Medication double-checking procedures in clinical practice: A cross-sectional survey of oncology nurses' experiences

Abstract

Background Double-checking is widely recommended as an essential method to prevent medication errors. However, prior research has shown that the concept of double-checking is not clearly defined, and that little is known about actual practice in oncology, for example, what kind of checking procedures are applied.
Objective To study the practice of different double-checking procedures in chemotherapy administration and to explore nurses' experiences, for example, how often they actually find errors using a certain procedure. General evaluations regarding double-checking, for example, frequency of interruptions during and caused by a check, or what is regarded as its essential feature was assessed.
Methods In a cross-sectional survey, qualified nurses working in oncology departments of 3 hospitals were asked to rate 5 different scenarios of double-checking procedures regarding dimensions such as frequency of use in practice and appropriateness to prevent medication errors; they were also asked general questions about double-checking.
Results Overall, 274 nurses (70% response rate) participated in the survey. The procedure of jointly double-checking (read-read back) was most commonly used (69% of respondents) and rated as very appropriate to prevent medication errors. Jointly checking medication was seen as the essential characteristic of double-checking—more frequently than ‘carrying out checks independently’ (54% vs 24%). Most nurses (78%) found the frequency of double-checking in their department appropriate. Being interrupted in one's own current activity for supporting a double-check was reported to occur frequently. Regression analysis revealed a strong preference towards checks that are currently implemented at the responders' workplace.
Conclusions Double-checking is well regarded by oncology nurses as a procedure to help prevent errors, with jointly checking being used most frequently. Our results show that the notion of independent checking needs to be transferred more actively into clinical practice. The high frequency of reported interruptions during and caused by double-checks is of concern.

Full text

Medication double-checking procedures
in clinical practice: a cross-sectional
survey of oncology nurses’experiences
D L B Schwappach,
1,2
Yvonne Pfeiffer,
1
Katja Taxis
3
To cite: Schwappach DLB,
Pfeiffer Y, Taxis K.
Medication double-checking
procedures in clinical
practice: a cross-sectional
survey of oncology nurses’
experiences. BMJ Open
2016;6:e011394.
doi:10.1136/bmjopen-2016-
011394
▸Prepublication history for
this paper is available online.
To view these files please
visit the journal online
(http://dx.doi.org/10.1136/
bmjopen-2016-011394).
Received 4 February 2016
Revised 17 May 2016
Accepted 25 May 2016
1
Swiss Patient Safety
Foundation, Zuerich,
Switzerland
2
Institute of Social and
Preventive Medicine (ISPM),
University of Bern, Bern,
Switzerland
3
Department of Pharmacy,
Unit of Pharmacotherapy and
Pharmaceutical Care,
University of Groningen,
Groningen, The Netherlands
Correspondence to
Dr David Schwappach;
schwappach@
patientensicherheit.ch
ABSTRACT
Background: Double-checking is widely
recommended as an essential method to prevent
medication errors. However, prior research has shown
that the concept of double-checking is not clearly
defined, and that little is known about actual practice in
oncology, for example, what kind of checking
procedures are applied.
Objective: To study the practice of different double-
checking procedures in chemotherapy administration
and to explore nurses’experiences, for example, how
often they actually find errors using a certain
procedure. General evaluations regarding double-
checking, for example, frequency of interruptions
during and caused by a check, or what is regarded as
its essential feature was assessed.
Methods: In a cross-sectional survey, qualified nurses
working in oncology departments of 3 hospitals were
asked to rate 5 different scenarios of double-checking
procedures regarding dimensions such as frequency of
use in practice and appropriateness to prevent
medication errors; they were also asked general
questions about double-checking.
Results: Overall, 274 nurses (70% response rate)
participated in the survey. The procedure of jointly
double-checking (read-read back) was most commonly
used (69% of respondents) and rated as very
appropriate to prevent medication errors. Jointly
checking medication was seen as the essential
characteristic of double-checking—more frequently than
‘carrying out checks independently’(54% vs 24%). Most
nurses (78%) found the frequency of double-checking in
their department appropriate. Being interrupted in one’s
own current activity for supporting a double-check was
reported to occur frequently. Regression analysis
revealed a strong preference towards checks that are
currently implemented at the responders’workplace.
Conclusions: Double-checking is well regarded by
oncology nurses as a procedure to help prevent errors,
with jointly checking being used most frequently. Our
results show that the notion of independent checking
needs to be transferred more actively into clinical
practice. The high frequency of reported interruptions
during and caused by double-checks is of concern.
INTRODUCTION
Medication errors pose a serious threat to
patients with cancer.
1–5
Walsh et al
6
reported
that among visits by adult patients with
cancer, 7.1% of medications were associated
with a medication error with more than half
of all errors occurring during administration.
