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Cost Effectiveness of Antimicrobial Catheters for Adults Requiring Short-term Catheterisation in Hospital
EUROPEAN UROLOGY 66 (2014) 615–618
available at www.sciencedirect.com journal homepage: www.europeanurology.com
Brief Correspondence
Cost Effectiveness of Antimicrobial Catheters for Adults Requiring Short-term Catheterisation in Hospital Mary Kilonzo a,*, Luke Vale b, Robert Pickard c, Thomas Lam d, James N’Dow d, for the Catheter Trial Group a
Health Economics Research Unit, University of Aberdeen, Aberdeen, UK; b Health Economics Group, Institute of Health and Society, Newcastle University,
Newcastle upon Tyne, UK; c Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK; d Academic Urology Unit, University of Aberdeen, Aberdeen, UK
Article info
Abstract
Article history: Accepted May 27, 2014
Catheter-associated urinary tract infection (CAUTI) is the second most common cause of hospital-acquired infection. A number of strategies have been put forward to prevent CAUTI, including the use of antimicrobial catheters. We aimed to assess whether the use of either a nitrofurazone-impregnated or a silver alloy–coated catheter was cost-effective compared with standard polytetrafluoroethylene (PTFE)–coated catheters. A decisionanalytic model using data from a clinical trial conducted in the United Kingdom was used to calculate the incremental cost per quality-adjusted life-year (QALY). We assumed that differences in costs and QALYs were driven by difference in risk of acquiring a CAUTI. Routine use of nitrofurazone-impregnated catheters was, on average, £7 (s9) less costly than use of the standard catheter over 6 wk. There was a >70% chance that use of nitrofurazone catheters would be cost saving and an 84% chance that the incremental cost per QALY would be less than £30 000 (s36 851; a commonly used threshold for society’s willingness to pay). Silver alloy–coated catheters were very unlikely to be costeffective. The model’s prediction, although associated with uncertainty, was that nitrofurazone-impregnated catheters may be cost-effective in the UK National Health System or a similar setting. # 2014 European Association of Urology. Published by Elsevier B.V. All rights reserved.
Keywords: Randomised controlled trial Antimicrobial catheters Catheter-associated symptomatic urinary tract infection Costs Cost effectiveness Decision-analytic model
* Corresponding author. Health Economics Research Unit, University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen, AB25 2ZD, UK. Tel. +44 1224 437176; Fax: +44 1224 437195. E-mail address: [email protected] (M. Kilonzo).
The prevention of catheter-associated urinary tract infection (CAUTI) is an important part of patient safety initiatives in many countries. The development of a CAUTI is likely to prolong a patient’s hospital stay by an estimated 0.5 d [1] to 5 d [2], and CAUTI adversely affects quality of life [1,3]. A potential way to reduce CAUTI risk is to use catheters containing antimicrobial agents designed to reduce bacterial colonisation [4]; available options include a nitrofurazone-impregnated catheter and a silver alloy– coated catheter.
Study methods are described in Supplement 1. We used data from a three-arm randomised controlled trial comparing nitrofurazone-impregnated catheters (n = 2153) and silver alloy–coated catheters (n = 2097) with standard polytetrafluoroethylene (PTFE)–coated catheters (n = 2144) for patients requiring short-term urethral catheterisation in hospital [5] to populate a decision-analytic model. The model was then used to predict the likelihood of antimicrobial catheters being cost-effective for short-term routine use in the setting of the UK National Health Service (NHS). The
http://dx.doi.org/10.1016/j.eururo.2014.05.035 0302-2838/# 2014 European Association of Urology. Published by Elsevier B.V. All rights reserved.
