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Keywords:

  • overactive bladder;
  • cost of illness;
  • burden

Abstract

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. ACKNOWLEDGEMENTS
  8. CONFLICT OF INTEREST
  9. REFERENCES

OBJECTIVE

To calculate up-to-date estimates of the economic impact of overactive bladder syndrome (OAB) with and without urgency urinary incontinence (UUI) on the health sector of six countries (Canada, Germany, Italy, Spain, Sweden and the UK), as OAB is a significant health concern for adults aged >18 years living in Western countries.

MATERIALS AND METHODS

The prevalence data derived from the EPIC study were combined with healthcare resource-use data to derive current direct and indirect 1-year or annual cost of illness estimates for OAB including UUI in Canada, Germany, Italy, Spain, Sweden and the UK. This model estimates the direct healthcare costs attributed to OAB, as well as the impact of work absenteeism.

RESULTS

The estimated average annual direct cost of OAB per patient ranged between €262 in Spain and €619 in Sweden. The estimated total direct cost burden for OAB per country ranges between €333 million in Sweden and €1.2 billion in Germany and the total annual direct cost burden of OAB in these six countries is estimated at €3.9 billion. In addition, nursing home costs were estimated at €4.7 billion per year and it was estimated that work absenteeism related to OAB costs €1.1 billion per year.

CONCLUSIONS

The cost of illness for OAB is a substantial economic and human burden. This study may under-estimate the true economic burden, as not all costs for sequelae associated with OAB have been included. Cost-effective treatments and management strategies that can reduce the burden of OAB and in particular UUI have the potential to significantly reduce this economic burden.


Abbreviations
OAB

overactive bladder syndrome

(U)UI

(urgency) urinary incontinence

QoL

quality of life.

INTRODUCTION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. ACKNOWLEDGEMENTS
  8. CONFLICT OF INTEREST
  9. REFERENCES

Increasing and competing demands on healthcare budgets coupled with the ageing populations in most Western countries is acknowledged to have caused pressure on health expenditure. In addition growing awareness of health issues, particularly those affecting older adults are prominent in both the medical literature and the popular media. Overactive bladder syndrome (OAB) and urinary incontinence (UI) are examples of such health issues. OAB is a highly prevalent condition affecting 12–17% of men and women [1–3]. About 28% of men and 49% of women reporting OAB symptoms also report UI with the vast majority being urgency UI (UUI) [1]. The condition is known to have serious impact on quality of life (QoL) and well-being [4,5].

Relatively few published studies exist that describe the cost of illness for OAB [6–8] but several exist for UI [9–14]. These studies vary in terms of the epidemiological data used, approach taken (bottom-up or top-down), costs included (direct, indirect or intangible) and country or regions for which costs are reported. Direct costs relate to diagnosis, delivering and/or receiving treatment as well as treating sequelae of the condition. Indirect costs include work absenteeism, impaired performance at work (presenteeism), and changes in job status. Intangible costs cover those that impact a persons well being and QoL and are difficult to calculate in monetary terms.

Annual direct costs of OAB were recently investigated from a social perspective in Germany and estimated at €3.98 billion [7]. The authors found a large share (45%) of the total costs were for nursing care (€1.80 billion) and medication (2%) had the smallest share (i.e. €0.08 billion). Another study documented that institutionalized patients account for 25% of the total costs of OAB in the USA [11]. Studies in the UK and USA have documented direct costs associated with UI care exceed those associated with other common chronic illnesses such as coronary care and cancer care [15].

There are several other conditions closely associated with OAB that may also influence the total costs. These conditions include, but are not limited to depression, disturbed sleep, falls and fractures, skin infections, and UTIs [16–22]. Some authors propose the evidence for an association between the risk of falling and the presence of UI in older people merits targeted interventions [18]. It has been found that these conditions are related to a significant cost in patients with OAB [6,11,19].