Although not all medication errors are
harmful, consequences can be serious or dis-
astrous, especially in patients with cancer.
Strategies that have been recommended to
improve patient safety in oncology include
electronic prescribing, standardisation of
processes and order forms, shifting
medication-related tasks to clinical pharma-
cists and use of checklists for safe administra-
tion of drugs.
7–11
Double-checking (DC) of
medication is the safety intervention fre-
quently called for, especially to prevent
administration errors. The Institute for Safe
Medication Practices (ISMP) recommends
the implementation of the double-check, but
judiciously, and in a standardised process.
12
The ISMP also points to the importance of
independence of checking procedures where
the first professional does not communicate
the results to expect to the second profes-
sional. The UK National Patient Safety
Agency recommends healthcare organisa-
tions to ‘use DC systems such as an inde-
pendent check by another practitioner, and
dose checking software in ‘Smart’infusion
pumps and syringe drivers’.
13
DC can be
defined as a procedure that requires two
Strengths and limitations of this study
▪This is the first investigation into double-
checking procedures and common violations in
cancer care.
▪We provide evidence that the value of double-
checking procedures as perceived by nurses is
attributed to the joint action rather than the inde-
pendence of checks and thus does not match
current recommendations claiming that checks
need to be carried out independently to increase
safety.
▪The survey response rate is satisfactory and the
sample includes nurses from three large hospi-
tals. However, results may be subject to bias due
to the self-reported nature of the data.
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qualified health professionals, usually nurses, checking
the medication before administration to the patient. DC
is a redundant function based on the subjective theory
that human errors can be minimised by other individuals’
compensatory behaviour.
14
The strategy is borrowed from
system engineering where redundancy is used to achieve
safety and reliability in technical systems. In broad terms,
redundancy means that a system component (eg, mass
storage) is duplicated and serves as a back-up in case of
failure. Redundancy as a design strategy for healthcare
systems has been discussed by Tamuz and Harrison
15
in
the context of high-reliability theory and normal accident
theory. Despite the proliferation of the procedure and its
ad hoc plausibility, there is a paucity of research into the
effectiveness of DC to either support or refute this prac-
tice.
16
In this context, it is important to note that DC
medication administrations is a time-consuming and thus
resource-intensive process.
17–19
There is widespread support for DC, but most recom-
mendations and guidelines lack details on what constitu-
tes a double-check and how it should be performed. In
practice, various forms of DC procedures are implemen-
ted including, for example, a single person conducting
the same check twice; a second person verifying the
check of the first professional (do-and-show check); a
single person checking against some form of compu-
terised support (eg, calculations performed by an infu-
sion pump); two professionals checking independently
of each other, and sequentially or together (eg, read-
read back). Owing to such variability in DC processes, it
is not surprising that there are reports about confusion
and misconceptions among healthcare professionals.
20 21
In a recent qualitative study in Canada, DC was inconsist-
ently conceptualised among healthcare professionals
with a variety of ambiguous but ‘taken as understood’
meanings attached to it.
21
Nurses at many departments
today perform countless single and double drug verifica-
tions, often under inadequate working conditions (eg,
insufficient light, space, noise) and without any compen-
sation for the time needed to perform these checks.
Often, these checks are done superficially
22
and ‘true
independence’of checks—the central feature for suc-
cessful error detection—is hard to achieve in practice.
Non-independent checks are prone to confirmation bias
and their value is thus uncertain. Violations of DC pro-
cedures are frequent, probably due to the workload and
lack of standardisation.
22 23
Furthermore, DC itself can
negatively impact safety by causing a considerable
number of additional interruptions in workflow. Finally,
diffusion of responsibility can lead to a false sense of
safety through reliance on the following check
24
and
thus increase risk. In qualitative studies, nurses indicated
that DC reduced the perceived responsibility of indivi-
duals because they trust in the second checking person
to find potential mistakes—an effect which is often
called ‘social loafing’.
20 25
In oncology, DC is frequently recommended and
claimed as a ‘state of the art’procedure.
26 27
The American
Society of Clinical Oncology (ASCO) and the Oncology
Nursing Society (ONS) standards for the administration of
chemotherapy require that before chemotherapy adminis-
tration, at least two practitioners (1) verify patient identifi-
cation using at least two identifiers; (2) confirm with the
patient the planned treatment, drug route and symptom
management; (3) verify the accuracy of the drug name,
dose, volume, rate of and route of administration, expir-
ation dates/times and appearance and physical integrity of
the drugs; (4) sign to indicate verification was done.
16
The
Swiss nursing standards on chemotherapy administration
are not binding and state that, depending on the institu-
tional policy, a double-check of the drug and the dose
should be conducted during preparation and administra-
tion.
