Delayed in Toilet Training Association with Pediatric Lower Urinary Tract Dysfunction: A Systematic Review and Meta-analysis

Background: Globally, attitudes and practices towards toilet training have changed several decades ago and children are completing toilet training at a later age compared to previous generations. Concurrently, there has been an increase in the incidence of pediatric bladder bowel dysfunction (BBD), including lower urinary tract dysfunction (LUTD). Whether the fact of delayed toilet training may negatively impact the ability of children to obtain bladder and bowel control and cause LUT dysfunction remains controversial.

Objectives: To investigate the association between age at initiation of toilet training or approach to toilet training and the risks of lower urinary tract (LUT) dysfunction.

Methods: A comprehensive search of the CENTRAL, EMBASE and MEDLINE via Ovid SP, and CINAHL via EBSCO databases was conducted to identify RCTs, cohort or case-control studies investigating the association between age at initiation of toilet training, approach used for toilet training, and pediatric LUT dysfunction.

Results: A total of 10 studies with 24,121 participants (aged 5-17) were included for pooled analysis. Overall, the odds ratio (OR) with 95% confidence interval (95%CI) of LUT dysfunction in children who initiated toilet training at a younger age when compared to those who initiated toilet training at an older age, was 0.71 (0.63-0.81), P < 0.001), irrespective of the approach used for toilet training (Table). Subgroup analysis for day-time incontinence (persistent daytime wetting) was 0.77 (0.62-0.95), P = 0.014; although the outcomes for enuresis fluctuated, favorable results were still observed in the earlier training group (OR:0.63, 95%CI:0.43-0.94, P = 0.023). Subgroup analysis for age at initiating toilet training vs LUT dysfunction also showed favorable results in children who were trained earlier, i.e., before 24 months (OR:0.77, 95% CI 0.63-0.94, P = 0.009). Sensitivity analysis confirmed that the results were robust.

Discussion: Although the definition about the age of initial toilet training varied greatly in studies, findings from the current study suggested that the optimal time for initiating toilet training may be prior to the age of 24 months; if toilet training was initiated after 24 months or later, it may result in increased prevalence of LUT dysfunction. Since no RCTs studies were included in the current meta-analysis, well-designed longitudinal studies with larger sample size and from different cultural background are needed to confirm these results.

Conclusion: This meta-analysis presents preliminary findings that show the incidence of LUTD may be decreased by initiating toilet training in children at a younger age.