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 Table of Contents  
Year : 2022  |  Volume : 5  |  Issue : 2  |  Page : 69-74

Quality improvement project of a closed catheter system to reduce catheter-associated urinary tract infections during acute inpatient rehabilitation using stepped-wedge design

1 Department of Physical Medicine and Rehabilitation, University of Texas Health Science Center at Houston, McGovern Medical School, Texas, USA
2 TIRR Memorial Hermann, Texas, USA
3 Department of Pediatrics, University of Texas Health Science Center at Houston, McGovern Medical School, Texas, USA

Date of Submission19-Jul-2021
Date of Decision06-May-2022
Date of Acceptance07-May-2022
Date of Web Publication07-Jun-2022

Correspondence Address:
Dr. Argyrios Stampas
TIRR Memorial Hermann, 1333 Moursund St, Houston, TX 77030, Texas
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jisprm.JISPRM-000142

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Objective: To investigate if an indwelling catheter with a one-way valve (BioFlo® [BF]) reduces the incidence of catheter-associated urinary tract infections (CAUTIs). Methods: Prospective quality improvement project. Design: Stepped-wedge nursing unit enrollment in acute inpatient rehabilitation facility (IRF) was conducted over 9 months. All patients admitted to IRF that used an indwelling catheter at any time during admission were included, with all days and types of voiding methods collected when in the study period. Comparisons were between BF versus usual care (Foley catheter), with incidence of CAUTI as the primary outcome measure. Results: There were 227 patients: 21 using BF only, 146 using Foley only, and 60 using both. This resulted in 206 Foley users and 81 BF users. The BF group had a greater percentage of patients with CAUTI compared to the Foley group (30% vs. 17%, P = 0.021). Using generalized linear modeling and adjusting for confounders revealed an 89% increased risk of CAUTI in the BF group compared to the Foley group (odds ratio: 1.89, P = 0.033). Bayesian analysis determined that the probability of BF increasing the rate of CAUTI was 96% (95% credible interval: 0.95–2.7). Conclusions: Maintaining a closed catheter system with BF does not reduce the rates of CAUTIs during acute inpatient rehabilitation.

Keywords: Rehabilitation hospitals, urinary catheterizations, urinary tract infections

How to cite this article:
Stampas A, Hua J, Naumann H, Martinez CI, Roberts D, Pedroza C. Quality improvement project of a closed catheter system to reduce catheter-associated urinary tract infections during acute inpatient rehabilitation using stepped-wedge design. J Int Soc Phys Rehabil Med 2022;5:69-74

How to cite this URL:
Stampas A, Hua J, Naumann H, Martinez CI, Roberts D, Pedroza C. Quality improvement project of a closed catheter system to reduce catheter-associated urinary tract infections during acute inpatient rehabilitation using stepped-wedge design. J Int Soc Phys Rehabil Med [serial online] 2022 [cited 2023 May 28];5:69-74. Available from: https://www.jisprm.org/text.asp?2022/5/2/69/346839

  Introduction Top

Catheter-associated urinary tract infections (CAUTIs) are the most common hospital-acquired infections (HAIs), accounting for greater than 560,000 (>30%) of HAIs, and are associated with increased morbidity, lengths of stay, hospital costs, and mortality.[1] According to the Centers for Disease Control and Prevention (CDC), HAIs are avoidable, estimating that 17%–69% of CAUTIs are preventable.[2] Subsequently, in 2008, the Centers for Medicare and Medicaid Services no longer compensated hospitals for the costs related to treating CAUTIs.[3],[4] Hospital systems have been exploring ways to reduce CAUTIs, including the removal of indwelling catheters that may be unnecessary, estimated to occur in one-third of patients with catheters.[5]

