LETTERS. - O'Dowd, Tom; O'Dowd, Siobhan; Baker, Alastar; Griffin, Fiona; Stokes, M.; Ralston, C.; Stack, C.; Robson, N.; Redington, Andrew; Bush, Andrew; Shinebourne, Elliot; Scallan, Michael; et al. (BMJ: British Medical Journal (International Edition), 1993)