Preventing Hospital-Acquired Urinary Tract Infection in the United States: A National Study
Sanjay Saint
()
0
1
2
Christine P. Kowalski
2
Samuel R. Kaufman
0
1
Timothy P. Hofer
0
1
2
Carol A. Kauffman
1
2
Russell N. Olmsted
3
Jane Forman
2
Jane Banaszak-Holl
4
Laura Damschroder
1
2
Sarah L. Krein
1
2
0
Veterans Affairs/ University of Michigan Patient Safety Enhancement Program
1
Department of Internal Medicine, University of Michigan Medical School
2
Veterans Affairs Ann Arbor Healthcare System
3
Saint Joseph Mercy Health Care System
,
Ann Arbor, Michigan
4
University of Michigan School of Public Health
(See the editorial commentary by Nicolle on pages 251-3) Background. Although urinary tract infection (UTI) is the most common hospital-acquired infection in the United States, to our knowledge, no national data exist describing what hospitals in the United States are doing to prevent this patient safety problem. We conducted a national study to examine the current practices used by hospitals to prevent hospital-acquired UTI. Methods. We mailed written surveys to infection control coordinators at a national random sample of nonfederal US hospitals with an intensive care unit and 50 hospital beds (n p 600 ) and to all Veterans Affairs (VA) hospitals (n p 119). The survey asked about practices to prevent hospital-acquired UTI and other device-associated infections. Results. The response rate was 72%. Overall, 56% of hospitals did not have a system for monitoring which patients had urinary catheters placed, and 74% did not monitor catheter duration. Thirty percent of hospitals reported regularly using antimicrobial urinary catheters and portable bladder scanners; 14% used condom catheters, and 9% used catheter reminders. VA hospitals were more likely than non-VA hospitals to use portable bladder scanners (49% vs. 29%; P ! .001), condom catheters (46% vs. 12%; P ! .001), and suprapubic catheters (22% vs. 9%; P ! .001); non-VA hospitals were more likely to use antimicrobial urinary catheters (30% vs. 14%; P p .002). Conclusions. Despite the strong link between urinary catheters and subsequent UTI, we found no strategy that appeared to be widely used to prevent hospital-acquired UTI. The most commonly used practicesbladder ultrasound and antimicrobial catheterswere each used in fewer than one-third of hospitals, and urinary catheter reminders, which have proven benefits, were used in !10% of US hospitals.
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Hospital-acquired infections are a common, costly, and
potentially lethal patient safety problem [1, 2]. The
most common hospital-acquired infection is urinary
tract infection (UTI), which accounts for almost 40%
of all nosocomial infections [35]. Most
hospitalacquired UTIs are associated with urinary catheters, a
commonly used device among hospitalized patients. Up
to 25% of hospitalized patients have a urinary catheter
placed during their stay [3, 6]; these catheters often
cause considerable discomfort and embarrassment to
patients [79]. The substantial morbidity associated
with nosocomial UTI generates additional health care
costs [911].
Several practices have been evaluated to prevent
hospital-acquired UTI [12, 13]. Such practices include
using indwelling catheters only when necessary, removing
catheters when no longer needed via the use of various
reminder systems, using antimicrobial catheters in
patients at highest risk of infection, using external (or
condom-style) catheters in appropriate men, using
portable ultrasound bladder scans to detect postvoid
residual urine amounts, maintaining proper insertion
technique, and using alternatives to indwelling urethral
catheters, such as suprapubic or intermittent
catheterization [13]. Practices that are no longer recommended
because of lack of evidence include use of antimicrobial
agents in the drainage bag, rigorous frequent meatal cleaning,
and use of bladder irrigation [13].
Despite the frequency with which hospital-acquired UTI
occurs, little is known about what American hospitals are doing
to prevent it. Therefore, we conducted a national study to
answer this question and to explain variations in prevention
practices among hospitals. Because we were especially curious how
being part of a centralized system of health care delivery would
affect our findings, we oversampled hospitals that were part of
the Department of Veterans Affairs (VA).
Data collection. As part of a larger study [14], we undertook
a national evaluation to understand what US hospitals are doing
to prevent device-associated infection and why they are using
some practices rather than others. The first phase of this
studythe focus of this articlewas a survey sent to infection
control coordinators at 719 hospitals across the nation. The
national survey sample included all VA medical centers that
had operating acute care beds in 2004 (n p 119) and a stratified
random sample of non-VA general medical and surgical
hospitals with 50 beds and with intensive care beds. The national
non-VA sample was stratified into 2 groups (hospitals with 50
250 beds and those with 251 beds), and a random sample
of 300 hospitals was selected from each group. The non-VA
hospitals were identified using data obtained from the 2005
American Hospital Association (AHA) Annual Survey Database
(fiscal year 2003 data).
