A Markov model was constructed to estimate the cost-effectiveness of several types of catheters for intermittent self-catheterization in a simulated SCI population with a mean age of 40 years (Bermingham et al. 2013; United Kingdom). The model projected forward to a lifetime time horizon. The comparators included hydrophilic coated catheters, gel reservoir coated catheters, single-use sterile non-coated catheters, clean non-coated catheters changed daily and clean non-coated catheters changed weekly. The Markov model included six different health states related to an individual’s movement between no symptomatic urinary tract infection, different catheter associated urinary tract infection states and death. Results were presented as cost per QALY. In the base case result, gel reservoir catheters were calculated to cost £54,350 per QALY more compared to non-coated catheters. The cost per QALY was even higher for hydrophilic catheters. Between the different options for non-coated catheters, catheters changed weekly were more effective and less expensive than catheters changed daily or single use catheters. In the scenario where non-coated catheters are not an option, the cost per QALY of gel reservoir catheters compared to hydrophilic catheters was £3,075 more per QALY gained. The sensitivity analyses did little to change the results of the analysis suggesting that the model was robust even with uncertainty. The authors noted that there were concerns with the conclusions of this study expressed by the stakeholders of the guidelines for which this study was to inform (patient groups, manufacturers and National Health Service trusts). There were liability concerns from clinicians regarding catheter infections if single use non-coated catheters were recommended to patients. Also, there were concerns regarding the off-label recommendation by a government organization for multiple uses of a single use catheter. The level of evidence regarding this recommendation was reported as low to very low quality. Thus, the recommendation was revised to allow patient choice of gel reservoir and hydrophilic catheters.
A second cost effectiveness analysis by Clark and colleagues was conducted to compare hydrophilic versus uncoated catheters from the UK National Health Service perspective (Clark et al. 2016). A long-term Markov model was constructed to include long-term effects of catheter use. Model inputs in this study were based on published materials. The outcomes of interest were QALYs, life year (LY) and urinary tract infection (UTI) events avoided. The results presented an additional £2100 per person cost with the use of hydrophilic catheters with a gain of 0.35 QALYs, 0.64 LYs and 16% reduction in UTI events lifetime. The incremental cost effectiveness ratio was £6100 per QALY and £3300 per life year gained. According to the probabilistic sensitivity analysis, all results were below the UK willingness-to-pay threshold of £20,000 which means they were potentially fundable through the public health care system. The authors concluded that the use of hydrophilic catheters were “highly cost effective.”
In a similar study by Watanabe and colleagues, the model developed by Clark and colleagues was localized to the Japanese health care system (Watanabe et al. 2017). Most of the model inputs were based on published literature sources. Treatment for UTI and cost of UTIs, damage of the urethra, kidney and bladder stones were obtained from a survey of an expert panel, urologists and SCI specialists. The study was based on the Japanese health care payers’ perspective. The clinical outcomes of interest were QALYs, LYs and the number of pyuria events avoided. The use of hydrophilic catheters was costlier per person by 1,279,886 yen (2014 yen), but increased QALYS by 0.334 and LYs by 0.781. The ICER was 3,826,351 yen/QALY, 1,639,562 yen/LY and 152,731 yen per pyuria event avoided. In sensitivity analyses, the resulting incremental cost effectiveness ratio (ICER)s were highly sensitive to the cost of the hydrophilic catheters and the risk of UTI in hydrophilic and non-hydrophilic catheters. At a willingness-to-pay threshold of 5,000,000 to 6,700,000 yen per QALY in previous Japanese studies, hydrophilic catheters would have a 67% to 78% probability of being cost effective. Watanabe and colleagues conclude that hydrophilic catheters “can be considered highly cost-effective in Japan from a payer’s perspective.”
Another long-term model based on the study by Clark and colleagues was constructed from the Brazilian public health care payer perspective (Truzzi et al. 2018). Model inputs were obtained from published sources. The clinical outcomes of interest included QALYs, LYs and number of UTIs avoided. The use of hydrophilic catheters had a higher cost of 31,221 BRL per person compared to uncoated catheters but an additional 0.54 LYs and 0.255 QALYs. This resulted in an ICER of 122,330 BRL per QALY, 57,432 BRL per LY gained and 9,778 BRL per UTI avoided. The results remained cost effective with sensitivity analyses. According to the authors, hydrophilic catheters can be considered cost-effective from the perspective of the Brazilian public health care system using a willingness-to-pay threshold of 147,000 BRL.
To understand the economic impact of hydrophilic catheters to the Italian Healthcare service, another long-term economic analysis using Bermingham and colleagues’ model was conducted (Rognoni & Tarricone 2017). Most of the model inputs were based on published sources. The cost of UTIs was estimated through questionnaires completed by urologists and neuro-urologists. The clinical outcomes of interest were QALY, LYs and UTIs avoided. The use of hydrophilic catheters was estimated to result in an increase in LY of 1 year, and an increase in QALYs of 0.9. The cost of hydrophilic catheters was €21,500 more compared to uncoated catheters (€82,915 versus €62,457). The ICER was calculated to be €24,405 per QALY and €20,761 per LY gained. The use of hydrophilic catheters over a life time is estimated to result in a 50% reduction in UTIs. With a large range of willingness-to-pay thresholds in Italy (€25,000-€66,400), the probability that hydrophilic catheters would be cost effective range from 47% to 98%. The model inputs that resulted in the largest impact on the ICER were the relative risk of developing a symptomatic UTI, number of symptomatic UTIs per year experienced by individuals using uncoated catheters, cost of hydrophilic catheters and the number of catheters used per day.
Another long-term cost effectiveness analysis was conducted from the public health care payer and societal perspective in Ontario, Canada using the model developed by Clark and colleagues as the foundation (Welk et al. 2018). The study examined the incremental cost effectiveness of hydrophilic catheters to uncoated catheters. Publicly available sources and results from published studies were used as model inputs. The societal perspective included sick leave, early retirement and early death impact related to illness. Costs were standardized to 2016 Canadian dollars (CAD). This study observed a 0.72 QALY gain for the hydrophilic catheters compared to uncoated catheters with an additional cost of $47,017 CAD. The resulting ICER was $66,634 per QALY. If the utility benefit of receiving hydrophilic catheters was removed from the model, the ICER would increase to $132,485. The model was sensitive to unit cost of hydrophilic catheters and uncoated catheters and impact on urinary tract infections. When examining the cost effectiveness from the societal perspective, hydrophilic catheters had lower costs and better QALYs compared to uncoated catheters.