Diagnosis,Evaluation, and Treatment of Mixed Urinary Incontinence in Women

Mixed urinary incontinence (MUI) is a common clinical problem in the community and hospital setting. The broad definition of the term makes it difficult to diagnose, as well as determine effective treatment strategies. There are no current guidelines recommended for physicians. The estimated prevalence of this condition is approximately 30% in all women with incontinence. It has also been suggested that patients with MUI report more bothersome symptoms than either stress or urge incontinence; approximately 32% of 40- to 64-year-olds with MUI report symptoms of depression. The authors examine the diagnosis, evaluation, and treatment of patients with MUI.Key words: Mixed urinary incontinence, Detrusor overactivity, Stress incontinence, Urge incontinence, Urodynamic stress incontinence, Pelvic organ prolapse, Transvaginal tapeMixed urinary incontinence (MUI) is the leading cause of incontinence in the community and hospital setting.¹ The term refers to a combination of symptoms, with the patient exhibiting features of both stress urinary incontinence (SUI) and urge urinary incontinence (UUI); it may also refer to a combination of features of urodynamic SUI and detrusor hyperactivity.¹ The current International Continence Society guidelines define MUI as a complaint of the involuntary loss of urine during exertion, sneezing, or coughing, as well as leakage associated with urgency.²The term MUI is extremely broad because it may refer to equal stress and urge symptoms, stress-predominant symptoms, urge-predominant symptoms, urodynamic SUI (USUI) with detrusor overactivity (DO), or USUI with clinical urge symptoms but no DO.³ The challenge of this broad definition is that it leads to inconsistencies when evaluating treatment options and outcomes. In an attempt to validate diagnostic questions that could later be used in an epidemiological survey, Sandvik and colleagues⁴ defined MUI based on subjective answers to a structured questionnaire designed for their study.⁴ SUI was presumed if a positive answer was given to the question: “Do you lose urine during sudden physical exertion, lifting, coughing, or sneezing?” If the patient responded positively to the question: “Do you experience such a strong and sudden urge to void that you leak before reaching the toilet?” then a diagnosis of UUI was presumed. MUI was considered if a positive answer was given to both questions. In contrast, Brubaker and colleagues⁵ reported that strict definitions based on self-reported symptoms do not properly categorize patients as having MUI. Their group believed that patients should be broken down into MUI subgroups of SUI and UUI rather than describing it as a single entity. However, without a precise definition or understanding of the role of these stress and urge subcomponents, the assessment of an intervention for SUI or UUI is challenging.⁶The prevalence rates of MUI vary widely in the literature. In a secondary analysis of the Stress Incontinence Surgical Treatment Efficacy Trial (SISTEr), Brubaker and colleagues⁵ evaluated 655 women for the presence of incontinence and their response to treatment. They found that 50% to 93% of women fell into the category of MUI based on patient-reported answers to the Medical Epidemiologic and Social Aspects of Aging (MESA) and Urinary Distress Inventory (UDI) questionnaires. However, when objective criteria such as urodynamic findings were used, only 8% of women were categorized with MUI. Dooley and associates⁷ compared physical examination findings and responses to the MESA and UDI questionnaires in 551 women with a mean age of 56 ± 16 years. They estimated a prevalence rate of 30% of MUI in all women with urinary incontinence.According to Dooley and associates,⁷ in their cohort, MUI was more bothersome to patients than either pure SUI or UUI. In a cross-sectional population-based study across 6 European countries that included over 300 patients, the effects of overactive bladder (OAB) symptoms on employment, social interactions, and emotional well-being were evaluated by direct interview or a telephone-conducted interview. Irwin and associates⁸ found 32% of patients aged 40 to 64 years reported being depressed. In addition, they determined that symptoms of OAB have a statistically significant negative impact on emotional well-being both at home and at work.We sought to examine the existing literature on MUI and better understand the role urodynamic testing (UDS) plays in its diagnosis. In addition, we sought to examine treatment methods so that better treatment outcomes may be achieved.