28
There is, however, neither a definition of a robust
checking procedure given in the document nor recom-
mendations proposed on how DC should exactly be
performed.
Despite its wide diffusion, very little is known about
DC practices in cancer care. This study addresses this
gap using a cross-sectional survey among oncology
nurses. The main aim of our study was to describe prac-
tice patterns (types, frequencies and independence of
checks performed) and oncology nurses’experiences
with the double-check in chemotherapy administration.
Our primary research question was to assess which spe-
cific DC routines are implemented and what the experi-
ences with them are. We examined what constitutes a
‘good double-check’for cancer nurses, how frequently
procedures are violated, which barriers nurses perceive
in conducting DC in practice, and whether they would
prefer an expansion or a reduction of DC procedures.
Our secondary research question was to investigate
nurses’judgements about the appropriateness of the
various different DC procedures in discovering medication
errors and the factors affecting their evaluations. We
hypothesised that nurses have clear judgements on the
value of different DC routines based on their prior experi-
ences and their professional expertise. Understanding
nurses’assessments of suitability of DC procedures is crucial
for implementing any changes to current DC practices and
for developing a consistent conceptualisation of DC.
A further secondary research question was to deter-
mine if there were differences in DC practices between
inpatient and outpatient care. Since clinical processes
and working conditions (eg, patient flow and through-
put, staffing, etc) often differ considerably between
wards and ambulatory infusion units, we assumed that
this may also impact how double-checks are performed
and perceived. Knowledge about these differences
would be useful for designing DC procedures and pol-
icies that are adapted to the specific setting and context.
METHODS
Sample
Three hospitals participated with their oncology depart-
ments (two university hospitals, one large regional
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hospital). From each hospital, the oncology wards and
ambulatory units took part. All qualified nurses (ie,
nursing staff authorised to prepare and administer
chemotherapy) working on the participating units
received the survey together with a prepaid envelope
and a chocolate bar. Return of the survey was considered
as implied informed consent. Our study does not involve
interventions, no health-related data or biological mater-
ial are being analysed, the data were completely anon-
ymised and approached individuals could easily refuse
participation by not returning the survey.
Survey
Development
The survey was developed by the investigators based on
the literature, consultations with experts and clinical
staff, and initial field observations. The main challenge
in developing the survey was the inconsistent, vague and
variable concepts held by nurse clinicians and the
various procedures implemented in practice. It became
obvious that simply asking details about ‘the double-
check’would result in non-interpretable data due to
non-standardised use of the term. Therefore, we
assessed which checking procedures are performed in
practice during initial field observations. One author
visited all participating units and observed DC practices
to gain an understanding of the different forms of DC
procedures implemented. In informal conversations
during and after observation, nurses were asked about
the procedures in a non-judgemental manner until the
core steps, their sequence, the actions and interactions
between staff were clear for each scenario. The initial
observations also gave insights into common rules
embedded in checking procedures (which are not
necessarily written down anywhere). For example, medi-
cations should be administered by a nurse involved in
the DC and not by a third person, and double-checks
should not be carried out in series for the medications
of several patients. Finally, the field observations were
also useful to collect information about the environmen-
tal conditions under which DC is performed (eg, rooms,
light, noise). On the basis of the observations, we devel-
oped (1) a set of scenarios describing certain proce-
dures and (2) survey questions that were asked for every
kind of scenario in order to be able to compare the
scenarios.
Six experts from nursing, oncology, clinical pharmacy
and hospital risk management gave feedback on a survey
draft. The survey was pretested for clarity and wording
in a sample of n=39 health care workers (HCW) from
two hospitals not participating in the main study. Only
minor adjustments were made.
Survey instrument
The survey consisted of two main sections: In the first
section (reported here), we used scenarios describing
DC procedures implemented in clinical practice and
asked responders to rate these scenarios regarding
various aspects. This allowed us to assess practice pat-
terns, experiences with different DC procedures and
clinicians’judgements of the effectiveness of DC proce-
dures in discovering medication errors. We used these
scenarios of different DC procedures to obtain detailed
evaluations and to avoid the loosely and inconsistently
defined ‘umbrella concept’of DC. In this section, we
also asked some general items related to DC, for
example, regarding unit policy or perception of essential
elements of DC. The second survey part (not reported
herein) assessed norms and beliefs in DC effectiveness
for medication safety.
