Cost-effectiveness analysis of extended-release formulations of oxybutynin and tolterodine for the management of urge incontinence

GetReal in mathematical modelling: a review of studies predicting drug effectiveness in the real world

The performance of a drug in a clinical trial setting often does not reflect its effect in daily clinical practice. In this third of three reviews, we examine the applications that have been used in the literature to predict real‐world effectiveness from randomized controlled trial efficacy data. We searched MEDLINE, EMBASE from inception to March 2014, the Cochrane Methodology Register, and websites of key journals and organisations and reference lists. We extracted data on the type of model and predictions, data sources, validation and sensitivity analyses, disease area and software. We identified 12 articles in which four approaches were used: multi‐state models, discrete event simulation models, physiology‐based models and survival and generalized linear models. Studies predicted outcomes over longer time periods in different patient populations, including patients with lower levels of adherence or persistence to treatment or examined doses not tested in trials. Eight studies included individual patient data. Seven examined cardiovascular and metabolic diseases and three neurological conditions. Most studies included sensitivity analyses, but external validation was performed in only three studies. We conclude that mathematical modelling to predict real‐world effectiveness of drug interventions is not widely used at present and not well validated. © 2016 The Authors Research Synthesis Methods Published by John Wiley & Sons Ltd.

Cost effectiveness of mirabegron compared with tolterodine extended release for the treatment of adults with overactive bladder in the United Kingdom

BACKGROUND

Overactive bladder (OAB) is highly prevalent and is associated with considerable morbidity and reduced health-related quality of life. β3-adrenergic receptor (β3-AR) stimulation is a novel alternative to antimuscarinic therapy for OAB.

OBJECTIVE

The objective of this analysis was to assess the cost effectiveness of the β3-AR agonist mirabegron relative to tolterodine extended release (ER) in patients with OAB from a UK National Health Service (NHS) perspective.

METHODS

A Markov model was developed to simulate the management, course of disease, and effect of complications in OAB patients over a period of 5 years. Transition probabilities for symptom severity levels and probabilities of adverse events were estimated from the results of the randomised, double-blind SCORPIO trial in 1,987 patients with OAB. Other model inputs were derived from the literature and on assumptions based on clinical experience.

RESULTS

Total 5-year costs per patient were £1,645.62 for mirabegron 50 mg/day and £1,607.75 for tolterodine ER 4 mg/day. Mirabegron was associated with a gain of 0.009 quality-adjusted life-years (QALYs) with an additional cost of £37.88. The resulting incremental cost-effectiveness ratio (ICER) was £4,386/QALY gained. In deterministic sensitivity analyses in the general OAB population and several subgroups, ICERs remained below the generally accepted willingness-to-pay (WTP) threshold of £20,000/QALY gained. The probability of mirabegron 50 mg being cost effective relative to tolterodine ER 4 mg was 89.4 % at the same WTP threshold.

CONCLUSIONS

Mirabegron 50 mg/day is likely to be cost effective compared with tolterodine ER 4 mg/day for adult patients with OAB from a UK NHS perspective.

Cost-effectiveness of a fixed-dose combination of solifenacin and oral controlled adsorption system formulation of tamsulosin in men with lower urinary tract symptoms associated with benign prostatic hyperplasia

BACKGROUND

Storage symptoms, associated with benign prostatic hyperplasia (BPH), often co-exist with voiding symptoms in men with lower urinary tract symptoms (LUTS). Storage symptoms are likely to be most bothersome, and may not be adequately resolved by treatment with α-blocker or antimuscarinic monotherapy. A recent randomised controlled phase 3 trial (NEPTUNE) demonstrated that a fixed-dose combination (FDC) of solifenacin 6 mg plus an oral controlled absorption system (OCAS™) formulation of tamsulosin (TOCAS, 0.4 mg) improved storage symptoms, as well as quality of life, compared with TOCAS alone in men with moderate-to-severe storage symptoms and voiding symptoms. This analysis aimed to assess the cost-effectiveness of a FDC tablet of solifenacin 6 mg plus TOCAS relative to tolterodine plus tamsulosin given concomitantly, from the perspective of the UK National Health Service (NHS).

METHODS

A Markov model was developed for men aged ≥45 years with LUTS/BPH who have moderate-to-severe storage symptoms and voiding symptoms. The model calculated cost-effectiveness over an analytical time horizon of 1 year and estimated total treatment costs, quality adjusted life years (QALYs) and incremental cost-effectiveness ratio.