While identification and removal of the forgotten, short-term indwelling urinary catheter may be a valuable method to reduce the rates of CAUTI in many hospital settings, it may not be as relevant at an inpatient rehabilitation facility (IRF). Inpatient rehabilitation patients with neurogenic bladders rely heavily on indwelling catheters for safely emptying their bladders. Herein lies the challenge of CAUTI reduction rates in the IRF setting. Although data on HAIs in the IRF setting are sparse, estimates range from 6 to 13 per 1000 patient care days.[6] Mylotte et al. found similar amounts of urinary tract infections (UTIs) in the IRF setting (29.8%) as described by others, with 40% of the subjects at the IRF requiring the use of an indwelling catheter.[6]

Systems and strategies to reduce CAUTI rates have been widely studied, including hand hygiene, catheter types, policies for the replacement of catheters, and antibiotic prophylaxis.[7] One consideration to prevent CAUTIs is to maintain a closed system, which is a sterile catheter placed into the bladder using aseptic technique that flows into a sterile collection bag. A study from 1966 demonstrated a dramatic reduction in the risk of infection with the use of a closed urinary catheter system, and the CDC has used this to support level IB evidence for their guidelines in the prevention of CAUTI.[2],[8],[9] Furthermore, the CDC recommends keeping the collecting bag below the lever of the bladder at all times.[2],[9] During rehabilitation, breaking this closed system occurs when switching from a large collection bag (bed bag) to a smaller leg bag, which allows for easier patient mobility during therapy sessions. Alternatively, switching to a bed bag at night allows for greater volume collection without the need to empty the smaller leg bag until the morning. The CDC recommendations are also neglected when the bag is elevated above the level of the bladder during transfers.

The BioFlo® (BF) catheter system is a novel Food and Drug Administration-approved indwelling catheter system with a valve that maintains the closed system with bag changes, presumably reducing the risk of bacterial contamination and CAUTIs. Furthermore, the valve prevents urine from the bag to travel backward and return to the bladder, which may happen when the bag is elevated above the level of the bladder. The thought was that the use of BF in patients admitted to the IRF would yield reduced incidence rates of CAUTIs compared to our usual care catheter (named Foley throughout), a prelubricated 100% silicone catheter with a silver alloy coating (Bard LUBRI-SIL® I. C. Infection Control Foley Catheters).

  Methods Top

The BF catheter was adopted in a staged manner (stepped wedge), with an unbiased distribution (random order via random number generator) across 6 nursing units over 6 months, rather than all at once, to improve the evaluation of the quality impact of the new catheter [Figure 1]. Before introducing BF, the study began with 2 months of usual care data collection, in which only the Foley catheter was used when an indwelling urethral catheter was indicated. Once a unit was assigned to BF, all new urethral catheters on that unit would utilize BF. Existing Foley catheters would remain in place until catheter replacement was needed, at which point the Foley would be switched to BF. There were no other changes to patient care. As part of usual care, most patients experienced several voiding methods throughout their rehabilitation admission [Figure 2]. They also entered the study at various times of nursing unit enrollment. Patients were excluded if they were discharged within 3 days of admission. Readmissions were counted as separate admissions if the leave of absence was >2 weeks. The days of the leave of absence were not counted toward study days because voiding data could not be collected. All units had training and competency in the use of both types of indwelling catheters.
Figure 1: Stepped-wedge unit assignment and numbers of patients allocated to groups

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Figure 2: Examples of possible voiding methods experienced by patients enrolled in the study. SV = Spontaneous Voiding; IC = Intermittent Catheterization; UTI description based on voiding method: * = Foley catheter-associated UTI (CAUTI); # = IC; ^= BioFlo® CAUTI; + = SV. UTI: urinary tract infection, CAUTI: Catheter-associated urinary tract infection