Surveys were mailed to all hospitals in March 2005, along
with a prepaid return envelope, a cover letter inviting
participation, a study brochure, and an incentive. One week later, a
reminder postcard was mailed to all sites from which we had
not received a completed survey. Four weeks after the initial
mailing, another survey, letter, and prepaid return envelope
were sent to the nonresponders. All mailings were addressed
to Infection Control Coordinator, with the explanation that
if there was 11 infection control professional (ICP) at that
particular facility, the ICP who supervised or coordinated the
other ICPs should complete the survey. If the facility did not
have an ICP, we indicated that the survey should be completed
by someone involved in infection control, such as a hospital
epidemiologist. In addition to the survey, data were also
obtained from the 2005 AHA Database and the 2003 Area
Resource File [15]. Institutional review board approval was
obtained from the VA Ann Arbor Healthcare System (Michigan).
Survey measures. In a series of questions, respondents were
asked how frequently certain catheter-related UTI practices
were used for adults in their acute care facility (figure 1).
Frequency was measured on a scale from 1 to 5 (with 1 being
never and 5 being always), with regular use defined in
our analyses by a rating of 4 or 5. The practices of interest
were use of antimicrobials in the drainage bag, use of portable
bladder ultrasound for determining postvoid residual, use of a
urinary catheter reminder or stop-order, use of an antimicrobial
urinary catheter (either nitrofurazone-releasing or a silver alloy
Foley catheter), use of condom catheters in men, and use of
suprapubic catheters. Respondents were also asked about the
monitoring practices related to UTI and urinary catheters used
at their facility.
Additional characteristics of the facility included whether the
facility had a hospital epidemiologist, whether the lead ICP
was certified in infection control and epidemiology, whether
the facility was participating in some type of collaborative effort
to encourage use of infection control practices, whether the
facility had hospitalists (if this question was not answered on
our survey, then data were supplied from the AHA database),
and a safety culture score. The safety culture score [16] was
the average of the following 2 items, both scaled from 1
(strongly agree) to 5 (strongly disagree): (1) Leadership is
driving us to be a safety-centered institution, and (2) I would
feel safe being treated here as a patient. Before averaging the
items, we reverse-scored them, so that higher scores indicated
greater safety-centeredness. Finally, academic affiliation was also
considered and defined as having residency training approval
by the Accreditation Council for Graduate Medical Education,
as specified in the AHA database.
Statistical analysis. We used sample weights based on the
probabilities of selection in each stratum and the relevant
survey commands found using Stata software, version 9.0
(StataCorp), to estimate the full population of VA hospitals and
non-VA acute care hospitals with 50 hospital beds and an
intensive care unit (ICU). We then conducted bivariate analyses
that compared VA and non-VA hospitals. Results are reported
either as weighted proportions (with Pearson x2 test results)
or as weighted means (with 95% CIs and adjusted Wald test
results). Finally, we used weighted logistic regression to
determine which of our primary independent variables were
associated with the use of each infection prevention practice, while
simultaneously adjusting for other factors, such as the facilitys
number of ICU beds, nurse staffing (nursing full-time
equivalents per adjusted average daily census), and metropolitan
location. Logistic regression results are presented as ORs with
95% CIs. All reported P values are 2-tailed.
The overall survey response rate was 72% (80% for the VA
sample and 70% for the non-VA sample). Table 1 compares
VA and non-VA hospitals with regard to a number of
characteristics. Several statistically significant differences were
noted, including the existence of approved residency training
programs (at 75% of VA hospitals and 24% of non-VA
hospitals), presence of a hospital epidemiologist (50% and 39%,
respectively), ICP certification in infection control (75% and
57%, respectively), registered nurse staffing levels (mean level,
1.7 and 1.2, respectively), and safety culture score (mean level,
7.5 and 8.0, respectively).
Table 2 compares VA and non-VA monitoring practices for
urinary catheters and UTIs. The monitoring practices were
generally similar across VA and non-VA hospitals. Specifically, more
than one-half of hospitals did not have a system for monitoring
which patients had catheters placed, three-quarters did not
monitor duration of catheterization, nearly one-third did not
conduct any type of UTI surveillance, and few hospitals used
urinary catheter teams. However, VA hospitals that had
implemented a monitoring practice were more likely than
nonVA hospitals to have localized it to specific units, rather than
implementing it facilitywide.
