Saudi Journal of Kidney Diseases and Transplantation

: 2011  |  Volume : 22  |  Issue : 1  |  Page : 167--173

Epidemiology of nocturnal enuresis in basic schoolchildren in Aden Governorate, Yemen

Khalida Anwer Yousef1, Huda Omer Basaleem2, Mariam Taher bin Yahiya2,  
1 Department of Pediatrics, Faculty of Medicine & Health Sciences, Aden University, Yemen
2 Department of Community Medicine and Public Health, Faculty of Medicine & Health Sciences, Aden University, Yemen

Correspondence Address:
Huda Omer Basaleem
Department of Community Medicine and Public Health, Faculty of Medicine and Health Sciences, Aden University


Nocturnal enuresis is a common problem among children and adolescents. Data regarding this problem in schoolchildren in Yemen are scarce. This study was aimed to determine the prevalence of nocturnal incontinence in Aden school going children, describe its severity and identify the relation between nocturnal enuresis with personal and family characteristics. The study was a cross-sectional survey conducted on the public basic schoolchildren in Aden, Yemen, in the period November 2007-April 2009. A random, multistage sample of 890 students was taken from four districts in eight schools and divided into two strata: males and females. Data were obtained by using pre-recoded questionnaire, which was completed by parents. The response rate was 73.7% (656 students); 113 (17.2%) cases of nocturnal enuresis were encountered. Nocturnal enuresis de-creased by age from 31.5% at 6-8 years to 8.7% at 15+ years (P < 0.05). Primary nocturnal enuresis affected 76.1%, of which the majority of children were bedwetting every night. Positive family history of nocturnal enuresis, deeper sleep, daytime enuresis, tea drinking, being non working father or with less education showed significant association with the occurrence of enuresis in the students. Stressful events in the previous 6 months of the study were twice more frequently noted. The study concluded that the prevalence of nocturnal enuresis in Aden public school children and its associated factors are almost comparable with that reported in epidemiological studies from various countries. Health education will encourage the parents to be aware, cope with this problem and seek appropriate medical advice.

How to cite this article:
Yousef KA, Basaleem HO, Yahiya MT. Epidemiology of nocturnal enuresis in basic schoolchildren in Aden Governorate, Yemen.Saudi J Kidney Dis Transpl 2011;22:167-173

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Yousef KA, Basaleem HO, Yahiya MT. Epidemiology of nocturnal enuresis in basic schoolchildren in Aden Governorate, Yemen. Saudi J Kidney Dis Transpl [serial online] 2011 [cited 2022 Jan 27 ];22:167-173
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Enuresis is defined as an involuntary and un­desirable bedwetting, in the absence of congenital or acquired defects of the central nervous system or the urinary tract in a child five years or over, especially in boys. [1],[2],[3],[4],[5],[6] It is a common problem worldwide among children and adole­scents, across all races and cultures, but usually underreported. Though this condition is labeled benign, it often leads to important social im­plications and disturbances both in affected children and their parents. [2],[5],[7],[8],[9] Nocturnal enuresis (NE) is primary when the child has never been continent of urine for a prolonged period and secondary if incontinence recurs after a period of continence of 6 months. [1],[8],[9],[10] Most children with primary NE have no disease me­chanism explaining the enuresis. [1],[9]

Primary NE is the most common type with at least one episode of bedwetting/month in 15- 30% of 6 year olds and 4-16% of 12 year olds, with spontaneous remission rate of 14% per year. [2],[4],[8],[9],[10],[11] Another classification of NE from the recent urology literature is based on the presence of other bladder symptoms. Poly­symptomatic NE is bedwetting associated with severe urgency, severe frequency, or other signs of irritable bladder. Monotonous NE is bed wetting associated with normal daytime urina­tion. [8],[9] The final common pathway in physio­logical or monosymptomatic NE is the inabi­lity to recognize the sensation of a full bladder during sleep and a small functional bladder to awaken from sleep to urinate into the toilet. Both etiological factors may represent inhe­rited normal variation, as the evidence for genetic predisposition is strong. [4],[9],[10] Causes of NE may be a small bladder capacity, exce­ssive output of urine during sleep due to inade­quate antidiuretic hormone production, anxiety events experienced by the child, genetic, upper airway obstruction such as enlarged tonsils or adenoid and less frequently structural problems in urinary tract or nervous system. [4],[9],[10] Most studies have consistently found that the risk factors for enuresis are male gender, low age and family history of enuresis, divorced parents and deep sleep. [2],[3],[4],[6] To our knowledge, data regarding this problem in schoolchildren in Yemen are scarce. Therefore, the purpose of carrying out this study was to determine the prevalence, severity, and associated factors with NE in basic schools in Aden Governorate.

