Table 3.

Summary of reviewed studies according to their type and the site of stimulation.

	Non control	Placebo control	Other form of control
Sacral	Yokozuka et al. [11] Skeil and Thorpe [15] Walsh et al. [13]	Bower et al. [23] Hasan et al. [12]	Fjorback et al. [30] Walsh et al. [29] Soomro et al. [14]
PTNS	Amarenco et al. [37] De Seze et al. [19] McGuire et al. [16]	Booth et al. [45] Bellette et al. [20]	Schreiner et al. [18] Svihra et al. [17] Hasan et al. [12]
Suprapubic/other	Okada et al. [26]	Bower et al. [23]	Hasan et al. [12]