Physicians have a good sense of the symptoms and causes of overactive bladder, and clear guidelines exist for diagnosis. Thanks to advertising for pharmaceuticals and other products, even many members of the general public are aware of this condition and know that treatments are available.
Underactive bladder (UAB), on the other hand, is a condition that is poorly understood and not well-studied. Currently, a clear definition of what constitutes UAB is lacking. Even most specialists don’t know how to recognize it. This dearth of information is the motivation behind a collaborative research investigation that has been ongoing for over two years. The effort aims to develop patient-reported outcome measures that can ultimately enable research and treatment for UAB.
“There are urodynamic parameters that we think are characteristic of this condition, but we really don’t know much about it,” said Michael O’Leary, MD, MPH, a senior urologic surgeon at the Brigham’s Division of Urology and one of the study’s principal investigators. “Once you have clear guidelines for what constitutes a particular condition, it makes the job of studying it much easier.”
Establishing Metrics to Characterize UAB
The initial goal of the collaboration is to generate a screening method for UAB based on symptoms and then to validate those questions based on what is already known about the condition. Accordingly, the investigators are aiming to develop a questionnaire for UAB that is similar to those established for conditions like erectile dysfunction and chronic pelvic pain syndrome. The project was begun in response to a request from the National Institute of Diabetes and Digestive and Kidney Diseases, which is funding the research.
“Our job is to better characterize UAB,” Dr. O’Leary said. “So the first thing we need to do is to find out what the patient experience is. Because this condition is symptom-driven, having a way to measure patient-reported outcomes will be valuable.”
Early results have identified a number of indicators that are shared with detrusor underactivity, a potential causal factor for UAB. The study so far has collected data on people aged 40 to 89, with the majority over age 70, and has included both men and women. Dr. O’Leary estimated that up to 20 percent of the elderly population may experience UAB, but noted that the condition is so understudied that its frequency is difficult to determine.
The prominent symptoms identified so far include frequent urination, decreased sensation, incontinence and frequently waking to urinate. The fact that many of these symptoms are similar to other bladder disorders makes diagnosis more challenging, the researchers said.
“The classic teaching is that you would expect underactive bladder to look like retention,” said the Brigham’s Elodi Dielubanza, MD, an associate surgeon and a co-investigator in the study. “In reality, when you encounter patients with UAB, it’s a lot more heterogeneous and nuanced. We currently have no way to understand what the expected patterns might be.
“The difficulty in this work is about trying to recognize something that is so poorly understood. We have to work backwards and start with the patient experience first.”
Identifying the Needs of an Undertreated Condition
This study involves researchers in urology and urogynecology at the Brigham and Massachusetts General Hospital. The New England Research Institute is providing expertise in epidemiology and data collection and management.
“Because this condition is not often diagnosed, currently it tends not to get treated,” Dr. O’Leary said. “Some patients who have a poorly contractile bladder may need to do self-catherization, but there is no standard treatment. The pharmaceutical industry is interested in potential development of new drugs. But before any treatments can be developed, we need to know much more about the underlying causes of this condition, in addition to having a way to measure any benefit that may come from treatments.”