Table 3.

Subgroup analysis performed with patient and study-level characteristics considered as potential sources of heterogeneity.

	N	Summary RR (95% CI)a	RR=1 (z)	P value	I2 (%)
Endpoint myocardial infarction
All studies	16	1.54 (1.28–1.85)	4.64	<0.001	80.9
Subdivision
Coronary heart disease at baseline
Yes	6	1.02 (0.77–1.36)	0.15	0.879	55.3
No	10	1.84 (1.53–2.21)	6.53	<0.001	77.2
Composite endpoint
Yes	3	2.10 (1.66–2.66)	6.19	<0.001	0.0
No	13	1.45 (1.19–1.77)	3.64	<0.001	82.9
Prospective cohort study
Yes	6	1.88 (1.56–2.26)	6.61	<0.001	46.8
No	10	1.32 (1.02–1.72)	2.12	0.034	85.1
Endpoint all-cause mortality
All studies	13	1.95 (1.50–2.54)	4.98	0.001	95.4
Subdivision
Coronary heart disease at baseline
Yes	8	2.12 (1.48–3.04)	4.10	<0.001	94.8
No	5	1.58 (1.29–1.94)	4.43	<0.001	73.2
Prospective cohort study
Yes	5	2.60 (1.64–4.13)	4.04	<0.001	90.1
No	8	1.64 (1.38–1.95)	5.59	<0.001	83.5
Endpoint heart failure
All studies	9	4.62 (3.13–6.83)	7.68	<0.001	96.1
Subdivision
Coronary heart disease at baseline
Yes	3	2.84 (1.65–4.91)	3.75	<0.001	88.3
No	6	5.92 (4.08–8.58)	9.38	<0.001	92.0
Prospective cohort study
Yes	2	8.68 (2.75–27.40)	3.69	<0.001	86.5
No	7	3.94 (2.84–5.48)	8.16	<0.001	94.0

RR (95% CI): relative risk with its 95% confidence interval.

^aEstimates from random effects model.