In 2002, the ICS released updated, standardized definitions for OAB, incontinence, and other LUTS [23]. OAB was described as ‘urgency, with or without urgency incontinence, usually with frequency and nocturia, in the absence of pathological or metabolic conditions that might be able to explain these symptoms’. Urgency UI (UUI) comprises a subset of the total OAB population and is defined as an ‘involuntary leakage accompanied by or immediately preceded by urgency’.

To address the need for current prevalence data using the ICS 2002 definition, a large epidemiological survey, the EPIC study, was undertaken in Canada, Germany, Italy, Sweden and the UK [1]. The study was primarily designed to investigate the self-reported prevalence of OAB in the general population and to evaluate the impact of OAB on patient bother, healthcare-seeking behaviours and other consequences such as depression, and work productivity [24–26].

The objective of the present research was to use data provided by EPIC and other recent cost of illness studies to report updated estimates of the direct cost to the national healthcare and social services of six Western countries: Canada, Germany, Italy, Spain, Sweden and the UK. In addition we sought to quantify the indirect cost to society of lost productivity associated with people having OAB symptoms.

MATERIALS AND METHODS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. ACKNOWLEDGEMENTS
  8. CONFLICT OF INTEREST
  9. REFERENCES

MODEL STRUCTURE

A cost of illness model was developed using a 1-year time frame based on OAB prevalence data and costs outlined in Table 1. A societal perspective is taken in this modelling approach.

Table 1.  Costs for OAB and UUI included in the present economic analysis
Cost categoryType
Excess direct costs for OAB and UUITreatment costs
Medical consultations
Incontinence pad use
Depression
Direct costs for UUIUTIs
Skin infections
Fractures from fall
Indirect costs for OAB and UUINursing home admissions (UUI)
Loss of productivity due to work absenteeism (OAB)  (excess costs)

OAB PREVALENCE DATA AND POPULATION ESTIMATES

The EPIC study was a cross-sectional population-based survey of people aged ≥18 years and was conducted in Canada, Germany, Italy, Sweden, and the UK [1]. Computer-assisted telephone interviews were conducted between April 2005 and December 2005 using a geographically stratified random sample of the population in each country. The 2002 ICS definition of OAB was used to classify those interviewed [23]. To account for the underlying sampling frame and to provide representative population prevalence estimates, the sample population was weighted by age, sex, household size, and country size.

Prevalence rates for OAB and UUI were obtained directly from the EPIC study for Canada, Germany, Italy, Sweden and the UK [1]. These rates were stratified by country, sex and 5-year age brackets from the age of 18 years. Spain was included in a previous cross-sectional European Study [2]. However, this study used an older version of the ICS definitions of OAB and UUI. As Spain was not included in the EPIC study, a weighted average prevalence rate in each age group over all five countries from the EPIC study was used for the prevalence in Spain.

The prevalence rate of OAB symptoms among men and women aged ≥18 years in the general population was 10.9% for men and 12.9% for women [1]. The country with the lowest reported overall prevalence was Canada (8.0% men; 8.9% women) and the country with the highest was Sweden (13.2% men; 19.6% women) [1]. The estimated prevalence rate of UUI was 1.8% in men and 3.9% in women aged >18 years. Germany had the lowest prevalence (men 1.5%; women 3.0%) and Sweden the highest rate (2.8% men; 9.9% women) [1] (Table 2).

Table 2.  Prevalence of OAB and UUI and estimated number of individuals with OAB and UUI in six Western countries
CountryGenderPrevalence of OABTotal estimated no. of individuals with OABPrevalence of UUITotal estimated no. of individuals with UUI
SwedenMen13.2469 1372.8100 795
Women19.6719 9279.9365 241
ItalyMen10.72 374 4041.7374 578
Women11.62 833 6233.3811 728
CanadaMen 8.01 009 3652.5312 311
Women 8.91 173 4654.4572 514
GermanyMen11.33 637 7171.5489 037
Women13.04 473 0313.01 042 873
UKMen 8.72 005 7321.8427 432
Women10.22 536 5784.51 116 763
SpainMen10.81 804 6451.8243 048
Women12.82 412 7263.9536 547
TotalTotal11.825 221 0332.96 365 266

Individual country population estimates were sourced from national statistic websites [27–30]. Applying the OAB prevalence rates from EPIC to the population figures gave estimates of the expected number of men and women affected by OAB symptoms.

