Frailty, Socioeconomics, and Specialist Access Drive Overactive Bladder Care Disparities - Ekene Enemchukwu
January 3, 2025
Ruchika Talwar interviews Ekene Enemchukwu about her Medicare-based study examining disparities in overactive bladder (OAB) treatment, particularly focusing on the utilization of beta-3 agonists versus anticholinergic medications. The research reveals that while frail and older adults are more likely to receive beta-3 agonists, aligning with current guidelines to avoid anticholinergics due to dementia risks, significant socioeconomic and racial disparities exist in medication access. The study finds that patients seeing urologists or gynecologists are twice as likely to receive beta-3 agonists, but high out-of-pocket costs present a major barrier, with beta-3 agonists costing significantly more than anticholinergics. While dual eligibility status and cost adjustments eliminate some racial disparities, Indigenous populations continue to face additional barriers. Dr. Enemchukwu emphasizes the importance of shared decision-making and considering alternative treatment options when cost barriers exist.
Biographies:
Ekene Enemchukwu, MD, MPH, FACS, FPMRS, Medical Director of Urology, Stanford Multidisciplinary Pelvic Health Center, Palo Alto, CA
Ruchika Talwar, MD, Assistant Professor of Urology, Urologic Oncologist, and Associate Medical Director in Population Health, Vanderbilt University Medical Center, Nashville, TN
Biographies:
Ekene Enemchukwu, MD, MPH, FACS, FPMRS, Medical Director of Urology, Stanford Multidisciplinary Pelvic Health Center, Palo Alto, CA
Ruchika Talwar, MD, Assistant Professor of Urology, Urologic Oncologist, and Associate Medical Director in Population Health, Vanderbilt University Medical Center, Nashville, TN
Read the Full Video Transcript
Ruchika Talwar: Hi, everyone. Welcome back to UroToday's Health Policy Center of Excellence. As always, my name is Ruchika Talwar, and I'm a urologic oncologist in Nashville, Tennessee. Today, I'm really excited to be joined by Dr. Enemchukwu, who is a female reconstructive urologist at Stanford. She recently published a study exploring the intersection of frailty, specialized care, and socioeconomic factors that potentially drive disparities in oral pharmacotherapy class utilization within our Medicare population, who's seeking care for overactive bladder. Really interesting study, significant health policy implications, and I'm really excited to have her share this work today. Thank you so much for taking the time to chat with us, Dr. Enemchukwu.
Ekene Enemchukwu: Thank you. Thanks for the invitation. Well, thanks so much for that introduction and also for the invitation. I'm Ekene Enemchukwu. I'm at Stanford, and I'm going to talk a little bit about OAB, frailty, and specialized care, sociodemographic disparities in oral pharmacotherapy. As we all know, OAB is a debilitating, distressing condition that's characterized by urgency, frequency, and urgency incontinence. It's a very costly condition, costing over $80 billion in direct and indirect costs annually, lots of negative impact on quality of life, and it significantly impacts adults over the age of 65.
So older adults, over 30%, are impacted by this for a number of reasons. And it's been confirmed on urodynamic studies. And frailty really adds another layer of complexity to this. These patients are often over the age of 65. They have reduced physiologic reserves. They develop frailty. And there are studies that have shown that frailty has a stronger association with OAB than age alone. And so the new AUA/SUFU guidelines are great in that they've revamped the way we treat patients or the way we discuss treating patients.
It's no longer a stepwise approach to therapy. Now it's more of a menu that you are discussing with the patient in a shared decision-making model. And so pharmacologic therapy obviously is still on that menu: beta-3 agonists and antimuscarinics. And the concern is that anticholinergics in older adults have been associated with conditions like cognitive conditions and also dementia. And so they're commonly prescribed for conditions like depression and OAB. And as we know, in older adults, they're more likely to have impairments in the blood-brain barrier.
And so the concern is with longer-term use that these changes may be permanent. And in some of our prior work, we have found that with long-term use, there's a 46% increased risk of incident dementia. In this study by Welk and colleagues, they found that between anticholinergics versus those using beta-3 agonists, there was a 23% increased risk of incident dementia in folks who were using anticholinergics.
And so our societies have all put out statements really emphasizing the importance of counseling patients, using beta-3 agonists or alternatives whenever possible. If we have to use anticholinergics, really using those that have a low propensity to cross the blood-brain barrier, avoiding short-acting medications, avoiding use of AUGS-recommending women over the age of 70, and really using procedures or advanced therapies when possible if we need to avoid adverse events.