616
EUROPEAN UROLOGY 66 (2014) 615–618
Table 1 – Values for variables used in the base-case economic model Variable Risk of infection for standard catheter
Value 0.126
Risk of infection for nitrofurazone catheter
–0.021
Risk of infection for silver alloy catheter
–0.001
Utility** of a CAUTI over 6 wk Additional utility associated with not acquiring a CAUTI over 6 wk Health care costs for patients without a CAUTI (2012 pounds sterling) Additional health care costs for patients with a CAUTI Cost of nitrofurazone catheter Cost of silver alloy catheter Cost of standard catheter
0.075 +0.006 £3529.08 £572.56 £5.53 £6.75 £0.90
Source and distribution Based on the value from the trial analysis. b distribution* [10]; a (number of events in group) = 271; b (number of people without the event in the group) = 1873. Based on the estimated absolute risk difference between nitrofurazone and standard catheters. Normal distribution (SD: 0.01). Based on the estimated absolute risk difference between silver alloy and standard catheters. Normal distribution (SD = 0.01). Based on trial data. b distribution: a and b derived from mean (0.075369) and SD (0.02454) of QALYs for a CAUTI. Based on the RCT adjusted analysis difference in QALYs. Assumed normal distribution (SD = 0.001). The cost estimate was based on all participants without CAUTI (n = 5630). Log-normal distribution derived from mean costs (£3529.08) and median costs (£2466.39) derived from trial data. Based on the adjusted analysis results cost difference estimate from trial data. Normal distribution (mean = £572.56; SD = £445). Manufacturer: Rochester Medical Ltd., Lancing, UK. Point estimate, no distribution attached. Manufacturer: Bard Medical, Crawley, UK. Point estimate, no distribution attached. NHS Supplies.y Point estimate, no distribution attached.
CAUTI = catheter-associated urinary tract infection; NHS = National Health Service; QALY = quality-adjusted life-year; RCT = randomised controlled trial; SD = standard deviation. * The b distribution is constrained on the interval 0–1 and is characterised by two parameters, a and b. ** Utility is the benefit from the intervention derived using the EQ-5D-3L. y NHS catalogue product categories [9].
analysis used health status measurements derived from the EQ-5D (3 level) and costs reported in 2012 pounds sterling. No discounting was performed, as the events for each participant took place over <1 yr. Details of the parameters used in the model are presented in Table 1. Data on the risk of infection for standard catheters and the absolute risk differences between nitrofurazone or silver alloy and standard PTFE catheters were based on trial outcomes [5]. For each intervention, we calculated the extra cost incurred per quality-adjusted life-year (QALY) gained—the incremental cost effectiveness ratio. The probability of each intervention’s being cost-effective was calculated using different willingness-to-pay thresholds, including £30 000 (s36 851) per QALY suggested by the UK National Institute for Health and Clinical Excellence [6]. Sensitivity analysis examined the effect of uncertainty in cost and QALY estimates [7] by sampling values from an assigned distribution for each variable using Monte Carlo simulation. Further sensitivity analyses were performed to determine whether patients who had CAUTI were more likely to incur extra costs or have a worse health state for reasons unconnected to CAUTI, such as a more severe underlying illness or worse general health. For these analyses, we used trial participant subgroups that we considered to represent more homogeneous populations; the subgroups comprised admissions to obstetrics and gynaecology speciality wards, patients with an EQ-5D-3L score of 1 (perfect health) at 3 d after catheter removal, and participants who were recorded as having a symptomatic CAUTI treated with antibiotics at 3 d following catheter removal. Model predictions were that routine use of nitrofurazone catheters was, on average over the 6 wk of trial participation, associated with the lowest cost (£3595 [s4416]), followed by standard catheters (£3602 [s4425]) and silver alloy catheters (£3608 [s4432]) (Table 2). On average,