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Data collected through the electronic medical record (EMR) included demographics, type and days of voiding method, and UTIs. A UTI was defined clinically as a positive urinalysis (bacterium >105 CFU/ml) and culture with symptoms, including, but not limited to, febrile of >38°C, suprapubic tenderness, costovertebral angle pain/tenderness, urinary frequency, urinary urgency, and/or dysuria, which resolved after antibiotic treatment.[10] Physician investigators (JH, HN, and CM) performed the chart review to confirm the clinical diagnosis of UTI. They could not be blinded to the catheter being used because the UTI was attributed to the voiding method that was used 2 days before the diagnosis of UTI.[11] The physician chart reviewers were blinded to the analyses. As part of our hospital requirements, symptomatic CAUTIs are reported to the National Healthcare Safety Network, which would include both BF and Foley CAUTIs. Therefore, a CAUTI was defined as a UTI in which the patient had a BF or Foley catheter used 2 days before the urine collection.

We conducted a power analysis using historical values from our facility. We assumed 3 CAUTIs in 30 days in all 6 units combined. We also assumed an average of 5.1 indwelling catheter patients per unit per month, with each patient having 15 catheter days (77 catheter days per unit per month). Assuming a rate of 0.0065 CAUTI per catheter day, two-sided alpha of 0.05, a total of 4158 catheter days, 9 periods in the stepped-wedge design as shown in [Figure 1], and intraclass correlation coefficient of 0.01–0.05, the study would have 78%–82% power to detect a difference of 0.006 between BF and Foley rates of CAUTI, e.g., rate of 0.0065 versus 0.0005 for Foley and BF, respectively.

Kruskal–Wallis rank test and Fisher's exact test compared continuous and categorical data, respectively, for group comparisons. Multilevel mixed-effects generalized linear modeling was performed to evaluate the association of CAUTIs to catheter use. The model adjusted for duration of injury, age, sex, diagnosis, admission FIM score, sequence of unit enrollment, with the exposure set to the catheter days and included a random effect for patients to account for repeated observations. Bayesian Poisson analysis was performed with a neutral prior centered at relative risk of 1 with 95% credible interval of 0.33–3, utilizing the same variables to provide the probability of CAUTI associated with the catheter used. Stata 14.0 (StataCorp, 2015) was used for the frequentist analyses, with P < 0.05 set for significance. R (R Core Team, Vienna, Austria, 2017) was used for the Bayesian analyses. The SQUIRE guidelines were used in reporting the outcomes.[12] This study was reviewed by the UTHealth at Houston Institutional Review Board and considered a quality improvement project.

  Results Top

In this 9-month trial from December 2018 to August 2019, there were 227 patients requiring the use of indwelling catheterization, the majority of which had spinal cord injury (SCI) [Table 1]. During the course of the study, 146 (64%) patients only used the Foley catheter, 21 (9%) patients only used the BF, and 60 (26%) patients used both.
Table 1: Demographics of patients with indwelling catheter use

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[Table 2] compares patients based on device use, Foley versus BF. Patients that used both the devices were counted as separate observations for each group. There were 206 patients that used a Foley and 81 patients that used a BF. Patients that used BF had more days in the study (32 vs. 26, P = 0.038) and had a longer length of stay in rehabilitation (35 vs. 29, P = 0.01) compared to the Foley group, with subsequently more days of catheter use compared to the Foley group (15 vs. 10, P < 0.001). More patients in the Foley group were admitted with an indwelling catheter (159 [77%]) compared to the BF group (49 [60%], P = 0.005). There were a similar number of patients with UTI (both CAUTI and non-CAUTI) in both the groups(Foley [76; 37%] and BF [39; 48%], P = 0.084). However, the BF group was associated with a greater percentage of patients with CAUTIs (24 [30%] vs. 34 [17%], P = 0.021) and a greater percentage of CAUTIs (28 [30%] vs. 39 [27%], P = 0.028). CAUTIs per thousand days of catheter use were also greater in the BF group compared to the Foley (19.8 vs. 15, P = 0.073), although it did not reach significance.
Table 2: Comparison of Foley and Bioflo® groups

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To further evaluate the relationship between CAUTIs and the type of catheter used, as well as to account for the repeated patients in the groups, multilevel mixed-effects generalized linear modeling was performed. This model adjusts for catheter days per device as an offset. The odds of a BF CAUTI was 89% greater compared to a Foley CAUTI (P = 0.033). Noteworthy, none of the covariates in the model achieved significance, including duration of injury, age, sex, FIM scores, and diagnoses. Bayesian analysis determined that the probability of BF increasing the rate of CAUTI was 96% (95% credible interval: 0.95–2.7).

