Hypothesis / aims of study
Reusable intermittent catheters have recently been demonstrated to be safe, cost-effective and acceptable to those who wish to use them (1,2). It is likely they have potential to reduce environmental impact by decreasing the use of single-use catheters, but the comparative impacts of single-use and reusable catheters are unknown.
The aims of this study were to determine the environmental impact of:
• Only reusable catheters, and reusable catheters plus single-use catheters combined, compared to single-use only catheters
• A range of single-use catheter designs
Study design, materials and methods
A “cradle-to-grave" life-cycle analysis, to ISO standards 14044:2006 and 14040:2006, was used to determine seventeen areas of environmental impact for the selected catheters. We have focussed here on climate change as the category of highest importance.
Single-use catheter selection: Using the UK prescription cost analysis database (3), catheters were systematically identified, categorised by design feature and quantified. Four categories were selected for analysis: catheters with a hard, plastic-based case, catheters with an integrated drainage bag, and catheters with a hydrophilic coating with or without a water-filled sachet.
From each category we selected the three most prescribed catheters, without representing an individual manufacturer more than once. For the hydrophilic catheters we only used those with water sachets and then excluded the water sachet data to allow comparison with the other categories.
Reusable catheter selection: We used the Cliny catheterTM (Create Medic Co., Ltd.) - the only available catheter licensed for re-use (up to 28 days) in Europe.
Three samples of each catheter were weighed and characterised including their packaging. Catheter materials were identified using publicly available technical data sheets and robust, defendable assumptions where data were missing.
Impact calculations were based on 28 days of intermittent catheterisation. For single use catheters the calculation was based on using 4 catheters per day. For the reusable catheter calculations were based on: all reusable catheters (all 4 catheterisations per day using a reusable catheter); and mixed-use (2.8 reusable and 1.2 single-use catheters) which was the average daily use in the MultICath Trial. For mixed-use the single-use catheter impact component was calculated in two ways (see figure legend).
Interpretation of results
Reusables vs single-use: Based on an intermittent catheterisation rate of 4 times per day if a reusable catheter was used for all catheterisations, or in combination with a single-use catheter as part of mixed-use, climate change impact was less than using only single-use catheters. This was the case for both male and female catheters and for all single-use catheter designs.
Comparison of single-use designs: For the hydrophilic catheters (with or without water sachets), the climate change impact was similar and intra-category variation was low.
The hard case and integrated bag categories showed higher climate change impact than the hydrophilic catheters (with or without water sachets) but with high intra-category variation. In some cases, the impact was twice as much as the hydrophilic catheter categories.
Product weight (catheter plus packaging) was the main determinant of climate change impact. The climate change impact of both reusable and single-use catheters could be reduced by better catheter design to reduce the materials and packaging used.