participants allocated to the nitrofurazone catheter had the highest QALYs over 6 wk, followed by the silver alloy and then the standard catheter. There is a 70% chance that nitrofurazone would be the least costly option and a >80% probability that it would be considered cost-effective when society is willing to pay a maximum of £30 000 (s36 851) per QALY (Table 2). Silver alloy had virtually no chance of being considered cost-effective. Our modelled analysis using data from a robust randomised controlled trial suggested that nitrofurazoneimpregnated catheters may be cost-effective for use in the UK NHS. The principal driver for this result was that cost savings from avoiding an infection would compensate for the increased unit cost of the nitrofurazone catheter compared with the standard catheter. However, cost savings were modest, and the confidence interval included zero, suggesting borderline clinical and statistical significance. Nevertheless, given the volume of catheterisation within well-resourced health care organisations and the high likelihood of this situation’s occurring, even this small difference may lead to substantial savings. This finding should be treated cautiously, given the limitations of the analysis and the uncertainty, particularly regarding estimates of key parameters such as length of hospital stay. Silver alloy–coated catheters were highly unlikely to be considered cost-effective for the UK NHS. The main driver was that it was unlikely that the observed reduction in risk of CAUTI was minimal, and any cost saving would not be sufficient to compensate for higher catheter cost. Similarly, any gain in QALYs was unlikely to be large enough to justify any increased expenditure. This conclusion is important, as some health care organisations have deployed this catheter for routine use [8]. In summary, we found no health– economic evidence to support the use of sliver alloy–coated urethral catheters. The conclusion is grounded in a trial encompassing a large, representative sample of the NHS
617
EUROPEAN UROLOGY 66 (2014) 615–618
Table 2 – Results of the model analysis and the subgroup analysis Intervention
Cost
Incremental cost
QALY
Incremental QALY
ICER
Base-case analysis Nitrofurazone £3595 (s4416)* 0.0823 Standard £3602 (s4425) £7 (s9) 0.0822 –0.0001 Dominated Silver alloy £3608 (s4432) £12.67 (s16) 0.0822 0 Dominated Participants admitted into the obstetrics speciality ward Standard £1905.403 0.0874 Nitrofurazone £1907.226 £1.82 0.0876 0.00015 £11 497 Silver alloy £1911.12 £3.87 0.0874 –0.00014 Dominated Participants who at 3 d had had an EQ-5D score = 1 (full health) Nitrofurazone £2678.43 0.10106 Standard £2695.51 £17.08 0.10098 –0.00008 Dominated Silver alloy £2700.33 £21.9 0.10098 –0.00007 Dominated 3-d symptomatic antibiotic-treated CAUTI outcome Nitrofurazone £3644.58 0.08118 Standard £3671.06 £26.48 0.08108 –0.00010 Dominated Silver alloy £3675.43 £30.85 0.08109 –0.00009 Dominated Probability (%) of being cost-effective at different threshold values for society’s willingness to pay for an additional QALY Threshold £0 £10 000 £20 000 £30 000 £50 000 s0 s12 284 s24 567 s36 851 s61 418 Base-case analysis Nitrofurazone 72 77 80 83 88 Standard 28 23 20 17 12 Silver alloy 0 0 0 0 0 CAUTI = catheter-associated urinary tract infection; ICER = incremental cost effectiveness ratio; QALY = quality-adjusted life-year. Cost in euros based on average exchange rate to year ending March 2013; £1 = s1.2284 (www.hmrc.gov.uk/exrate/exchangerates-1213.pdf).
*
patient population that would be expected to receive the silver alloy catheter if it were adopted for routine use. Our focus on the costs and health state (QALY) differences between patients who acquired a CAUTI and those who did not acquire one did not account for differences among trial participants who had an infection and those who did not. This means that our analysis may be confounded by participants who had a CAUTI having more severe underlying conditions or surgical complications and hence being more likely to incur higher costs and have impaired health status for additional reasons other than their CAUTI. However, predictions made by the model using the base-case analysis were not sensitive to change when the subgroup analyses were undertaken. Decisions whether or not to implement routine use of nitrofurazone catheters are complex. At present, at least within the United Kingdom, these catheters appear little used, and commercial production has stopped. Additionally, our favourable results were associated with a degree of uncertainty. Concerning silver alloy catheters, organisations in which they are already in use are ones that have an opportunity to reallocate resources without loss of benefit, whereas those organisations considering implementation may wish to await further evidence of benefit or the emergence of alternatives. The findings are likely to be applicable to countries with health care systems or models of care similar to that of the UK NHS. Author contributions: Mary Kilonzo had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Analysis and