 Subjects and Methods

Through a cross-sectional population-based survey, a random multistage sample of the ba­sic schoolchildren (Grade one to nine) in the public schools of Aden, Yemen, was taken. Sample size was calculated according to the formula [12] : n = k2 (pq)/d 2 .

Taking into consideration the percentage of NE to be [20]%, [1],[3],[4],[8],[9],[11] the following sample size was calculated:


Assuming a non-response of 30%, the sample size (n) was increased to 683 + 204 = 887- 890. Fifty percent of the eight Aden districts were selected randomly, i.e. four districts were studied: Sera, Khormakser, Al-Mansora and Al­Sheikh-Othman and two schools in each dis­trict were selected randomly, one for males (Bahamesh, Khalid bin Al-Walid, Nashwan, 30 November, respectively) and one for females (Al-Gurbani, Hashim Abdulla, Saeed Nagi and Al-Abadi, respectively). The required sample size in each school was counted proportionally according to the percentage of students in the selected school from the total of students in all selected schools. The students were chosen by systematic sampling technique as follows:


The schools were visited several times by the author to maximize the response. The sampling details are shown in [Table 1].{Table 1}

For the execution of the study, formal request from the Faculty of Medicine and Health Sciences, Aden University, was presented to the office of education and the school health office in Aden Governorate to get the nece­ssary information about the basic schools in Aden and the permission to carry out the study.

Data were obtained by using pre-coded self­administered questionnaire, which was com­pleted by parents of the studied children on vo­luntary basis, with an explanatory note about the purpose of the study. The questionnaire consisted of two parts: the first part sought information on socio-demographic characte­ristics including age, sex, school grade, resi­dency, parents' education and working status, family size, number of siblings, birth order, economic status (subjective), type of sleep and the presence of NE and type (primary or se­condary). The second part included information on the severity of enuresis, history of NE in family and the possible associated factors such as daytime incontinence (daytime wetting when the child awakes), dysuria, constipation, con­sumption of tea, previous experience of frigh­tening and emotionally stressful events in the last six months such as fearful event, parents' travel and divorce, exposure to physical abuse, arrival of new baby and others. History of di­seases such as urinary tract infection and ab­normality, diabetes, spine abnormality and up­per respiratory tract obstruction was also asked for in the studied children. The effect of enu­resis on child with respect to achievement at school and whether the child was punished for enuresis or taken for medical consultation were recorded. Data were analyzed using SPSS, ver­sion 13. Chi-square test (x 2 ) was used to test the association between having enuresis and potentially associated variables. Results were considered significant at P < 0.05.


The total returned questionnaires were 656, giving a total response rate of 73.7% [Table 1]. The respondents were 316 males (48.2%) and 340 females (51.8%) [Table 1] and [Table 2]. One hundred and thirteen (17.2%) cases of NE were encountered. [Table 2] shows that the prevalence of enuresis was nearly equal in both the sexes. The same table also shows that NE decreased by age from 31.5% at 6-8 years to 8.7% at 15+years (P < 0.05).

Primary NE was a common clinical problem affecting 76.1% of students as shown in [Table 3]. In [Table 4], the family history is seen to have a significant association with the occurrence of enuresis in the studied students, which accoun­ted to 37.2% compared to 9% among those with negative family history. NE was significantly higher when parents were enuretic (42.9%) than when siblings were affected (31.1%).{Table 2}{Table 3}{Table 4}

[Table 5] shows that the numbers of siblings and birth order had no relation with NE, while deep sleepers and tea drinking habit in enuretic students was of significance. More NEs were encountered among those having daytime enu­resis (45.5%). Stressful events were found twice more commonly in enuretic students (24.2% vs. 12.4%, P < 0.05).{Table 5}

[Table 6] reveals that residency; family size, economic status of the family, mother's edu­cation and work had no relation with NE, while father's education and working status had significant association with the occurrence of enuresis.{Table 6}

Urinary complaints such as dysuria and cons­tipation in enuretics were 41.7% and 41.0%, respectively, and showed significant association with NE (χ2 = 27.668, df = 1, P value <0.005).

NE did not affect achievement at school in 87.6% of enuretics. Punishment was not the solution tool applied by most parents of enu­retic students (82.3%). On the other hand, me­dical advice was also not sought by majority of the parents (80.5%). Parents seeking medical ad­vice had majority of the children (91%) with primary enuresis and 91% caregivers were con­cerned when their children had severe enu­resis, once per day or 1-3 times/week.


