Letter: More screening call

Sir: There you go again ("Bad doctors are a dangerous cancer", 29 July) - as if unsatisfactory work in the medical field has always been or could be exposed by journalists and lawyers rather than by the medical profession itself and as if satisfactory practice is a matter of adhering to predetermined rules laid down like the Ten Commandments, rather than a matter of continuous revision.

It was not journalists or lawyers who introduced cervical screening, nor do you appear to understand the inherent difficulties involved or the fact that the best practice evolves in the light of experience. All biology, including its application to medicine, is subject to variation around a mean; and to expect every practitioner to achieve the mean standard is comparable to President Johnson's famous gaffe when he promised, on being informed that 50 per cent of Americans had an IQ below 100, to put it right if re-elected. That he succeeded merely demonstrates that the mean shifts with time. Your attitude to medicine does you no credit nor medicine nor society any good.

JOHN A DAVIS

Cambridge