In terms of hospital-acquired UTI prevention practices used,
30% of hospitals overall reported regularly using antimicrobial
urinary catheters and portable bladder scanners, 14% regularly
used condom catheters in men, 9% regularly used catheter
reminders and suprapubic catheters, and 3% regularly used
antimicrobial agents in the drainage bag. Figure 2 compares
VA and non-VA hospitals with regard to various
hospitalacquired UTI prevention practices. VA hospitals were
significantly more likely than non-VA hospitals to use portable
bladder scanners (49% vs. 29%; P ! .001), condom catheters in men
(46% vs. 12%; P ! .001), and suprapubic catheters (22% vs.
9%; P ! .001). Non-VA hospitals were significantly more likely
to use antimicrobial urinary catheters (30% vs. 14%; P p
.002).
Table 3 shows the results of a multivariable logistic regression
analysis assessing the association between our independent
variables of interest and the use of hospital-acquired UTI
prevenMean no. of intensive care unit beds (95% CI)
Approved residency training
Have hospitalists
Participate in a collaborative
Mean safety culture scoreb (95% CI)
Have hospital epidemiologist
Infection control professional certified in infection control
Mean no. of full-time RN equivalents per adjusted
average daily census (95% CI)
Located in metropolitan area
County population, mean no. of persons (95% CI)
Non-VA hospitalsa
(n p 2671 )
NOTE. Data are percentage of hospitals, unless otherwise indicated. RN, registered nurse.
a Weighted sample size reflecting the total population of hospitals represented by the respondent sample. For the non-VA hospital
sample, the population represented is general medical and surgical hospitals with 50 beds and with intensive care unit beds.
b Score ranging from 2 to 10.
tive practices (ORs of 11.0 indicate that the variable increases
the odds of regular use of the practice or device). Residency
training was significantly associated with the use of a urinary
catheter reminder or stop-order. Hospitals in which the ICP
was certified in infection control were significantly more likely
to use antimicrobial urinary catheters. Compared with non-VA
facilities, VA hospitals were 18 times more likely to use condom
catheters for men (P ! .001), 14 times more likely to use
suprapubic catheters (P ! .001), more than twice as likely to use
portable bladder ultrasound scanners (P p .017), but only
twofifths as likely to use antimicrobial catheters (P p .021).
Participating in a collaborative effort to reduce health
careassociated infection was not associated with the use of any of the
practices, nor was the presence of either hospitalists or a
hospital epidemiologist.
DISCUSSION
Several noteworthy findings emerged from our national survey.
First, only a minority of hospitals monitored which of their
hospitalized patients had urinary catheters, despite the strong
link between catheters and subsequent UTI. Second, we could
find no single, widely used strategy to prevent hospital-acquired
UTI; the most commonly used practicesbladder ultrasound
and antimicrobial catheterswere each used in fewer than
onethird of hospitals. Third, VA hospitals were more likely than
non-VA hospitals to use portable bladder scanners, condom
catheters, and suprapubic catheters but were less likely to use
antimicrobial urinary catheters. Finally, despite evidence of
benefit and high face validity, urinary catheter reminders were used
in !10% of hospitals.
Although we are unaware of other national studies that have
attempted to characterize what US hospitals are doing to
prevent UTIeven though it is the most common
hospital-acquired infection in the countryour findings are best
understood in the context of the available literature evaluating several
of the practices about which respondents were queried. The
use of antimicrobial catheters, for example, is a rather
controversial practice to prevent catheter-related UTI, given the
conflicting data [17, 18]. An article in the Cochrane Database of
Systematic Reviews [19] concluded that the use of antimicrobial
catheters in place of noncoated catheters appears to reduce the
risk of bacteriuria. Although another recent systematic review
confirmed this assessment, the latter review highlighted the
major limitation of most studies evaluating antimicrobial
catheters: their reliance on asymptomatic bacteriuria rather than a
clinically more relevant outcome, such as symptomatic UTI or
catheter-related bacteremia [20]. In addition, the acquisition
cost of an antimicrobial catheter tray is $5 more than that of
a noncoated catheter tray [21], likely further dampening the
enthusiasm for their use.