RESOURCE USE AND COSTS

A comprehensive review of the literature was conducted to ascertain all the relevant costs and consequences associated with OAB and UUI. These costs were classified as direct (those borne directly by the healthcare or social service sectors) or indirect (lost productivity). In addition, we identified costs that are incurred by individuals with OAB and costs that are specifically associated with UUI and the consequences of persistent UUI symptoms as shown in Table 1.

Resource use estimates for the proportion of the OAB population with physician consultations for urinary symptoms, incontinence pad use, clinical depression (as measured by the Center for Epidemiological Studies-Depression Scale) [31], and prescription medications for bladder symptoms were sourced directly from the nested case-control component of the EPIC study described elsewhere [24–26]. In some situations (e.g. men in certain age groups with UUI reporting pad use), the sample sizes for resource utilization were too small in the EPIC study to provide stable estimates of OAB with UUI stratified by gender. However, adequate estimates were available for OAB with any type of UI. The use of these probabilities is a conservative estimate because in all cases, the resource use estimates for OAB with UUI were greater than those for OAB with any type of UI. For the purposes of these analyses, individuals with OAB with UI were assumed to have the same direct resource utilization as individuals with OAB and UUI.

For this economic evaluation, the incremental prevalence of clinical depression, incontinence pad use and prescription medications for bladder symptoms was calculated by subtracting the prevalence in the EPIC control population (general population without OAB) from the prevalence in the OAB population. This was done to estimate the excess likelihood of resource utilization directly associated with OAB compared with the general population. In the EPIC study, individuals with OAB symptoms were asked to report whether or not they had sought health care related to their urinary symptoms. Therefore, an incremental prevalence of medical consultations was not calculated and the prevalence of medical consultation for urinary symptoms among OAB population was directly used in the model.

The likelihood of individuals with UUI experiencing any of the other specified consequences of persistent symptoms (i.e. UTIs, skin infections, falls and fractures, nursing home admissions) was taken from previous publications on the economic burden of OAB [8]. To test the impact of these assumptions and the literature-based data on our estimates, all of these inputs were varied in sensitivity analyses. Policies for admission into nursing home and payment sources vary from one country to another. For this reason, costs related to nursing homes were estimated separately from the other direct costs.

The impact of lost productivity from OAB symptoms was measured in the EPIC study using the general health version of the Work Productivity and Activity Impairment questionnaire [32]. Overall, 61% of subjects that were aged <65 years included in the survey were employed. Absenteeism (work hours missed) among employed individuals aged <65 years was assessed. As reasons for absenteeism can be varied, it was necessary to use the incremental likelihood of absenteeism attributed to OAB compared with the general population. About 4.2% of the OAB population reported excess absenteeism and on average individuals with OAB reported missing work ≈2 h per week (data on file 2007). It was assumed that the average working day was 8 h long and 47 annual working weeks comprised each year.

The impact on work productivity of OAB was valued using the Human Capital approach [33]. Data on wage earnings from each of the countries was sourced from the Canada National Statistic agency [27] and Eurostat [30]. The sample sizes for absenteeism were too small in the EPIC study to provide stable estimates of OAB with UUI stratified by gender; however, adequate estimates were available for OAB with any type of UI. The use of OAB with any type of UI is a conservative estimate because the absenteeism estimate for OAB with UUI was greater than for OAB with any type of UI. For the purposes of these analyses, individuals with OAB with UI we assumed to have the same work impact as individuals with UUI.

Unit costs for each of the six countries were taken from locally or internationally published sources [34–57]. The direct costs included in our model were based on the literature as was done in the economic evaluations of OAB that included similar direct costs [6,8]. The resource use probabilities and costs are provided in Table 3.