And so our study—we were really interested in looking at, as Dr. Talwar mentioned earlier, the intersection between frailty and age and OAB therapy utilization. And we also thought it was really important to look at disparities based on other demographic factors. And so our primary outcome was a beta-3 agonist prescription claim during the study period. And so this was a retrospective study using a 20% random sample of the Medicare Fee-for-Service data between 2013 and 2018.
In this study, our study population were beneficiaries who were enrolled in parts A, B, and D. They all had to have OAB based on ICD-9 and 10 codes. They were all treated with an anticholinergic or beta-3 agonist using National Drug Codes, and they all had to have one year of continuous enrollment prior to the index date. We excluded those who had end-stage renal disease, urinary retention, or neurogenic bladder, and we used provider taxonomy to identify our provider types. We used a claims-based frailty index to categorize patients into not frail, prefrail, and frail. Then we used logistic regression to explore associations.
And so what we found—we had a cohort of over 700,000 beneficiaries that had OAB. Of those, about 16% were treated. The mean age was about 75, about 71% of those were female, 83% were non-Hispanic white, about 12% were considered frail, and almost 20% were dual eligible, which we used also as a surrogate for lower socioeconomic status.
And so, as you can see here, the majority of our treated cohort were prescribed or filled an anticholinergic prescription during the study period. And you can see that there's a significant difference in the median copay for these prescriptions. And so we were really interested in looking at the factors that were associated with beta-3 agonist claims. And we were pleasantly surprised to find that frail status was associated with a 16% higher odds of filling a mirabegron prescription, as was advancing age—a 25% higher odds—being from the South region versus the Midwest.
And if you were treated, or your prescription was prescribed, by a urologist or a gynecologist, you were almost two times more likely to have filled a mirabegron prescription. And if you were dual eligible, you were three times more likely to fill the prescription. But if you were Black or Indigenous, you were less likely to have filled a mirabegron prescription.
And so we wanted to better understand what was driving the sociodemographic disparities. And so we first started looking at our univariate model. And on that, we immediately saw that Hispanic, Black, and American Indian and Alaskan Natives were less likely to have a mirabegron prescription claim, whereas for Asian, there was no difference with white.
So we started to think about the things that might impact that, and we looked at out-of-pocket costs and dual eligibility. And when we adjusted for that, at that point, Asian race was more likely to fill a mirabegron prescription than white, and Hispanic showed no difference. But for Black and American Indian and Alaskan Native, it remained a lower odds.
So we removed dual eligibility to look just at out-of-pocket costs. And we were really surprised to find that the odds for Asian patients went up even more, as it did for Hispanic, and that there was no difference with Black beneficiaries anymore. But American Indian and Alaskan Native remained lower odds.
And so we started to think about what the implications of these findings are when we look at the racial and ethnic findings: certainly a lower likelihood of a beta-3 agonist prescription claim in this population. And when we adjust for cost, those disparities seem to disappear for most groups except for American Indian and Alaskan Native. And the thought there is that, at least a large barrier seems to be out-of-pocket costs, which is not surprising and is consistent with the literature.
But for our Indigenous populations, I think there are certainly other barriers that are keeping them from being able to fill these prescriptions, whether that's access or prescribing patterns and where they're able to seek care. When we adjusted for out-of-pocket costs and dual eligibility, though, we did see that there was a lower odds for Black and American Indian and Alaskan Native. And this is where it was a little bit more complicated. We started to think about what that might mean.
When we looked at those models, dual eligibility reduced the odds for all of the minority groups. And so the thought there is that there are other barriers, other than out-of-pocket costs, that are impacting these groups that may be related to social determinants of health, other access issues, other resources, barriers, stigma—other things that we're not able to capture here in our model.
And then, as we looked at out-of-pocket costs, as we mentioned, we saw that there were significantly higher out-of-pocket costs for beta-3 agonists. And we've seen in the literature that for Medicare, that can be over $500 per fill until the deductible is met, versus $75 for anticholinergics. If you look at Cost Plus—which I updated this today—it's $295 a month out-of-pocket versus $6.50 for an anticholinergic. So again, significant difference. And then also GoodRx, $400 versus $11.
So despite the resources that we have available, insurance and others, if the out-of-pocket costs remain high, that's going to continue to drive these disparities. I think the pleasant surprise here was really that frail adults had a 16% higher odds, and older adults had a 25% higher odds, of having a beta-3 agonist claim, which is the right thing and in line with the guidelines that say that we really need to be avoiding anticholinergics in these populations.