DC scenarios and related survey items
In the field observations, we identified five different
core DC procedures implemented in practice. For each
of them, we developed a brief description and an illus-
tration of the main steps (scenarios A–E, see figures 1
and 2). Each participant responded to all scenarios and
was asked the same set of questions for each scenario:
1. Item 1: how appropriate this type of DC is to prevent
medication errors (‘appropriateness rating’; 7-point
Likert from ‘very appropriate’to ‘not appropriate at
all’);
2. Item 2: whether this type of DC is being performed
at their unit (yes routinely/only in exceptions/no/
don’t know); if yes:
3. Item 3: how many of such double-checks they person-
ally conduct on an average working day, including
cytostatics, potassium, antiemetics (none/1–5/6–10/
more than 10);
4. Item 4: how frequently they detect errors, discrepan-
cies or inconsistencies during a double-check of this
type (daily or several times daily/weekly or several
times weekly/monthly or several times monthly/few
times per year/never);
5. Item 5: whether they would eliminate this type of
DC, in case they were free to decide for their unit
(yes/no keep as is/perform only in exceptions);
6. Item 6, only for scenarios C, D, E, which describe
counting and calculating: whether the second nurse
already knows the results of her colleague when she
repeats the procedure (eg, whether she can see the
ticket with the number of tablets or the flow rate, etc;
yes/no).
Generalised items
Participants were then asked to complete a number of
generalised items: they were asked to indicate the ex-
istence of guidelines for DC at their unit; essential
elements of a good double-check; number of double-
checks at their unit; the frequency of violations of DC
procedures (see table 3 for details); frequency of inter-
ruptions caused by DC and conditions interfering with
performing a good double-check; practice and prefer-
ences towards the DC of premedications (drugs given
prior to chemotherapy to prevent side effects of
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treatment, eg, antiemetic drugs and steroids); and
recent experience of severe medication errors. Finally,
respondents completed a few sociodemographic and
work-related items.
Analysis
Survey responses were descriptively analysed. Owing to
item-level missing data, the sample size varies slightly
per item. χ
2
tests were conducted to identify group dif-
ferences between wards and ambulatory infusion units.
In order to test for differences in nurses’appropriate-
ness ratings (item 1 listed above) between DC scenarios,
analysis of variance (ANOVA) was used.
To answer our secondary research question, that is,
determine predictors for the appropriateness ratings
(item 1 listed above), logistic regression analysis was con-
ducted. Since each responder evaluated five scenarios,
the unit of analysis in this regression model was the
judgement provided in response to the scenarios, and
not the individual respondent. The sample size for this
analysis is thus n=number of responders×number of
rated scenarios. The dependent variable (appropriate-
ness rating, item 1 listed above) was dichotomised with
values 1–4=not appropriate and values 5–7=appropriate.
Type of DC procedure evaluated (scenarios A–E),
current implementation of this DC procedure at the
unit, and perceived essential element of a good double-
check were included as predictors (independent vari-
ables). With this analysis, we assess the impact of nurses’
current DC practices at their workplace on their ratings
Figure 1 Double-checking scenarios and descriptions provided in the survey.
Figure 2 Illustration of double-checking procedure A provided in the survey.
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of appropriateness of the distinct DC procedures. In
other words, we correct DC appropriateness ratings for a
bias towards ‘current practice’. Personal and work-
related characteristics were included to adjust the appro-
priateness ratings. We used cluster robust SEs to relax
the assumption of independence of observations within
individuals. All tests were two-sided and a p value <0.05
was considered significant.
RESULTS
Of the 389 distributed surveys, 274 were completed
and returned (response rate=70%). Sample details
are provided in table 1. The majority of responders
were experienced nurses working on wards for at least
25 hours per week in direct patient care. The majority
of nurses (80%) reported that there were internal
guidelines explaining which checks were required for
which medications and that they knew them well.
Knowing that such guidelines existed but not knowing
their contents well was reported by 11%. The remain-
der were not aware of guidelines for their unit.
Overall, 68 responders (25%) reported that one or
more serious medication errors had taken place in
their unit during the past 12 months. Of those, the
majority (68%) believed that the last serious
error could have been prevented with a thorough
double-check.
Practice patterns and experiences with DC procedures
Table 2 reports practice patterns and experiences with
the different DC scenarios. ‘read-read back’of orders
and infusion bag labels (scenario A) was the most widely
implemented DC procedure. A repetitive single check of
order and infusion bag (scenario B) was least common.
Within each type of DC scenario, the largest fraction of
responders was involved in 1–5 checks per average
working day. Nurses working on ambulatory units were
involved in significant higher frequencies of double-
checks. Summarised across the different DC procedures,
48% of all frequency ratings provided by ambulatory
nurses indicate performance of >5 checks per day versus
15% of these ratings reported by nurses on ward
(p<0.001). The reported frequency with which DC proce-
dures detected errors and inconsistencies varied consid-
erably. Approximately a fifth of nurses practising
procedures B (repetitive single check) and C (repetitive
single check of order, calculations and drugs for prepar-
ation) reported that these checks detected inconsisten-
cies at least several times a week. In contrast, the more
widely implemented DC procedures were reported to
detect inconsistencies with a much lower frequency. Only
between 37% (scenario C) and 51% (scenario E) of parti-
cipants reported that commonly the second nurse did
not know the results of her preceding colleague when
she repeated a counting or calculating procedure (truly
independent check). Across all presented DC proce-
dures, the majority of responders would not eliminate
the procedure from their routines (range 73–94%).
