National trends in neuromodulation for urinary incontinence among insured adult women and men, 2004-2013: the Urologic Diseases in America Project

Abstract

Objective:

To examine US trends in neuromodulation for urinary incontinence (UI) treatment from 2004-2013.

Methods:

This study utilized two data sources: the Optum^© de-identified Clinformatics® Data Mart Database for privately insured adults aged 18-64 years with a UI diagnosis (N≈40,000 women and men annually) and the Medicare 5% Sample for beneficiaries aged ≥65 years with a UI diagnosis (N≈65,000 women and men annually). We created annual cross-sectional cohorts and assessed prevalence of UI-related neuromodulation procedures among men and women separately from 2004-2013. Analyses were conducted overall and stratified by age, race/ethnicity, and geographic region.

Results:

Nearly all neuromodulation procedures occurred in outpatient settings. Sacral neuromodulation (SNM) procedures for UI in both women and men grew steadily from 2004-2013, with more procedures performed in women than men. Among women with UI, SNM prevalence grew from 0.1-0.2% in 2004 to 0.5-0.6% in 2013. Posterior tibial nerve stimulation (PTNS) experienced growth from 2011-2013. Chemodenervation of the bladder with onabotulinumtoxinA (BTX) combined with other injectable procedures (including urethral bulking) remained stable over time.

Conclusions:

From 2004-2013, SNM procedures remained relatively uncommon but increased consistently. PTNS experienced growth starting in 2011 when PTNS-specific insurance claims became available. BTX trends remain unclear; future studies should assess it separately from other injectable procedures. Neuromodulation has a growing role in UI treatment, and ongoing trends will be important to examine.

Introduction:

Since its introduction and adoption, neuromodulation has impacted the care of urinary incontinence (UI) and remains an important modality for the management of urgency incontinence. Therapeutic neuromodulation using chemical agents or electric stimuli is used to restore function and relieve symptoms resulting from a wide variety of disorders in appropriately selected patients.¹ These technologies are being utilized to improve urologic and colorectal conditions, in addition to a myriad of muscular and neurologic disorders.^2-6 Examining national trends in the utilization of UI-related neuromodulation procedures is critical as health care access, delivery, cost, safety, and outcomes are increasingly emphasized.

In the last two decades, the management of medically refractory OAB has been impacted by the introduction of three safe and effective minimally-invasive neuromodulation modalities, including sacral neuromodulation (SNM), posterior tibial nerve stimulation (PTNS), and chemodenervation of the bladder via onabotulinumtoxinA injection (BTX) of the detrusor.^{4, 7-9} Each of these procedures are included in the American Urological Association (AUA)/Society of Urodynamics, Female Pelvic Medicine, and Urogenital Reconstruction (SUFU) guidelines on overactive bladder¹⁰ and have been approved by the United States (US) Food and Drug Administration (FDA) for the treatment of OAB and other specific indications.

Despite the expanded role of neuromodulation in urology, the literature lacks a comprehensive assessment of recent trends in neuromodulation for UI treatment in the US. The Urological Diseases in America (UDA) project, a federally sponsored collaboration between the National Institutes of Diabetes and Digestive and Kidney Diseases, Social & Scientific Systems, and Johns Hopkins University, sought to address this knowledge gap by assessing multiple large administrative claims databases (https://www.niddk.nih.gov/about-niddk/strategic-plans-reports/urologic-diseases-in-america).¹¹ We describe findings from the UDA project to demonstrate the prevalence of neuromodulation for UI among insured adults in the US over a 10-year period.

Material and Methods:

Descriptions of the study populations and UDA methods have been published previously.¹² Briefly, this study utilized two data sources: 1) the Optum^© de-identified Clinformatics^® Data Mart Database (CDM) for privately insured adults aged 18-64 years with a UI diagnosis (N≈35,000 women and 5,000 men annually) and 2) the Centers for Medicare & Medicaid Services Medicare 5% Sample (henceforth referred to as “Medicare”) for beneficiaries aged ≥65 years with a UI diagnosis (N≈45,000 women and 20,000 men annually).¹³

Annual cohorts were created for each study year from 2004-2013. Eligible participants for each annual cohort were all CDM enrollees or Medicare fee-for-service beneficiaries who: 1) had a UI diagnosis, 2) resided in the US, 3) met the requisite age requirements as of January 1 of that year (18-64 years for CDM, ≥65 years for Medicare), and 4) had full and continuous enrollment in private insurance or Medicare for that year or until time of death. The Copernicus Group Independent Review Board^® designated this project exempt from review.