  Discussion Top

In this stepped-wedge quality improvement project, we found no benefit from the use of maintaining a closed catheter system to prevent the occurrence of CAUTI during inpatient rehabilitation. Although there were more catheter days in the BF, adjusting for this confounding variable still resulted in 89% increased odds of developing a CAUTI with BF compared to Foley, in our population of acute rehabilitation patients. Furthermore, the preferred metric, CAUTI per thousand days, was higher in the BF group compared to the Foley group, although this did not reach significance. However, there were a significantly greater proportion of patients that developed CAUTI attributed to BF compared to Foley. Finally, Bayesian analysis determined that the rate of CAUTI attributed to BF increased by 96%. These results were surprising, considering that maintenance of a closed catheter system is considered critical in the prevention of CAUTI.

Maintaining a closed system has been touted by the CDC as the recommended technique to prevent CAUTI,[2],[9] referencing research from as early as 1966.[8] Other organizations have also developed guidelines which recommend the closed catheter system to prevent CAUTI.[11],[13],[14],[15] The urinary catheter system is considered a closed system when a sterile catheter is placed into the bladder using aseptic technique and is connected to a sterile, closed collection bag. A closed system is thought to reduce intraluminal causes of CAUTI. However, it has been reported that the vast majority of bacteriuria is through extraluminal migration ascending the urethra from the perineum.[16] The closed catheter system would not confer any benefit from extraluminal CAUTI. However, we would expect the intraluminal rates of CAUTI to reduce when maintaining a closed system.

During IRF admission, routine clinical care can violate the CDC guidelines for using a closed Foley catheter system when (1) the collection bags are exchanged and (2) when the collection bag is elevated above the level of the bladder. The BF system seemed to be especially promising for the IRF setting because of the one-way valve preventing retrograde flow of urine from the collection bag to the bladder, as well as maintaining a closed system with bag exchanges. Throughout the IRF admission, patients work on gaining independence with transfers, mobility, and activities of daily living, which involves management of their urine collection bag. Depending on the circumstances, this may include changing the larger collection bag to a more mobile leg bag or leaving the bag at a higher elevation when transferring to a lower elevation. Retrograde flow of urine from the collection bag and catheter is thought to increase the risk of CAUTI.[17] Conventional indwelling catheter systems would violate the closed system with either of these events. Despite presumably maintaining the closed system with BF, we did not see a reduced rate of CAUTI in the IRF setting. These findings contradict the importance of maintaining a closed catheter system to reduce the rates of CAUTIs in the IRF setting.

One possible explanation for the lack of benefit in maintaining the closed system may be that perhaps the vast majority of CAUTIs that occur during IRF admission are extraluminal, regardless of diagnosis. Another explanation may be that the importance of the closed catheter system may not be as beneficial in the active rehabilitation population that is training to gain independence with mobility and activities of daily living, rather than the postoperative or critically ill patients that may be confined to the bed. Although the guidelines suggest that their recommendations are intended “for all health care facilities,”[11] the paucity of information about catheter use and infections in the IRF setting would not make the recommendations generalizable. For example, the vast majority of the patients in this study had a neurologic diagnosis, in which neurogenic bowel and bowel incontinence is common and has been cited as a root cause of CAUTI.[18] Maintaining a closed catheter system would be of no benefit with extraluminal migration from stool incontinence. More research is needed to identify the causes of CAUTI in the IRF setting.