interpretation of data: Kilonzo, Vale. Drafting of the manuscript: Kilonzo, Vale, Pickard, Lam, N’Dow. Critical revision of the manuscript for important intellectual content: Kilonzo, Vale, Pickard, Lam, N’Dow. Statistical analysis: Kilonzo, Vale. Obtaining funding: Kilonzo, Vale, Pickard, Lam, N’Dow. Administrative, technical, or material support: Kilonzo, Vale, Pickard, Lam, N’Dow. Supervision: None. Other (specify): None. Financial disclosures: Mary Kilonzo certifies that all conflicts of interest, including specific financial interests and relationships and affiliations relevant to the subject matter or materials discussed in the manuscript (eg, employment/affiliation, grants or funding, consultancies, honoraria, stock ownership or options, expert testimony, royalties, or patents filed, received, or pending), are the following: Thomas Lam authored the Cochrane Review on antimicrobial catheters. Funding/Support and role of the sponsor: This project was funded by the UK National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Programme (project number 05/46/01) and is published in full in the Health Technology Assessment. The views and opinions expressed in this report are those of the authors and do not necessarily reflect those of the HTA programme, NIHR, National Health Service, or UK Department of Health. The Health Services Research Unit (HSRU) and the Health Economics Research Unit (HERU) are funded by the Chief Scientist Office of the Scottish Government Health Directorates. The authors accept full responsibility for the research. Acknowledgment statement: The Catheter Study Group would like to thank all the members of the Catheter Trial: Graeme Maclennan, Kathy Starr, Gladys McPherson, K. Gillies, Alison McDonald, Kathy Walton, Brian Buckley, Cathryn Glazener, Charles Boachie, Jennifer Burr, John Norrie, and Adrian Grant. The study group would also like to thank the patients who willingly participated in the study and completed their
Study concept and design: Kilonzo, Vale, Pickard, Lam, N’Dow.
questionnaires and diaries. We also thank all principal investigators,
Acquisition of data: Kilonzo, Vale.
research nurses/fellows, and other staff at each of our centres. We
618
EUROPEAN UROLOGY 66 (2014) 615–618
particularly thank Rashmi Bhardwaj, for leading and motivating the
[3] Tambyah PA, Knasinski V, Maki DG. The direct costs of nosocomial
excellent team of research nurses in the North East of England. We thank
catheter-associated urinary tract infection in the era of managed
all members of the Trial Steering Committee and the Data Monitoring
care. Infect Control Hosp Epidemiol 2002;23:27–31.
Committee. Thanks to the Catheter Study office staff (Karen McIntosh
[4] Schumm K, Lam TBL. Types of urethral catheters for management of
and Anne Duncan) for administration of the trial. We thank the
short-term voiding problems in hospitalised adults. Cochrane Da-
Comprehensive Local Research Networks and Primary Care Research
tabase Syst Rev 2008:CD004013.
Networks of the UK National Institute for Health Research and all the
[5] Pickard R, Lam T, Maclennan G, et al. Types of urethral catheter for
participating English National Health Service Trusts and Scottish Health
reducing symptomatic urinary tract infections in hospitalised
Boards who facilitated recruitment of their patients.
adults requiring short-term catheterisation: multicentre randomised controlled trial and economic evaluation of antimicrobial- and antiseptic-impregnated urethral catheters (the CATHETER trial).
Appendix A. Supplementary data
Health Technol Assess 2012;16:1–197. [6] National Institute for Health and Care Excellence. Process methods
Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/ j.eururo.2014.05.035.
and guide: guide to methods of technology appraisal. www.nice.org. uk/media/D45/1E/GuideToMethodsTechnologyAppraisa12013.pdf. Accessed 14 October 2013. [7] Briggs AH, Wonderling DE, Mooney CZ. Pulling cost-effectiveness analysis up by its bootstraps: a non-parametric approach to confi-
References
dence interval estimation. Health Econ 1997;6:327–40. [8] Department of Health and National Health Service Purchasing and
[1] Saint S, Veenstra DL, Sullivan SD, Chenoweth C, Fendrick AM. The
Supply Agency. The Bardex I.C. silver alloy and hydrogel-coated
potential clinical and economic benefits of silver alloy urinary
catheter. The Healthcare Associated Infections (HCAI) Technology
catheters in preventing urinary tract infection. Arch Intern Med 2000;160:2670–5. [2] Plowman R, Graves N, Griffin M, et al. The socioeconomic burden of hospital acquired infection. London, UK: Pubic Health Laboratory Service; 1999.