RESULTS

The FDC tablet of solifenacin 6 mg plus TOCAS was associated with lower total annual costs (£860 versus £959) and increased QALYs (0.839 versus 0.836), and was therefore dominant compared with tolterodine plus tamsulosin. Time horizon, discontinuation or withdrawal rates, drug cost and utility values were the main drivers of cost-effectiveness. The probability that the FDC tablet of solifenacin 6 mg plus TOCAS is cost-effective was 100% versus tolterodine plus tamsulosin, at a willingness-to-pay threshold of £20,000/QALY gained.

CONCLUSIONS

The FDC tablet of solifenacin 6 mg plus TOCAS provides important clinical benefits and is a cost-effective treatment strategy in the UK NHS compared with tolterodine plus tamsulosin for men with both storage and voiding LUTS/BPH.

Cost effectiveness of fesoterodine and tolterodine for the treatment of overactive bladder with urge urinary incontinence in Spain and Finland

BACKGROUND

Overactive bladder is a prevalent condition worldwide that is associated with a considerable burden, both on the patient and on society.

OBJECTIVE

Our objective was to assess the economic value of fesoterodine compared with tolterodine extended release (ER) for the treatment of overactive bladder (OAB) with urge urinary incontinence (UUI) in Spain and Finland.

METHODS

A decision-tree economic model estimated the 52-week costs and quality-adjusted life-years (QALYs) of OAB/UUI patients initiating treatment with fesoterodine 4 mg/day or tolterodine ER. Individuals were evaluated for treatment response (UUI fewer than one episode/day) and persistence at weeks 4, 12, and 24. Titration from fesoterodine 4 mg/day to 8 mg/day was permitted at week 4. At week 12, non-responders discontinued treatment permanently. Efficacy, discontinuation, and utility data were derived from four clinical trials of fesoterodine. OAB-related costs, including physician visits, laboratory tests, incontinence pads, and comorbidities (fracture, skin infection, urinary tract infections, depression, and nursing home) were also included.

RESULTS

A total of 19.5 % and 18.0 % of fesoterodine and tolterodine ER patients remained on treatment until week 52, respectively. QALYs were higher with fesoterodine than tolterodine ER (0.762 vs. 0.760). In Spain, fesoterodine treatment had higher total costs than (generic) tolterodine ER (€6,697 vs. 6,597), resulting in a cost of €15,633/QALY gained. In Finland, fesoterodine was cost saving relative to (non-generic) tolterodine ER (€7,885 vs. 8,024). Sensitivity analysis confirmed that these findings were robust to the expected price decrease for generic tolterodine ER in Finland.

CONCLUSION

Fesoterodine is cost effective or cost saving relative to tolterodine ER for the treatment of OAB with UUI in two European countries. Payers and prescribers should consider a broad scope of costs to make informed cost-conscious choices of antimuscarinic treatment.

Cost-effectiveness analysis of anti-muscarinic agents for the treatment of overactive bladder

OBJECTIVE

To determine the cost-effectiveness of pharmacologic treatments for overactive bladder (OAB) in the US.

METHODS

A decision model was constructed based on studies of effectiveness, adverse consequences, co-morbid conditions, and medical costs for the treatment of OAB. Treatment success was defined as no incontinence episodes for 3-7 days or 3-7 consecutive dry days. Estimates of treatment success were obtained from clinical trials and included darifenacin, fesoterodine, oxybutynin immediate release (IR), oxybutynin extended release (ER), oxybutynin topical gel, oxybutynin transdermal patch, solifenacin, tolterodine IR, tolterodine ER, trospium IR, and trospium ER. Probabilistic sensitivity analysis was conducted using Monte Carlo simulation.

RESULTS

A total of 51 OAB studies were identified and 11 reported treatment success. Mean continence rates varied in the literature from 21.0% with trospium IR to 51.0% with solifenacin. The 95% CI for solifenacin's success rate was statistically higher than other regimens due to the higher continence rates from the clinical trials. Oxybutynin IR and oxybutynin ER were significantly less costly than other products. The product with the lowest incremental cost-effectiveness ratio (ICER) relative to oxybutynin IR was solifenacin at $1338 (± 168) per additional continent patient. The cost-effectiveness acceptability curve indicated that oxybutynin IR was the most cost-effective regimen when willingness-to-pay values were less than $10,000 per additional continent patient. Solifenacin was most cost-effective at higher willingness-to-pay values.