Portable bladder ultrasound scanners have been used to
measure urinary retention and have been advocated, by some, to
reduce the need for catheterization. A recent review [22]
concluded that bladder scanners accurately measure urine volume
(using urethral catheterization as the benchmark). Additionally,
portable ultrasound scanners were found to reduce the number
of intermittent catheterizations and to perhaps even decrease
the risk of UTI [22]. One group found that the use of bladder
scans decreased catheter-related UTIs from 87% to 38% in one
unit and from 81% to 50% in another unit over a 12-month
period [23]. The cost of purchasing the specific type of scanner
used in this study was $8300 [23]. Although no experimental
Has a system for monitoring which patients have urinary
catheters placed
Routinely monitors duration and/or discontinuation of
urinary catheters
Has an established surveillance system for monitoring urinary
tract infection rates
Feedback on urinary tract infection rates to direct care providers
Has a urinary catheter team
Percentage of hospitals
Yes, facilitywide
Yes, unit specific
studies with large, representative patient populations have been
conducted to confirm these possible benefits [22, 24], 30%
of US hospitals appear to be using this technology.
Alternative devices (e.g., condom or suprapubic catheters)
are an option for appropriate patients [2527]. A recently
reported randomized trial comparing condom catheters with
indwelling urethral catheters in hospitalized men found that use
of a condom catheter instead of an indwelling catheter lowered
the incidence of bacteriuria; this protective effect was seen
primarily in men who did not have dementia [28]. A secondary
finding was that patients reported that an external urinary
collection device was more comfortable than an indwelling
catheter, supporting previous data [8]. A recent meta-analysis of
14 studies comparing suprapubic with urethral catheters found
that patients given a suprapubic catheter had significantly lower
rates of bacteriuria and less discomfort, compared with those
given a urethral catheter [29].
Urinary catheter reminders have also been used to decrease
urinary catheterization rates. Because 180% of patients who
develop a UTI during hospitalization have a urinary catheter,
and because the risk of infection increases as the duration of
catheterization increases, perhaps the best infection prevention
strategy against hospital-acquired UTI would be to limit
urethral catheterization. When the unjustified use of many
catheters is considered, coupled with frequent lack of physician
awareness of catheter presence [6], techniques that alert
physicians to the catheter status of their patients may help reduce
inappropriate catheterization [9]. Several studies support the
use of catheter reminders. A study performed at a VA medical
center evaluated a computerized reminder with a
before-andafter crossover design that prompted physicians either to
remove or continue the urinary catheter 72 h after catheter
insertion [30]. These investigators found that the computerized
reminder shortened the duration of catheterization by 3 days
while not affecting recatheterization [30]. A nurse-based
reminder, in which nurses were instructed to remind physicians
to remove unnecessary urinary catheters, was demonstrated in
a Taiwanese ICU to reduce the duration of catheterization (7
vs. 4.6 days; P ! .001) and UTI rates (11.5 vs. 8.3 cases per 1000
catheter-days; P p .009) [31]. Finally, a controlled trial using
a pretest-posttest design in 4 hospital wards at an academic
medical center showed that a paper-based reminder placed in
the medical record after 48 h of catheterization significantly
reduced the proportion of time that patients had catheters in
place; there was no significant difference in the number of
urethral recatheterizations between intervention and control
groups, and the intervention was found to be economically
efficient [32].
Responding hospitals that were members of a collaborative
effort to reduce health careassociated infection were no more
likely to use any of the infection prevention practices studied
than were hospitals that were not part of a collaborative. This
finding is in contrast to the findings of a previous report, which
focused on vascular catheter-related bloodstream infection and
found collaborative membership was associated with the use
of several preventive practices [33]. However, this is probably
not a true discrepancy. Collaborative approaches focusing on
prevention of hospital-acquired UTI have not been vigorously
pursued in the United States, but several collaborative initiatives
have recently been launched to prevent infection associated
with vascular catheters, including the Institute of Healthcare
Improvements 100,000 Lives campaign [34] and the Keystone
Center for Patient Safety and Quality Institutes project in
Michigan ICUs [35]. There is now, however, a statewide
collaborative initiative under way in Michigan that will evaluate
a bladder bundle to help reduce the burden of
hospitalacquired UTI (http://www.mhakeystonecenter.org).
