Table 2.

Subgroup analysis of the association between MTHFR A1298C polymorphism and CHD

Subgroup analysis	Genetic model
	C vs. A			CC vs. AA			CC vs. AC			AC vs. AA			Dominant model			Recessive model
	No.	OR	95% CI	No.	OR	95% CI	No.	OR	95% CI	No.	OR	95% CI	No.	OR	95% CI	No.	OR	95% CI
Summary	16	1.13	0.92–1.37	15	1.33	0.92–1.92	15	1.25	0.98–1.60	16	1.05	0.81–1.36	16	1.10	0.84–1.43	15	1.38	1.10–1.73
HWE
Consistent	12	1.02	0.85–1.21	11	1.02	0.73–1.42	11	1.14	0.85–1.52	12	1.00	0.78–1.28	12	1.00	0.79–1.28	11	1.10	0.83–1.44
Inconsistent	4	1.55	0.94–2.57	4	2.97	1.89–4.66	4	1.59	1.01–2.50	4	1.11	0.40–3.06	4	1.37	0.56–3.36	4	2.21	1.49–3.27
Down’s syndrome
Without	14	1.20	0.98–1.47	13	1.47	1.01–2.14	13	1.29	1.00–1.66	14	1.14	0.86–1.50	14	1.19	0.90–1.57	13	1.44	1.14–1.82
With	2	0.69	0.48–0.98	2	0.50	0.19–1.31	2	0.86	0.33–2.23	2	0.59	0.36–0.95	2	0.57	0.36–0.92	2	0.66	0.26–1.68
Region
Europe	6	1.06	0.81–1.40	6	1.36	0.85–2.17	6	1.48	1.05–2.09	6	0.91	0.62–1.35	6	0.98	0.66–1.46	6	1.40	1.01–1.94
Asia	6	1.27	0.87–1.85	5	1.44	0.67–3.13	5	1.06	0.68–1.66	6	1.27	0.79–2.04	6	1.28	0.80–2.05	5	1.42	0.95–2.14
America	3	0.81	0.55–1.21	3	0.62	0.26–1.50	3	0.78	0.37–1.65	3	0.82	0.49–1.36	3	0.78	0.45–1.34	3	0.72	0.35–1.49
Sample size
Large (>100)	9	1.05	0.90–1.22	8	1.10	0.82–1.49	8	1.30	0.96–1.77	9	1.01	0.80–1.28	9	1.03	0.83–1.28	8	1.21	0.91–1.62
Small (<100)	7	1.13	0.69–1.87	7	1.60	0.74–3.45	7	1.17	0.78–1.76	7	1.02	0.51–2.05	7	1.09	0.54–2.21	7	1.68	1.17–2.41