Despite anecdotal reports suggesting that few women with MS present to a urologist with a complaint of SUI, our prospective questionnaire based study determined that SUI is not uncommon amongst women with MS. The SUI prevalence rate of 55.9% (80/143) in women with MS is consistent with the 2005 NARCOMS data but greater than SUI prevalence rates estimated from general population studies [4
]. A recent study by Markland et al. [7
] analyzed data from the National Health and Nutrition Examination Survey, which defined SUI as a positive response to the question, "During the past 12 months, have you leaked or lost control of even a small amount of urine with activity like coughing, lifting or exercise
?" The study reported an age standardized SUI prevalence of 25% in adult women. The higher prevalence rate in women with MS indicates that some degree of SUI is common in this unique population of women. The exact reason for a higher prevalence rate of SUI in women with MS compared to the general female population is unclear and merits further research. When women with MS and SUI were compared to women with MS and no SUI, several patterns were reflective of general population based studies. Women with SUI were significantly older and tended to be heavier, two recognized risk factors for the development of SUI [6
The UDI-6 and IIQ-7 allowed patients to characterize their SUI and to indicate the degree of impact SUI has on their physical activity. When women with MS and SUI answered UDI-6 question #3, just under half of the women (46%) were moderately or greatly bothered by their SUI. Although just over half of the women (54%) were only slightly bothered by their SUI, answers to the IIQ-7 questionnaire demonstrated that SUI has a significant negative impact on their lives. When women with MS and SUI were compared to women with MS and no SUI, the women with SUI had significantly higher overall IIQ-7 scores and IIQ-7 question #2 scores (P<0.001). Nearly one third of women with MS and SUI (31%) indicated that SUI had at least a moderate or great impact on their physical activity. Physical activity and exercise are recommended in MS patients, based on literature demonstrating that exercise improves fatigue, fitness, and QoL [12
]. The negative impact of SUI adds to the activity limitations caused by other neurologic impairments, and further compromises the MS patient's ability to maintain their functional status and independence.
The high prevalence rate, the significant degree of bother and the negative impact on their lives highlights the importance of screening women with MS for SUI. If treatment of SUI is being considered, a recent United Kingdom consensus panel recommends the use of urodynamics to identify underlying lower urinary tract dysfunction [13
]. Women with MS are susceptible to other forms of lower urinary tract dysfunction, such as detrusor sphincter dysnergia, and future research should examine the treatment of SUI in this patient population.
The majority of patients (59%) with any form of UI were not under the care of urologist, which suggests that this unique patient population is underserved in terms of their urologic needs. Despite the need for more stringent evaluation of SUI in women with MS to identify coexisting lower urinary tract dysfunction, treatment options are available with the potential to improve their QoL [14
]. Reasons for limited urologic care include restricted access to a urologist familiar with lower urinary tract dysfunction and inadequate patient education regarding treatments for UI. Neurologists with a MS focused practice will encounter UI in their patients and may feel well equipped to conservatively manage UI. In addition, competing medical issues may overshadow UI and leave patients with limited time and energy to address their urologic concerns.
This single institution study did have several limitations. Due to the nature of the study, there was no objective measure of SUI, no standardized functional status and the questionnaire did not assess menopausal status or ethnicity, factors known to influence the prevalence of SUI [15
]. Finally, the study design is subject to a degree of selection bias since we only captured women actively seeking medical care. This selection bias may have contributed to an overestimation of the prevalence of SUI in the overall population of women with MS.
Based on the results of this questionnaire based study, the prevalence of SUI in women with MS is 55.9% (80/143). Using a contemporary cohort of women with MS, this study supports the SUI prevalence data captured in the 2005 NARCOMS survey [8
]. While just over half of women with MS and SUI indicated that they are not significantly bothered by their SUI, SUI has a significant negative impact on their QoL and nearly one third reported a significant impact on their physical activity. These women may benefit from treatment of their SUI and screening for SUI should not be overshadowed by assessment and treatment of overactive bladder.