Abstract
Methods This article has had a long gestation. Much of the evidence comes from my experience over nearly 30 years, first as leader of the computer evaluation unit at the Charing Cross Hospital, London (1974-80), then as a general practice system supplier (1980-90), and as a supplier of clinical information systems for hospital doctors (1990-9). An initial version of the article was written in 1993 and extended for the NHS Executive's integrated clinical workstation project 1995. A later version was presented at the AMIA Symposium, Washington DC, November 2001 (proceedings, pp 42-6).