I'm sorry to trouble you again, but I am anxious to follow up the questions I raised in my letter to you of 2 December 1997 (also in my letter of the same date to the Chief Medical Officer), about the scale and cost of iatrogenic disease in the NHS. To recap: What is the Department's best estimate (ballpark figure or range) of the cost to the NHS of injury from prescribed drugs taken with therapeutic intent, expressed as a proportion of the national drug bill - and, given that about half of all iatrogenic disease is avoidable, shouldn't more be done to control it?

I was prompted to write by the report in today's Journal of the American Medical Association (Lazarou J et al, JAMA, 1998; 279: 1200-1205), a meta-analysis which estimates that the overall incidence of serious ADRs in US hospitals was 6.7%, and of fatal ADRs 0.32% of hospitalised patients. This implies that (in 1994) over two million patients had serious adverse drug reactions, including 100,000 deaths - making adverse drug reactions between the fourth and sixth leading cause of death.

I can think of no reason to conclude that NHS figures would be substantially different, hence the very rough estimate I suggested in the paper I sent you on 12 March. This suggested that "in the UK, each year, prescribed drugs cause a few tens of thousands of deaths, and a few hundreds of thousands of hospital admissions, plus a few millions of sometimes quite troublesome side effects, usually never counted at all." Would the Department broadly agree?

Of course there is uncertainty about the figures but, clearly [a] the problem of drug-induced illness does need to be addressed; and [b] is certainly not properly addressed by the MCA/CSM 'Yellow Card' ADR reporting scheme.

Could someone please now let me know what are the best estimates available in the Department of the extent and cost of drug-induced illness in the NHS? Many thanks.