Evidence relating cigarettes, cigars and pipes to cardiovascular disease and stroke: Meta-analysis of recent data from three regions

Table 4 Acute myocardial infarction and current vs never cigarette smoking – results from random effects meta-analyses

Full output table	Factor	Level	No. of RRs	No. of studies	RR (95%CI)	Test of heterogeneity by level (NS = P ≥ 0.1) and trend if relevant, P value
	All		13	10	2.72 (2.40-3.08)	< 0.001
5	Sex	Combined	2	2	2.98 (2.20-4.04)
		Males	4	4	2.30 (1.57-3.37)
		Females	7	7	2.83 (2.40-3.34)	NS
6	Region	N. America	3	2	3.42 (2.93-3.99)
		Europe	10	8	2.54 (2.22-2.90)	< 0.01
7	Study population	National	5	3	2.85 (2.16-3.77)
		Regional	7	6	2.69 (2.18-3.33)
		Other	1	1	2.51 (2.33-2.71)	NS
8	Year of start of baseline	< 1988	2	2	1.81 (1.28-2.56)
		1988+	11	8	2.93 (2.58-3.32)	< 0.05
9	Number of cases	< 1000	7	6	2.52 (1.96-3.25)
		1000+	6	4	2.87 (2.46-3.35)	NS
10	Lowest age considered	< 30	5	3	3.02 (2.09-4.35)
		30-44	6	5	2.58 (2.20-3.04)
		45+	2	2	2.88 (2.40-3.46)	NS trend NS
11	Yr of follow-up	10-< 20	10	7	2.78 (2.40-3.23)
		20-< 30	2	2	2.88 (2.40-3.46)
		30+	1	1	2.11 (1.81-2.46)	< 0.05 trend < 0.01
12	Endpoint	Died	2	1	2.99 (1.34-6.67)
		Diagnosed	11	9	2.71 (2.38-3.08)	NS
13	Number of adjustment factors	None	1	1	1.47 (1.08-2.01)
		Age only	3	2	2.52 (2.34-2.71)
		More	9	7	2.89 (2.48-3.37)	< 0.001
14	Disease definition standard	No	6	7	2.43 (2.06-2.87)
		Yes	7	5	3.14 (2.63-3.74)	< 0.05