Frequent readers of
our columns know that although we sometimes recommend double checks as patient
safety interventions we usually classify them as “weak” interventions. In our
March 27, 2012 Patient Safety Tip of the Week “Action
Plan Strength in RCA’s” we put together a set of slides lumping action
interventions into weak, intermediate or strong categories in a visual analogy
with the success of various traffic signs in slowing speeders. Click
here to see them (remember: images are more likely to be remembered than
words!) Importantly, double checks are listed as weak interventions that are
only slightly better than the very weakest ones.
A new systematic
review (Alsulami 2012)
searched for studies on double checking and dose calculations in adults and
children and found only 16 articles that met the inclusion criteria. Almost all
were qualitative studies, reflecting information gleaned from interviews,
surveys, etc. Only 3 studies had quantitative data and showed relative
reductions in the 30% range for medication administration and pharmacy
dispensing errors. The authors conclude that there is insufficient evidence to
either support or refute the practice of double checking the administration of
medicines and that clinical trials are needed to establish whether double
checking medicines are effective in reducing medication errors.
Double checks are often recommended when we are dealing with administration of high-risk medications. Even though we have emphasized that double checks are a relatively weak intervention (we also know from other industries that the error rate when a supervisor checks someone else’s work may be 10% or higher), the literature suggests a medication error reduction of about 30% when using a double check system (see our July 15, 2008 Patient Safety Tip of the Week “Heparin Flushes.....Again!”). Also, for any high-risk medications you need to do truly independent double checks (see our March 30, 2010 Patient Safety Tip of the Week “Publicly Released RCA’s: Everyone Learns from Them” for a description of independent double checks). Another nice article on independent double checks in preventing medication errors (ISMP Canada 2005) describes the independent double check process and calculates that independent double checks would reduce the error rate of a process having an error rate of 5% all the way down to 1 in 400.
Our January 2010
What’s New in the Patient Safety World column “ISMP
Article on Double Checks” highlighted an article “Santa
checks his list twice. Shouldn’t we?” that puts the independent double
check process in perspective. They cite some studies done in community
pharmacies that show double checks found errors in 2.6% to 4.2% of cases, about
half of which were potentially significant. And the “average’ error checking
rate is about 5%. But they also discuss how difficult it is for someone to pick
up their own errors (because of phenomena such as confirmation bias) and point
out that double checks work best when they are performed truly independently.
They recommend that double checks be limited to hi-alert medications (like insulin, heparin, chemotherapy, TPN, etc.) and to very complex processes or hi-risk patient populations. Don’t use double checks when some more fundamental re-engineering of the system is needed. And learn from errors uncovered during the double check process. They do suggest continuation of “natural” double checks you are already doing, such as when a nurse checks the accuracy after a pharmacist has dispensed a drug. We’ll second that one - particularly since over-reliance on computers often discourages those double checks (see our November 3, 2009 Patient Safety Tip of the Week “Medication Safety: Frontline to the Rescue Again!”).
So what can go wrong
during double checks? Armitage (Armitage 2008) looked at
incident reports of medication errors and did semi-structured interviews with
healthcare workers across multiple disciplines to qualitatively assess issues
related to double checks. The incident reports showed that medication errors
occurred despite double checking and that seldom was there ever any review as
to why the double checking failed to prevent the errors. The interviews
revealed several themes that staff felt contributed to the failure of double
checks to prevent medication errors. One theme was deference to authority.
This occurs when the individual being asked to perform the double check
perceives the first checker to be above them in the “hierarchy”. Note that
sometimes it was the other person’s formal title or status that put them
“above” in the hierarchy. For example, it could be the new hire double checking
the work of an experienced worker. But at other times it was a perceived skill,
often their ability to perform mathematical calculations rapidly, that put them
in a position of authority!
