Development of a novel scale for primary monosymptomatic nocturnal enuresis: Nocturnal Enuresis Symptom Score (NESS)

Monosymptomatic nocturnal enuresis (MNE) is defined as urinary incontinence occurring during sleep in absence of daytime lower urinary tract symptoms. International Children Continence Society (ICCS) classifies treatment success as complete response (100 % resolution of symptoms), partial response (50-99 % reduction in symptoms) and no response (<50 % resolution of symptoms). There are no symptom scores for management or follow-up for MNE in the existing literature.

In this study, we aimed to develop a symptom score for monitorization of MNE treatment.

Existing symptom scores were investigated, experts' recommendations for items were collected and 20 children with MNE's caregivers were interviewed with open-ended questions to build the draft questionnaire. Generated items were applied to 20 different caregivers of children with MNE as a pilot study, and Nocturnal Enuresis Symptom Score was generated with a total of 9 questions with a 0-3 scale for each item. Stability, reliability and validity was analysed, A ROC curve was built to determine a cut-off value for response assessment.

The study included 85 children (51 (60 %) boys, 34 (40 %) girls) aged 9 (5-17) years. Cronbach's alpha for items was 0.867. One month follow-up showed non-response in 24 (28 %), partial response in 31 (37 %) and complete response in 30 (35 %) children based on ICCS classification Decreased number of wet nights were observed in 17 % (0-50), 73 % (50-87) and 100 %, whereas NESS score improvements were 7 %, 35 % and 78 % respectively (r = 0.708). With a cut-off NESS value of 25.6; 72 % of sensitivity and 70 % of specificity were achieved to discriminate between partial and non-responders. ICCS classification (<50 %) and NESS classification (<25 %) for non-responders were strongly correlated (r = 0.893). A cut-off value of NESS over 15.5 predicts the non-responder group with 69 % sensitivity and 62 % specificity with an AUC of 0.664.

In previous studies, different measurements were used to assess the outcomes of different management strategies for MNE such as the number of wet nights per 15 or 30 days or existing QoL questionnaires. Those studies were limited by a lack of standardized disease-specific methods for decision-making. Our symptom score may help clinicians to better classify treatment responses with a cut-off value of 25.6 % reduction. The major limitation is the lack of linguistic validation in different populations, which may be a topic for future research.

NESS may be useful to monitor patients with MNE in a standardized manner.