We investigated whether electrical stimulation was better than no treatment at all or better than other available treatments for curing or improving stress urinary incontinence (SUI) symptoms in women. We also investigated whether SUI was cured or improved by adding electrical stimulation to other treatments, compared to other treatments and to different types of electrical stimulation. Finally, we investigated whether electrical stimulation represented value for money.
About 25% to 45% of women worldwide have problems with leaking urine involuntarily. Women with SUI often leak urine with physical exertion such as coughing or sneezing. SUI can be treated with pelvic floor muscle exercises, vaginal cones, drug therapy or surgery, but there are various problems with these treatments. A possible alternative is electrical stimulation with non-implanted devices, whereby an electrical current is delivered through vaginal electrodes.
How up-to-date is this review?
We searched for studies that had been published up to 27 February 2017.
We found 56 trials (involving a total of 3781 women, all with stress urinary incontinence but some with urgency urinary incontinence as well) comparing electrical stimulation to no treatment or to any other available treatment.
For cure or improvement of SUI, electrical stimulation was probably better than no active or sham treatment. There was not enough evidence to say whether it was any better than pelvic floor muscle training for curing or improving SUI, or for quality of life. Adding electrical stimulation to pelvic floor muscle training may not make much difference to cure or improvement of SUI. It is uncertain whether it offers any improvement in quality of life compared with pelvic floor muscle training.
We found that few women reported adverse effects with electrical stimulation, but there was not enough reliable evidence comparing electrical stimulation to other treatments to know more about its safety.
There was not enough evidence comparing electrical stimulation to other existing treatments such as drug therapy, pelvic floor muscle training plus vaginal cones, surgery, or different forms of electrical stimulation, to provide evidence-based guidance on which would be better, and for which women, in curing or improving SUI or in improving quality of life. There was no information from these studies to judge value for money.
Quality of the evidence
There is some evidence to support the use of electrical stimulation for stress urinary incontinence in women, but we are still very uncertain about the full potential of this treatment because of the low quality of the existing evidence. While we found evidence indicating that electrical stimulation may be better than no treatment, we did not find enough well-designed trials with enough women to fully answer our review questions, so we do not yet know if ES is better or worse than other treatments.
The current evidence base indicated that electrical stimulation is probably more effective than no active or sham treatment, but it is not possible to say whether ES is similar to PFMT or other active treatments in effectiveness or not. Overall, the quality of the evidence was too low to provide reliable results. Without sufficiently powered trials measuring clinically important outcomes, such as subjective assessment of urinary incontinence, we cannot draw robust conclusions about the overall effectiveness or cost-effectiveness of electrical stimulation for stress urinary incontinence in women.
Several treatment options are available for stress urinary incontinence (SUI), including pelvic floor muscle training (PFMT), drug therapy and surgery. Problems exist such as adherence to PFMT regimens, side effects linked to drug therapy and the risks associated with surgery. We have evaluated an alternative treatment, electrical stimulation (ES) with non-implanted devices, which aims to improve pelvic floor muscle function to reduce involuntary urine loss.
To assess the effects of electrical stimulation with non-implanted devices, alone or in combination with other treatment, for managing stress urinary incontinence or stress-predominant mixed urinary incontinence in women. Among the outcomes examined were costs and cost-effectiveness.
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, CINAHL, ClinicalTrials.gov, WHO ICTRP and handsearches of journals and conference proceedings (searched 27 February 2017). We also searched the reference lists of relevant articles and undertook separate searches to identify studies examining economic data.
We included randomised or quasi-randomised controlled trials of ES with non-implanted devices compared with any other treatment for SUI in women. Eligible trials included adult women with SUI or stress-predominant mixed urinary incontinence (MUI). We excluded studies of women with urgency-predominant MUI, urgency urinary incontinence only, or incontinence associated with a neurologic condition. We would have included economic evaluations had they been conducted alongside eligible trials.
Two review authors independently screened search results, extracted data from eligible trials and assessed risk of bias, using the Cochrane 'Risk of bias' tool. We would have performed economic evaluations using the approach recommended by Cochrane Economic Methods.
We identified 56 eligible trials (3781 randomised participants). Eighteen trials did not report the primary outcomes of subjective cure, improvement of SUI or incontinence-specific quality of life (QoL). The risk of bias was generally unclear, as most trials provided little detail when reporting their methods. We assessed 25% of the included trials as being at high risk of bias for a variety of reasons, including industry funding and baseline differences between groups. We did not identify any economic evaluations.
For subjective cure of SUI, we found moderate-quality evidence that ES is probably better than no active treatment (risk ratio (RR) 2.31, 95% CI 1.06 to 5.02). We found a similar result for cure or improvement of SUI (RR 1.73, 95% CI 1.41 to 2.11), but the quality of evidence was lower. We are very uncertain if there is a difference between ES and sham treatment in terms of subjective cure because of the very low quality of evidence (RR 2.21, 95% CI 0.38 to 12.73). For subjective cure or improvement, ES may be better than sham treatment (RR 2.03, 95% CI 1.02 to 4.07). The effect estimate was 660/1000 women cured/improved with ES compared to 382/1000 with no active treatment (95% CI 538 to 805 women); and for sham treatment, 402/1000 women cured/improved with ES compared to 198/1000 with sham treatment (95% CI 202 to 805 women).
Low-quality evidence suggests that there may be no difference in cure or improvement for ES versus PFMT (RR 0.85, 95% CI 0.70 to 1.03), PFMT plus ES versus PFMT alone (RR 1.10, 95% CI 0.95 to 1.28) or ES versus vaginal cones (RR 1.09, 95% CI 0.97 to 1.21).
Electrical stimulation probably improves incontinence-specific QoL compared to no treatment (moderate quality evidence) but there may be little or no difference between electrical stimulation and PFMT (low quality evidence). It is uncertain whether adding electrical stimulation to PFMT makes any difference in terms of quality of life, compared with PFMT alone (very low quality evidence). There may be little or no difference between electrical stimulation and vaginal cones in improving incontinence-specific QoL (low quality evidence). The impact of electrical stimulation on subjective cure/improvement and incontinence-specific QoL, compared with vaginal cones, PFMT plus vaginal cones, or drugs therapy, is uncertain (very low quality evidence).
In terms of subjective cure/improvement and incontinence-specific QoL, the available evidence comparing ES versus drug therapy or PFMT plus vaginal cones was very low quality and inconclusive. Similarly, comparisons of different types of ES to each other and of ES plus surgery to surgery are also inconclusive in terms of subjective cure/improvement and incontinence-specific QoL (very low-quality evidence).
Adverse effects were rare: in total nine of the women treated with ES in the trials reported an adverse effect. We identified insufficient evidence to compare the risk of adverse effects in women treated with ES compared to any other treatment. We were unable to identify any economic data.