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 8751 children (4507 men and 4244 women) with parentreported 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 91/2years-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 5899 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 5 trajectories of urinary incontinence from 4 to 9 years using longitudinal latent class analysis: (1) normative development of daytime and night-time bladder control (63.0% of the sample), (2) delayed attainment of bladder control (8.6%), (3) bedwetting alone (no daytime wetting) (15.6%), (4) daytime wetting alone (no bedwetting) (5.8%) and (5) 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: OR for bedwetting at 14 years= 23.5, 95% CI (15.1 to 36.5), daytime wetting (6.98 (4.50 to 10.8)), nocturia (2.39 (1.79 to 3.20)), urgency (2.10 (1.44 to 3.07)) and passing hard stools (2.64 (1.63 to 4.27)) (reference category= normative development). The association with adolescent bedwetting was weaker for children with bedwetting alone (3.69 (2.21 to 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.