Characteristics of the double-check and violations
Participants were clearly discordant on what constitutes
the essential characteristic of a good double-check: ‘two
persons check the medication together’was selected as
the main feature by 54%; ‘two persons make the same
checks successively’was selected by 22% of responders
and 24% answered that ‘one person independently
repeats a process (eg, counting) without knowing the
results of her preceding colleague’was the crucial char-
acteristic of a good double-check. There were no signifi-
cant differences in evaluations of the main feature of a
good double-check between nurses working on wards or
at ambulatory units. Nurses reported different types of
violations of medication safety rules related to DC with
varying levels of frequency (table 3): Performing the
double-check for medications of several patients in
series—without a break and without completing the
drug administration before starting the double-check for
the next patient—was the most commonly reported devi-
ation from safe DC rules. Of responders, 36% reported
any of the three types of violations to happen at least
several times per week at their unit (ambulatory infusion
unit: 46%; ward=32%, p=0.074).
Table 1 Characteristics of survey responders (n=274)
Responders
Characteristic n Per cent
Female gender 240 91
Age, mean (SD), years 37 (10)
18–25 31 12
26–40 149 56
41–55 67 25
56–65 17 6
Qualification*
Qualified nurse 205 76
Oncology nursing expert 42 16
Head nurse 17 6
Other 4 1
Primary place of work
Ward/oncology day care unit 220 82
Ambulatory infusion unit 48 18
Weekly hours in direct patient care (hours/week)
<10 14 5
10 to 25 60 23
25 to 40 123 47
>40 67 25
Experience with barcode scanning
(eg, blood products)
123 46
Preparation of cytostatics at unit 82 31
Years of practice in oncology
<1 25 10
1 to 5 89 36
5to10 55 22
>10 79 32
*Categories may not sum up to 100% due to missing values.
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Number of double-checks at unit
When asked to consider the number of double-checks at
their unit, most surveyed nurses regarded the scheduled
number of double-checks in their unit as good and
appropriate (78%). Additional double-checks were
favoured by 17%. Only a small minority said that there
should be fewer double-checks (5%). A preference
towards additional double-checks was significantly more
frequent among responders working on wards compared
with ambulatory infusion units (21% vs 2%, p=0.005).
Half of the respondents (49%) reported that premedica-
tions were not double-checked at all at their unit (19%
routinely and 28% occasionally). The group of respon-
ders was nearly equally split in their preference for or
against the DC of premedications: Fifty-five per cent said
they would favour and 45% would opt against a routine
DC of all premedications, were they free to decide for
their unit. Those who already routinely performed
double-checks on premedications were much more
likely to support this procedure (90%) as compared with
those who checked them only occasionally or not at all
(47%, OR=10.43, p<0.001).
Interruptions and barriers for DC performance
Many nurses reported that they were frequently inter-
rupted in their own tasks to support a colleague doing a
double-check: 1–5 interruptions of their current activity
per day were reported by 39%; a substantial fraction
(20%) experienced more than 5 interruptions per day.
Nurses working at ambulatory infusion units self-
reported significantly more interruptions than nurses
working on wards (40% vs 16% reporting more than five
interruptions per day, p=0.001). Almost all of the respon-
dents (96%) reported at least one factor which fre-
quently interferes with performing good DC (multiple
answers possible): 78% felt disturbed by hurry and
hectic at the unit, 78% by interruptions and distractions,
58% by noise and poor illumination in the medication
Table 2 Practice patterns and experiences with different double-checking (DC) procedures (scenarios; for item wordings,
see Methods section)
DC procedure, n (% within DC procedure)
ABCDE
Type of DC performed at unit (item 2)
Routinely 185 (69) 57 (21) 87 (33) 117 (45) 175 (66)
Exceptionally 40 (15) 34 (13) 43 (16) 64 (24) 8 (3)
Not performed 45 (17) 175 (66) 131 (50) 81 (31) 81 (31)
Number of double-checks responder is doing on an average day* (item 3)
None 16 (7) 21 (23) 20 (15) 21 (12) 14 (8)
1 to 5 158 (70) 40 (44) 81 (62) 133 (74) 138 (76)
6 to 10 36 (16) 14 (16) 13 (10) 14 (8) 15 (8)
>10 15 (7) 15 (17) 17 (13) 11 (6) 14 (8)
DC performed ‘truly’independently* (item 6)
Yes ––47 (37) 81 (46) 89 (51)
Frequency of detection of errors/inconsistencies during DC* (item 4)
Never/rarely†167 (75) 49 (55) 72 (56) 114 (64) 130 (72)
Several per month 39 (17) 23 (26) 31 (24) 48 (27) 37 (20)
Several per week/day†18 (8) 17 (19) 26 (20) 17 (9) 14 (8)
Preference to eliminate this type of DC* (item 5)
Eliminate completely 7 (3) 2 (2) 2 (2) 5 (3) 1 (1)
Do it only in exceptional cases 23 (10) 22 (25) 26 (20) 30 (17) 10 (6)
Keep as is 194 (87) 65 (73) 100 (78) 144 (80) 167 (94)
*Only participants who reported that the type of DC is being performed at their unit (routinely/occasionally) answered these items.
