Abstract: The review included 27 RCTs involving 1803 children. Of these, six were multi-arm and one was also a cross-over study. Most studies were small, with numbers randomised ranging from 16 to 202. A total of 19 studies were at high risk of bias for at least one domain. Few studies reported data suitable for pooling due to heterogeneity in interventions, outcomes and measurements. Individual conservative interventions (lifestyle, behavioural or physical) versus no treatment Transcutaneous electrical nerve stimulation (TENS) versus sham (placebo) TENS. More children receiving active TENS may achieve continence (risk ratio (RR) 4.89, 95% confidence interval (CI) 1.68 to 14.21; 3 studies; n = 93; low-certainty evidence). One individual conservative intervention versus another individual or combined conservative intervention Pelvic floor muscle training (PFMT) with urotherapy versus urotherapy alone. We are uncertain whether more children receiving PFMT with urotherapy achieve continence (RR 2.36, 95% CI 0.65 to 8.53, 95% CI 25 to 100; 3 studies; n = 91; very low-certainty evidence). Voiding education with uroflowmetry feedback and urotherapy versus urotherapy alone. Slightly more children receiving voiding education with uroflow feedback and urotherapy may achieve continence (RR 1.13, 95% CI 0.87 to 1.45; 3 studies; n = 151; low-certainty evidence). Urotherapy with timer watch versus urotherapy alone. We are uncertain whether urotherapy plus timer watch increases the number of children achieving continence compared to urotherapy alone (RR 1.42, 95% CI 1.12 to 1.80; 1 study; n = 58; very low-certainty evidence). Combined conservative interventions versus other combined conservative interventions TENS and standard urotherapy versus PFMT with electromyographic biofeedback and standard urotherapy. We are uncertain whether there is any evidence of a difference between treatment groups in the proportions of children achieving continence (RR 1.11, 95% CI 0.73 to 1.68; 1 study; n = 78; very low-certainty evidence). PFMT with electromyography biofeedback and standard urotherapy versus PFMT without feedback but with standard urotherapy. We are uncertain whether there is any evidence of a difference between treatment groups in the proportions of children achieving continence (RR 1.05, 95% CI 0.72 to 1.52; 1 study; n = 41; very low-certainty evidence). Individual conservative interventions versus non-conservative interventions (pharmacological or invasive, combined or not with any conservative interventions) PFMT versus anticholinergics. We are uncertain whether more children receiving PFMT than anticholinergics achieve continence (RR 1.92, 95% CI 1.17 to 3.15; equivalent to an increase from 33 to 64 per 100 children; 2 studies; n = 86; very low-certainty evidence). TENS versus anticholinergics. We are uncertain whether there was any evidence of a difference between treatment groups in the proportions of children achieving continence (RR 0.81, 95% CI 0.05 to 12.50; 2 studies; n = 72; very low-certainty evidence). Combined conservative interventions versus non-conservative interventions (pharmacological or invasive, combined or not with any conservative interventions) Voiding education with uroflowmetry feedback versus anticholinergics. We are uncertain whether there was any evidence of a difference between treatment groups in the proportion of children achieving continence (RR 1.02, 95% CI 0.58 to 1.78; 1 study; n = 64; very low-certainty evidence). The review found little reliable evidence that can help affected children, their carers and the clinicians working with them to make evidence-based treatment decisions. In this scenario, the clinical experience of individual clinicians and the support of carers may be the most valuable resources. More well-designed research, with well-defined interventions and consistent outcome measurement, is needed.

Plain-language summary: The review identified 27 studies involving 1803 children. Twelve studies declared funding from outside sources. One of these was funded by Astellas Pharma, while another study was provided with special batches of placebo and medication free of charge, as well as materials for pad tests free of charge from another company. Cochrane Reviews assess the 'certainty' or reliability of the evidence using standardised methods that consider the way studies were designed, conducted and reported, differences between studies or populations, and the combined results of studies. Most of the studies identified for this review were small and many were poorly designed and not reported clearly. Most of the evidence was considered to be of very low certainty, meaning that little can be said with any certainty about the effectiveness of treatments. Transcutaneous electrical nerve stimulation (TENS) may be more effective than no treatment for ending or reducing daytime wetting. We are uncertain whether urotherapy (behavioural programmes in which children - and sometimes carers - are taught about how the bladder works, proper toileting postures and methods, scheduled toileting, and planning what and how much to drink) is more effective when supplemented with PFMT, voiding education with feedback, or watches with alarms set to remind children when to go to the toilet. We are uncertain whether feedback that shows children how their muscles are working or how their bladder is emptying improves the effectiveness of TENS with urotherapy compared to PFMT plus feedback and urotherapy. We are also uncertain whether PFMT and urotherapy plus feedback improves the effectiveness of PFMT and urotherapy alone. We are uncertain whether pelvic floor muscle training (PFMT) or TENS are more effective than anticholinergics (drugs that can reduce signals from the brain that cause the bladder to contract and empty). We are uncertain whether voiding education plus uroflowmetry (a test to measure the volume of urine) and feedback increases the number of continent children compared to anticholinergics. No serious adverse events were reported that were considered to be related to study treatments. Most non-serious adverse events and side effects were mild or moderate in severity and were in children receiving pharmaceutical interventions. These included common pharmaceutical side effects such as nausea, abdominal pain, dry mouth, drowsiness and headache. There is a lack of good-quality research evidence that can help children, their carers and doctors and nurses to make decisions about treatments. More well-designed research may provide much needed evidence about the effectiveness of promising interventions in children with daytime urinary incontinence, such as TENS, PFMT and timers on watches (or mobile phones) to remind children about toileting schedules. However, it is hoped that this review will draw attention to the need for research into effective treatments for daytime wetting in children.