And then specialized care—so urologists and gynecologists are twice as likely to be associated with a beta-3 agonist claim. That can be due to a number of reasons. A lot of patients may see their primary care doctor first and may start with an anticholinergic because that was what was least expensive for them. And if their symptoms persist, by the time they see a specialist, they may be ready to fill a beta-3 agonist prescription, or maybe at that point they've failed the others. Their insurance company may be covering their medication with a lower copay. So those are the main thoughts I wanted to share with the group here today. So thanks so much.
Ruchika Talwar: Thank you so much. So interesting. And I think you bring up many points. One important thing to consider is the significant financial burden of mirabegron even when a patient is insured. I think it can't be underscored there. And this concept of underinsurance, I think even in dual eligible patients, is really important because $500 a month is not feasible for a lot of folks. So just curious to hear your thoughts on how we can try to overcome some of those barriers that may not be within our control specifically. What are some resources that have worked?
Ekene Enemchukwu: Yeah, I think that's a very great point. I think in my patient population, what we've tried to do—one thing that's been helpful is that mirabegron is finally generic. Unfortunately, we're still waiting for the price to catch up and for the price to come down. We're not really seeing that. We do hear from different colleagues around the country that they may have some pharmacies where they're finding that patients are getting lower out-of-pocket costs. So we have our fingers crossed.
But beyond that, for me and my patients, what I generally will do is look at our Canadian pharmacies as another option. We generally can get that for them for under $100 a month, which again, as you mentioned, is still a lot of money for a lot of people. And so that's generally been the best option that we've been able to give. I think with time, the out-of-pocket costs are certainly coming down for patients, and with the newer beta-3 agonists like vibegron as well, we're finding that that's being covered better with lower copays.
Ruchika Talwar: Yeah. Again, it's a problem I don't have a great solution for, but I think it's important that we at least raise this concern and flag it so we know to proactively bring up financial considerations when we prescribe these medications. So as we wrap up here—I mean, great study, important insights—what are the biggest takeaways that you want our UroToday community to keep in mind when seeing patients with OAB?
Ekene Enemchukwu: Yeah, I think that's important. I think it's important to discuss the risks of long-term anticholinergic use with patients and that they understand, as they're making a decision, this should be a shared decision model as we're discussing OAB. I think it's also important that we understand that if we're counseling on risks with older patients, we don't say, "OK, they can't afford mirabegron, so I'm just going to put them on oxybutynin." I don't think that's the answer either.
I think we then need to go to the new 2024 OAB guidelines and look at those menu of options and review those with patients, and understand that we can offer them now a lot of minimally invasive—what we previously used to call third-line—therapies that are pretty low risk and that patients can do at home. And in that way avoid medicines that may be harmful to them.
Ruchika Talwar: Yeah, all great points. Well, thank you so much for sharing your study and your expertise. And this is such an important topic. We're grateful for the time you took this evening.
Ekene Enemchukwu: Thank you so much.
Ruchika Talwar: And to our audience, thanks again for tuning in. We'll see you next time.
Ruchika Talwar: Hi, everyone. Welcome back to UroToday's Health Policy Center of Excellence. As always, my name is Ruchika Talwar, and I'm a urologic oncologist in Nashville, Tennessee. Today, I'm really excited to be joined by Dr. Enemchukwu, who is a female reconstructive urologist at Stanford. She recently published a study exploring the intersection of frailty, specialized care, and socioeconomic factors that potentially drive disparities in oral pharmacotherapy class utilization within our Medicare population, who's seeking care for overactive bladder. Really interesting study, significant health policy implications, and I'm really excited to have her share this work today. Thank you so much for taking the time to chat with us, Dr. Enemchukwu.
Ekene Enemchukwu: Thank you. Thanks for the invitation. Well, thanks so much for that introduction and also for the invitation. I'm Ekene Enemchukwu. I'm at Stanford, and I'm going to talk a little bit about OAB, frailty, and specialized care, sociodemographic disparities in oral pharmacotherapy. As we all know, OAB is a debilitating, distressing condition that's characterized by urgency, frequency, and urgency incontinence. It's a very costly condition, costing over $80 billion in direct and indirect costs annually, lots of negative impact on quality of life, and it significantly impacts adults over the age of 65.
