Table 2.

Stratified pooled odds ratios and 95% confidence intervals of NSAIDs intake and prostate cancer

Subgroup	Number of studies	Odds ratio (95% confidence interval)	Heterogeneity
			P	I 2(%)
Aspirin
USA	14	0.937 (0.900, 0.975)	0.012	52.0
Other countries	10	0.969 (0.934, 1.006)	0.000	70.0
Cohort studies	13	0.930 (0.894, 0.967)	0.025	48.6
Case-control studies	11	0.976 (0.940, 1.013)	0.000	69.0
NSAIDs
USA	3	0.922 (0.836, 1.016)	0.011	77.7
Other countries	8	1.212 (1.174, 1.251)	0.000	92.7
Cohort studies	4	1.022 (0.938, 1.113)	0.000	90.2
Case-control studies	7	1.205 (1.167, 1.245)	0.000	93.3
NA-NSAIDs
USA	6	1.009 (0.927, 1.099)	0.807	0.0
Other countries	8	0.915 (0.869, 0.964)	0.001	70.3
Cohort studies	5	0.992 (0.909, 1.083)	0.629	0.0
Case-control studies	9	0.922 (0.876, 0.971)	0.002	67.9