Objectives:
This study is purposed to investigate the effects and safety of Bojungikgi-tang for stress urinary continence by systemic review and meta-analysis of the randomized controlled trials (RCTs).


Methods:
RCTs on the treatment of Bojungikgi-tang for stress urinary continence were selected among the literature published until December 2019 in seven domestic and foreign databases (Pubmed, The Cochrane library, CAJ, Wangfang, CiNii, RISS, and Korean Traditional Knowledge Portal). The quality of the literature was evaluated using the Cochrane''s Risk of Bias tool, and RevMan 5.3 was used for the synthesis of results. Meta-analysis was performed with the total effective rate, the volume of urine leakage per hour, and the International Consulting on Insurance Questionnaire-Short Form (ICIQ-SF) scores as evaluation indicators.


Results:
Total 694 patients with stress urinary incontinence were finally selected from 8 RCTs. Meta-analysis has shown that in five studies, the total effective rate of the combined treatment Plevic Floor Muscle Training (PFMT) and Bojungikgi-tang is statistically significantly higher than that of PFMT alone (odds ratio(OR): 4.03, 95% CI 2.54, 6.39, P<0.00001 ,I²=0). In two studies, The volume of urine leakage per hour of the combined treatment Plevic Floor Muscle Training (PFMT) and Bojungikgi-tang was statistically significantly lower than that of PFMT alone (standardized mean difference(SMD): ?3.94, 95% CI ?4.41ml/h, -3.44ml/h, P<0.00001, I²=0). In three studies, ICIQ-SF scores of the combined treatment Plevic Floor Muscle Training (PFMT) and Bojungikgi-tang were statistically significantly lower than those of PFMT alone (standardized mean difference(SMD): ?1.55, 95% CI ?2.46, -0.63, P<0.00001, I²=91). In each study, western medicine and biofeedback were respectively treated in combination with Bojungikgi-tang. and the total effective rate was higher than those performed alone (p<0.05). In one study comparing the combined treatment Plevic Floor Muscle Training (PFMT) and Bojungikgi-tang with surgical treatment, the treatment group increased the Blade Neck Descent (BND) during Valsalva maneuver and decreased the Retrovesical Angle (RA) to indicate a favorable outcome (p<0.05). Two cases of diarrhea were reported in relation to the safety of the Bojungikgi-tang and no other studies had significant side effects. Overall, the risk of bias was uncertain or low in the quality assessment of the literatures.


Conclusions: This study suggests that Western medical treatment combined with Bojungikgi-tang for stress urinary incontinence might be more effective in improving symptoms than conventional Western medical treatment alone. However, the number of literature included in the meta-analysis was insufficient, and the quality of the selected literature was generally low. Therefore, high-quality clinical studies on herbal medicine treatment for urinary incontinence would be required in the future.