CONCLUSION

There was broad overlap in effectiveness among the anti-muscarinic products, except solifenacin had a significantly higher continence rate. Oxybutynin IR and oxybutynin ER were significantly less costly than other anti-muscarinic regimens, and these two products have a useful role to play in the management of OAB. However, for patients unable to tolerate the lower cost products, formularies benefit from solifenacin among branded products since the cost-effectiveness acceptability curve demonstrated it was the product most likely to be cost-effective after oxybutynin IR.

Overactive Bladder Syndrome: The Social and Economic Perspective

Overactive bladder syndrome (OAB) is a highly prevalent condition associated with a significant impairment of patients’ Quality of Life (QoL) because of its adverse effects on social, sexual, interpersonal, and professional functions. Cost-of-illness analyses showed the huge economic burden related to OAB for patients, public healthcare systems, and society, secondary to both direct and indirect costs. These types of cost analyses, however, exclude intangible costs related to QoL impairment. Recently, many novel therapies have been introduced, arising the need to apply the modern methodology of Health Technology Assessment (HTA) to new therapies in order to evaluate objectively their value in terms of both improvement in length/Quality of Life and costs. By producing information on the clinical, economic, organizational, social and ethical impact of health technologies, HTA has been used worldwide to inform decision makers at different levels in health systems. The HTA approach demonstrated, worldwide, to be a useful approach to increase the level of appropriateness in the use of medical technology and, as a consequence of that, of resources. Health utilities are instruments that allow a measurement of QoL and its integration in the economic evaluation using the Quality-of-life-Adjusted-Life-Years (QALYs) model and cost-utility analysis. The development of suitable instruments for quantifying utility in the specific group of OAB patients is vitally important to extend the application of cost-utility analysis in OAB and to guide healthcare resources allocation for this disorder. Studies are required to define the cost-effectiveness of available pharmacological and non-pharmacological therapy options.

Persistence and adherence in the treatment of overactive bladder syndrome with anticholinergic therapy: a systematic review of the literature

Overactive bladder syndrome (OAB) is a chronic condition that has an impact on patients' daily activities and health-related quality of life (HRQL). Anticholinergic therapy is often prescribed following insufficient results with behaviour modification alone; however, rates of treatment discontinuation are consistently high. This study systematically reviewed persistence and adherence data in patients with OAB treated with anticholinergic therapy. A search focused on the intersection of OAB, persistence/adherence, and anticholinergic therapy was conducted in MEDLINE and EMBASE. Articles published after 1998 were reviewed and selected for inclusion based on prespecified criteria. A total of 147 articles and two abstracts were included in the review. Results from 12-week clinical trials showed high rates of discontinuation, ranging from 4% to 31% and 5% to 20% in treatment and placebo groups, respectively. Unsurprisingly, rates of discontinuation found in medical claims studies were substantially higher, with 43% to 83% of patients discontinuing medication within the first 30 days and rates continuing to rise over time. Findings from medical claims studies also suggest that over half of patients never refill their initial prescription and that adherence levels tend to be low, with mean/median medication possession ratio (MPR) values ranging from 0.30 to 0.83. The low levels of persistence and adherence documented in this review reveal cause for concern about the balance between the efficacy and tolerability of anticholinergic agents. Strategies should be identified to increase persistence and adherence. New agents and non-pharmacologic alternatives with good efficacy and minimal side effects should be explored.

Social, economic, and health utility considerations in the treatment of overactive bladder

Overactive bladder (OAB) is a highly prevalent urinary syndrome with a profound impact on quality of life (QoL) of affected patients and their family because of its adverse effects on social, sexual, interpersonal, and professional function. Cost-of-illness analyses showed the huge economic burden related to OAB for patients, public healthcare systems, and society, secondary to both direct and indirect costs; however, intangible costs related to QoL impact are usually omitted from these analyses. Recently many novel treatment modalities have been introduced and the need to apply the modern methodology of health technology assessment to these treatment strategies was immediately clear in order to evaluate objectively their value in term of both improvement in length/quality of life and costs. Health utilities are instruments that allow a measurement of QoL and its integration in the economic evaluation using the quality-adjusted life-years model and cost-utility analysis. The development of suitable instruments for quantifying utility in the specific group of OAB patients is vitally important to extend the application of cost-utility analysis in OAB and to guide healthcare resources allocation for this disorder. Studies are required to define the cost-effectiveness of available pharmacological and nonpharmacological therapy options for this disorder.

