Introduction and hypothesis: This systematic review and meta-analysis was aimed at investigating the safety and short- and long-term efficacy of electrical stimulation (ES) in women with stress urinary incontinence (SUI).
Methods: PubMed, Embase, and the Cochrane database were searched for randomized controlled trials (RCTs) conducted up to 2020. Studies comparing ES with sham ES or no intervention were included. Standardized mean differences (SMDs), weighted mean differences (WMDs), relative risks (RR), and 95% confidence intervals (CIs) were calculated.
Results: This study included 9 RCTs, involving a total of 982 patients, of whom 520 received ES. Our results showed that in the short term (< 3 months), compared with sham ES or no intervention, ES significantly improved incontinence-specific quality of life (IQOL) (p = 0.003; SMD = 0.90 [95% CI, 0.30 to 1.50]; I2 = 88%) and reduced urine leakage (p < 0.00001; WMD = -6.15 [95% CI, -8.29 to -4.01]; I2 = 0%) but did not significantly reduce the frequency of incontinence episodes (p = 0.34; WMD = -0.98 [95% CI, -2.99 to 1.04]; I2 = 85%). In the long term (3-7.5 months), ES significantly improved IQOL (p = 0.0009; SMD = 1.14 [95% CI, 0.47 to 1.81]; I2 = 91%) and reduced the frequency of incontinence episodes (p = 0.0009; WMD = -2.45 [95% CI, -3.90 to -1.01]; I2 = 79%) but did not significantly reduce urine leakage (p = 0.27; WMD = -9.21 [95% CI, -25.57 to 7.14]; I2 = 71%). There was no significant difference in adverse events between ES and sham ES or no intervention (p = 0.36; RR = 1.34 [95% CI, 0.72 to 2.50]; I2 = 0%). A test for subgroup differences showed that electroacupuncture (EA) improved long-term IQOL to a greater extent than vaginal ES (VES), whereas there was no significant difference in efficacy between EA and VES in short- or long-term reduction of urine leakage, frequency of incontinence episodes, or short-term IQOL improvement.
Conclusions: ES may improve short- and long-term IQOL for women with SUI, but it appears to provide only short-term reduction in urine leakage and long-term reduction in frequency of incontinence episodes. However, we cannot draw any conclusion on the safety between ES and sham ES or no intervention because of the rarity of adverse events. It is still uncertain whether EA is comparable or superior to VES owing to an insufficient number of studies and patients. The conclusions should be considered carefully because of the limited quality and quantity of the RCTs included. Further rigorous RCTs with adequate sample sizes and long follow-up are necessary to fully validate our findings.