Noteworthy in the mixed-effects model, only the catheter type, BF vs. Foley, was significantly associated with CAUTI, with BF associated with an 89% increased risk of CAUTI compared to Foley catheter. Our findings did not support the findings from Letica-Kriegel et al., a large study of over 45,000 patients from urban academic health systems, which found SCI and the female sex a significant risk factor for CAUTI.[18] They also found a cumulative risk hazard as the duration of catheter use increases, suggesting an incremental risk of CAUTI for each day of catheterization, with a median duration of 7 days of catheter use for the CAUTI group compared to 4 days for those who did not.[18] Although we could not assess the risk of CAUTI based on indwelling catheter days due to the study design involving usual care and changing voiding methods, the BF group had about 5 more days of BF catheter use compared to the Foley group. This may contribute to the increased association of CAUTI seen in the BF group.

We offer several other possible explanations for the 89% greater risk of CAUTI seen in the BF group. The usual care indwelling catheter in our facility has a silver alloy coating and hydrogel that minimizes biofilm formation, which may have led to the superiority in CAUTI rates compared to BF. Another explanation may be part of the design of the BF system, which retains urine above the valve until enough pressure is achieved to open the valve. This retained urine could certainly be a nidus for infection in the IRF population, as urine retention is a risk factor for UTI. Furthermore, nursing reported an increased need to irrigate the BF group more frequently due to sediments causing an obstruction near the valve apparatus. Irrigation of the BF, much like the Foley, is with aseptic technique designed to maintain the closed system. However, unless discovered immediately, this sediment obstruction would lead to further urine retention, even bladder overdistention, which may increase the risk of UTI from bladder ischemia. Finally, another possibility is that patients already had bacteriuria at the time of BF placement, and it was merely a matter of timing before symptomatic CAUTI. This is less likely considering that the duration of injury was similar between the BF and Foley group, more patients were admitted with an indwelling catheter in the Foley group compared to BF, and duration of injury was not a significant confounding variable.

There were several limitations in this quality improvement project. Primarily, the usual care of voiding management introduces substantial variability as patients trial different voiding methods. To mitigate this concern, we used the stepped-wedge design to balance confounders known to exist in all studies relying on usual care. Another limitation is understanding whether the closed system was already contaminated when the BF was placed. Considering that nearly all patients had a catheter before the BF, they were all likely contaminated before introducing a closed system. Preexisting bacteriuria in a closed system likely obviates its efficacy. Urine cultures or empiric antibiotics may be needed in some patients before catheter insertion, but this practice is not recommended due to concern for antimicrobial resistance, health-care costs for antibiotics, and the potential for side effects of antibiotic administration. Finally, this was a single-site trial and may lack generalizability to other IRFs.

  Conclusions Top

Based on this usual care, stepped-wedge quality improvement project, the use of the BF system during inpatient rehabilitation increased the rate of CAUTI compared to usual care indwelling catheters. Further research is needed to evaluate whether maintaining a strict closed catheter system is relevant to the IRF setting.

Financial support and sponsorship

The research efforts of Dr. Stampas are supported by Mission Connect, a project of the TIRR Foundation.

Conflicts of interest

There are no conflicts of interest.

