Urinary catheterization from 1997 to 2018: a Dutch population-based cohort

Background: Our aim was to evaluate the use of indwelling, intermittent and external urinary catheters in neurogenic and non-neurogenic bladder patients in the Netherlands from 1997 to 2018. Methods: Data were retrieved from a population-based cohort containing information about the extramural use of medical devices in the insured population in the Netherlands. The insured population increased from 9.9 million people in 1997 to 17.1 million people in 2018 (64–100% of the Dutch population). Users are expressed by users per 100,000 insured people and total users, corrected for the overall Dutch population. The expenditures are corrected for inflation and expressed by total costs and costs per user. Results: During this 21-year period, indwelling catheter (IC) users doubled from 159 per 100,000 people (24,734 users) to 315 per 100,000 people (54,106 users). Clean intermittent catheter (CIC) users increased from 92 per 100,000 people (14,258 users) in 1997 to 267 per 100,000 people (45,909 users) in 2018. Of all users, 20.7% had an associated neurogenic disorder and 44.9% a non-neurogenic disorder in 2018. The total expenditure on extramural use of urinary catheters increased from 27.7 million euros in 1997 to 84.4 million euros in 2018. IC costs increased from 6.0 million euros in 1997 to 6.7 million euros in 2018, while CIC costs rose from 16.4 million euros to 74.6 million euros. Urine drainage bag costs decreased from 17.2 million in 2001 to 5.3 million in 2018. Conclusions: IC use has increased substantially over the past 21 years, despite the fact that CIC use increased as well. It seems that the main driver behind the prevalence in IC and CIC use, is the rise in incontinence care in older patients and the adaption of preferred CIC use in professional guidelines. At least one fifth of all users catheterize due to neurogenic reasons.


Introduction
Indwelling catheterization has been used for centuries for those who fail to drain their bladder (urinary retention) or fail to control their bladder (urinary incontinence). Urinary retention is seen in patients with neurogenic and non-neurogenic disorders. The most common associated neurogenic disorders are spinal cord injury, spina bifida or meningomyelocele, multiple sclerosis and morbus Parkinson. 1 Associated non-neurogenic disorders are, for example, benign prostate obstruction, or the onset of urinary retention can occur post-partum or post-pelvic surgery. 2 In many cases, a single underlying cause is unknown, and underactivity of the detrusor muscle might be a contributing factor. Unfortunately, it is often unclear how detrusor underactivity occurs and is therefore referred to as idiopathic.
Another reason for catheterization is urinary incontinence, which can be subdivided into stress, urge, and mixed urinary incontinence. Different treatment methods are available for urinary incontinence, but pads are widely used, especially in nursing homes with mostly vulnerable patient populations. The risk of pressure sores is high in immobile and fragile people using pads. 3 Therefore, together with the high workload due to incontinence, pads are often replaced for indwelling catheters (ICs) to prevent, or after the development of, pressure sores. In patients with urinary incontinence treated with an IC, urine follows the path of least resistance and is drained by the IC, preventing any leakage. Another treatment option is the use of a condom catheter. This catheter, also referred as an external catheter (EXC), is not inserted into the bladder, but is fitted around the penis with a sheath similar to a condom. It is used for urinary incontinence and urinary retention, but is not advised for patients with neurogenic high-pressure bladders due to the elevated risk for renal deterioration. 4,5 For patients suffering from only urinary retention, the treatment of choice is clean intermittent catheterization (CIC). CIC is the insertion and removal of a catheter in the bladder to drain the urine for a short time and is mostly performed four to six times a day. Compared with indwelling catheterization, CIC is the preferred treatment due to the reduced risk for complications like catheter-associated urinary tract infections, bladder stones, and renal deterioration. 4,6 However, the ability to perform CIC depends on different factors, including personal factors (e.g. hand function and position of the urethral meatus) and healthcare policies for the reimbursement of urinary catheters.
According to the review of Feneley et al. 7 the costs of ICs accounted for around 380 million USD in 2007. Looking at the economic burden of all urinary catheters, the market size was valued at 3.4 billion USD in 2015, with a gradual growth in future perspective. Around 60% of the expenditure on urinary catheters is consumed by disposable intermittent urinary catheters. 8 In The Netherlands, urinary equipment, including ICs and disposable catheters for CIC, is reimbursed for neurogenic and non-neurogenic bladder patients. It is hypothesized that the prevalence of CIC use is higher in countries with reimbursement agreements than countries without or with partial reimbursement, but actual data on urinary catheter use are lacking for most countries. A previous study showed that CIC use and costs in The Netherlands increased substantially in the past 2 decades. 9 This increase in CIC use is in line with the overall population growth, the aging population, and the adaption of the recommendation in professional guidelines of urologist and rehabilitation physicians for the preferred use of intermittent catheters.
The present study investigated the trends in extramural (non-hospitalized and non-institutionalized) use of all urinary catheters, including indwelling and external catheters in neurogenic and non-neurogenic patients, including the costs in the Netherlands between 1997 and 2018. In addition, we examined the age and sex distribution for IC, CIC and EXC use. This study was performed in comparison with the results of a previous study on intermittent urinary catheter use in the Netherlands between 1997 and 2018. 9 Our hypothesis was that the adaption of the recommendation of CIC use for urinary retention resulted in a decline of IC and EXC use in the Netherlands. Furthermore, we hypothesized a large amount of the neurogenic bladder patients use intermittent catheters for their treatment of chronic urinary retention, and that the prevalence of IC and EXC use increases with age.

