Doctors 'making fewer diagnostic errors'

Heart disease diagnosis has dramatically improved

The number of errors made by doctors in diagnosing diseases has halved since the 1970s, say researchers.

A comparison of the diagnosis given by doctors in hospitals with the results of post mortems showed that the number of mistakes has fallen dramatically in the past three decades.

The number of diagnostic errors was halved between 1972 and 1992, mainly through a reduction in misdiagnosis of cardiovascular diseases.

Dr Franco Salomon

The study by researchers at the University of Zurich in Switzerland looked at the deaths of 300 patients in 1972, 1982 and 1992.

The greatest improvement was in heart disease and stroke, but there was little improvement in diagnosing cancers.

Rates of detection were slightly improved for infectious diseases.

The researchers suggested the lack of change in cancer diagnosis rates could be because a great deal of time had always been given to investigating tumours.

The frequency of major errors fell from 30% in 1972, to 18% in 1982 and 14% in 1992.

Meanwhile, the rate of minor errors rose from 23% in 1972 to 46% in 1992.

Non-invasive techniques

The total number of diagnostic procedures per year increased from 191 in 1972 to 259 in 1992, mainly because of non-invasive techniques, such as ultrasonography, and endoscopies.

Dr Franco Salomon, one of the researchers, said: "The number of diagnostic errors was halved between 1972 and 1992, mainly through a reduction in misdiagnosis of cardiovascular diseases.

"This improvement was probably the result of new technical procedures and improved clinical skills.

"Since errors are inevitable, strategies to improve medical performance have to be developed continuously. The acceptance of fallibility and the detection of errors are a prerequisite for such strategies."

Further studies were needed to establish if the number of errors could be cut further.

Dr Salomon added that the study showed the value of post mortems in allowing the medical profession to make advances.