Table 3.  Resource utilization probabilities and unit costs (€) per patient with OAB per annum
ResourceProbabilityCosts, €
CanadaGermanyItalySpainSwedenUK
  • *

    Assumed to be the same probability as medical treatments.

Prescription medication treatments for urinary symptomsExcess for OAB 0.03458598673265659247
Incontinence pad useExcess for OAB 0.20135161247247194116
Clinical depressionExcess for OAB 0.077551 6105255251 2661 314
Diagnostic procedures*Excess for OAB 0.0331227725140
Medical consultations – GPOAB Related 0.37160394668284281
UTIsUUI 0.174267291812237
Skin InfectionsUUI 0.084243291812237
FracturesUUI 0.0237027169141172175
Nursing home admissions – individuals aged >60 yearsUUI 0.0711 32927 20134 717137712 77111 796

TOTAL ECONOMIC IMPACT

The total economic impact on health and social service systems of these six countries was calculated by multiplying the estimated number of people with OAB symptoms by the estimated cost per person. All costs are presented in 2005 Euros (€) and separate analyses were run for direct and indirect costs.

SENSITIVITY ANALYSIS

To account for any uncertainty over input values (resource use and costs), we varied these values in one-way sensitivity analysis for direct costs not including nursing home or loss productivity costs. In our sensitivity analysis, variables were either changed using data within a meaningful range based on results from the EPIC study or plausible assumptions and the impact of these changes were then assessed on the final model. This is an indicator of how much each parameter impacts on total costs. Table 4 shows the variables included in the sensitivity analysis.

Table 4.  Variables included in sensitivity analyses
Input variableVariation range
Percentage, % 
 Frequency of UUI patients reporting symptoms of depression 11–16
 Frequency of OAB without UUI patients reporting symptoms of depression 1.2–5
 Prevalence of OAB 6.8–15.8
 Proportion of UUI patients treated for UTIs conditions  12–22
 Proportion of UUI patients treated for skin conditions   3–13
 Proportion of UUI patients treated using drug therapy   7–13.1
 Proportion of OAB without UUI patients treated using drug therapy   4–6
 Proportion of OAB without UUI patients using incontinence pads   1–10
 Proportion of UUI patients using incontinence pads  14–41
 Proportion of UUI patients with medical consultation46.1–57.4
 Proportion of OAB without UUI patients with medical consultation  27–30.1
Cost, € 
 OAB drug treatment per annum246.62–598.33
 Incontinence pads per pad  0.25–0.43
 Physician visits per visit 15.88–99.88

RESULTS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. ACKNOWLEDGEMENTS
  8. CONFLICT OF INTEREST
  9. REFERENCES

PREVALENCE OF OAB AND UUI

The prevalence of OAB varied by country (from 13.2% men and 19.6% women in Sweden to 8.0% men and 8.9% women in Canada) and increased with age [1]. Germany had the largest estimated number of people aged >18 years with OAB symptoms (≈8 million), followed by Italy with ≈5.1 million. Sweden had the fewest with an estimated 1.1 million people with OAB symptoms (Table 2). It was estimated that Germany and the UK have the highest number of individuals with UUI (1.5 million each) and Sweden with the least (460 000) (Table 2). The difference in absolute numbers of individuals with OAB in each country is largely a factor of the overall country population sizes with Germany and the UK being two of the largest in the study.

DIRECT SOCIETAL COSTS

The expected excess mean annual cost associated with the diagnosis (diagnostics), treatment (medications and incontinence pad use), medical consultations, and treatment of clinical depression associated with OAB ranged from €255 per person in Spain to €584 per person in Sweden (Table 5). The costs shown in Table 5 represent an average across all patients with OAB (i.e. annual costs for depression among patients were divided by the total number of patients in each country).

