Indirect comparison of interventions using published randomised trials: systematic review of PDE-5 inhibitors for erectile dysfunction

BACKGROUND: There are no randomised and properly blinded trials directly comparing one PDE-5 inhibitor with another in a normal home setting. Valid indirect comparisons with a common comparator must examine equivalent doses, similar duration, similar populations, with the same outcomes reported in the same way. METHODS: Published randomised, double-blind trials of oral PDE-5 inhibitors for erectile dysfunction were sought from reference lists in previous reviews and electronic searching. Analyses of efficacy and harm were carried out for each treatment, and results compared where there was a common comparator and consistency of outcome reporting, using equivalent doses. RESULTS: Analysis was limited by differential reporting of outcomes. Sildenafil trials were clinically and geographically more diverse. Tadalafil and vardenafil trials tended to use enriched enrolment. Using all trials, the three interventions were similar for consistently reported efficacy outcomes. Rates of successful intercourse for sildenafil, tadalafil and vardenafil were 65%, 62%, and 59%, with placebo rates of 23–28%. The rates of improved erections were 76%, 75% and 71%, respectively, with placebo rates of 22–24%, and NNTs of 1.9 or 2.0. Reporting of withdrawals was less consistent, but all-cause withdrawals for sildenafil, tadalafil and vardenafil were 8% 13% and 20%. All three drugs were well tolerated, with headache being the most commonly reported event at 13–17%. There were few serious adverse events. CONCLUSION: There were differences between trials in outcomes reported, limiting comparisons, and the most useful outcomes were not reported. For common outcomes there was similar efficacy between PDE-5 inhibitors

An information-based solution for the puzzle of testimony and trust

Original article can be found at: http://www.tandf.co.uk/ Copyright Taylor & FrancisIn this paper, I offer a contribution to the debate on testimony that rests on three elements: the definition of semantic information (Floridi, 2004), the analysis of trust as a second-order property of first-order relations provided in (Taddeo, 2010), and Floridi’s Network Theory of Account (NTA) (Floridi, Forthcoming). I argue that testimony transmits semantic information and it is neither grounded on trust nor is it justified by it. Instead, I show that testimony is an occurrence of a first-order relation of communication affected by the second-order property of trust. I then defend the view that an epistemic agent can acquire some knowledge, on the basis of the information communicated through testimony, if and only if the agent is able to connect the transmitted information to the conceptual network of interrelation to which it belongs. I refer to Floridi’s NTA to show how such a network allows the epistemic agent to achieve knowledge on the basis of semantic information.Peer reviewe