Enuresis (bedwetting) affects up to 20% of five-year-olds and can have considerable social, emotional and psychological effects. Treatments include alarms (activated by urination), behavioural interventions and drugs.To assess the effects of enuresis alarms for treating enuresis in children.We searched the Cochrane Incontinence Specialised Register, which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE In-Process, MEDLINE Epub Ahead of Print, ClinicalTrials.gov, WHO ICTRP, and handsearching of journals and conference proceedings (searched 25 June 2018), and reference lists of relevant articles.We included randomised or quasi-randomised trials of enuresis alarms or alarms combined with another intervention for treating nocturnal enuresis in children between 5 and 16 years old.Two review authors independently assessed risk of bias and extracted data.We included 74 trials (5983 children). At treatment completion, alarms may reduce the number of wet nights a week compared to control or no treatment (mean difference (MD) -2.68, 95% confidence interval (CI) -4.59 to -0.78; 4 trials, 127 children; low-quality evidence). Low-quality evidence suggests more children may achieve complete response (14 consecutive dry nights) with alarms compared to control or no treatment (RR 7.23, 95% CI 1.40 to 37.33; 18 trials, 827 children) and that more children may remain dry post-treatment (RR 9.67, 95% CI 4.74 to 19.76; 10 trials, 366 children; low-quality evidence). At treatment completion, we are uncertain whether there is any difference between alarms and placebo drugs in the number of wet nights a week (MD -0.96, 95% CI -2.32 to 0.41; 1 trial, 47 children; very low-quality evidence). Alarms may result in more children achieving complete response than with placebo drugs (RR 1.59, 95% CI 1.16 to 2.17; 2 trials, 181 children; low-quality evidence). No trials comparing alarms to placebo reported the number of children remaining dry post-treatment. Compared with control alarms, code-word alarms probably slightly increase the number of children achieving complete response at treatment completion (RR 1.11, 95% CI 0.97 to 1.27; 1 trial, 353 children; moderate-quality evidence) but there is probably little to no difference in the number of children remaining dry post-treatment (RR 0.91, 95% CI 0.79 to 1.05; moderate-quality evidence). Very low-quality evidence means we are uncertain if there are any differences in effectiveness between the other different types of alarm. At treatment completion, alarms may reduce the number of wet nights a week compared with behavioural interventions (waking, bladder training, dry-bed training, and star chart plus rewards) (MD -0.81, 95% CI -2.01 to 0.38; low-quality evidence) and may increase the number of children achieving complete response (RR 1.77, 95% CI 0.98 to 3.19; low-quality evidence) and may slightly increase the number of children remaining dry post-treatment (RR 1.39, 95% CI 0.81 to 2.41; low-quality evidence). The evidence relating to alarms compared with desmopressin in the number of wet nights a week (MD -0.64, 95% CI -1.77 to 0.49; 4 trials, 285 children) and the number of children achieving complete response at treatment completion (RR 1.12, 95% CI 0.93 to 1.36; 12 trials, 1168 children) is low-quality, spanning possible harms and possible benefits. Alarms probably slightly increase the number of children remaining dry post-treatment compared with desmopressin (RR 1.30, 95% CI 0.92 to 1.84; 5 trials, 565 children; moderate-quality evidence). At treatment completion, we are uncertain if there is any difference between alarms and tricyclics in the number of wet nights a week, the number of children achieving complete response or the number of children remaining dry post-treatment, because the quality of evidence is very low. Due to very low-quality evidence we are uncertain about any differences in effectiveness between alarms and cognitive behavioural therapy, psychotherapy, hypnotherapy and restricted diet. Alarm plus desmopressin may reduce the number of wet nights a week compared with desmopressin monotherapy (MD -0.88, 95% CI -0.38 to -1.38; 2 trials, 156 children; low-quality evidence). Alarm plus desmopressin may increase the number of children achieving complete response (RR 1.32, 95% CI 1.08 to 1.62; 5 trials, 359 children; low-quality evidence) and the number of children remaining dry post-treatment (RR 2.33, 95% CI 1.26 to 4.29; 2 trials, 161 children; low-quality evidence) compared with desmopressin alone. Alarm plus dry-bed training may increase the number of children achieving a complete response compared to dry-bed training alone (RR 3.79, 95% CI 1.85 to 7.77; 1 trial, 80 children; low-quality evidence). It is unclear if there is any difference in the number of children remaining dry post-treatment because of the wide confidence interval (RR 0.56, 95% CI 0.15 to 2.12; low-quality evidence). Due to very low-quality evidence, we are uncertain about any differences in effectiveness between alarm plus bladder training versus bladder training alone. Of the 74 included trials, 17 reported one or more adverse events, nine reported no adverse events and 48 did not mention adverse events. Adverse events attributed to alarms included failure to wake the child, ringing without urination, waking others, causing discomfort, frightening the child and being too difficult to use. Adverse events of comparator interventions included nose bleeds, headaches and abdominal pain. There is probably a slight increase in adverse events between code-word alarm and standard alarm (RR 1.34, 95% CI 0.75 to 2.38; moderate-quality evidence), although we are uncertain because of the wide confidence interval. Alarms probably reduce the number of children experiencing adverse events compared with desmopressin (RR 0.38, 95% CI 0.20 to 0.71; 5 trials, 565 children; moderate-quality evidence). Very low-quality evidence means we cannot be certain whether the adverse event rate for alarms is lower than for other treatments.Alarm therapy may be more effective than no treatment in reducing enuresis in children. We are uncertain if alarm therapy is more effective than desmopressin but there is probably a lower risk of adverse events with alarms than with desmopressin. Despite the large number of trials included in this review, further adequately-powered trials with robust randomisation are still needed to determine the full effect of alarm therapy.