†Distinct categories merged for analysis.
Table 3 Frequency of self-reported deviations from double-checking (DC) safety rules
Deviation from DC safety rules
Several
times daily
Several times
weekly
Several times
monthly
Less frequently
or never
How frequently is a scheduled double-check done only
superficially, not completed or not conducted at all?
2 (0.7%) 16 (6%) 25 (9%) 239 (84%)
How frequently does a patient get her medication from
staff who were not involved in the DC of this
medication?
6 (2%) 27 (10%) 44 (17%) 188 (71%)
How frequently are the medications of several patients
double-checked in series without a break?
29 (11%) 42 (16%) 54 (21%) 135 (52%)
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room, 53% by problems in finding a colleague for DC,
29% by overcrowded rooms and 25% by their own
fatigue.
Appropriateness of DC procedures and its predictors
Responders evaluated the appropriateness of each of the
five DC procedures for preventing medication errors,
irrespective of whether they performed this type of
check in their daily routines. The differences in the
appropriateness ratings between DC procedures were
considerable (ANOVA F=76.6, p<0.0001). The ratings
were highest for scenarios A (mean=6.0, CI 5.8 to 6.1)
and E (mean=6.0, CI 5.8 to 6.1), followed by D (mean
5.5, CI 5.3 to 5.7), C (mean=4.9, CI 4.8 to 5.2) and B
(mean=3.9, CI 3.7 to 4.2). Results of the logistic regres-
sion analysis confirm that the appropriateness of the five
different DC procedures was judged differently, even
after adjusting for other variables (table 4). DC proce-
dures B and C were perceived as significantly less useful
in preventing medication errors compared with proce-
dures A and E. DC procedures which were implemented
at the responder’s work environment and thus currently
personally experienced scored systematically higher on
the appropriateness rating, even after adjusting for the
type of check and other variables: procedures nurses
were currently using at their unit were more than 17
times more likely to be judged appropriate compared
with procedures outside their scope of current
experience. The difference between the categories ‘not
practiced’and ‘occasionally practiced’explained, on
average, a one-point difference on the response scale.
Finally, female gender was the only personal and work-
related variable affecting the perceived benefitofDC
procedures for preventing medication errors. Working
on wards or at ambulatory units did not affect appropri-
ateness ratings.
DISCUSSION
To the best of the authors’knowledge, this is the first
analysis of nurses’experiences with and evaluations of
different procedures of DC of medication in cancer
care. We surveyed experienced oncology nurses from
three large hospitals including wards and ambulatory
infusion units. The response rate was satisfactory.
Positive experiences and support for DC
Nurses in our study had positive attitudes towards DC,
expressed in the high appropriateness ratings of all
checking procedures and the fact that more than half of
the respondents would also prefer to extend the double-
check to premedications. The five described DC proce-
dures were regarded to be of different value with the
joint ‘read-read back’check involving two nurses being
rated the most appropriate. The strong, general support
for DC is connected to the personal experiences
reported by the nurses: Depending on the DC scenario
Table 4 Results of logistic regression analysis with dichotomised double-check appropriateness rating as the outcome;
model with cluster robust SEs
OR 95% CI p Value
Double-check type (to reference ‘A’)
B 0.184 0.107 to 0.317 <0.001
C 0.491 0.290 to 0.832 0.008
D 1.128 0.626 to 2.032 0.688
E 2.078 1.185 to 3.641 0.011
DC performed at own unit (to reference ‘yes, regularly’)
Occasionally 0.211 0.126 to 0.354 <0.001
No 0.058 0.035 to 0.096 <0.001
Essential characteristic of DC (to reference ‘two nurses check together’)
Repeated single check 1.683 0.915 to 3.096 0.094
Two independently 1.597 0.936 to 2.725 0.086
Age, years 1.008 0.986 to 1.031 0.455
Female gender 3.183 1.363 to 7.432 0.007
Weekly working hours in direct patient care (to reference ‘<25 hours’)
25 to 40 0.601 0.348 to 1.037 0.067
>40 0.668 0.359 to 1.244 0.204
Experienced with barcode scanning 0.959 0.616 to 1.493 0.853
Head nurse 0.574 0.234 to 1.405 0.224
Working on ward (vs ambulatory infusion unit) 0.703 0.404 to 1.223 0.212
Serious medication error in the past 12 months 0.775 0.470 to 1.278 0.318
Number of observations 1190
Number of individuals 248
R
2
0.35
Overall model p <0.001
DC, double-checking.
