Table 1 Overview of characteristics of 110 included randomized clinical trials
Characteristics | Â |
|---|---|
Median sample size (range) | 195 (13-817) |
Median year of publication (range) | 2006 (1998-2012) |
Parallel group design | 98 (89) |
Crossover group design | 10 (9) |
Study run-in phase with placebo reported | 2 (2) |
Commercial funding | 89 (81) |
Single center study | 9 (8) |
Continent: | |
    Across continents | 24 (22) |
    Africa | 1 (1) |
    Asia | 20 (18) |
    Europe | 16 (15) |
    North America | 23 (21) |
    Oceania | 2 (2) |
    South America | 5 (5) |
Type of PDE-5 inhibitor: | |
    Sildenafil | 55 (50) |
    Vardenafil | 28 (26) |
    Tadalafil | 27 (25) |
Condition studied: | |
    Broad spectrum | 68 (62) |
    Cardiovascular disease | 5 (5) |
    Depression | 5 (5) |
    Diabetes | 9 (8) |
    Prostatic cancer | 6 (6) |
    Metabolic syndrome | 3 (3) |
    Multiple sclerosis | 2 (2) |
    Post-traumatic stress syndrome | 2 (2) |
    Spinal cord injury | 2 (2) |
    Renal failure | 4 (4) |
    Other | 4 (4) |
Risk of bias: | |
Random sequence generated adequately | |
    Low | 22 (20) |
    Unclear | 88 (80) |
    High | 0 (0) |
Allocation concealed adequately | |
    Low | 16 (15) |
    Unclear | 93 (85) |
    High | 1 (1) |
Participants blinded adequately | |
    Low | 58 (53) |
    Unclear | 51 (46) |
    High | 1 (1) |
Caregivers blinded adequately | |
    Low | 17 (16) |
    Unclear | 93 (85) |
    High | 0 (0) |
Outcome assessors blinded adequately | |
    Low | 17 (16) |
    Unclear | 93 (85) |
    High | 0 (0) |
Overall blinded adequately | |
    Yes | 5 (5) |
    No | 48 (44) |
    Unclear | 57 (52) |
Other study methods: | |
ITT analysis | 5 (5) |
Balanced baseline prognostic factors | 82 (75) |
Naïve to intervention | 10 (9) |
Outcomes | Â |
Dichotomeous outcome, GEQ reported | 69 (63) |
Most common AEs reported* | 70 (64) |
Methods used to monitor AEs | |
Prospective or routine monitoring | 22 (20) |
Spontaneous reporting | 13 (12) |
Patient checklist, questionnaire or diary | 4 (4) |
Systematic survey of patients | 1 (1) |
Not clear | 65 (59) |