Enuresis is one of the common disorders in pediatric population. It is now generally accep­ted that 15-20% of children have some degree of nighttime wetting at 5 years of age, with a spontaneous resolution rate of approximately 15% per year. [2],[4],[8],[9],[10],[11] Worldwide, the prevalence of enuresis among 6-12-year-old children is reported as 1.4-28%. [2],[3],[6],[7],[11],[13],[14],[15],[16] In our study, the prevalence of NE was 17.2%, which is similar to that reported in a study done in An­kara, Turkey (17.2%) [2] and the UK (18.9%), [14] but lower than that reported in Mukala primary school children, Hadramout, Yemen (28.6%) (Aljefri H.M, personal communication), Zaria, Nigeria (22.2%), [7] and Amman, Jordan (23.8%), [3] but is higher than the prevalence reported in Mumbai, India (7.61%), [6] Malaysia [15] and United Arab Emirates [16] (each 8%), and Tafila, Jordan (8.8%). [11]

Similar to that reported in a study done in another Yemeni city (Mukala), our subjects had no gender difference in the prevalence of enu­resis, but this was not in accordance with some studies done in Turkey, [2] Iran, [5] India, [6] Nigeria, [7]

Jordan, [3],[11] UAE [16] and China, [17] which reported it to be mostly associated with male gender, but was disputed by other reports. [18] On the other hand, the study finding that the pre­valence of NE decreases with age is similar to most reported studies [1]-[3],[11],[17],[19],[20] and also the report from Mukala city. Furthermore, our fin­ding about the severity of NE is similar to findings reported in Turkey, [2] Jordan [11] and Iran. [20]

Autosomal dominant inheritance linked to chromosomes 8, 12, 13 and 22 has been described. [4],[8],[9] In the present study also, a positive family history of enuresis was seen in 37.2% of enuretics. We also found that NE was found more among relatives (65.5%), parents (42.9%) than among siblings (31.1%) of enuretic chil­dren, which is in accordance with some studies. [2],[4],[9],[20],[21] This lifts the burden of guilt from the enuretic children and dispels the theory that enuresis is behavioral in origin.

In our study and in the study from Mukala city (personal communication), factors asso­ciated with NE included daytime enuresis and tea drinking habits, which were similar to that reported in other studies, possibly due to the diuretic effect of tea.4,6,9,20,21 Deep sleep (25.6%) was observed to have a significant effect on the prevalence of NE compared to light sleep (13.7%) and is consistent with the findings reported in multiple studies. Though the number of siblings in this study had no effect on NE, other reports, including the one from Mukala city, show the reverse. [2]

Our study and the study done in Mukala, Yemen, showed similar associations of econo­mic status, education and working status of father and mother, in contrast to the study done in Turkey. [2],[3],[6],[7],[11],[20],[22]

Anxiety-causing events occurring in a child after the age of 4 might lead to wetting after the child has been dry for 6 months. [8],[10] In our study also, stressful events occurred twice more frequently in the previous 6 months in enu­retic students (24.2%), this was also documen­ted by other studies from Turkey, [2] India [6] and locally from Mukala city.

Anatomical problems are only seen in a very few patients with enuresis, the common one being bladder maturation delay. Dysuria and constipation were infrequent, which is in agreement with other reports [2],[8],[9] but differs from the study done in Mukala city. Upper airway obs­truction was found in 10 (37.7%) of 28 enu­retic children, nearly similar to the study done in Mukala in which 7 (41.2%) of the enuretics had upper airway obstruction. Studies reported that NE is associated with upper airway obs­truction, and tonsillectomy and adenoidectomy may diminish NE in 76% of cases. [23]

NE in our study did not affect the school achievement in enuretics, unlike the reports from Turkey, [2] India, [6] United Arab Emirates, [16] Morocco [24] and Mukala.

Majority of the parents sought medical advice in our study when the NE was severe and did not apply punishment as a tool to manage at home. Other authors have also mentioned that medical advice is not sought in majority of the patients. [2],[6],[11],[17],[21] Nonetheless, the Jordanian [3] and Iranian families [5] were more concerned and had early medical advice.

In conclusion, NE is encountered in Yemeni children similar to those of other countries and can have a considerable impact on children and their families. Delay in seeking medical advice can affect the child's self-esteem and interpersonal relationships and health education will encourage parents to be aware of the problem, cope with it and seek appropriate me­dical advice. Further studies need to be carried out in the future in other governorates to ex­plore this problem.


We are greatly indebted to the principals, health staff and social workers in the studied schools for their utmost cooperation. Our ap­preciation is extended to the students and their parents who cooperated and offered time and attention, without which the study would not have been possible. We would like also to thank Dr. Sina Abdulla Yousef, assistant prof­essor, Department of Community Medicine and Public Health, Faculty of Medicine and Health Sciences Aden, Yemen, for her help in statistics.


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