Innovation Programme: showcase hospitals report no. 1; 2009. [9] National Health Service. NHS catalogue product categories. my.supplychain.nhs.uk/catalogue. Accessed August 2011. [10] Briggs A, Sculpher M, Claxton K, editors. Decision Modelling for Health Economic Evaluation. Oxford: Oxford University Press; 2006.
available at www.sciencedirect.com journal homepage: www.europeanurology.com
Brief Correspondence
Cost Effectiveness of Antimicrobial Catheters for Adults Requiring Short-term Catheterisation in Hospital Mary Kilonzo a,*, Luke Vale b, Robert Pickard c, Thomas Lam d, James N’Dow d, for the Catheter Trial Group a
Health Economics Research Unit, University of Aberdeen, Aberdeen, UK; b Health Economics Group, Institute of Health and Society, Newcastle University,
Newcastle upon Tyne, UK; c Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK; d Academic Urology Unit, University of Aberdeen, Aberdeen, UK
Article info
Abstract
Article history: Accepted May 27, 2014
Catheter-associated urinary tract infection (CAUTI) is the second most common cause of hospital-acquired infection. A number of strategies have been put forward to prevent CAUTI, including the use of antimicrobial catheters. We aimed to assess whether the use of either a nitrofurazone-impregnated or a silver alloy–coated catheter was cost-effective compared with standard polytetrafluoroethylene (PTFE)–coated catheters. A decisionanalytic model using data from a clinical trial conducted in the United Kingdom was used to calculate the incremental cost per quality-adjusted life-year (QALY). We assumed that differences in costs and QALYs were driven by difference in risk of acquiring a CAUTI. Routine use of nitrofurazone-impregnated catheters was, on average, £7 (s9) less costly than use of the standard catheter over 6 wk. There was a >70% chance that use of nitrofurazone catheters would be cost saving and an 84% chance that the incremental cost per QALY would be less than £30 000 (s36 851; a commonly used threshold for society’s willingness to pay). Silver alloy–coated catheters were very unlikely to be costeffective. The model’s prediction, although associated with uncertainty, was that nitrofurazone-impregnated catheters may be cost-effective in the UK National Health System or a similar setting. # 2014 European Association of Urology. Published by Elsevier B.V. All rights reserved.
Keywords: Randomised controlled trial Antimicrobial catheters Catheter-associated symptomatic urinary tract infection Costs Cost effectiveness Decision-analytic model
* Corresponding author. Health Economics Research Unit, University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen, AB25 2ZD, UK. Tel. +44 1224 437176; Fax: +44 1224 437195. E-mail address: [email protected] (M. Kilonzo).
The prevention of catheter-associated urinary tract infection (CAUTI) is an important part of patient safety initiatives in many countries. The development of a CAUTI is likely to prolong a patient’s hospital stay by an estimated 0.5 d [1] to 5 d [2], and CAUTI adversely affects quality of life [1,3]. A potential way to reduce CAUTI risk is to use catheters containing antimicrobial agents designed to reduce bacterial colonisation [4]; available options include a nitrofurazone-impregnated catheter and a silver alloy– coated catheter.
Study methods are described in Supplement 1. We used data from a three-arm randomised controlled trial comparing nitrofurazone-impregnated catheters (n = 2153) and silver alloy–coated catheters (n = 2097) with standard polytetrafluoroethylene (PTFE)–coated catheters (n = 2144) for patients requiring short-term urethral catheterisation in hospital [5] to populate a decision-analytic model. The model was then used to predict the likelihood of antimicrobial catheters being cost-effective for short-term routine use in the setting of the UK National Health Service (NHS). The
http://dx.doi.org/10.1016/j.eururo.2014.05.035 0302-2838/# 2014 European Association of Urology. Published by Elsevier B.V. All rights reserved.