So older adults, over 30%, are impacted by this for a number of reasons. And it's been confirmed on urodynamic studies. And frailty really adds another layer of complexity to this. These patients are often over the age of 65. They have reduced physiologic reserves. They develop frailty. And there are studies that have shown that frailty has a stronger association with OAB than age alone. And so the new AUA/SUFU guidelines are great in that they've revamped the way we treat patients or the way we discuss treating patients.
It's no longer a stepwise approach to therapy. Now it's more of a menu that you are discussing with the patient in a shared decision-making model. And so pharmacologic therapy obviously is still on that menu: beta-3 agonists and antimuscarinics. And the concern is that anticholinergics in older adults have been associated with conditions like cognitive conditions and also dementia. And so they're commonly prescribed for conditions like depression and OAB. And as we know, in older adults, they're more likely to have impairments in the blood-brain barrier.
And so the concern is with longer-term use that these changes may be permanent. And in some of our prior work, we have found that with long-term use, there's a 46% increased risk of incident dementia. In this study by Welk and colleagues, they found that between anticholinergics versus those using beta-3 agonists, there was a 23% increased risk of incident dementia in folks who were using anticholinergics.
And so our societies have all put out statements really emphasizing the importance of counseling patients, using beta-3 agonists or alternatives whenever possible. If we have to use anticholinergics, really using those that have a low propensity to cross the blood-brain barrier, avoiding short-acting medications, avoiding use of AUGS-recommending women over the age of 70, and really using procedures or advanced therapies when possible if we need to avoid adverse events.
And so our study—we were really interested in looking at, as Dr. Talwar mentioned earlier, the intersection between frailty and age and OAB therapy utilization. And we also thought it was really important to look at disparities based on other demographic factors. And so our primary outcome was a beta-3 agonist prescription claim during the study period. And so this was a retrospective study using a 20% random sample of the Medicare Fee-for-Service data between 2013 and 2018.
In this study, our study population were beneficiaries who were enrolled in parts A, B, and D. They all had to have OAB based on ICD-9 and 10 codes. They were all treated with an anticholinergic or beta-3 agonist using National Drug Codes, and they all had to have one year of continuous enrollment prior to the index date. We excluded those who had end-stage renal disease, urinary retention, or neurogenic bladder, and we used provider taxonomy to identify our provider types. We used a claims-based frailty index to categorize patients into not frail, prefrail, and frail. Then we used logistic regression to explore associations.
And so what we found—we had a cohort of over 700,000 beneficiaries that had OAB. Of those, about 16% were treated. The mean age was about 75, about 71% of those were female, 83% were non-Hispanic white, about 12% were considered frail, and almost 20% were dual eligible, which we used also as a surrogate for lower socioeconomic status.
And so, as you can see here, the majority of our treated cohort were prescribed or filled an anticholinergic prescription during the study period. And you can see that there's a significant difference in the median copay for these prescriptions. And so we were really interested in looking at the factors that were associated with beta-3 agonist claims. And we were pleasantly surprised to find that frail status was associated with a 16% higher odds of filling a mirabegron prescription, as was advancing age—a 25% higher odds—being from the South region versus the Midwest.
And if you were treated, or your prescription was prescribed, by a urologist or a gynecologist, you were almost two times more likely to have filled a mirabegron prescription. And if you were dual eligible, you were three times more likely to fill the prescription. But if you were Black or Indigenous, you were less likely to have filled a mirabegron prescription.
And so we wanted to better understand what was driving the sociodemographic disparities. And so we first started looking at our univariate model. And on that, we immediately saw that Hispanic, Black, and American Indian and Alaskan Natives were less likely to have a mirabegron prescription claim, whereas for Asian, there was no difference with white.
So we started to think about the things that might impact that, and we looked at out-of-pocket costs and dual eligibility. And when we adjusted for that, at that point, Asian race was more likely to fill a mirabegron prescription than white, and Hispanic showed no difference. But for Black and American Indian and Alaskan Native, it remained a lower odds.
So we removed dual eligibility to look just at out-of-pocket costs. And we were really surprised to find that the odds for Asian patients went up even more, as it did for Hispanic, and that there was no difference with Black beneficiaries anymore. But American Indian and Alaskan Native remained lower odds.
And so we started to think about what the implications of these findings are when we look at the racial and ethnic findings: certainly a lower likelihood of a beta-3 agonist prescription claim in this population. And when we adjust for cost, those disparities seem to disappear for most groups except for American Indian and Alaskan Native. And the thought there is that, at least a large barrier seems to be out-of-pocket costs, which is not surprising and is consistent with the literature.
