabeling of mislabeled or unlabeled blood specimens by ordering physician increases the chance of mislabeled specimen.
  • Multiple different requisitions with different styles and designs leads to error prone environment in test ordering and specimen login.
  • No work aids exist; staff members rely on memory, their own and others, to determine how work is done.
  • Process and procedure documents are not controlled and many versions exist, leading to non-standard work and work-arounds.
  • Process and procedure documents are outdated, not matched to how work is done, or fail to account for commonly encountered problems.


  • Poor communication at shift change regarding problem specimens that still require resolution enables a failure to complete the task.
  • Large clinical laboratory is organized with many vertical, analytic divisions (e.g., chemistry, hematology, virology) that do not share their best practices regarding quality improvement.
  • Verbal communication between workforce and supervisor regarding reporting of a new reference interval is interpreted differently by staff.
  • The clinician is verbally abusive to laboratorians who call for clarification of an order or to give critical results.
  • The employee is new and is trying to establish him/herself in the existing social order.
  • Cultural and language differences cause team communication issues.

Management/ Organization

  • Lab medical director has a financial incentive to do fee-for-service anatomic pathology rather than participate significantly in lab quality improvement.
  • Management tends to focus on financial concerns and employee satisfaction while giving lip service to patient safety.
  • Doing the “right thing” is not recognized or rewarded; there is no consequence for operating outside of defined practice; violating rules is the only way to meet production requirements (lack of positive reinforcement).
  • There are members of the executive/managerial team who feel they are “above” the rules that govern other staff members.
  • There are goal conflicts (e.g., speed vs. accuracy).
  • Employees are not recognized for a job well done.

Bonnie Messinger is quality manager and Peggy Ahlin is director of quality and compliance at ARUP, Salt Lake City, Utah


AHRQ PSNet (Patient Safety Net). Available online. Accessed May 19, 2009.

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Patient Safety Focus Editorial Board

Michael Astion, MD, PhD
Department of Laboratory Medicine
University of Washington, Seattle

Peggy A. Ahlin, BS, MT(ASCP)
ARUP Laboratories
Salt Lake City, Utah 
James S. Hernandez, MD, MS 
  Mayo Clinic Arizona
Scottsdale and Phoenix

Devery Howerton, PhD

Centers for Disease Control and Prevention
Atlanta, Ga.

Sponsored by ARUP Laboratories, Inc.