Multiplace Delivery System

Monthly Hyperbaric Safety Notice: March 2006

The Hazards of Checklists

Background

Checklists for equipment, checklists for people, checklists for processes, pre-use checklists, post use checklists, pre-operating checklists, start up checklists, shut down checklists, sometimes it seems our working lives are overrun with checklists. Yet despite the amount of checklists we are required to complete every day of our working lives, accidents and incidents still happen. Of the 479 chamber and equipment incidents reported to the Hyperbaric Incident Monitoring Study (HIMS) from 1992 to end 2003, 25% reported failure to check as a contributing factor to the incident. However, failure to check is not restricted to hyperbaric medicine. It is a contributing factor in incidents and accidents throughout the health care industry and has been a major contributor in catastrophic airline crashes, nuclear energy accidents and the Piper Alpha oil rig disaster.

The Issue
Let’s not forget that in many cases these checks are done by two people. In healthcare and aviation, in particular, the two person verbal response checklist is common, we may be performing the same check many times per day, and yet accidents still happen. So why is it so? How can two people, one reading out the task and the other doing the check and responding, tick off something as checked when it isn’t? Is it complacency? The old “familiarity breeds contempt”? or do the reasons go deeper than that?

Psychologists have a term for a skilled action developed through repeatedly practicing the same action, such as driving a car, they call this automaticity. Conscious automaticity permits us to “undertake a range of practised behaviours without using a great deal of conscious effort or attention”1. Apparently our cognitive system, instead of processing the task one step at a time, recognizes the task and automatically applies a set of rules to the procedure, freeing up working memory. To return to the learning to drive analogy, with practice our previously conscious movements become more fluid and coordinated until we are able to drive effectively and skilfully. At this stage we are automatized yet still consciously aware of our actions.

While conscious automaticity can benefit us by allowing us to perform multiple tasks it is involuntary automaticity that concerns us. Toft and Mascie-Taylor1 cite Barshi, who argues that automaticity has “a cost that manifests itself in procedures that are highly routinized but require close attention, such as verbal checklists procedures. In such procedures, errors occur because the routine leads to automaticity.”2 When this happens we start to see what we know we should be seeing, rather than what we are actually seeing. For example we may look at a valve that we know is always in the open position and not notice that somebody has closed it. To reinforce how this can happen, in a recent conversation with one of our hyperbaric attendants he mentioned that in the past he had anticipated the next question on the checklist due to the repetitive nature of the check and by doing this he was not checking the current task effectively.

Prevention
So how do we prevent involuntary automaticity? First, look at your system to see what can be engineered differently so that a check is not needed. Obviously certain things cannot be engineered out and will still need checking so try and come up with innovative checking techniques. In our Unit the technician has a checklist which he reads out to the inside attendant before each treatment, the treatment will not start until all checks get the correct verbal response. It is the technician’s duty to observe the attendant and ensure the check is actually being done and not just responded to. I have a number of versions of the checklist with the questions in a different order in each list, I routinely change the version of the checklist so that regular attendants do not get used to the checking order. On a personal note, if I am operating the chamber for the same attendant on consecutive treatments I will vary the checklist order as I read it out. We have found that by varying the order of the list we have had far fewer errors and fewer things “missed in check” than we had in the past.

Bottom Line
No matter how good we are, or may think we are, we are all prone to becoming overfamiliar with our tasks and going into autopilot without realising it. It’s the same old thing day after day, why should any of the valve positions have changed in the few minutes between treatments? Effective checking prevents incidents, varying the order of the checklist prevents checking by rote and helps to prevent incidents. Don’t think you are immune to all this because at the end of the day no matter how long you’ve been in the game: All Humans Make Errors!!

References
Toft B, Mascie-Taylor H. Involuntary automaticity: a work-system induced risk to safe health care. Health Services Management Research 2005, 18:211-216

Barshi I, Healy A. Checklist procedures and the cost of automaticity. Memory cogn 1993, 21:496-505

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Contributing Author: Stephen John Goble

Steve has held the position of head hyperbaric technical officer at Royal Adelaide Hospital, in Adelaide, Australia, since 1985. He arrived in Adelaide by way of the British Royal Navy (Clearance Diver) and the offshore commercial diving industry. Steve is a founding member of the Hyperbaric Technicians and Nurses Association (HTNA) and edits their journal (‘Offgassing’). Steve is closely associated with, and intimately involved in, HIMS (Hyperbaric Incident Monitoring Study), and is extensively published on topics ranging from technical and safety issues, standards, incident reporting and decompression accidents.

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