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presented, between 45% and 25% of participants indi-
cated that at least several errors per month had been
detected using this method. Thus, in everyday work life,
nurses commonly make the experience that inconsisten-
cies are detected with DC. In contrast, inconsistencies
not found during checking and the extent of errors
which remain invisible but could be found with other
checking procedures are not personally experienced.
Thus, every ‘hit’sends a positive feedback and reinforces
the positive attitude towards DC. Our finding that
two-thirds of nurses who experienced a recent medica-
tion error believed that this error could have been pre-
vented with thorough DC suggests that the selective
confirmation of DC may cause a generalisation of its per-
ceived effectiveness.
Preferences towards current practice
While the variance in appropriateness ratings confirms
that participants responded sensitively to the scenario
descriptions and adjusted their judgement accordingly,
our results also emphasise a ‘bias towards the known’
with regard to currently practised DC procedures.
Whether a certain check was implemented at the unit
was a significant independent predictor for a high
appropriateness rating. This status quo bias is also
expressed in various other survey items: for example, the
vast majority of responders indicated that they would not
eliminate or change the frequency of specific checks
and regarded the extent of checks at their unit as
‘just right’. Nurses who currently routinely perform
double-checks on premedications strongly supported
this procedure, whereas those who currently do not
double-check were reserved about introducing this prac-
tice. Our results lend support to an Australian study
which reported a reluctance to de-implementation of
DC among nurses. In this study, nurses held strong views
against single-checking before the practice was changed
from DC to single-checking.
29
This preference against
change demonstrates the virtual ‘inviolability’of the
double-check notwithstanding the increasing evidence
questioning the effectiveness of currently implemented
DC procedures.
Independence of checks
Our study confirms the qualitative research regarding
the variability in interpretations and ideas of what consti-
tutes a double-check, the importance of independence
of checks and how it can be achieved.
20 21
Only a
quarter regarded the independence of checks as the
essential feature of DC, whereas twice as much selected
‘doing the checks together’. In scenarios which allow
configuration of an independent check (scenarios C–E),
only 37–51% of responders reported that the routine is
currently implemented in order to achieve independ-
ence (ie, not knowing the results of the co-worker). This
points to a structural and prevalent misunderstanding of
the rationale behind DC procedures. One basic pre-
requisite for the redundancy principle to be successful
is the independence between redundant ‘units’.
30
In technical systems, this requirement is usually satisfied
because non-living objects (eg, computers) which serve
as a backup for other non-living objects are unaware of
each other. Their performance is unaffected by the pres-
ence or absence of the redundant unit. In contrast, this
principle is typically violated in social systems. Human
participants are aware that their co-workers will conduct
redundant checks. Independence within the specific
check itself can be more or less simulated (eg, by not
sharing information as recommended in DC guide-
lines).
12
Yet, even simply knowing that a second check
will be conducted may negatively affect motivation and
result in the tendency to make less effort. The violation
of independence can result in greater diffusion of
responsibility and thus decreased system safety.
14
This has
been confirmed in qualitative studies, in which nurses
indicated that DC would reduce the perceived responsi-
bility of individuals because others would pick up poten-
tial mistakes.
20 25
Oncology nurses in our survey judged
the read-read back procedure, a routine which relies on
the presence and literal ‘dialogue’of two nurses, as most
appropriate. These professionals are persistently con-
fronted with administering high-risk drugs to vulnerable
patients and the genuine function of DC here may
indeed be to share responsibility for safe drug administra-
tion. Furthermore, the identified misconception of the
independence principle and its importance in combin-
ation with the finding that many nurses felt disturbed by
environmental factors means that while doing their
checks together, nurses are subject to the same environ-
mental impacts, such as insufficient light or noise or
interruptions. Consequently, we advocate critically dis-
cussing what true independence in DC means and how it
can be achieved in clinical practice. Our results also
support the proposition to define what is meant by a
double-check more precisely.
21
Potential hazards connected to DC
Recent analyses of incidents revealed how many collab-
orative cross-checks failed and did not prevent severe
incidents.
31
On the basis of our findings, we would like
to raise awareness about potential hazards that may be
connected to DC.