616
EUROPEAN UROLOGY 66 (2014) 615–618
Table 1 – Values for variables used in the base-case economic model Variable Risk of infection for standard catheter
Value 0.126
Risk of infection for nitrofurazone catheter
–0.021
Risk of infection for silver alloy catheter
–0.001
Utility** of a CAUTI over 6 wk Additional utility associated with not acquiring a CAUTI over 6 wk Health care costs for patients without a CAUTI (2012 pounds sterling) Additional health care costs for patients with a CAUTI Cost of nitrofurazone catheter Cost of silver alloy catheter Cost of standard catheter
0.075 +0.006 £3529.08 £572.56 £5.53 £6.75 £0.90
Source and distribution Based on the value from the trial analysis. b distribution* [10]; a (number of events in group) = 271; b (number of people without the event in the group) = 1873. Based on the estimated absolute risk difference between nitrofurazone and standard catheters. Normal distribution (SD: 0.01). Based on the estimated absolute risk difference between silver alloy and standard catheters. Normal distribution (SD = 0.01). Based on trial data. b distribution: a and b derived from mean (0.075369) and SD (0.02454) of QALYs for a CAUTI. Based on the RCT adjusted analysis difference in QALYs. Assumed normal distribution (SD = 0.001). The cost estimate was based on all participants without CAUTI (n = 5630). Log-normal distribution derived from mean costs (£3529.08) and median costs (£2466.39) derived from trial data. Based on the adjusted analysis results cost difference estimate from trial data. Normal distribution (mean = £572.56; SD = £445). Manufacturer: Rochester Medical Ltd., Lancing, UK. Point estimate, no distribution attached. Manufacturer: Bard Medical, Crawley, UK. Point estimate, no distribution attached. NHS Supplies.y Point estimate, no distribution attached.
CAUTI = catheter-associated urinary tract infection; NHS = National Health Service; QALY = quality-adjusted life-year; RCT = randomised controlled trial; SD = standard deviation. * The b distribution is constrained on the interval 0–1 and is characterised by two parameters, a and b. ** Utility is the benefit from the intervention derived using the EQ-5D-3L. y NHS catalogue product categories [9].
analysis used health status measurements derived from the EQ-5D (3 level) and costs reported in 2012 pounds sterling. No discounting was performed, as the events for each participant took place over <1 yr. Details of the parameters used in the model are presented in Table 1. Data on the risk of infection for standard catheters and the absolute risk differences between nitrofurazone or silver alloy and standard PTFE catheters were based on trial outcomes [5]. For each intervention, we calculated the extra cost incurred per quality-adjusted life-year (QALY) gained—the incremental cost effectiveness ratio. The probability of each intervention’s being cost-effective was calculated using different willingness-to-pay thresholds, including £30 000 (s36 851) per QALY suggested by the UK National Institute for Health and Clinical Excellence [6]. Sensitivity analysis examined the effect of uncertainty in cost and QALY estimates [7] by sampling values from an assigned distribution for each variable using Monte Carlo simulation. Further sensitivity analyses were performed to determine whether patients who had CAUTI were more likely to incur extra costs or have a worse health state for reasons unconnected to CAUTI, such as a more severe underlying illness or worse general health. For these analyses, we used trial participant subgroups that we considered to represent more homogeneous populations; the subgroups comprised admissions to obstetrics and gynaecology speciality wards, patients with an EQ-5D-3L score of 1 (perfect health) at 3 d after catheter removal, and participants who were recorded as having a symptomatic CAUTI treated with antibiotics at 3 d following catheter removal. Model predictions were that routine use of nitrofurazone catheters was, on average over the 6 wk of trial participation, associated with the lowest cost (£3595 [s4416]), followed by standard catheters (£3602 [s4425]) and silver alloy catheters (£3608 [s4432]) (Table 2). On average,
