Risk Factors for Nocturnal Enuresis in School-Age Children

Although nocturnal enuresis is common in children, its etiology is multifactorial and not fully understood. We evaluated potential risk factors for presence and severity of nocturnal enuresis.
Materials and Methods:

A validated, reproducible questionnaire was distributed to 8,230 school children in Sydney, Australia. Nocturnal enuresis was defined as any wetting in the previous month and categorized as mild (1 to 6 nights), moderate (7 or more nights but less than nightly) or severe (nightly).
Results:

Parents of 2,856 children (mean ± SD age 7.3 ± 1.3 years) completed the questionnaire (response rate 35%). Overall prevalence of nocturnal enuresis was 18.2%, with 12.3% of patients having mild, 2.5% moderate and 3.6% severe enuresis. Multivariate analysis showed that daytime incontinence (OR 4.8, 95% CI 2.9 to 7.9), encopresis (OR 2.7, 95% CI 1.6 to 4.4), bladder dysfunction (OR 3.6, 95% CI 2.4 to 5.3) and male gender (OR 2.0, 95% CI 1.3 to 3.1) were associated with severe nocturnal enuresis after adjustment for age. Emotional stressors (OR 2.3, 95% CI 1.2 to 4.2) and social concerns (OR 2.4, 95% CI 1.2 to 4.5) were associated with moderate nocturnal enuresis only.
Conclusions:

Encopresis and daytime incontinence are significant modifiable risk factors for nocturnal enuresis. Expressed as population attributable risk, 23% of nocturnal enuresis is associated with encopresis and daytime incontinence. Psychosocial factors appear to contribute to moderate but not severe nocturnal enuresis.

N octurnal enuresis is a common pediatric problem. The prevalence varies in epidemiological studies from 3.8% to 25% according to patient age and the definition used. At age 5 years 15% to 25% of children experience nocturnal enuresis. Prevalence of nocturnal enuresis decreases with increasing age, with about 15% of children spontaneously achieving nighttime bladder control annually. 9 In adults the prevalence of nocturnal enuresis is estimated at 1% to 2%.

The etiology of nocturnal enuresis is multifactorial and hypothesized to be related to problems with arousal, small bladder capacity and large overnight urine production. 10 ADHD, constipation, encopresis, developmental problems, male gender and young age are also reportedly associated with nocturnal enuresis. However, previous studies have not evaluated whether these associations of risk factors vary with severity. Nocturnal enuresis is a heterogeneous disorder. The spectrum of severity is wide but important from a management perspective, with older children (older than 7 years) who wet frequently requiring treatment. We sought to determine independent risk factors for nocturnal enuresis for each stratum of severity, with particular focus on the most severe cases.