Diagnoses and procedures were identified using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and Current Procedural Terminology (CPT) codes. UI patients in a given calendar year were those with at least one Evaluation & Management claim at any time during that year with an ICD-9-CM diagnostic code indicative of UI (Supplementary Table 1).¹² UI patients were identified as having SNM, PTNS, or an injectable procedure during the year if a claim was identified with a qualifying procedural code (Supplementary Table 2) and a primary ICD-9-CM code for UI. Unfortunately, the UDA Annual Data Report, on which this manuscript is based, assessed injectable procedures with BTX and urethral bulking procedures combined.¹¹ BTX is considered a neuromodulation procedure while urethral bulking is not; urethral bulking procedures could not be removed for this manuscript.

Among each annual cohort, we calculated the prevalence of UI-related neuromodulation and injectable procedures. Regarding the reported percentage of UI patients with “any neuromodulation procedures” (annual prevalence), patients were only counted once per year even if they underwewnt a repeat procedure of the same or another type. Similarly, for the percentage of UI patients with a specific type of procedure (SNM, injectable, and PTNS), patients who underwent one or more of each procedure type in a year were counted as a single patient within that category. In these analyses, a patient would be counted within each procedure category that they underwent. For example, if a patient underwent a PTNS and SNM in the same year, they would be counted in the prevalence calculation for each of those categories for a given year, but only once for the prevalence calculation for any neuromodulation procedure. Of note, neuromodulation analyses were performed both including and excluding PTNS. Analyses including PTNS were conducted separately because the Centers for Medicare and Medicaid Services did not publish a Category 1 CPT code specific to PTNS until 2011. All analyses were stratified by sex and examined by age, geographic region, and service location (inpatient vs. ambulatory). Analyses were conducted in SAS 9.4. (SAS Institute, Inc., Cary, NC).

Results:

Study Population

The majority (70%) of female CDM enrollees were aged 45-64 years, 78% identified as non-Hispanic white, and approximately half (51%) resided in the South. Male CDM enrollees were slightly older (79% aged 45-64 years), but otherwise similar. Age distributions were similar for female and male Medicare beneficiaries (65% and 68% aged ≥75 years, respectively), as were racial/ethnic distributions (89% and 87% non-Hispanic white, respectively) and geographic distributions (41% and 42% residing in the South, respectively).

Neuromodulation Procedures

Nearly all neuromodulation procedures were performed in an outpatient setting. Overall, neuromodulation procedures were more common among women than among men. This trend held for injectables as well, regardless of whether PTNS was included (Figures 1a-b) or excluded (Figures 1c-d).

Figure 1.

Prevalence of neuromodulation procedures* among UI patients, stratified by gender, 2004-2013

* Only includes procedures with a primary diagonsis of urinary incontinence.

† Data Source:Optum© De-indentified clinformatics® Data Mart (ages=18-64),2004-2013. Enrollees had full enrollement in commericial health plan during each year.

‡ Data source:Centers for Medicare and Medicaid Services, Medicare 5% Sample(ages 65+),2004-2013. Beneficiaries are age 65 years and over with continuous and full Part A and B enrollement and no HMO enrollement during each year.

UI urinary incontienece.

Sacral Neuromodulation

Excluding PTNS, the prevalence of SNM procedures among women was low but increased steadily from 2004-2013 (Figure 1). The prevalence grew from 0.1% in 2004 to 0.5% in 2013 among CDM enrollees and from 0.2% in 2004 to 0.6% in 2013 among Medicare beneficiaries. Among CDM enrollees, the 55-64 year age group experienced the most consistent increase in prevalence over the study period (Figure 2b). Among Medicare beneficiaries, SNM procedures were primarily performed among women aged 65-79 years (Figure 3b). A higher prevalence of SNM procedures was observed among privately insured women in the Midwest (Figure 2c) and among female Medicare beneficiaries in the South (Figure 3c).

Figure 2.

Neuromodulations* excluding office-based PTNS procedures among female UI patients in Optum© De-identified Clinformatics® Data Mart, a) overall, and stratified by b) age and c) geographic region, 2004-2013†

* Only includes procedures with a primary diagonsis of urinary incontinence.

† Data Source:Optum© De-indentified clinformatics® Data Mart (ages=18-64),2004-2013. Enrollees had full enrollement in commericial health plan during each year.

PTNS,perctaneous tibial nerve stimulation;UI urinary incontienece.

Figure 3.

Neuromodulations* excluding office-based PTNS procedures among female Medicare UI patients, a) overall, and stratified by b) age and c) geographic region, 2004-2013†

* Only includes procedures with a primary diagonsis of urinary incontinence.

† Data source:Centers for Medicare and Medicaid Services, Medicare 5% Sample(ages 65+),2004-2013. Beneficiaries are age 65 years and over with continuous and full Part A and B enrollement and no HMO enrollement during each year.