participants allocated to the nitrofurazone catheter had the highest QALYs over 6 wk, followed by the silver alloy and then the standard catheter. There is a 70% chance that nitrofurazone would be the least costly option and a >80% probability that it would be considered cost-effective when society is willing to pay a maximum of £30 000 (s36 851) per QALY (Table 2). Silver alloy had virtually no chance of being considered cost-effective. Our modelled analysis using data from a robust randomised controlled trial suggested that nitrofurazoneimpregnated catheters may be cost-effective for use in the UK NHS. The principal driver for this result was that cost savings from avoiding an infection would compensate for the increased unit cost of the nitrofurazone catheter compared with the standard catheter. However, cost savings were modest, and the confidence interval included zero, suggesting borderline clinical and statistical significance. Nevertheless, given the volume of catheterisation within well-resourced health care organisations and the high likelihood of this situation’s occurring, even this small difference may lead to substantial savings. This finding should be treated cautiously, given the limitations of the analysis and the uncertainty, particularly regarding estimates of key parameters such as length of hospital stay. Silver alloy–coated catheters were highly unlikely to be considered cost-effective for the UK NHS. The main driver was that it was unlikely that the observed reduction in risk of CAUTI was minimal, and any cost saving would not be sufficient to compensate for higher catheter cost. Similarly, any gain in QALYs was unlikely to be large enough to justify any increased expenditure. This conclusion is important, as some health care organisations have deployed this catheter for routine use [8]. In summary, we found no health– economic evidence to support the use of sliver alloy–coated urethral catheters. The conclusion is grounded in a trial encompassing a large, representative sample of the NHS
617
EUROPEAN UROLOGY 66 (2014) 615–618
Table 2 – Results of the model analysis and the subgroup analysis Intervention
Cost
Incremental cost
QALY
Incremental QALY
ICER
Base-case analysis Nitrofurazone £3595 (s4416)* 0.0823 Standard £3602 (s4425) £7 (s9) 0.0822 –0.0001 Dominated Silver alloy £3608 (s4432) £12.67 (s16) 0.0822 0 Dominated Participants admitted into the obstetrics speciality ward Standard £1905.403 0.0874 Nitrofurazone £1907.226 £1.82 0.0876 0.00015 £11 497 Silver alloy £1911.12 £3.87 0.0874 –0.00014 Dominated Participants who at 3 d had had an EQ-5D score = 1 (full health) Nitrofurazone £2678.43 0.10106 Standard £2695.51 £17.08 0.10098 –0.00008 Dominated Silver alloy £2700.33 £21.9 0.10098 –0.00007 Dominated 3-d symptomatic antibiotic-treated CAUTI outcome Nitrofurazone £3644.58 0.08118 Standard £3671.06 £26.48 0.08108 –0.00010 Dominated Silver alloy £3675.43 £30.85 0.08109 –0.00009 Dominated Probability (%) of being cost-effective at different threshold values for society’s willingness to pay for an additional QALY Threshold £0 £10 000 £20 000 £30 000 £50 000 s0 s12 284 s24 567 s36 851 s61 418 Base-case analysis Nitrofurazone 72 77 80 83 88 Standard 28 23 20 17 12 Silver alloy 0 0 0 0 0 CAUTI = catheter-associated urinary tract infection; ICER = incremental cost effectiveness ratio; QALY = quality-adjusted life-year. Cost in euros based on average exchange rate to year ending March 2013; £1 = s1.2284 (www.hmrc.gov.uk/exrate/exchangerates-1213.pdf).
