Epidemiology

Nocturnal enuresis (bedwetting) is common among school-aged children (1):

• more common in boys than girls at all ages (2)
• around one in six 5-year-olds, and at least one in fifty 7-year-old boys and one in a hundred 7-year-old girls, have nocturnal enuresis (wetting the bed) more than once a week

Owing to the differences in defnitions and methods of diagnosis, the exact prevalence of bedwetting is unknown. In UK, prevalence decreases with age:

• in 5 year olds - 15 to 20% wet the bed on average twice a week
• in 7 year olds - 7%
• in 10 year olds - 5%
• between 12 to 14 year olds - 2% to 3%
• those aged 15 and over - 1% to 2% (3)

NICE state that (2):

• bedwetting (nocturnal enuresis) less than 2 nights a week has a prevalence of 21% at about 4 and a half years and 8% at 9 and a half years. More frequent bedwetting (more than 2 nights per week) is less common and has a prevalence of 8% at 4 and a half years and 1.5% at 9 and a half years (1)

The prevalence is also higher amongst children in residential care (3).

In some children, the problem can persist, with around 0.8% of girls and 1.6% of boys aged 15-16 years wetting at least once every 3 months (1)

Daytime enuresis is less common and it has been estimated that it may occur in 2% of 5 year old children and this becomes less frequent with age.

• it is more common in girls than boys
• often accompanied by nocturnal enuresis e.g. - around 10-28% of children with bedwetting have bladder problems during the day as well (3).

Around 15% becomes dry each year without treatment (3) although in older children this is unlikely and they are more likely to have severe symptoms (4)

Reference:

• 1. Drug and Therapeutics Bulletin (2004), 42 (5): 33-37
• 2. NICE (October 2010).Nocturnal enuresis - The management of bedwetting in children and young people
• 3. Glazener CM, Evans JH. Simple behavioural and physical interventions for nocturnal enuresis in children. Cochrane Database Syst Rev. 2004;(2)
• 4. Watson L. Enuresis. InnovAiT 2010;3(2):91-94