Social, economic, and health utility considerations in the treatment of overactive bladder

Overactive bladder (OAB) is a highly prevalent urinary syndrome with a profound impact on quality of life (QoL) of affected patients and their family because of its adverse effects on social, sexual, interpersonal, and professional function. Cost-of-illness analyses showed the huge economic burden related to OAB for patients, public healthcare systems, and society, secondary to both direct and indirect costs; however, intangible costs related to QoL impact are usually omitted from these analyses. Recently many novel treatment modalities have been introduced and the need to apply the modern methodology of health technology assessment to these treatment strategies was immediately clear in order to evaluate objectively their value in term of both improvement in length/quality of life and costs. Health utilities are instruments that allow a measurement of QoL and its integration in the economic evaluation using the quality-adjusted life-years model and cost-utility analysis. The development of suitable instruments for quantifying utility in the specific group of OAB patients is vitally important to extend the application of cost-utility analysis in OAB and to guide healthcare resources allocation for this disorder. Studies are required to define the cost-effectiveness of available pharmacological and nonpharmacological therapy options for this disorder.

The economic value of reducing medication dosing frequency with drug delivery technologies: an evidence assessment

OBJECTIVE

To critically evaluate published cost-effectiveness studies of novel drug products requiring less-frequent medication dosing compared to conventional formulations of the same drug substance.

METHODS

A search was conducted in the Medline and Embase databases for cost-effectiveness studies published before May 2009 that compared two or more drug delivery technologies formulated with the same active drug substance. The Quality of Health Economic Studies (QHES) grading criteria for cost-effectiveness studies was applied to the selected publications.

RESULTS

The literature search identified approximately 907 articles of which six cost-effectiveness studies met the inclusion criteria. The studies spanned four chronic conditions, were conducted from various international perspectives and used decision-analytic models to project economic outcomes. The base-case results of all six studies indicated that the drug product with sustained therapeutic efficacy was either more effective and less costly ('dominant') or more cost effective than the conventional formulation of the same drug substance. Quality scores ranging from 70 to 84 (scale 0 to 100) were assigned to the studies, with a mean of 78.

LIMITATIONS

This review likely did not capture all relevant drug delivery technologies and drug products. Only one reviewer critically evaluated the cost-effectiveness studies and independently assigned quality scores using the QHES grading criteria, which may be limited in its ability to identify poorly analyzed studies.

CONCLUSION

Evaluation of the published literature suggests that drug products with less-frequent medication dosing can be cost effective when compared to conventional formulations, but assessments are challenging because of complex relationships among therapeutic drug levels, dosing frequency, medication adherence, and health outcomes. Additional product-specific, comparative, pragmatic studies in this area are needed.

Oxybutynin extended release for the management of overactive bladder: a clinical review

Overactive bladder (OAB) is a common condition which negatively impacts the quality of life of afflicted patients. This can result in alterations in social interactions at home, in the workplace and in the community, often leading to depression and poor self esteem as well as loss of productivity. Traditional mainstays of treatment include both behavioral therapy and pharmacotherapy. Oxybutynin immediate release (IR) represents the first such medication approved by the FDA specifically for treatment of OAB in 1975. Nevertheless, bothersome side effects in addition to thrice daily dosing often led to treatment cessation which raised the question that patients may actually prefer to live with their OAB symptoms rather than incur side effects or complex dosing schemes. Pharmacological advances ultimately led to development of a long-acting formulation of oxybutynin in the form of oxybutynin extended release (ER) with the hope that this drug would maintain efficacy while decreasing bothersome side effects and improve compliance with the convenience of once daily dosing regimen. This paper will review the major clinical studies involving oxybutynin ER as well as its role in different patient populations and potential concerns with its use.

Methods for integrating medication compliance and persistence in pharmacoeconomic evaluations

OBJECTIVES

Suboptimal compliance and failure to persist with drug treatments are important determinants of therapeutic nonresponse and are of potential economic significance. The present article aims to describe the methodologies that may be appropriate for integrating noncompliance and nonpersistence in economic evaluations.

