Table 3.
Results of subgroup analyses by outcome type and NSAIDs type
|
Study characteristics |
Number of studies |
OR (95% CI) |
P
OR
value |
Effect model |
Heterogeneity |
|
|---|---|---|---|---|---|---|
| I 2 (%) | P value | |||||
|
Risk of prostate cancer incidence |
|
|
|
|
|
|
|
Any NSAIDs |
|
|
|
|
|
|
|
Studies of total prostate cancer |
11 |
0.90 (0.75, 1.07) |
0.25 |
Random |
93.5 |
<0.001 |
| Case–control studies |
8 |
0.97 (0.79, 1.20) |
0.78 |
Random |
93.8 |
<0.001 |
| Cohort studies |
3 |
0.71 (0.47, 1.07) |
0.10 |
Random |
81.4 |
0.005 |
| Studies in North America |
6 |
0.73 (0.60, 0.88) |
0.001 |
Random |
79.6 |
<0.001 |
| Studies in Europe |
5 |
1.29 (1.25, 1.34) |
<0.001 |
Fixed |
37.2 |
0.17 |
|
Studies of advanced prostate cancer |
5 |
0.86 (0.52, 1.40) |
0.54 |
Random |
94.2 |
<0.001 |
|
Aspirin |
|
|
|
|
|
|
|
Studies of total prostate cancer |
23 |
0.92 (0.87, 0.97) |
0.002 |
Random |
66.2 |
<0.001 |
| Case–control studies |
13 |
0.92 (0.85, 0.99) |
0.040 |
Random |
63.7 |
0.001 |
| Cohort studies |
10 |
0.91 (0.83, 0.99) |
0.040 |
Random |
71.7 |
<0.001 |
| Studies from North America |
16 |
0.92 (0.86, 0.97) |
0.003 |
Random |
53.7 |
0.006 |
| Studies from Europe |
7 |
0.94 (0.82, 1.08) |
0.40 |
Random |
80.7 |
<0.001 |
| High quality studies |
8 |
0.89 (0.81, 0.98) |
0.022 |
Random |
77.2 |
<0.001 |
| Long-term aspirin use (≥4 years) |
8 |
0.88 (0.79, 0.99) |
0.038 |
Random |
66.8 |
0.004 |
|
Studies of advanced prostate cancer |
13 |
0.81 (0.73, 0.89) |
<0.001 |
Fixed |
23.9 |
0.20 |
| Case–control studies |
7 |
0.84 (0.73, 0.98) |
0.025 |
Fixed |
23.7 |
0.18 |
| Cohort studies |
6 |
0.77 (0.67, 0.89) |
<0.001 |
Fixed |
23.5 |
0.26 |
| Studies from North America |
9 |
0.82 (0.75, 0.89) |
<0.001 |
Fixed |
14.0 |
0.32 |
| Studies from Europe |
4 |
0.88 (0.75, 1.03) |
1.22 |
Fixed |
48.2 |
0.12 |
| High quality studies |
6 |
0.81 (0.72, 0.92) |
0.002 |
Fixed |
38.1 |
0.152 |
|
Studies of non-advanced prostate cancer |
6 |
0.96 (0.87, 1.07) |
0.460 |
Fixed |
33.6 |
0.177 |
|
Non-aspirin NSAIDs |
|
|
|
|
|
|
|
Studies of total prostate cancer |
17 |
1.01 (0.90, 1.13) |
0.86 |
Random |
90.1 |
<0.001 |
| Case–control studies |
11 |
0.97 (0.81, 1.17) |
0.74 |
Random |
93.0 |
<0.001 |
| Cohort studies |
6 |
1.07 (0.95, 1.20) |
0.25 |
Random |
69.6 |
0.006 |
| Studies from North America |
11 |
0.94 (0.85, 1.05) |
0.28 |
Random |
68.8 |
<0.001 |
| Studies from Europe |
6 |
1.18 (1.06, 1.32) |
0.002 |
Random |
71.1 |
0.004 |
|
Studies of advanced prostate cancer |
9 |
0.99 (0.77, 1.28) |
0.97 |
Random |
81.6 |
<0.001 |
|
Studies of non-advanced prostate cancer |
3 |
1.00 (0.90, 1.12) |
0.943 |
Fixed |
0.0 |
0.897 |
|
Any COX2 inhibitors |
|
|
|
|
|
|
|
Studies of total prostate cancer |
5 |
1.10 (0.90, 1.33) |
0.36 |
Random |
48.7 |
0.099 |
|
Studies of advanced prostate cancer |
3 |
1.20 (0.79, 1.83) |
0.40 |
Fixed |
0.0 |
0.87 |
|
Risk of prostate cancer-specific mortality |
|
|
|
|
|
|
|
Any NSAIDs (including aspirin use alone) |
|
|
|
|
|
|
|
Studies of total prostate cancer |
8 |
1.00 (0.68, 1.47) |
0.99 |
Random |
95.3 |
<0.001 |
|
Aspirin |
|
|
|
|
|
|
|
Studies of total prostate cancer |
6 |
0.86 (0.78, 0.96) |
0.005 |
Fixed |
39.2 |
0.15 |
| Studies from North America |
3 |
0.85 (0.50, 144) |
0.55 |
Random |
63.8 |
0.063 |
| Studies from Europe | 3 | 0.85 (0.76, 0.95) | 0.005 | Fixed | 12.8 | 0.32 |
CI, confidence interval; COX-2, cyclooxygenase enzymes-2; OR, odds ratio.