  References Top

Tambyah PA, Knasinski V, Maki DG. The direct costs of nosocomial catheter-associated urinary tract infection in the era of managed care. Infect Control Hosp Epidemiol 2002;23:27-31.  Back to cited text no. 1
Centers for Disease Control and Prevention Catheter-Associated Urinary Tract Infections (CAUTI); 2017. Available from: https://www.cdc.gov/infectioncontrol/guidelines/cauti/index.html. [Last accessed on 2022 May 29].  Back to cited text no. 2
Hidron AI, Edwards JR, Patel J, Horan TC, Sievert DM, Pollock DA, et al. NHSN annual update: Antimicrobial-resistant pathogens associated with healthcare-associated infections: Annual summary of data reported to the National Healthcare Safety Network at the Centers for Disease Control and Prevention, 2006-2007. Infect Control Hosp Epidemiol 2008;29:996-1011.  Back to cited text no. 3
Saint S. Clinical and economic consequences of nosocomial catheter-related bacteriuria. Am J Infect Control 2000;28:68-75.  Back to cited text no. 4
Saint S, Wiese J, Amory JK, Bernstein ML, Patel UD, Zemencuk JK, et al. Are physicians aware of which of their patients have indwelling urinary catheters? Am J Med 2000;109:476-80.  Back to cited text no. 5
Mylotte JM, Graham R, Kahler L, Young L, Goodnough S. Epidemiology of nosocomial infection and resistant organisms in patients admitted for the first time to an acute rehabilitation unit. Clin Infect Dis 2000;30:425-32.  Back to cited text no. 6
Meddings J, Saint S, Krein SL, Gaies E, Reichert H, Hickner A, et al. Systematic review of interventions to reduce urinary tract infection in nursing home residents. J Hosp Med 2017;12:356-68.  Back to cited text no. 7
Kunin CM, McCormack RC. Prevention of catheter-induced urinary-tract infections by sterile closed drainage. N Engl J Med 1966;274:1155-61.  Back to cited text no. 8
Gould CV, Umscheid CA, Agarwal RK, Kuntz G, Pegues DA, Healthcare Infection Control Practices Advisory Committee. Guideline for prevention of catheter-associated urinary tract infections 2009. Infect Control Hosp Epidemiol 2010;31:319-26.  Back to cited text no. 9
Stampas A, Dominick E, Zhu L. Evaluation of functional outcomes in traumatic spinal cord injury with rehabilitation-acquired urinary tract infections: A retrospective study. J Spinal Cord Med 2019;42:579-85.  Back to cited text no. 10
Hooton TM, Bradley SF, Cardenas DD, Colgan R, Geerlings SE, Rice JC, et al. Diagnosis, prevention, and treatment of catheter-associated urinary tract infection in adults: 2009 International Clinical Practice Guidelines from the Infectious Diseases Society of America. Clin Infect Dis 2010;50:625-63.  Back to cited text no. 11
Ogrinc G, Davies L, Goodman D, Batalden P, Davidoff F, Stevens D. SQUIRE 2.0 (Standards for QUality Improvement Reporting Excellence): Revised publication guidelines from a detailed consensus process. BMJ Qual Saf 2016;25:986-92.  Back to cited text no. 12
Conway LJ, Larson EL. Guidelines to prevent catheter-associated urinary tract infection: 1980 to 2010. Heart Lung 2012;41:271-83.  Back to cited text no. 13
WHO Guidelines Approved by the Guidelines Review Committee. Guidelines on Core Components of Infection Prevention and Control Programmes at the National and Acute Health Care Facility Level. Geneva: World Health Organization, Copyright © World Health Organization; 2016.  Back to cited text no. 14
Lo E, Nicolle LE, Coffin SE, Gould C, Maragakis LL, Meddings J, et al. Strategies to prevent catheter-associated urinary tract infections in acute care hospitals: 2014 update. Infect Control Hosp Epidemiol 2014;35 Suppl 2:S32-47.  Back to cited text no. 15
Saint S, Chenoweth CE. Biofilms and catheter-associated urinary tract infections. Infect Dis Clin North Am 2003;17:411-32.  Back to cited text no. 16
Singha P, Locklin J, Handa H. A review of the recent advances in antimicrobial coatings for urinary catheters. Acta Biomater 2017;50:20-40.  Back to cited text no. 17
Letica-Kriegel AS, Salmasian H, Vawdrey DK, Youngerman BE, Green RA, Furuya EY, et al. Identifying the risk factors for catheter-associated urinary tract infections: A large cross-sectional study of six hospitals. BMJ Open 2019;9:e022137.  Back to cited text no. 18


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  [Table 1], [Table 2]


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