Trends in the Utilization of Minimally Invasive Therapies for Overactive Bladder Among Older Adults: A National Medicare Study

ABSTRACT

Objective

To examine population-based trends in utilization of minimally invasive therapies (MITs) for overactive bladder (OAB) stratified by age and frailty among Medicare beneficiaries.

Methods

This population-based study used a 20% sample of fee-for-service Medicare beneficiaries to investigate rates of utilization for MIT for OAB [onabotulinumtoxinA injections (BTX), percutaneous tibial nerve stimulation (PTNS), and sacral neuromodulation (SNM)] from 2015 to 2020. Adjusted incidence rates of each MIT were further stratified by age and frailty, measured by the Claims-based Frailty Index (CFI), using multivariable logistic regression.

Results

Among 5,944,458 beneficiaries, 39,211 (0.7%) underwent an MIT for OAB during the study period. Overall adjusted incidence increased from 141.2 per 100,000 in 2015-159.3 per 100,000 in 2019 (a 13% relative increase), driven largely by BTX (40% relative increase). Incidence decreased across all MITs in 2020. Among beneficiaries aged 66-84, greater levels of frailty were associated with higher use of all 3 therapies. However, this association was not observed in beneficiaries over age 85, where rates of use were uniformly low regardless of frailty status.

Conclusion

Use of MITs for OAB increased from 2015 to 2019, mainly driven by increases in BTX. For all 3 types of MITs, greater levels of frailty were associated with increased utilization among beneficiaries <85 years, regardless of age, while rates for all 3 procedures were low regardless of frailty for beneficiaries ≥85, indicating that utilization of these procedures is driven more by age than frailty in the oldest age group. Further research is needed to determine the factors which influence MIT utilization rates.

Older and frail adults are disproportionately affected by overactive bladder (OAB), yet they are also the patients most vulnerable to the potential harms of systemic pharmacotherapy. Minimally invasive therapies (MITs)—including intravesical onabotulinumtoxinA injections (BTX), posterior tibial nerve stimulation (PTNS), and sacral neuromodulation (SNM)—avoid the systemic anticholinergic burden of oral pharmacotherapy, and therefore have side-effect profiles that may be particularly well suited to older and frail patients. Emerging evidence, drawn largely from observational claims-based cohorts, suggests that older and frail adults undergoing MIT achieve procedural outcomes and treatment persistence comparable to those of younger, healthier patients.^1,2 While high-quality studies comparing efficacy down to symptom-level effects are scarce, MITs remain, in principle, attractive options for older and frail adults.

The rate at which older adults are receiving these therapies, however, is unknown. MIT utilization among Medicare beneficiaries—a group which is disproportionately burdened by OAB—has not been established. Understanding utilization in this population is important because clinical decision-making in older adults is shaped by both chronological age and frailty. Since frailty is increasingly recognized as a stronger predictor of postprocedural outcomes than age,^3–5 there is concern that clinicians may withhold MITs based on age alone, potentially under-treating robust older adults who stand to benefit. Characterizing the relative contributions of age and frailty to MIT utilization is therefore essential to identify whether current patterns reflect age-friendly, frailty-informed care.

To address this knowledge gap, we conducted a cross-sectional study using a 20% random sample of all fee-for-service Medicare beneficiaries from 2015 to 2020. Adjusted utilization rates for each procedure (BTX, PTNS, SNM) were calculated and further stratified by frailty and age. These findings document real-world trends in utilization of MITs for OAB in older adults with and without frailty, and provide a baseline for understanding future trends.