Second, we cannot exclude a selection bias and a reporting bias, since we only contacted tinnitus patients, who had presented at a tertiary tinnitus clinic and who had reported the existence of headaches, when they presented at the tinnitus clinic.
Participants were considered an incident case of diabetes on the date of their first "yes" response to glucose-lowering medication use or the following questions: "Has a doctor ever said you have diabetes or sugar in the blood?" (2006 February 7 , 2008 or "Since we last contacted you, has a doctor said you have diabetes or sugar in the blood?" (February 7 , 2008 April 18 , 2011
One explanation is to take into account some predetermined bias inherent to the response and collaboration of the representatives of the national radiological societies whom we contacted, since they were responsible for promoting participation to this survey among their members.
It had been seven years since we made contact.
When a patient had been hospitalized since inclusion in the study, we contacted hospitals to obtain the information whether pneumonia or another illness was the reason for the hospitalization.
Since we enrolled only contacts with smear positive TB patients, it was not possible to examine the effect of smear negative and the positivity of tests when the index case had a cough.
The study was not eligible for ethics committee approval according to Danish law, since we had no contact with patients, did not perform any interventions or used biological material.
The main limitation of this study is that these findings, albeit reported by credible sources, may not accurately reflect the true vaccine and antiviral use in Africa, especially since we were unable contact representatives in 14 countries and did not get a response from 9 countries, many of which are lower income.
He told me that he has since been contacted by other alleged victims of Poulter.
