Comparison 1. Gene therapy versus no gene therapy control.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Amputation‐free survival	4	756	Odds Ratio (M‐H, Random, 95% CI)	1.68 [0.75, 3.76]
2 Complete ulcer healing	5	238	Odds Ratio (M‐H, Fixed, 95% CI)	2.16 [1.02, 4.59]
3 Amputation (above‐ankle amputation of the index limb)	11	1336	Odds Ratio (M‐H, Fixed, 95% CI)	1.06 [0.77, 1.46]
4 All‐cause mortality	12	1685	Odds Ratio (M‐H, Fixed, 95% CI)	0.93 [0.66, 1.31]
5 ABI ‐ change from baseline	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
6 Pain symptom scores (VAS)	2	152	Mean Difference (IV, Fixed, 95% CI)	‐0.22 [‐0.83, 0.38]