A second theme was reduction
of responsibility. This is the complacency that tends to occur when someone
feels that someone else will catch any mistakes that they made. We’ll actually
take that a step further and note that we all have a tendency in the
information age to think that “the computer says it’s ok so it must be ok”. But
the other phenomenon he included under reduction of responsibility was that
social interactions and unrelated conversations often interfere with the double
checking process. The latter reminds us of the use of “the sterile cockpit”
in aviation in which no extraneous conversation is allowed to occur during high
risk activities such as takeoff and landing.
A third theme as auto-processing.
This might involve two people standing together with one reading item by item
and the other simply nodding assent to each. The fourth theme was lack of
time.
Many of the above
themes become less salient if one makes sure the process is truly an independent
double check. Having the two parties do their checks separated from each other
by both distance and time prevents them from both following the same error.
Theoretically that separation could also keep the identity of the first checker
unknown to the second checker, thus avoiding the deference to authority factor.
Realistically, however, in most healthcare environments today there are so few
workers at one time that it would be very difficult to avoid knowledge of the
identities of both parties.
Armitage borrows
heavily on the aviation safety literature for potential solutions. One
suggested solution is use of checklists. ISMP provides a simple
checklist of items to be considered during the independent double check (ISMP
2008). This checklist adds a key element often missing in double checks: a
cognitive element that asks questions like “does this drug make sense for this
patient’s diagnosis?” and “has appropriate monitoring been put in place?”.
You’ll find that checklist helpful.
Indeed, checklists
have been used successfully in the double checking process but there is a
science to developing such checklists (White 2010).
White and colleagues looked at the independent double checking process for
administering outpatient chemotherapy medications. They used a very realistic
simulation environment to observe nurses administering chemotherapy using two
different checklists. While use of the two checklists did not differ
significantly in detection of pump programming errors, there was a significant
difference in the ability to detect other types of errors. They found that
using very specific items, rather than more general warnings, significantly
improved certain error types. For example, more errors occurred with a
checklist that simply told them to check the medication label against the
original order than with a checklist that specified the exact elements to check
on the label and the order. Also, a general reminder to “think
critically” and “remember the 5 rights” had virtually no impact. (We
love the concept in John Nance’s book mentioned in our June 2, 2009 Patient
Safety Tip of the Week “Why
Hospitals Should Fly…John Nance Nails It!” where everyone always asks
themselves “Could what I’m about to do cause harm to this patient?” but this
article by White et al. would suggest that won’t actually have much of an
impact). White et al. conclude that for
independent double checking the most important factor is completion by the
second individual of a well-designed checklist with specific items for each
high-risk error. They provide a nice table of 7 important steps in
developing such checklists.
Tamuz and Harrison (Tamuz 2006)
apply to healthcare some concepts from other industries and two leading
complimentary theories of safety we’ve talked about in the past – High
Reliability Theory and Normal Accident Theory. They point out that double
checks are a form of social redundancy and basically require one fallible person
to monitor the work of another fallible person. They also note that when people
hear and see what they expect to see, their effectiveness is reduced. They note
that although double checks do share many desirable attributes of the High
Reliability Organization they are seldom carried out as recommended. They cite
a study (Smetzer
2003) that showed norms for double checking high-hazard medications were
routinely followed in only 45% of hospitals. They also note that such double
checking often becomes a “superficial routine task” and people may lose sight
of its importance. They also note that Normal Accident Theory would note that
people who are aware others are duplicating their efforts may diffuse
responsibility and lead some individuals to overlook safety checks.
One medical center
found that despite having the double check policy, medication events continued
to occur (Brannan
2010). Investigation of those events found inconsistencies in how staff were
completing the double check and that there were no defined processes included
in their policy on how to complete an independent double check. So they revised
their policy to include the actual procedure and they also added a forcing
function in their electronic medical record that forces the nurse to obtain a
witness prior to documenting medication administration and bag changes.
