The Irish Haemophilia Society advised its members to keep using clotting concentrates even after an Irish haemophiliac was diagnosed with AIDS, the tribunal was told.
The advice from the society in early 1985 was that the risk to a haemophiliac of contracting AIDS was much less than the risk of death if treatment was withheld, Mr Shay Farrelly, former chairman of the society, said.
The advice was issued just weeks after the first Irish haemophiliac was diagnosed with AIDS at St James's Hospital, Dublin, in November 1984. He had contracted the condition from contaminated blood products.
In an information bulletin for members in January, 1985, which was examined by the tribunal, the IHS said only a fraction of 1 per cent of haemophiliacs worldwide had contracted AIDS at that stage. It "strongly urged" all haemophiliacs to continue taking treatment.
"The risk to a haemophiliac of death or serious physical damage due to withholding of treatment is much greater than the risk of contracting AIDS," it said.
It added that even though most of the patients with haemophilia who had developed AIDS had been treated with concentrate "to date there is no specific evidence indicating that there is a greater risk with concentrate than with cryoprecipitate or fresh frozen plasma".
Mr Farrelly said the information would have been passed by the leading treater of haemophiliacs at the time, Prof Ian Temperley, before it was issued.
The tribunal, which is now investigating the response of the IHS to the infection of more than 220 haemophiliacs in the State with HIV and hepatitis C, will hear evidence today from its chairman, Mr Brian O'Mahony, who is also president of the World Federation of Haemophiliacs.