Research Studies
The prevalence of urinary incontinence is not increased in Native American women from South Dakota
Fiegen MM, Benson KD, Hanson JD, Prasek J, Hansen KA, Van Eerden P. The prevalence of urinary incontinence in American Indian women from a South Dakota tribe. Int Urogynecol J 2012 23 (4): 473-479.
Why they did the study
Epidemiological and clinical studies have been conducted in various female populations and have revealed risk factors and contributing variables for urinary incontinence [UI]. This pilot study was initiated to determine the prevalence of UI and associated risk factors in a population of Native American women. This group of women has not been previously studied relative to the medical issue of UI.
How they did it
This was a pilot cross-sectional study. Participants were recruited as a convenience sample from one tribe at the local Indian Health Service (HIS) in Sioux Falls, South Dakota and through “word of mouth” from other community members. From June to September of 2008, a questionnaire was administered by a local nursing student, who was a member of the tribe, at the IHS facility. When questionnaires were returned to the nursing student, she reviewed them to confirm that each question had been answered by each participant. Inclusion criteria for participation in the study required that subjects were female, at least 18 years of age or older, Native American and not pregnant.
The Urogenital Distress Inventory (UDI-6) Short Form was chosen for use in this pilot study to assess UI symptoms and establish the demographic features of this sample. In addition to determining the subtype of UI, the UDI-6 provides data on the degree to which symptoms associated with UI are troubling to women. Data on the reliability and validity of the UDI-6 demonstrated that it is psychometrically strong and can be self-administered. In addition, positive responses to subscale questions (obstruction, stress incontinence, or bladder overactivity) are correlated with a corresponding diagnosis of UI and its severity.
In addition to the six questions of the UDI-6, the survey questionnaire included various demographic questions (i.e., age) and questions targeted at UI risk factors, including BMI, history of diabetes, urinary tract infections, pregnancy history, substance use and smoking status. Because the UDI-6 questionnaire had not been previously used in this American Indian population, the definitions of stress and urge incontinence was provided in writing for each participant to refer to as they filled out the questionnaire. To make the questionnaire more culturally sensitive to Native American women, the form had Native American art and pictures imbedded with it.
The demographic and medical characteristics of women with each subtype of UI were statistically compared with those of the remaining sample.
What they found
A total of 234 eligible participants provided completed questionnaires. The average age was 42.7 (±13.8) years, BMI was 30.6 (±6.6) and average parity was 3 (±2.02). Type II diabetes and cigarette smoking were reported in 25.8% and 49.4%, respectively, of the study group. Overall, the average BMI and parity in this sample and the frequency of type II diabetes and smoking were much higher than those reported in the general American population.
The overall frequency of moderate and severe stress UI was 15.4%, urgency UI was 2.14%, and mixed UI was 20.5% based on the UDI-6 responses. Women classified as having mixed UI were older than women who did not have mixed UI (53.2±12.5 years versus 40.0±12.7, p<0.001) had a higher BMI (33.3±6.3 kg/m2 versus 29.9±6.5, p=0.0013) and were more likely to have type II diabetes (77.8% with diabetes versus 27.4%, p=0.002). All other comparisons of incontinence group (i.e., urge and stress) to the remaining sample were not significant. There was a statistically significant relationship between parity and mixed UI (chi-square with 12 degrees of freedom=45.0, p<0.001). As parity increased, the number with mixed UI increased.
Why it matters
The prevalence of UI has been studied throughout the world in various populations and ethnic groups including US Caucasian, African American and Hispanic-American women. The same data are unavailable for Native American women because they have not been included in UI research. These data are urgently needed because UI represents a collection of debilitating symptoms in all women and results in billions of dollars expended by the health care systems.
Well-documented risk factors for UI include age, parity, and obesity as well as other risk factors including smoking, menopause, restricted mobility, chronic cough, chronic straining due to constipation, and previous urogenital surgery. Differences in prevalence, quantity, and type of UI have been seen in the USA between African American and Caucasian women although the frequency of risk factors for UI was generally similar in these two populations. In contrast, the results of this study show that although Native American women may have certain risk factors for UI, they have similar rates of mixed UI and their rates of stress and urge UI are lower than that reported in other studies of American women. The Native American subjects in this study with mixed UI, however, had an increased incidence of type II diabetes, increased BMI, advanced age and higher parity when compared to the remainder of the study population similar to other epidemiological studies.
Further study of UI in this group of Native American women is important. Those women identified with incontinence will then receive evidence-based medical therapy for their specific condition. Hopefully the identification and treatment of these conditions in this underserved group of women will improve their quality of life.
Next question
The cross-sectional, small and convenience sample of Native American women from one tribe in this study limits the generalization of the results to Native American women as a whole and prevents a full comparison with rates of UI in other populations. Other risk factors such as genetic factors and obstetric events have not been addressed in this preliminary study. The authors, therefore, plan to evaluate the risk factors for UI in a larger, prospective, random, multi-tribe sample accompanied by clinical evaluation to confirm the actual prevalence of UI in Native American women.
