Pfizer Canada Inc. responded to my initial request1 1 month after it was mailed. Three other companies replied more rapidly, but most took longer than Pfizer Canada; relatively speaking, Pfizer Canada's response was prompt. In its response, Pfizer Canada did list all of the relevant trials, but 3 additional papers were listed that did not fulfil the criteria in my request. One was an uncontrolled nonblinded trial,2 the second was a retrospective subanalysis of data from double-blind, placebo-controlled studies3 and the third analyzed safety and tolerability data from a series of double-blind, placebo-controlled studies and open-label extension studies.4
Joel Lexchin Emergency Physician University Health Network Toronto, Ont.