Study: Most OAB Cases Go Untreated
Only about one fourth of individuals aged 45 years and older diagnosed with overactive bladder (OAB) receive medical treatment for the condition, a study showed. Men were less likely to received OAB medications than women.
Using a 12-month IMS Health data set of clinical information on more than 187 million patients, Kevin T. McVary, MD, of Northwestern University's Feinberg School of Medicine in Chicago, and his collaborators identified 102.5 million patients aged 45 years and older.
In this group, 7.2 million (7.1%) had an OAB diagnosis (approximately 2.6 million men and 4.6 million women). Only 24.4% were treated pharmacologically for OAB symptoms and 74.4% of this treated group was women. Only 17.1% of male OAB sufferers aged 45 years and older received treatment during the study period compared with 28.6% of female OAB patients in this age group, the investigators reported in European Urology (2009; published online ahead of print).
The proportion of treated patients increased significantly with age for both genders. The investigators defined treated patients as those who filled a prescription for either an anticholinergic or tricyclic antidepressant.
The prevalence of OAB diagnosis increased with age. For patients aged 45-54, 55-64, and 65 and older, the prevalence was 4.9, 6.7%, and 9.6%, respectively.
“One potential reason for the relatively low frequency of treatment in both men and women may be the associated cost,” the researchers wrote, noting that several studies recently estimated the economic burden of OAB disease at more than $12 billion annual, which includes direct medical costs, direct nonmedical costs, and indirect costs. Thus, cost alone may discourage many patients from starting medical therapies.
Moreover, many patients may have opted for lifestyle or behavioral modifications, such as decreased fluid intake, Dr. McVary's group stated. Lower rates of treatment also may be due to insufficient symptom relief and adverse effects of medication, as well as physician and patient preference for nondrug approaches.
“However, although all these factors may contribute to the lack of administered medical therapies, they certainly do not explain the entire phenomenon or gender differences,” the authors noted.
The researchers said the observed discrepancies and gender bias could be related to the presence of incontinence or other comorbidities. They cited data from the National Overactive Bladder Evaluation Program suggesting that “although the prevalence of OAB symptoms was similar among men and women, the frequency of women with OAB symptoms and incontinence increased at a faster rate with age compared with men.”
Thus, the authors noted, if incontinence is the driving factor for medical intervention, then it is not surprising that a higher but steady proportion of women in each age group is being treated.
With regard to why OAB often goes untreated in men, Dr. McVary and his colleagues said this may be related to a “historic misclassification” of OAB symptoms as prostatism. Many of these men may have been treated with other medications for benign prostatic hyperplasia (BPH), according to the investigators. They cited recent research showing that these medications were prescribed for most men with OAB symptoms and no BPH diagnosis.
Furthermore, the authors noted that in their study, men may not have received treatment because of mild symptom severity, a lack of associated incontinence or bother, concern about the adverse effects of the medications, and intervention with BPH therapies, including medication and surgery.
Dr. McVary's group speculates that the men in their study may have been proportionately undertreated as a result of the presence and concern about lower urinary tract symptoms secondary to BPH.