One reason for including VA hospitals in this national study
was to assess the effects of centralization on the use of UTI
prevention practices. Although we cannot precisely separate
centralization from other attributes of the VA health care
nantly male patient population of the VA, leading VA hospitals
system, the systems hierarchical structure is perhaps its most
to focus on practices that affect primarily men, such as use
salient and distinctive characteristic. With this caveat,
cenof condom catheters. Similarly, the use of portable bladder
tralization does seem to be relevant in terms of the use of
ultrasound scanners and suprapubic catheters might be used
infection prevention practices, but not in a straightforward
preferentially in VA hospitals because of the concern for
bladmanner. VA status is statistically significant for 4 of 5 practices
der outlet obstruction owing to a patients enlarged prostate
described in table 3. The higher rate of use of condom
cathgland. On the other hand, we cannot explain why VA hospitals
eters at VA hospitals may simply be related to the
predomiuse antimicrobial urinary catheters less often than non-VA
Characteristic
Approved residency training
Have hospitalists
Participate in a collaborative
Safety culture score
Have hospital epidemiologist
Portable
1.1 (0.601.96)
1.1 (0.641.93)
1.4 (0.842.35)
1.1 (0.861.38)
0.7 (0.431.25)
1.5 (0.852.64)
2.3 (1.164.47)
4.1 (1.4811.11)
0.7 (0.281.69)
0.7 (0.331.51)
1.3 (0.901.87)
0.9 (0.362.21)
0.6 (0.261.47)
0.9 (0.322.77)
OR (95% CI)
Antimicrobial urinary catheters Condom catheters for men
0.8 (0.411.56)
1.1 (0.652.03)
1.4 (0.852.36)
1.1 (0.851.30)
0.7 (0.381.14)
1.9 (1.023.38)
0.4 (0.160.86)
1.3 (0.632.82)
1.2 (0.602.56)
1.2 (0.622.30)
1.3 (0.951.65)
1.3 (0.652.52)
0.6 (0.321.26)
8.1 (3.8717.12)
Suprapubic
catheters
0.8 (0.341.69)
1.6 (0.693.47)
1.3 (0.642.57)
1.1 (0.841.51)
1.0 (0.442.09)
0.6 (0.281.27)
4.3 (1.909.53)
hospitals. We were, surprised, however, that urinary catheter
reminders were not used more frequently at VA facilities,
because VA hospitals have a superb computerized order entry
system that can be programmed to prompt physicians about
catheter presence [30].
Although we used national sampling and achieved an
excellent response rate, several important limitations of our
survey-based study should be considered. First, we relied on
selfreported data from the lead ICP at each site to determine which
practices were being used to prevent nosocomial UTI. Although
it is possible that an individual respondent may have overstated
or understated the use of the various practices, we have no
reason to believe this would be a systematic problem. Second,
although our sampling strategy aimed to obtain a nationally
representative sample, it is possible that participating hospitals
were different from nonparticipating hospitals, thereby making
the results less generalizable. Third, our multivariable model
does identify some factors associated with the use of certain
practices; however, we are unable to determine the causal
relationship between these factors and the use of certain practices.
A qualitative study in which interviews and site visits are
conducted would be able to provide detailed data to gain insights
into why hospitals are using some practices and not others. We
are currently conducting such a qualitative evaluation.
Limitations notwithstanding, we have provided a snapshot
of what practices US hospitals are currently using to prevent
hospital-acquired UTI. Furthermore, we identified several
characteristics that are associated with the use of various practices.
The precise reasons underlying a hospitals decision to use one
practice over another are best elucidated using qualitative rather
than quantitative evaluation [14], at least at this stage of our
understanding. Nevertheless, our study has important policy
implications, especially in light of Medicares recent decision
to decline reimbursement for the extra cost of treating
preventable complications during hospitalization, including
catheter-related UTI [36]. Despite the strong link between urinary
catheters and subsequent UTI, we found that no single strategy
was widely used for the prevention of nosocomial UTI. The
most commonly used practicesbladder ultrasound and
antimicrobial catheterswere each used in fewer than one-third
of hospitals. Finally, despite reasonable evidence supporting the
use of urinary catheter reminders, fewer than 1 in 10 hospitals
in this country used this simple and economically attractive
method for preventing unnecessary catheterization.
Acknowledgments
Financial support. Department of Veterans Affairs, Health Services
Research and Development Service (SAF 04031), and Ann Arbor VA
Medical Center/University of Michigan Patient Safety Enhancement
Program. S.S. is supported by an Advanced Career Development Award from
the Health Services Research and Development Program of the Department
of Veterans Affairs.
Potential conflicts of interest. S.S. has received honoraria for speaking
at a nosocomial infection conference sponsored by VHA (a
group-purchasing organization). All other authors: no conflicts.