Trajectories of urinary incontinence in childhood and bladder and bowel symptoms in adolescence: prospective cohort study

Objectives: To identify different patterns (trajectories) of childhood urinary incontinence and examine which patterns are associated with bladder and bowel symptoms in adolescence.
Design: Prospective cohort study.
Setting: General community.
Participants: The starting sample included 8,751 children (4,507 males, 4,244 females) with parent-reported data on frequency of bedwetting and daytime wetting for at least three of five time points (41/2, 51/2, 61/2, 71/2 and 91/2 years – hereafter referred to as 4 – 9 years). Study children provided data on a range of bladder and bowel symptoms at age 14 (data available for 5,899 participants).
Outcome measures: Self-reported bladder and bowel symptoms at 14 years including daytime wetting, bedwetting, nocturia, urgency, frequent urination, low voided volume, voiding postponement, passing hard stools and low stool frequency.
Results: We extracted five trajectories of urinary incontinence from 4 – 9 years using longitudinal latent class analysis: (i) normative development of daytime and nighttime bladder control (63.0% of the sample), (ii) delayed attainment of bladder control (8.6%), (iii) bedwetting alone (no daytime wetting) (15.6%), (iv) daytime wetting alone (no bedwetting) (5.8%), (v) persistent wetting (bedwetting with daytime wetting to age 9) (7.0%). The persistent wetting class generally showed the strongest associations with the adolescent bladder and bowel symptoms: odds ratio (OR) for bedwetting at 14 years = 23.5, 95% confidence interval (CI) (15.1, 36.5)], daytime wetting [6.98 (4.50, 10.8)], nocturia [2.39 (1.79, 3.20)], urgency [2.10 (1.44, 3.07)] and passing hard stools [2.64 (1.63, 4.27)] (reference category= normative development). The association with adolescent bedwetting was weaker for children with bedwetting alone [3.69 (2.21, 6.17)].
Conclusions: Trajectories of childhood urinary incontinence are differentially associated with adolescent bladder and bowel symptoms. Children exhibiting persistent bedwetting with daytime wetting had the poorest outcomes in adolescence.