Abstract General Information

Title

EVALUATION OF VOIDING FUNCTION IN CHILDREN WITH OVERACTIVE BLADDER BY USING HOME-UROFLOWMETRY AND ITS CLINICAL SIGNIFICANCE

Introduction and objective

Overactive bladder (OAB) in children is clinically common and seriously affects the children’s physical and mental health. Voiding frequency (VF) is an important basis for the diagnosis of OAB. Though hospital uroflowmetry is a non-invasive test to assess lower urinary tract function, it does not reflect VF. The advent of home-uroflowmetry allows patients to record their urinary flow rate at home while also recording VF. And urination at home shows true voiding state. Nevertheless, the assessment of OAB in children by home-uroflowmetry (HUF) and its clinical significance have not been reported in the literature. Thus, we investigated the feasibility of home-uroflowmetry in evaluating the VF using a home-uroflowmetry in children with OAB and healthy school-aged children of the same age.

Method

From May to November 2021, HUF was measured in 20 children between 7 and 10 years of age with OAB (OAB group, including 10 boys and 10 girls) and 30 volunteers of the same age (control group, including 15 boys and 15 girls) in outpatient clinics. The diagnosis of OAB meets the International Children's Continence Society (ICCS) criteria of urinary urgency and frequency with or without urinary incontinence. Urodynamic parameters comprising 24 hours, daytime and night time VF, average voiding volume (VV) per time, 24h VV, maximum flow rate (Qmax), and voiding time (VT) were analyzed.
Subsequently, a cross-sectional survey and whole-group sampling method were used to conduct a questionnaire survey on the VF among 520 normal school-aged children from five primary schools in China. The inclusion criteria: 7 to 10 years old; routine physical examination in good health; normal drinking water habits; no lower urinary tract symptoms. Exclusion criteria: abnormal urinary symptoms and urological disorders; neurological disorders; administration of drugs affecting urinary function.

Results

HUF results showed that the 24h, day, and night time VF were significantly higher, and the VV, Qmax, and VT significantly decreased, compared to that of 30 healthy children, respectively (P < 0.05). The results of home uroflowmetry measurements for children in the OAB group and control children are detailed in Table 1. A total of 490 questionnaires qualified for statistical analysis. The 24h, day and night time VF was 6.3 ± 0.96, 5.6 ± 0.90, and 0.7 ±0.59 times, respectively and sex and age showed no difference in VF (P > 0.05, table 2). The VF obtained from home-uroflowmetry was a little bit higher than the data acquired from the questionnaires but the difference was not significant (P > 0.05, table 3).



Table 1 Comparison of home-uroflowmetry results between OAB group and control group in children()
Group Sex (boy:girl) Age (Years) 24 hour-VF (times) Daytime VF (times) Night VF (times) VV (mL) Qmax (mL/s) VT (s) 24 h VV (mL)

OAB group 10:10 8.4 ± 1.14 11.3 ± 1.50 10.0 ± 1.16 1.3 ± 0.63 98.1 ± 15.83 16.1 ± 2.20 12.4 ± 2.56 1103.5 ± 225.98
control group 15:15 8.3 ± 1.06 6.6 ± 1.40 5.9 ± 1.20 0.7 ± 0.64 157.0 ± 24.23 19.1 ± 3.00 18.1 ± 2.71 1025.1 ± 217.78
t — 0.053 11.204 11.898 3.215 -9.574 -3.849 -7.492 1.229
P — 0.958 0.000 0.000 0.002 0.000 0.000 0.000 0.225

Table 2 Comparison of VF in different ages in 490 children aged 7～10 years old ()
　 Cases 24h VF (times) Daytime VF (times) Night VF (times)
490 6.3 ± 0.96 5.6 ± 0.90 0.7 ± 0.59
Sex
Boy 254 6.3 ± 0.92 5.6 ± 0.90 0.6 ± 0.60
Girl 236 6.3 ± 1.00 5.6 ± 0.90 0.7 ± 0.59
t -0.047 0.499 -0.915
P 0.962 0.618 0.361
Age
7 122 6.5 ± 1.00 5.6 ± 0.78 0.7 ± 0.67
8 153 6.4 ± 1.03 5.7 ± 1.07 0.7 ± 0.57
9 105 6.2 ± 0.90 5.5 ± 0.82 0.7 ± 0.58
10 110 6.3 ± 0.84 5.6 ± 0.84 0.7 ± 0.56
F 0.847 1.433 0.154
P 　 0.469 0.232 0.927

Table 3 Comparison of VF of different surveys ()
Case 24h VF (times) Daytime VF (times) Night VF (times)
Questionnaire 490 6.3 ± 0.96 5.6 ± 0.90 0.7 ± 0.59
Home-uroflowmetry 30 6.6 ± 1.40 5.9 ± 1.20 0.7 ± 0.64
t — -1.83 -1.556 -0.609
P — 0.068 0.12 0.543

Conclusion

This study showed that VF in children aged 7-10 years was not influenced by gender or age. HUF can easily, accurately, and objectively reflect information on voiding function such as VF, VV, Qmax, duration of voiding, urinary flow curve, and whether urinary incontinence occurs in children. HUF is a useful tool for accurate and objective evaluation of the voiding function of children with OAB.