Hydrophilic Catheters and Reduced Risk of Urinary Tract Infection

Extensive studies support scientific literature claiming that use of hydrophilic catheters reduce urethral trauma and urinary tract infections. This in turn can minimise the need for antibiotics. Because of these benefits, we now know that hydrophilic catheters are one of the most cost-effective ways to prevent long term urological complications in general and UTI in particular.

Effectiveness of hydrophilic coated catheters has been documented in the scientific literature and there is a general consensus that they reduce the risk of urological complications such as UTI and trauma (strictures, hematuria/ bleeding).^{4 5 7 8} For example, there are five recent meta-analyses available comparing efficacy between hydrophilic-coated and non-hydrophilic catheters^{9 10 11 12 3} concluding that use of hydrophilic catheters can reduce the risk of UTI by 16-64%^{9 10 11 12 3 13} and the risk of hematuria by 43%.¹² Summarising the literature some publications confirm this conclusion,^{4 5 7 12 14 15 16 17 18 19 20} while others claim that more evidence is needed.^{1 5 9 10 21 22 23} 

Very few conclude the opposite. Comparing UTI incidences reported in the literature, gives further support with figures between 40%-60% reported for single-use hydrophilic coated catheters as compared to figures around 70%-80% for non-coated catheters and/or catheter reuse.²⁴

Studies investigating UTI incidence are compromised by the facts that different UTI definitions are used, different populations are studied (e.g. patients with spinal cord injury, multiple sclerosis, spina bifida, benign prostatic hyperplasia) and different research perspectives are used (e.g. observational surveys, randomised controlled trials). To facilitate comparisons standardised definitions of UTI are proposed.^{1 5 25}

LoFric documentation: Reduced risk of UTI

• Results of a prospective randomised control trial comparing hydrophilic to uncoated catheters in children with neurogenic bladder.²⁶
  Randomised controlled trial in 78 children with neurogenic bladder dysfunction comparing hydrophilic-coated to non-coated catheters. Results show lower occurrence of UTI among users of hydrophilic-coated catheters after 1 year, 9% vs. 52% (p= 0.003).
• Intermittent catheterisation with hydrophilic and non-hydrophilic urinary catheters: systematic literature review and meta-analyses.¹²
  Meta-analysis concluding that the risk of UTI is reduced with the use of hydrophilic-coated catheters as compared to non-coated catheters.

"With some instruction, all patients with bladder dysfunction can benefit from [intermittent catheterisation] IC...²"

• Clean intermittent catheterisation revisited.²
  Review summarising important features related to successful intermittent catheterisation. It highlights the importance of infection prevention among catheter users and identifies hydrophilic-coated catheters as a cost-effective contributor. It acknowledges that hydrophilic catheters may vary in the quality of coatings and LoFric and the Urotonic^TM Surface Technology are described.
• Comparison of the microbiological milieu of patients randomised to either hydrophilic or conventional PVC catheters for clean intermittent catheterisation.²⁷
  Randomised controlled trial in 50 patients with myelomeningocele. Urine bacteria flora were compared between 25 LoFric users and 25 users of non-coated plastic catheters. After a 1 year follow-up, the results showed a 40% reduction of the average number of potentially pathogenic bacteria in the LoFric group.

"The use of [hydrophilic-coated] HC catheters for intermittent catheterisation in SCI patients is highly cost effective. The outcome is consistent irrespective of whether UTI data are collected in hospital or community settings...¹¹"

• A cost-effectiveness analysis of long-term intermittent catheterisation with hydrophilic and uncoated catheters.¹¹
  Health economy evaluation concluding that hydrophilic coated catheters are cost-effective as they are associated with lower number of UTI events, higher life-expectancy and better quality of life as compared to non-coated catheters.
• Intermittent catheterisation for long-term bladder management.⁹
  Meta-analysis of two randomised controlled trials with hydrophilic catheters, one with LoFric. The results propose a 20% risk reduction for UTI with hydrophilic-coated compared to non-hydrophilic catheters. It is however concluded that there is a lack of well-designed trials

^{Graph based on results reported by Li et al. 201333}

• Impact of hydrophilic catheters on urinary tract infections in people with spinal cord injury: systematic review and meta-analysis of randomised controlled trials.¹²
  Meta-analysis of 464 patients and five randomised controlled trials (RCT) with hydrophilic catheters, three with LoFric. The results propose a 64% risk reduction for UTI with hydrophilic-coated compared to non-hydrophilic catheters.

This meta-analysis combines five randomised controlled trials to create stronger evidence. A meta-analysis follows strict rules on how to search, select, validate, weigh and summarise studies specified in the PRISMA statement (Preferred Reporting Items for Systematic Reviews and Meta- analyses) and by the Cochrane Collaboration. The studies selected for the meta-analysis were all comparing hydrophilic-coated catheters to uncoated plastic catheter in spinal cord injured patients. The following studies were included:

• Cardenas et al. 2011: SpeediCath vs. non-coated plastic catheter in 200 newly injured patients.¹⁵
• Cardenas and Hoffman 2009: LoFric vs. non-coated plastic catheters in 45 patients with injury more than 6 months ago.¹⁴
• De Ridder et al. 2005: SpeediCath vs. non-coated plastic catheters in 123 newly injured patients.¹⁶
• Vapnek et al 2003: LoFric vs. reused non-coated plastic catheters in 63 patients, mainly spinal cord injury.¹⁹
• Sutherland et al 1996: LoFric vs. non-coated plastic catheters in 33 patients, mainly spinal cord injury.