First, our results highlight the interplay between DC
and interruptions in workflow: nurses reported frequent
interruptions caused by DC, particularly at the ambulatory
infusion units, and often felt disturbed by interruptions
during DC. Given the evidence that interruptions in
medication-related tasks are strongly associated with
errors, this is alarming.
32 33
On the basis of direct obser-
vation of medication administration, Trbovich et al
34
reported that nurses in ambulatory infusion units were
interrupted 22% of their time and frequently inter-
rupted during safety-critical stages. Our results confirm
that medication administration at ambulatory infusion
units may be particularly affected by frequent interrup-
tions. Prakash et al
35
recently investigated the effects of
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interruptions during chemotherapy verification and
administration on the frequency of errors. In this study,
nurses made significantly more errors in verification of
medication volumes in syringes and infusion pumps
when interrupted. Taking these studies into account,
our results indicate that without reorganising DC rou-
tines in clinical practice, the procedure may in fact
increase the risk for error.
Second, the strong general support for DC that we
observed coexists with frequent violations of important
DC rules. A third of responders were aware of at least
weekly non-adherence to safety rules at their unit, such
as DC medications for different patients in series
without a break. Such violations of safety rules under-
mine the value of DC procedures by limiting its poten-
tial effectiveness and promoting a false sense of safety.
Third, a considerable fraction of nurses (11%) in our
study reported that they did not know the contents of
medication administration guidelines at their unit well,
and nearly 10% were unaware whether such guidelines
existed. This finding per se is a matter of concern and
confirms that even local medical guidelines and safety
standards are often not well disseminated and known in
practice. It may also suggest that the guidelines in place
are not perceived as being usable or helpful for practice.
For example, the local guidelines of the participating
units we consulted mention DC, but do not provide any
details on how checks should be done. Taken together,
nurses may receive confirmation and safeguarding
during chemotherapy verification from doing checks
together and sharing responsibility rather than from
complying with (vague) guidelines.
LIMITATIONS
Our study has some limitations: First, it relies on self-
reported practices and experiences and is, as such,
subject to various biases. For example, nurses may
underestimate or overestimate the true prevalence of
DC rule violations or the frequency with which DC
detects inconsistencies. Second, to overcome the poor
conceptualisation of the umbrella term ‘double-check’,
we prepared descriptions of core subprocesses based on
observations in clinical practice. This has the advantage
that participants shared a basic common understanding
when answering survey questions. On the other hand,
specific aspects or steps of DC procedures in the specific
units may not have been taken into account in the scen-
arios or may have lured respondents into a false sense of
detail, although we have no indication of this (eg, in the
free-text response fields in the survey).
CONCLUSIONS
Generally, the survey showed that DC is a procedure well
supported by nurses working in oncology which, in their
experience, helps to detect errors. They used joint DC
frequently, preferred this method over others and rated
it appropriate to prevent medication errors. These
findings show that clinicians’perspectives are not match-
ing current recommendations claiming that checks need
to be carried out independently to increase safety. Thus,
knowledge about the importance of independence in
DC needs to be transferred more actively into clinical
practice, so that healthcare professionals implementing
and using DC procedures can adopt their procedures
accordingly. The high frequency of reported interrup-
tions during, and caused by, DC is a matter of great
concern. Existing ideas to reduce interruptions during
checking, such as quiet zones, need to be tested in
future research.
Acknowledgements The authors thank all nurses who participated in the
survey. The support of the clinical experts in providing feedback to the survey
and especially of Anna Götz (nursing expert) in survey design and field testing
is highly appreciated.
Contributors DLBS, YP and KT contributed to the design of the study and the
survey instrument. DLBS analysed the data. YP and KT contributed to the
interpretation of data. DLBS wrote the draft. YP and KT provided important
intellectual content. All authors approved the manuscript.
Funding This work was supported by a research grant from Krebsforschung
Schweiz (Cancer Research Switzerland, KFS-3496-08-2014) and an
unrestricted research grant by the Hanela-Stiftung.
Competing interests None declared.
Ethics approval Cantonal Ethics Committee Zuerich (KEK ZH Nr. 34-2015) on
the basis of the Swiss Legislation (Human Research Act, HRA).
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement No additional data are available.
Open Access This is an Open Access article distributed in accordance with
the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license,
which permits others to distribute, remix, adapt, build upon this work non-
commercially, and license their derivative works on different terms, provided
the original work is properly cited and the use is non-commercial. See: http://
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oncology nurses' experiences
clinical practice: a cross-sectional survey of
Medication double-checking procedures in
D L B Schwappach, Yvonne Pfeiffer and Katja Taxis
doi: 10.1136/bmjopen-2016-011394
2016 6: BMJ Open
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