PTNS,perctaneous tibial nerve stimulation;UI urinary incontienece.

Excluding PTNS, the prevalence of SNM procedures among male CDM enrollees dropped from 0.4% in 2004 to 0.1% in 2006 and then increased back to 0.4% by 2013 (Figure 1). Among male Medicare beneficiaries, SNM prevalence increased steadily over the study period, from 0.1% in 2004 to 0.4% in 2013.

Posterior Tibial Nerve Stimulation

Including PTNS with SNM procedures increased neuromodulation prevalence among women with UI. From 2011 to 2013, neuromodulation prevalence including PTNS increased from 0.5% to 0.8% among CDM enrollees and from 0.8% to 1.0% among Medicare beneficiaries (Supplementary Figures 1a and 2a).

Similarly, among men with UI, the prevalence of neuromodulation procedures including office-based PTNS procedures increased from 2011 to 2013 (Figure 1), rising from 0.4% to 0.7% among CDM enrollees and from 0.6% to 0.7% among Medicare beneficiaries.

Injectables

Among both CDM enrollees and Medicare beneficiaries with UI, the utilization of injectable procedures for UI remained relatively stable from 2004-2013, with a prevalence of ~1% for women and ~0.5% for men across the study period. Among women with UI, injectable prevalence was highest among CDM enrollees aged 55-64 years and Medicare beneficiaries aged 65-79. Little variation by age was observed among men with UI in either data source.

Comment:

We used two large administrative claims databases to examine national trends in the use of neuromodulation procedures among women and men with UI in the US from 2004-2013. Our findings are highly relevant given that health care access, utilization, and cost are increasingly important. Despite neuromodulation procedures being a widely-accepted treatment option that is supported as a 3^rd line therapy in the OAB guidelines, the prevalence of SNM for treatment of UI in both men and women was very low (≤1%) across all age cohorts. Although the use of this procedure increased over the time period examined, our findings point to potential opportunities for increasing its utilization for appropriate patients and the importance of continuing to monitor these trends over time. PTNS also experienced growth since its introduction in 2011, while BTX combined with urethral bulking remained stable.

SNM is a well-accepted third line treatment for OAB, non-obstructive idiopathic urinary retention, and fecal incontinence that has been FDA approved for urge urinary incontinence (UUI) since 1997. The increase in SNM use is likely reflective of its increasing acceptance as a treatment modality for medically refractory UUI. Other studies regarding SNM procedures (excluding PTNS) have also revealed increased utilization over time. One study that used the State Ambulatory Surgery Database from Florida showed increasing SNM rates from 2002 to 2009, with the majority of SNM surgeries performed for OAB without UUI.¹⁴ Another study of Medicare beneficiaries with an indication of any urologic condition showed a significant increase in SNM procedures from 2001-2010 and that SNM procedures were more common among beneficiaries who were female, White, younger than 65 years, and living outside the western US.¹⁵ A study of UI surgeries from 2000-2012 showed that the increase of BTX and SNM procedures corresponded to a decrease in bladder augmentation surgery.¹⁶

Many factors affect trends in SNM surgical management and may contribute to SNM utilization being <1% among patients with UI. UI is a common and broad diagnosis, and there is not a single treatment modality that is appropriate for all patients. UI is also frequently underdiagnosed and those who are diagnosed may be undertreated.^{17, 18} For those who are diagnosed, conservative approaches such as fluid and behavioral modifications and pelvic floor physical therapy are often the first line therapy and may help manage symptoms.¹⁸ Second line therapies in the form of medications are effective in a proportion of patients as well.¹⁸ Additionally, there is likely limited awareness of SNM among the public, and surgeons and other physicians are generally the gatekeepers of OAB/UI surgical management options. Case logs from the American Board of Urology (ABU) between 2003-2012 indicated that only 12% of ABU-certified urologists performed SNM or augmentation cystoplasty for the treatment of refractory OAB,¹⁹ suggesting a potential need to improve patient access to subspecialists who perform these procedures. Other barriers to SNM therapy may be patient preference, cost of the therapy, and/or perceptions about efficacy, complexity, and the role of neuromodulation in the management of OAB.