METHODS

MEDLINE and NHS-EED were searched for economic evaluations published in the period between 1997 and 2005. Articles were included if they explored the dependence of cost-effectiveness results on varying levels of some form of compliance-related measure. The different methodologies used were reviewed and articles were appraised critically. Alternative methodological approaches are proposed, illustrated by an example of the impact of different persistence rates on a treatment's cost-effectiveness.

RESULTS

Ten articles were selected for inclusion. These were generally scant on detail relating to how compliance/persistence was assessed and what the impact was on health outcomes. The methods used included Markov models and decision analyses. Markov models allow for persistence to be included directly in the analysis, as patients transit during each cycle. Net-benefit regression models are well suited for analyzing prospective and retrospective studies where patient-level data are available, whereas discrete event simulations have the potential to offer more flexibility.

CONCLUSIONS

Compliance and/or persistence are not included routinely in pharmacoeconomic analyses, despite their potential impact. Where compliance and/or persistence are included, a lack of methodological rigor and consistency in definitions often limits the usefulness of the analyses. The analytical techniques discussed in this article should serve as a basis for developing guidelines on appropriate methodology.

Pharmacoeconomic evaluation of antimuscarinic agents for the treatment of overactive bladder

STUDY OBJECTIVE

To compare the cost-effectiveness of various antimuscarinic agents for the treatment of overactive bladder (OAB).

METHODS

A decision-analysis model was developed and included clinical outcomes (i.e., therapy continued or discontinued, treatment success or failure, OAB-induced comorbidities) and costs for drugs and treatment of OAB-induced comorbidities (i.e., urinary tract infections, fractures, depression, and skin infections). Treatment success was defined as complete continence. A systematic MEDLINE literature search from January 1990-January 2006 identified English-language articles concerning the eight antimuscarinic drugs: darifenacin, solifenacin, trospium, immediate-release oxybutynin, extended-release oxybutynin, transdermal oxybutynin, immediate-release tolterodine, and extended-release tolterodine. Probabilities and cost data for these drugs were retrieved from the literature, and drug costs were based on 2005 average wholesale prices. The analysis was constructed from a payer's perspective. The time frame for the model was 3 months.

RESULTS

Expected costs for each patient with OAB ranged from $3373 when treated with solifenacin to $3769 when treated with immediate-release oxybutynin. The average cost/patient with continued and successful treatment was lowest for solifenacin ($6863). Solifenacin dominated all other antimuscarinic agents because they were associated with high costs and low effectiveness. Success rates were the key parameters driving the sensitivity analysis.

CONCLUSION

Among various antimuscarinic agents, solifenacin 5 mg had the lowest costs and highest effectiveness in the treatment of OAB.

Urinary incontinence: economic burden and new choices in pharmaceutical treatment

In the year 2000, an estimated 17 million community-dwelling adults in the United States had daily urinary incontinence (UI), and an additional 33 million suffered from the overlapping condition, overactive bladder. Estimates of the total annual cost of these conditions range up to 32 billion US dollar; the largest components are management costs and the expenses associated with nursing home admissions attributable to UI. In most cases, patients with UI can be treated with pharmaceutical agents, in addition to behavioral therapy. Until recently, pharmaceutical therapy for UI has been limited, especially because the adverse effects of available agents resulted in poor adherence to treatment regimens. Recent innovations in molecular design and new dosage forms of UI medications offer the promise of fewer and less severe adverse effects and, thus, better treatment outcomes for patients. Additionally, the availability of multiple agents within a therapeutic class offers health care providers a spectrum of choices with which to personalize treatment for each individual patient. New pharmacologic treatment options for UI have the potential to allow greater independence for older persons who reside at home and to delay or avoid the costs of admission to long-term care facilities. Alternate dosage forms, which include patches and sustained-release formulations, may benefit patients who have difficulty chewing, swallowing, or remembering to take medications. Although these newer products are generally more expensive than older forms of therapy, they typically have more favorable cost-effectiveness ratios. Access to these new medications for patients enrolled in public and private health care plans may help to reduce the economic and social burden of UI care.