Study design
For this retrospective, population-based database study, data were obtained from the Drug and Medical Devices Information System (Genees-en hulpmiddelen Informatie Project; GIP) of the Dutch Health Care Institute (Zorginstituut Nederland). This database contains information about all reimbursed prescriptions on extramural (non-hospitalized and non-institutionalized) medication and medical devices. Between 1997 and 2005, the GIP database only contains information about insured people under the Public Health Insurance Law (Ziekenfondswet), which was 63% of the total Dutch population. After 2006, the Healthcare Insurance Act was implemented and all insured people were included in the GIP database (100% of the total Dutch population in 2018). Data are based on number of prescriptions per patient per year. All data used were obtained and handled according to the Dutch privacy laws.
The following time trends were evaluated for the use of urinary catheters per year: (1) number of ICs, intermittent catheter and external catheter users in the Dutch population between from 1997 to 2018; (2) the distribution of different type of catheter users among different sex and age groups from 1997 to 2018; (3) the distribution of different type of catheter users; (4) among neurogenic and non-neurogenic bladder patients from 2012 to 2018; (5) costs for the total population of indwelling, intermittent and external catheters used from 1997 to 2018; (6) costs of different urinary catheter types and accessories per individual catheter user from 1997 to 2018.
In the Netherlands, all declarations of medical devices by pharmacists or medical devices suppliers are coded through ZI-numbers or the Generic Product Code for devices (Generieke Productcodes Hulpmiddelen: GPH). The ZI-numbers are published in the G-Standaard by Z-index, a database containing product information of medicines and medical devices that are dispensed or used in the Dutch healthcare system. 10 The GPH-codes are managed by Vektis, 11 a non-commercial database responsible for relaying pseudonymised data from the healthcare insurers to the National Healthcare Institute. The health insurance companies share these declarations with the GIP database. The GIP database links the ZI-numbers and GPH-codes to a corresponding ISO9999-code, which is translated into a classification. All urinary catheters and accessories are classified under the monitor code 'A1535 catheters' and are subcategorized by different ISO-codes. For this study, data were obtained from different ISO-codes, including the ISO-codes for ICs, disposable intermittent catheters, external catheters, and urine drainage bags and other accessories (e.g. disposable intermittent catheters is ISO92406).

Data analysis
Before data were obtained for the different type of ISO-codes, all links between ZI-numbers/GPHcodes and ISO-codes were analyzed and checked by visual control of the product names. In addition, all occurring ZI-numbers were checked with the product information in BeverOnline, a medical device database from Nigella IT . 12 13 By adjusting for the general price development of consumer goods and services, the changes in the expenditures on intermittent disposable catheters and accessories are the result of changes in volume and specific price movements. All expenditures are expressed in prices of 2018 in euros.

Results
The  Figure 1.   Users are expressed by users per 100,000 insured people in that specific age and sex category for the total Dutch population. Table 2. Etiology of catheterization in number of users for the total population.

Discussion
Urinary catheters are a widely used therapy for patients with an impaired bladder function. This study explored the trends in extramural use and costs of indwelling and external catheters in comparison with the results of intermittent urinary catheter use in the Netherlands from 1997 to 2018. The findings clearly show an increase in absolute and relative urinary catheter use and costs. In the past 2 decades, IC use more than doubled, alongside the threefold increase in CIC use. These results were rather unexpected, as we hypothesized that IC use would decline if CIC use increased. A possible explanation is the increased prevalence of urinary incontinence due to an aging population.  This study is the first describing the prevalence of neurogenic and non-neurogenic patients with urinary catheters in a total population. Small studies have been performed to address this in specific neurogenic bladder patient groups, but precise numbers could not be estimated. 4  Our results are in line with the IC use in England, Wales, and Northern Ireland. ICs were present in 3% of the people living in the community, as is in our study. An IC was used in 13% of care home residents. 17 We suspect that the use of indwelling and external catheters is also substantially higher in the Dutch care facilities (intramural). Although we put much effort into finding a suitable database on intramural use, this study only contains information about the extramural (outpatient) use of urinary catheters. Therefore, the main limitation of this study is that the use of urinary catheters in hospitals and care centers (e.g. rehabilitation centers) are not included in this analysis. This might have resulted in an underestimation, especially for indwelling and external urinary catheters. However, the data on extramural use is unique, as it is the first study using a population-based cohort.
Although the current study is based on the total non-hospitalized and non-institutionalized Dutch population, the findings show a substantial growth over the past 2 decades in use and costs for indwelling and intermittent urinary catheters. One fifth of all users had a neurogenic underlying condition, and almost half of those patients used only indwelling catheterization, which has never been described before. Only a part of the increased costs for catheters was due to price increase from manufacturers, while urine-drainage bag prices decreased, evidently. It seems that the main driver behind the prevalence in IC and CIC use is the rise in incontinence in older patients and the adaption of preferred CIC use in professional guidelines.
Author contributions SB contributed to the study design, data collection, data analysis, data interpretation, and article preparation. TD contributed to the data interpretation and article preparation. BB contributed to the study design, data interpretation, and article preparation.