Limited caffeine consumption as first-line treatment in managing primary monosymptomatic enuresis in children: how effective is it? A randomised clinical trial

OBJECTIVE: Evidence about the negative caffeine effect on enuresis in children remains understudied or poorly understood. The study aimed to investigate the effect of caffeine restriction on the improvement and severity of primary monosymptomatic nocturnal enuresis (PMNE). DESIGN: Randomised clinical trial. SETTING: Two referral hospitals in Tehran, Iran, from 2021 to 2023. PATIENTS: Five hundred and thirty-four PMNE children aged 6–15 years (each group 267). INTERVENTIONS: Amount of caffeine consumption was recorded by the feed frequency questionnaire and was estimated by Nutrition 4 software. Caffeine consumption per day in the intervention group was <30 mg, and in the control group, 80–110 mg. All children were asked to return 1 month later to check the recorded data. The ordinal logistic regression analysis was used to assay the effects of caffeine restriction on PMNE by relative risk (RR) at a 95% CI. MAIN OUTCOME MEASURES: The effect of limited caffeine consumption on the improvement and severity of PMNE. RESULTS: The mean age of the intervention and control groups was 10.9±2.3 and 10.5±2.5 years, respectively. The mean number of bed-wetting before caffeine restriction in the intervention and control group was 3.5 (SD 1.7) times/week and 3.4 (SD 1.9) times/week (p=0.91) and 1 month after intervention were 2.3 (SD 1.8) times/week and 3.2 (SD 1.9) times/week, respectively (p=0.001). Caffeine restriction significantly reduced the severity of enuresis in the intervention group. Fifty-four children (20.2%) improved (dry at night) in caffeine restriction and 18 children (6.7%) in the control group with RR 0.615 at 95% CI 0.521 to 0.726, p=0.001. The caffeine restriction significantly reduced the enuresis in children with a number-needed-to-treat benefit 7.417. It means you must treat 7.417 PMNE children with caffeine limitation to improve one child with enuresis (become dry). CONCLUSION: Caffeine restriction can be helpful in reducing PMNE or its severity. Constructive limitation of caffeine is suggested as one of the first-line treatments in the management of PMNE. TRIAL REGISTRATION NUMBER: IRCT20180401039167N3.