But for our Indigenous populations, I think there are certainly other barriers that are keeping them from being able to fill these prescriptions, whether that's access or prescribing patterns and where they're able to seek care. When we adjusted for out-of-pocket costs and dual eligibility, though, we did see that there was a lower odds for Black and American Indian and Alaskan Native. And this is where it was a little bit more complicated. We started to think about what that might mean.
When we looked at those models, dual eligibility reduced the odds for all of the minority groups. And so the thought there is that there are other barriers, other than out-of-pocket costs, that are impacting these groups that may be related to social determinants of health, other access issues, other resources, barriers, stigma—other things that we're not able to capture here in our model.
And then, as we looked at out-of-pocket costs, as we mentioned, we saw that there were significantly higher out-of-pocket costs for beta-3 agonists. And we've seen in the literature that for Medicare, that can be over $500 per fill until the deductible is met, versus $75 for anticholinergics. If you look at Cost Plus—which I updated this today—it's $295 a month out-of-pocket versus $6.50 for an anticholinergic. So again, significant difference. And then also GoodRx, $400 versus $11.
So despite the resources that we have available, insurance and others, if the out-of-pocket costs remain high, that's going to continue to drive these disparities. I think the pleasant surprise here was really that frail adults had a 16% higher odds, and older adults had a 25% higher odds, of having a beta-3 agonist claim, which is the right thing and in line with the guidelines that say that we really need to be avoiding anticholinergics in these populations.
And then specialized care—so urologists and gynecologists are twice as likely to be associated with a beta-3 agonist claim. That can be due to a number of reasons. A lot of patients may see their primary care doctor first and may start with an anticholinergic because that was what was least expensive for them. And if their symptoms persist, by the time they see a specialist, they may be ready to fill a beta-3 agonist prescription, or maybe at that point they've failed the others. Their insurance company may be covering their medication with a lower copay. So those are the main thoughts I wanted to share with the group here today. So thanks so much.
Ruchika Talwar: Thank you so much. So interesting. And I think you bring up many points. One important thing to consider is the significant financial burden of mirabegron even when a patient is insured. I think it can't be underscored there. And this concept of underinsurance, I think even in dual eligible patients, is really important because $500 a month is not feasible for a lot of folks. So just curious to hear your thoughts on how we can try to overcome some of those barriers that may not be within our control specifically. What are some resources that have worked?
Ekene Enemchukwu: Yeah, I think that's a very great point. I think in my patient population, what we've tried to do—one thing that's been helpful is that mirabegron is finally generic. Unfortunately, we're still waiting for the price to catch up and for the price to come down. We're not really seeing that. We do hear from different colleagues around the country that they may have some pharmacies where they're finding that patients are getting lower out-of-pocket costs. So we have our fingers crossed.
But beyond that, for me and my patients, what I generally will do is look at our Canadian pharmacies as another option. We generally can get that for them for under $100 a month, which again, as you mentioned, is still a lot of money for a lot of people. And so that's generally been the best option that we've been able to give. I think with time, the out-of-pocket costs are certainly coming down for patients, and with the newer beta-3 agonists like vibegron as well, we're finding that that's being covered better with lower copays.
Ruchika Talwar: Yeah. Again, it's a problem I don't have a great solution for, but I think it's important that we at least raise this concern and flag it so we know to proactively bring up financial considerations when we prescribe these medications. So as we wrap up here—I mean, great study, important insights—what are the biggest takeaways that you want our UroToday community to keep in mind when seeing patients with OAB?
Ekene Enemchukwu: Yeah, I think that's important. I think it's important to discuss the risks of long-term anticholinergic use with patients and that they understand, as they're making a decision, this should be a shared decision model as we're discussing OAB. I think it's also important that we understand that if we're counseling on risks with older patients, we don't say, "OK, they can't afford mirabegron, so I'm just going to put them on oxybutynin." I don't think that's the answer either.
I think we then need to go to the new 2024 OAB guidelines and look at those menu of options and review those with patients, and understand that we can offer them now a lot of minimally invasive—what we previously used to call third-line—therapies that are pretty low risk and that patients can do at home. And in that way avoid medicines that may be harmful to them.
Ruchika Talwar: Yeah, all great points. Well, thank you so much for sharing your study and your expertise. And this is such an important topic. We're grateful for the time you took this evening.
Ekene Enemchukwu: Thank you so much.
Ruchika Talwar: And to our audience, thanks again for tuning in. We'll see you next time.