Cost implications of antimuscarinic drugs in the treatment of overactive bladder syndrome

Overactive bladder syndrome is highly prevalent, particularly among the elderly. As well as the consequent morbidity, such as urinary infections, skin irritation and bone fractures, almost all aspects of quality of life, personal and social, are influenced. Therefore, the associated cost is substantial. Pharmacotherapy with antimuscarinics is the mainstay of treatment. Because of the good balance between efficacy, safety and tolerability, these drugs seem to be cost-effective therapeutic modalities for overactive bladder. In the milieu of a constantly ageing population, rising demand for the treatment of health conditions and the need for rational use of healthcare resources, further studies with long-term antimuscarinic drug treatment and follow-up are needed to redefine their therapeutic value.

The overactive bladder: review of current pharmacotherapy in adults. Part 1: pathophysiology and anticholinergic therapy

Overactive bladder is a syndrome characterised by urinary urgency, with or without urge incontinence, and usually with frequency and nocturia. It affects millions of people of all ages worldwide and causes significant morbidity, especially in terms of health-related quality of life. It poses a huge economic burden on health resources. Managing such patients involves a thorough history, physical examination and the use of pertinent investigations before the initiation of treatment. Therapy consists of lifestyle changes, bladder training, anticholinergics, second-line agents such as resiniferatoxin instillation or botulinum toxin injections into the bladder in refractory cases and, finally, in intractable cases, surgery. In the first part of this review of pharmacotherapy for the treatment of this condition, the focus is on the pathophysiological factors potentially involved in overactive bladder and covers the wide range of currently available first-line anticholinergic agents. Treatment algorithms are suggested on the basis of current literature.

Drug delivery systems improve pharmaceutical profile and facilitate medication adherence

Innovations in dosage forms and dose delivery systems across a wide range of medications offer substantial clinical advantages, including reduced dosing frequency and improved patient adherence; minimized fluctuation of drug concentrations and maintenance of blood levels within a desired range; localized drug delivery; and the potential for reduced adverse effects and increased safety. The advent of new large-molecule drugs for previously untreatable or only partially treatable diseases is stimulating the development of suitable delivery systems for these agents. Although advanced formulations may be more expensive than conventional dosage forms, they often have a more favorable pharmacologic profile and can be cost-effective. Inclusion of these dosage forms on drug formulary lists may help patients remain on therapy and reduce the economic and social burden of care.

Outcomes associated with pharmacotherapy in overactive bladder

Overactive bladder is one of the most prevalent medical conditions in the USA. Prevalence rates of overactive bladder are higher in women and increase with advanced age. Although the disease is not associated with mortality, it has significant impact on health-related quality of life amongst patients. Pharmacologic, as well as behavioral treatment therapies, are available for overactive bladder treatment with pharmacologic agents being the mainstay therapy. The purpose of this review is to outline the recent developments in the treatment of overactive bladder. This is an extensive review that provides important information on the outcomes associated with different pharmacotherapeutic agents used in overactive bladder. It concludes with the authors' opinions and suggestions for the future research in this area.

Pharmacological management of overactive bladder : a systematic and critical review of published economic evaluations

Overactive bladder is a common condition, with recent findings estimating the prevalence in adults at about 15%. Symptoms, including urinary urgency, high voiding frequency and urge incontinence, have been shown to decrease patients' quality of life. Given its high prevalence, the economic burden of overactive bladder is also substantial, with a recent estimate placing the annual cost in the US at 9.1 billion US dollars (year 2000 values). The objective of this review is to provide a critical appraisal of published economic evaluations of pharmacological and non-pharmacological treatments for overactive bladder. Published economic evaluations of treatments for overactive bladder have focused entirely on pharmacological treatments -- mainly on the two most commonly used drugs, oxybutynin and tolterodine, each of which is available in immediate- and extended-release formulations. Ten economic evaluations (more than half are cost-effectiveness studies) have been published. Modelling with decision trees or Markov models has been the predominant method. Evaluations comparing drug therapy with no treatment have concluded that drug therapy is cost effective. Analyses comparing the formulations of oxybutynin and tolterodine have produced highly inconsistent results, largely due to the sources of data employed for effectiveness and treatment discontinuation rates. There are no evaluations of drugs relative to non-pharmacological treatment, and there are other significant gaps in the economic evaluations of treatment to date. These include gaps resulting from a lack of reliable data on the performance of these drugs in real-world settings, particularly data on long-term persistence with treatment. A more definitive pharmacoeconomic comparison of oxybutynin and tolterodine formulations, incorporating all available clinical data, and other treatment options would help direct treatment.