*
patient population that would be expected to receive the silver alloy catheter if it were adopted for routine use. Our focus on the costs and health state (QALY) differences between patients who acquired a CAUTI and those who did not acquire one did not account for differences among trial participants who had an infection and those who did not. This means that our analysis may be confounded by participants who had a CAUTI having more severe underlying conditions or surgical complications and hence being more likely to incur higher costs and have impaired health status for additional reasons other than their CAUTI. However, predictions made by the model using the base-case analysis were not sensitive to change when the subgroup analyses were undertaken. Decisions whether or not to implement routine use of nitrofurazone catheters are complex. At present, at least within the United Kingdom, these catheters appear little used, and commercial production has stopped. Additionally, our favourable results were associated with a degree of uncertainty. Concerning silver alloy catheters, organisations in which they are already in use are ones that have an opportunity to reallocate resources without loss of benefit, whereas those organisations considering implementation may wish to await further evidence of benefit or the emergence of alternatives. The findings are likely to be applicable to countries with health care systems or models of care similar to that of the UK NHS. Author contributions: Mary Kilonzo had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Analysis and interpretation of data: Kilonzo, Vale. Drafting of the manuscript: Kilonzo, Vale, Pickard, Lam, N’Dow. Critical revision of the manuscript for important intellectual content: Kilonzo, Vale, Pickard, Lam, N’Dow. Statistical analysis: Kilonzo, Vale. Obtaining funding: Kilonzo, Vale, Pickard, Lam, N’Dow. Administrative, technical, or material support: Kilonzo, Vale, Pickard, Lam, N’Dow. Supervision: None. Other (specify): None. Financial disclosures: Mary Kilonzo certifies that all conflicts of interest, including specific financial interests and relationships and affiliations relevant to the subject matter or materials discussed in the manuscript (eg, employment/affiliation, grants or funding, consultancies, honoraria, stock ownership or options, expert testimony, royalties, or patents filed, received, or pending), are the following: Thomas Lam authored the Cochrane Review on antimicrobial catheters. Funding/Support and role of the sponsor: This project was funded by the UK National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Programme (project number 05/46/01) and is published in full in the Health Technology Assessment. The views and opinions expressed in this report are those of the authors and do not necessarily reflect those of the HTA programme, NIHR, National Health Service, or UK Department of Health. The Health Services Research Unit (HSRU) and the Health Economics Research Unit (HERU) are funded by the Chief Scientist Office of the Scottish Government Health Directorates. The authors accept full responsibility for the research. Acknowledgment statement: The Catheter Study Group would like to thank all the members of the Catheter Trial: Graeme Maclennan, Kathy Starr, Gladys McPherson, K. Gillies, Alison McDonald, Kathy Walton, Brian Buckley, Cathryn Glazener, Charles Boachie, Jennifer Burr, John Norrie, and Adrian Grant. The study group would also like to thank the patients who willingly participated in the study and completed their
Study concept and design: Kilonzo, Vale, Pickard, Lam, N’Dow.
questionnaires and diaries. We also thank all principal investigators,
Acquisition of data: Kilonzo, Vale.
research nurses/fellows, and other staff at each of our centres. We
618
EUROPEAN UROLOGY 66 (2014) 615–618
particularly thank Rashmi Bhardwaj, for leading and motivating the
[3] Tambyah PA, Knasinski V, Maki DG. The direct costs of nosocomial
excellent team of research nurses in the North East of England. We thank
catheter-associated urinary tract infection in the era of managed
all members of the Trial Steering Committee and the Data Monitoring
care. Infect Control Hosp Epidemiol 2002;23:27–31.
Committee. Thanks to the Catheter Study office staff (Karen McIntosh
[4] Schumm K, Lam TBL. Types of urethral catheters for management of
and Anne Duncan) for administration of the trial. We thank the
short-term voiding problems in hospitalised adults. Cochrane Da-
Comprehensive Local Research Networks and Primary Care Research
tabase Syst Rev 2008:CD004013.
Networks of the UK National Institute for Health Research and all the
[5] Pickard R, Lam T, Maclennan G, et al. Types of urethral catheter for
participating English National Health Service Trusts and Scottish Health
reducing symptomatic urinary tract infections in hospitalised
Boards who facilitated recruitment of their patients.
adults requiring short-term catheterisation: multicentre randomised controlled trial and economic evaluation of antimicrobial- and antiseptic-impregnated urethral catheters (the CATHETER trial).
Appendix A. Supplementary data
Health Technol Assess 2012;16:1–197. [6] National Institute for Health and Care Excellence. Process methods
Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/ j.eururo.2014.05.035.
and guide: guide to methods of technology appraisal. www.nice.org. uk/media/D45/1E/GuideToMethodsTechnologyAppraisa12013.pdf. Accessed 14 October 2013. [7] Briggs AH, Wonderling DE, Mooney CZ. Pulling cost-effectiveness analysis up by its bootstraps: a non-parametric approach to confi-
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