We also observed that PTNS utilization increased from 2011-2013. The US FDA cleared PTNS for treatment of urinary frequency, urinary urgency, and UUI in 2011, and a category I CPT code was approved by the Centers for Medicare and Medicaid Services effective January 1, 2011. PTNS is an office-based procedure in which the posterior tibial nerve is accessed using a 34-gauge acupuncture-like needle; electrical stimulation is then applied for 30 minutes per week for 12 consecutive weeks. Patients who respond to this treatment can continue with maintenance treatments every 3-4 weeks. It is important to bear in mind that the growth in absolute number of PTNS procedures we observed in later years should be interpreted with the knowledge that each patient who is treated with PTNS has repetitive procedures, typically ranging from 1 to 12 or more treatments. Nevertheless, the increasing prevalence of UI patients undergoing neuromodulation procedures (SNM and/or PTNS) suggests that this finding reflects an actual increase in PTNS utilization. Increasing use of PTNS may be attributable to the procedure’s low risk profile, minimally invasive nature, and patient interest in this modality. However, studies examining real world settings have shown that non-compliance with PTNS has been associated with lack of efficacy.²⁰

Utilization of injectable procedures for UI remained steady, albeit uncommon, during the study period. BTX gained FDA approval for neurogenic bladder in 2011 and for idiopathic OAB in 2013.²¹ Consequently, while this analysis captures BTX procedures, we can only demonstrate the beginning of the trend in BTX utilization. It is also important to take note that, in this analysis, “injectable procedures” included both BTX and urethral bulking injection therapy. While the former is used for OAB treatment, the latter is used for stress urinary incontinence, which is a completely different type of urinary leakage. While the explanation for the steady trend in utilization that we observed remains unclear, it is possible that BTX procedures increased while urethral bulking procedures decreased, which would result in the reported combined prevalence remaining stable. Alternatively, both urethral bulking and BTX procedures may have remained stable during this time period, but that BTX utilization had not yet gained momentum during the time frame of this analysis. Additionally, if the primary diagnosis was coded as neurogenic bladder rather than UI, the BTX procedure would not have been captured in this analysis, thus underestimating the utilization of BTX through the omission of neurogenic bladder patients with UI. We acknowledge that the inclusion of the urethral bulking CPT code in the analysis clouds the interpretation of the treatment trends, but ultimately decided it was better to include this data than exclude it altogether. Future studies should examine these procedure-specific trends separately, and BTX trends after 2013 should be assessed.

Our study was not without other limitations. While the objective of this study was to assess trends in neuromodulation treatment for UI specifically, SNM is also used to treat other urologic conditions, including OAB with or without UUI, urinary retention, and fecal incontinence. Given that OAB without UUI may be the most common diagnosis for which SNM is performed,¹⁴ this data may underestimate the utilization of SNM given that patients with OAB without UUI would not be captured using this methodology. Additionally, it should be noted that the neuromodulation procedures identified could have been associated with any UI code (i.e. stress, mixed, urgency, or other UI); UUI codes were not uniquely linked with SNM and PTNS procedures. Further, the lack of racial/ethnic diversity in our UI patient population precluded observation of meaningful racial/ethnic variation in neuromodulation use.

Additionally, the UDA project did not assess PTNS prevalence separately from other neuromodulation modalities due to the lack of available data on PTNS prior to 2011. Consequently, we were unable to disentangle the prevalence of PTNS procedures from the prevalence of SNM procedures. Nevertheless, our study does demonstrate an increase in neuromodulation prevalence from 2011-2013 when PTNS procedures began to be included. Given that there are three FDA approved guidelines-based neuromodulation procedures, we decided to present the data on all three procedures (BTX, SNM, PTNS) and acknowledge the limitations of the data. Future studies should estimate PTNS prevalence separately from that of SNM procedures in order to assess the growth of this increasingly popular procedure.

Our study is also vulnerable to the limitations inherent to claims data. For example, not all neuromodulation-related CPT codes currently available indicate with certainty that the full neuromodulation process occurred. There are two methods by which SNM may be tested prior to placement. Percutaneous nerve evaluation (PNE) consists of placement of a temporary test lead in the office or ambulatory surgical center (64561) followed by full surgical implantation of the permanent lead and implantable pulse generator (IPG) (64581 and 64590). The staged procedure consists of lead placement (64581) and subsequent IPG placement (64590) after a 1-2 week test period. Consequently, SNM utilization may be overestimated if some patients undergo PNE or lead placement without subsequent IPG implantation.

Despite these potential limitations, our study had several notable strengths. Use of two large health claims databases allowed us to examine treatment patterns for a large number of UI patients in the US population with geographic and age diversity over a ten year time period. Our study provides utilization patterns of three neuromodulation treatments (SNM, PTNS, and BTX), which are currently guideline-recommended third line therapy options for OAB/UUI.¹⁰

Conclusions:

Although the prevalence of SNM procedures among UI patients remained low from 2004-2013, a notable increase was observed over this time period. A growth in PTNS was demonstrated starting in 2011. While overall injectable treatments remained stable, the trend specifically related to BTX remains unclear. The application of neuromodulation procedures has changed the landscape of UI treatment, and it is anticipated that neuromodulation will continue to favorably impact the therapeutic armamentarium for the treatment of UI among both women and men in the US.