Table 1.
Baseline characteristics of included studies
| Study | Country | Main ethnicity | Study period | Study design | LOE | Total participants, N | Mean or median age (y) | PDE5-I period of use | PDE5-I users/controls (within 1 mo) | PDE5-I users/controls (within 1 y) | Incidence of NAION in PDE5-I users (%) | Quality score∗ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Flahavan et al, 2017 | UK | Caucasian | 2010–2015 | Prospective case-crossover study | 2b | 26 | 61.3 | Within 1 mo and 1 y of index date | 24/24 | 26/26 | NA | ★★★★★ |
| Nathoo et al, 2015 | Canada | Mixed | 2000–2011 | Retrospective case-control study | 3 | 1,238,399 | 69.8 | Within 1 mo and 1 y of index date | 67/85,373 | 75/91,559 | NA | ★★★★★★★★ |
| Campbell et al, 2015 | mixed | Mixed | 2008–2012 | Retrospective case-crossover study | 3 | 43 | 61.4 | Within 1 mo and 2 mo of index date | 43/43 | NA | NA | ★★★★★★★ |
| French et al, 2008 | USA | Mixed | 2004–2005 | Retrospective cohort study | 3 | 3,686,212 | 67 | Within 1 mo of index date | 8,344/3,677,868 | NA | 15/8,344 (0.18%) | ★★★★★★★ |
| 3,762,037 | 68 | 84,169/3,677,868 | 129/84,169 (0.15%) | |||||||||
| Margo and French, 2007 | USA | Mixed | 2004–2005 | Retrospective cohort study | 3 | 4,157,357 | 64 | Within 1 mo of index date | 479,489/3,677,868 | NA | 442/479,489 (0.09%) | ★★★★★★★ |
LOE = level of evidence; NA = not applicable; NAION = non-arteritic anterior ischemic optic neuropathy; PDE5-I = phosphodiesterase type 5 inhibitor.
∗
Points of Newcastle-Ottawa Scale score, where 1 star equals 1 point.