Table 5.  Estimated costs per patient with OAB per annum
Cost categoryCosts, €*
UKCanadaGermanyItalySpainSwedenTotal
  • *

    Costs averaged across all OAB patients;

  • †excess costs or costs directly related to OAB;

  • ‡costs for OAB with UUI.

Excess direct costs       
 Prescription medication treatments for urinary symptoms336281913589391
 Incontinence pad use48566610210280454
 Clinical depression2041182518282197934
 Diagnostics553113449
 Medical consultations – GP225129313249184650
 Total5153704322972555842453
Sequelae direct costs       
 UTIs6711532153
 Skin infections333211022
 Fractures49623428
 Total1319219735104
Other costs       
 Nursing home admissions – individuals aged >60 years38138510381580305623976

The expected mean annual cost of UUI-related UTIs, skin infections, and fractures ranged from €7 per person in Spain to €35 per person in Sweden. Lastly, we calculated the expected cost of the first year in a nursing home for individuals with UUI. These costs ranged widely from €1580 per person in Italy to €30 per person in Spain. (Table 5). The cost of depression and medical consultations for OAB were the main contributors to cost per patient (Table 5).

The total direct economic impact of OAB on the national healthcare system in the six countries is shown in Table 6. Most of the costs included in this model are the incremental costs associated with OAB (medical consultations, medications, incontinence pad use, diagnostics and treatment of clinical depression). The cost differs widely between the countries with Sweden showing the least cost (nearly €333 million) and Germany the highest cost (€1.2 billion). OAB affects >6.3 million people (Table 2) and the total cost in the six countries is ≈€3.9 billion (Table 6). UUI represents on average half of the total cost of OAB, despite the lower prevalence of the condition.

Table 6.  Total excess costs for OAB in six Western countries
 Cost, €
OAB without UUIOAB with UUITotal OAB
  • *

    Excluding nursing home and productivity costs;

  • †not costed.

Country   
 Canada127 297 947251 801 183379 099 130
 Germany648 671 008543 291 4941 191 962 502
 Italy282 709 258289 613 396572 322 654
 Spain194 876 594171 810 423366 687 017
 Sweden126 464 106206 472 949332 937 055
 UK412 901 556594 542 8251 007 444 381
Costs   
 Total direct*1 792 933 0372 057 583 2153 850 516 253
 Total nursing homeNA4 668 644 5064 668 644 506
 Total lost productivity857 803 084237 771 2411 095 574 325

NURSING HOME COSTS

The total annual nursing home costs for individuals with UUI was estimated to be €338 million in Canada, €1.6 billion in Germany, €1.8 billion in Italy, €261 million in Sweden, €23 million in Spain and €579 million in the UK for a total of €4.7 billion.

LOST PRODUCTIVITY COSTS

The total number of excess work hours lost from absenteeism attributable to OAB (<65 years old) was calculated to be 52 million per annum over the six countries (24 million for men; 28 million for women). The total annual cost of absenteeism associated with OAB was estimated to be €65 million in Canada, €375 million in Germany, €212 million in Italy, €66 million in Sweden, €142 million in Spain and €233 million in the UK for a total of €1.1 billion.

SENSITIVITY ANALYSIS

Varying the inputs to the model allowed the key cost drivers for direct costs (not including nursing home and loss productivity costs) to be evaluated. The prevalence of depression among OAB without UUI, as well as the costs associated with OAB medications and physician visits were identified as the most influential variables in the model. The tornado diagram shown in Fig. 1 describes the variability around these three parameters. Much of the variability may be explained by country differences in costs related to medications and medical visits. Total direct costs followed country population size, although analyses showed little sensitivity to the overall prevalence of the OAB. It seems that physician visits has a major impact on total costs.

image

Figure 1. One-way sensitivity analyses in six countries for prevalence of clinical depression among patients with OAB without UUI (a), for cost of physician visits (b), and for the cost of OAB medications (c).