We also came across
a great slide set on independent double checks for high-alert medications that
incorporates several short video vignettes showing the wrong way and right way
to do independent double checks (Intermountain
University). You’ll find these very helpful. They highlight many of the
errors commonly encountered with high-risk drugs like insulin and opiates and
show how the independent double check, done correctly, can help avoid some of
these common errors.
Another interesting
application of the double check is doing such checks in a homecare setting via
televideo monitoring (Bradford 2012).
Basically, with a desktop PC and a webcam one can verify the drug name, dose,
and gradations on syringes greater than 1 unit with close to 100% accuracy.
However, reading expiration dates on vials proved more difficult, with rates of
63%. While that was a homecare initiative, one might wonder whether similar
technologies could be utilized in the acute care or long-term care settings for
administration of certain drugs.
The bottom line:
double checks remain a relatively weak safety intervention and they are prone
to errors but, done correctly, the independent double check probably does
provide an additional element to our defenses against errors. So we recommend
you audit those processes for which you require double checks, see how often
you are actually doing them and doing them correctly, and then put some
structure into your double check process (eg. checklists, forcing functions,
etc.). But we agree with the conclusions of Alsulami et al. that further
research is needed to determine in a more scientific way best practices and
what parts of double checks are effective in reducing errors.
References:
Alsulami Z, Conroy
S, Choonara I. Original article: Double checking the administration of
medicines: what is the evidence? A systematic review. Arch Dis Child 2012; 97: 833-837
http://adc.bmj.com/content/97/9/833.abstract
ISMP Canada.
Lowering The Risk Of Medication Errors: Independent Double Checks. ISMP Canada
Safety Bulletin 2005; 5(1): 1-2, Janauary 2005
http://www.ismp-canada.org/download/safetyBulletins/ISMPCSB2005-01.pdf
ISMP. Santa checks his list twice. Shouldn’t we? Medication Safety Alert. Acute Care Edition. December 17, 2009
http://www.ismp.org/newsletters/acutecare/articles/20091217.asp
Armitage G. Double
checking medicines: defence against error or contributory factor? J Eval Clin
Pract 2008; 14(4): 513-519
http://www.ncbi.nlm.nih.gov/pubmed/19133335
ISMP. Conducting an independent double-check. Medication Safety Alert. Nurse Advise-ERR 2008; 6(12): 1, December 2008
http://www.ismp.org/Newsletters/nursing/Issues/NurseAdviseERR200812.pdf
White RE, Trbovich
PL, Easty AC, et al. Checking it twice: an evaluation of checklists for
detecting medication errors at the bedside using a chemotherapy model. Qual Saf
Health Care 2010; 19(6): 562–567
http://qualitysafety.bmj.com/content/19/6/562.full.pdf+html
Tamuz M, Harrison MI. Improving Patient Safety in Hospitals: Contributions of High-Reliability Theory and Normal Accident Theory. Health Services Research 2006; 41(4 Pt. 2): 1654-1676
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1955347/
Smetzer JL, Vaida
AJ, Cohen MR, et al. Findings from the ISMP Medication Safety Self-Assessment
for Hospitals. Joint Commission Journal on Quality and Safety 2003; 29 (11):
586–97.
http://www.ingentaconnect.com/content/jcaho/jcjqs/2003/00000029/00000011/art00003
Brannan B. University of Maryland Medical Center. Maryland Patient Safety Center. MPSC 2010 Annual Conference Solution Submission. Implementation of a Standardized Double Check Process. 2010
Intermountain
University. Medication High-Alert Double Check. Using an independent medication
double check to keep your patients safe.
http://www.ppag.org/attachments/courses/medcheck/medcheck.swf
Bradford N, Armfield NR, Young J, Smith AC. Feasibility and accuracy of medication checks via Internet video. Journal of Telemedicine & Telecare 2012; 18(3): 128-132
http://jtt.rsmjournals.com/content/18/3/128.abstract
http://www.patientsafetysolutions.com/