Table 2.

Results of meta-analysis of studies investigating effect of collaterals on mortality

Study	Odds collaterals	Odds no collaterals	N	Odds ratio	95 % CI	T-value	P-value
1. Antoniucci 2002	11/253	81/819	1164	0.44	0.23–0.84	−2.50	0.0125
2. Monteiro 2003	4/31	6/29	70	0.62	0.16–2.44	−0.68	0.0497
3. Elsman 2004	3/103	45/908	1059	0.59	0.18–1.92	−0.88	0.380
4. Meier 2007	25/201	170/416	812	0.30	0.19–0.48	−5.15	0.0001
5. Sorajja 2007	3/116	8/191	318	0.62	0.16–2.37	−0.70	0.483
6. Regieli 2009	2/261	4/612	879	1.17	0.21–6.44	+0.18	0.855
7. Desch 2010	3/66	22/144	235	0.30	0.09–1.03	−1.92	0.056
8. Steg 2010	155/1767	28/223	2173	0.70	0.46–1.07	−1.65	0.098
9. Ilia 2011	3/44	7/27	81	0.26	0.06–1.10	−1.83	0.068
Pooled odds ratio			6791	0.47	0.37–0.61	−5.90	0.0001

Heterogeneity chi-square value = 9.1724, 8° of freedom, not significant. I-square value = 12.8 % [< 50 % cut-off for no heterogeneity]