Download figure to PowerPoint

DISCUSSION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. ACKNOWLEDGEMENTS
  8. CONFLICT OF INTEREST
  9. REFERENCES

This studied showed the annual direct costs of OAB in six countries to be ≈€3.9 billion with additional costs for nursing home stays (€4.7 billion per year) and loss productivity due to work absenteeism (€1.1 billion is per year). The estimated total cost therefore for the ≈25 million patients with OAB in these countries is €9.7 billion. This analysis differed from other published studies because most other studies used incremental costs associated with OAB compared with the general population. Hence, the present cost estimates are slightly lower than previously published studies [6–8]. Varying the excess proportion of patients with OAB who experienced depression, costs associated with physician visits related to OAB symptoms as well as costs related to OAB medications exerted the most effect on annual cost estimates.

The EPIC study [1] was the first major multinational population-based study to assess the prevalence of OAB based on the 2002 ICS definitions of LUTS [23]. The OAB definition change [23] resulted in estimates of fewer people reporting OAB symptoms than in previously published figures [2]. It was also the first multinational population-based study to examine associations between OAB symptoms and depression, and the impact of OAB symptoms on work productivity. The present report, which was based on previous studies, used real-life population-based survey data to estimate the incremental impact of these cost consequences.

Sensitivity analysis revealed that costs related to medical visits and treatment exert the most effect on the total direct costs (excluding nursing home and lost productivity costs). Difference in costs related to OAB may vary substantially between countries as do country practice for the average number of visits per year, and the frequency of specialist visits. In addition, the overall population size with OAB symptoms has an impact. These factors are very influential for the total costs for physician visits and treatment patterns, which probably account for the differences seen. Previous work [8] reported pad use to be the primary cost driver and the probability of pad use and numbers of pads used were based on expert estimates. The present study used actual population-based survey data to populate the model, which may account for the differences seen.

One other study [6] in the USA used a similar methodology to ours for calculating OAB-related lost productivity costs in the USA. They reported lost productivity costs to be equal to ≈$841 million, which was comparable with our estimate of €1.1 billion. One of the limitations of the present study is that we were unable to extend the estimate of productivity loss associated with OAB to also include the productivity loss while at work (e.g. presenteeism). Recent research, suggests that presenteeism accounts for a larger proportion of productivity losses than absenteeism in OAB [24,25]. Many of the cost consequences in this model (e.g. depression, UTIs, fractures, skin infections) have been shown to be associated with OAB but caution should be used in interpreting this data, as more research is needed to prove a causal link.

This cost of illness estimates in the present study may under-estimate the true economic burden, as we have not been able to include all indirect costs (e.g. loss productivity data due to presenteeism was not included). The present study did not capture the psychological burden or the impact on health-related QoL caused by OAB. Future research should consider these issues to evaluate the total impact of OAB. However, the estimated cost burden to the healthcare sector even without these components is sufficiently large that countries with ageing populations should evaluate cost-effective treatments for OAB that have the potential to reduce both the human and economic burden.

ACKNOWLEDGEMENTS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. ACKNOWLEDGEMENTS
  8. CONFLICT OF INTEREST
  9. REFERENCES

Paul Mernagh from Fourth Hurdle Consulting for review and consultation on this manuscript and Christer Eksvärd for statistical programming contributions. Please note that the Copyright holder for author Laura Mungapen is Pfizer Inc.

CONFLICT OF INTEREST

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. ACKNOWLEDGEMENTS
  8. CONFLICT OF INTEREST
  9. REFERENCES

Debra E. Irwin, Laura Mungapen, Ian Milsom and Penny Reeves are Paid Consultants to Sponsor. Zoe Kopp is an Employee of Sponsor. Ian Milsom is a member of international advisory Boards for Pfizer, Astellas and Novartis and has participated in clinical trials for Astellas and Pfizer, the department where he works has received research grants from Pfizer and Astellas, and he has been a Lecturer for Pfizer, Astellas and Novartis. Source of funding: Pfizer, Inc.

REFERENCES

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. ACKNOWLEDGEMENTS
  8. CONFLICT OF INTEREST
  9. REFERENCES