The publication combines the results from the studies and concludes that UTI incidence was 49.6% in patients using hydrophilic catheters and 72.0% for patients using non-hydrophilic. The results for hematuria (bleeding) were 45.7% (hydrophilic) and 55.0% (non-hydrophilic) but for this comparison only four studies could be used. The results are expressed as ‘odds ratio’ and/or ‘odds’ which is a sort of approximation for risk. The odds ratio for UTI and hematuria decreased for patients on hydrophilic catheters as follows:

• UTI: 0.36; 95% CI 24-54% (p<0.00001).
• Hematuria: 0.57; 95% CI 35-92% (p=0.001).

The figures above could be interpreted as using hydrophilic catheters, compared to non-hydrophilic ones, reduces the expected risk for UTI by 64% and hematuria by 43%.

"...hyrophilic catheter usage was associated with reduced numbers of treated UTIs as compared with standard non-hydrophilic catheters in persons with spinal cord injury...¹⁴"

• Hydrophilic catheters versus noncoated catheters for reducing the incidence of urinary tract infections: a randomised controlled trial.¹⁴
  1 year follow-up of 22 LoFric users and 23 users of non-coated plastic catheters, showing evidence of fewer antibiotic treated UTIs in patients using LoFric compared to non-coated catheters.
• A prospective randomised trial of the LoFric hydrophilic coated catheter versus conventional plastic catheter for clean intermittent catheterisation.¹⁹
  1 year study on 22 LoFric users and 26 users who reused non-coated plastic catheters. The results showed that the use of hydrophilic catheters are associated with less hematuria and decrease in the rate of UTI. The study suggests that patients with higher rate of UTI may benefit the most from hydrophilic catheters, and that the lower infection risk is a result of reduced urethral trauma.

This randomised controlled trial compared the use of LoFric to a non-coated plastic catheter for intermittent catheterisation. The study included 62 patients, mainly with spinal cord injury, and the follow up period was 12 months. One patient was removed from analysis due to wrongful treatment and thirteen patients were lost during the follow up. Thus, 22 patients used LoFric for 12 months and 26 used non-coated plastic catheters for 12 months. In the hydrophilic-group, patients were given 120 catheters/month (4 per day) while in the PVC-group 30 catheters were given per month (1 per day) with the instructions to clean and reuse. The results showed twice as high hematuria score among the non-coated catheter users as compared to the hydrophilic-group where no significant hematuria was seen. Decrease in UTI rate in the hydrophilic-group was seen between baseline and follow up (0.44 to 0.14 monthly per patient). In the non-coated catheter group the UTI incidence remained more or less at the same level throughout the study (0.20 to 0.14 monthly per patient). The study reports of high patient satisfaction with LoFric catheters. The publication concludes that the use of hydrophilic catheters is associated with less hematuria and a decrease in the rate of UTI as compared to non-coated catheters. It proposes that patients with higher rate of UTI may benefit the most from use of hydrophilic catheters, and that the lower infection risk is a result of reduced urethral trauma.

"It seems reasonable and is indicated by our study that the hydrophilic catheter regimen has a preventive effect on urethral traumatic complications and that it can facilitate the healing of minor epithelial damage...⁶"

• Clean intermittent catheterisation in spinal cord injury patients: long-term follow up of a hydrophilic low friction technique.⁶
  Retrospective analysis that proposes that long term use of LoFric hydrophilic catheters reduces UTIs and prevents urethral trauma. For example, no new urethral trauma was identified during a 5-9 year follow up of 30 LoFric patients.
• Risk factors for bacteriuria and clinical urinary tract infection in patients treated with clean intermittent catheterisation.²⁸
  Observational 13-month follow-up of 302 users of intermittent catheterisation (95% used LoFric) identifying frequent low volume catheterisation as a way to reduce the risk of UTI.

"A lower infection score was found in the patients (mean score 2.1) using only low-friction catheters (LoFric) compared to those using plain PVC catheters (mean score 3.7) (p<0.05).²⁹"

• Physical complications in patients treated with clean intermittent catheterisation.²⁹
  Observational 13-month follow-up of 302 users of intermittent catheterisation (95% used LoFric) concluding fewer and less severe infections associated with LoFric use compared to non-coated plastic catheters with added lubricant. For example, patients using non-coated catheters had a 76% higher infection score.
• Bacteriuria in patients treated with clean intermittent catheterisation.³⁰
  Observational 13-month follow-up of 302 users of intermittent catheterisation (95% used LoFric) concluding low frequency of UTI with hydrophilic catheters (LoFric). For example, 86% of patients showed no clinical signs of UTI during the study period. The study suggests that the use of antibiotics in patients using intermittent catheterisation should be minimised and supports a frequency of more than 4 catheterisations per day to keep bladder volumes low and reduce the risk of UTI.