Relativeness of the definition of bladder and bowel continence for individuals with spina bifida: data from the National Spina Bifida Patient Registry
Maryellen S. Kelly, DNP, CPNP, MHSc1, Tiebin Liu, PhD2, Jonathan C. Routh, MD, MPH1, Heidi Castillo, MD3, Stacy T. Tanaka, MD, MS4, Kathryn Smith, DrPH, MN, RN5, Linda E. Krach, MD6, Amy Zhang, PhD2, Eileen Sherburne, PhD, APNP7, Jonathan Castillo, MD, MPH3, David Joseph, MD8, John S. Wiener, MD1.
1Duke University, Durham, NC, USA, 2Centers for Disease Control and Prevention, Atlanta, GA, USA, 3Texas Children's Hospital/Baylor College of Medicine, Houston, TX, USA, 4Vanderbilt University Medical Center, Nashville, TN, USA, 5University of Southern California, Los Angeles, CA, USA, 6Gillette Children's Specialty Healthcare, St Paul, MN, USA, 7Wisconsin Children's Hospital, Milwaukee, WI, USA, 8University of Alabama Medical Center, Birmingham, AL, USA.
BACKGROUND: The Centers for Disease Control and Prevention developed the National Spina Bifida Patient Registry (NSBPR), a multi-institutional patient registry, to better understand health outcomes in individuals living with spina bifida (SB). The annual NSBPR questionnaire utilizes ordinal categories for defining bladder and bowel continence. Previous NSBPR studies have used binary classifications created by researchers to define continence. This binary continence status may not accurately reveal the range of patient experience or capture changes to and from continence categories after interventions. In this study we aimed to 1) perform the first NSBPR analysis treating continence of both bladder and bowel as an ordinal outcome to compare to the binary definition and to subject variables; 2) explore how incontinence data correlate with undergarment usage; and 3) assess continence outcomes of continence surgery (bladder outlet surgery without bladder augmentation and antegrade continence enema (ACE) surgeries).
METHODS: Data from the most recent clinic visit for patients aged 5 years and older in the NSBPR were analyzed. The categories of bladder and bowel incontinence are: daily, weekly, monthly, less than monthly, and never. These ordinal responses were compared to the previously employed binary definition (daily/weekly/monthly vs. less than monthly/never). The categories for undergarment use are: underwear only, underwear with pad, and protective undergarment. Continence surgical outcome data were analyzed for those individuals who completed an annual visit form at least 3 months after the surgical intervention. Associations among categorical variables were evaluated by chi-square tests. Univariate and multinomial logistic regression models were used to test associations of ordinal continence status with age, sex, ethnicity/race, level of motor function, type of health insurance, and management. Statistical tests were all 2-sided, and p-values <0.05 were considered significant.
RESULTS: 7217 individuals with SB were included. Associations of continence with demographic and disease variables were similar to prior studies using the binary definition. If the binary definition were expanded to include the "monthly" ordinal response (daily/weekly vs. monthly/less than monthly/never), only 0.8-7.7% more patients would have been classified as continent of urine among the nine forms of bladder management and 5.8-16.5% for the seven forms of bowel management. These results include finding that 24% of individuals who report never having urinary incontinence reported using protective undergarments and 14% of the 1701 individuals that reported never having urinary or bowel incontinence still report use of protective undergarments. Of the 495 individuals who had bladder outlet surgery without bladder augmentation, 54% reported improved bladder continence post-operatively. Of 1396 individuals who had ACE surgery, 68% reported improved bowel continence at visits at least 3 months after surgery.
The previously used binary definition of bladder and bowel continence appears robust, as inclusion of the next ordinal variable of monthly did not markedly change the proportion of patients reporting continence. Undergarment choice is a poor surrogate for reported continence. After bladder continence surgery, nearly half achieved bladder continence; and after bowel continence surgery, about two thirds achieved bowel continence.
Back to 2021 Posters