Table 2.
Subgroup analyses of association between risk of non-arteritic anterior ischemic optic neuropathy and PDE5-I use (within 1-month period)
| Subgroup | Studies, n | Heterogeneity |
RR (95%CI) | |
|---|---|---|---|---|
| I2 | P value | |||
| Region of study | ||||
| USA | 2 | 50% | .13 | 1.07 (0.98–1.16) |
| UK | 1 | NA | 2.27 (0.99–5.21) | |
| Mixed countries∗ | 1 | NA | 2.15 (1.06–4.34)† | |
| Study design | ||||
| Case-crossover study | 2 | 0% | .92 | 2.20 (1.29–3.76)† |
| Cohort study | 2 | 50% | .13 | 1.07 (0.98–1.16) |
| Type of PDE5-I | ||||
| Tadalafil | 2 | 0% | .54 | 2.14 (1.20–3.84)† |
| Sildenafil | 2 | 0% | .63 | 2.25 (1.29–3.94)† |
| Vardenafil | 1 | NA | 0.71 (0.10–5.02) | |
NA = not applicable; PDE5-I = phosphodiesterase type 5 inhibitor; RR = relative ratio.
∗
United States, United Kingdom, France, Germany, Italy, and Spain.
†
P < .05.