Patients treated by older doctors in hospital have a higher mortality rate than those treated by younger doctors, according to a US study.

The study of over 736,000 hospital admissions found 30-day mortality rates rose from 10.8% in patients treated by doctors younger than 40 years to 12.1% in patients treated by doctors 60 years and over.

The researchers said that for every 77 patients treated by older doctors, one less patient would die if treated by younger doctors.

“This difference in mortality is comparable with the impact of statins for the primary prevention of cardiovascular mortality on all cause mortality, or the impact of beta blockers among patients with myocardial infarction,” they said.

A secondary analysis found the same association between doctors’ years of experience and patient mortality.

They said while clinical skills and knowledge accumulated with experience leading to improved quality of care, it was also possible that older doctors’ may not keep up with advances in scientific knowledge and technology.

The association between doctors’ age and patient mortality was not seen in doctors with the highest volume of patients.

An editorial in the BMJ suggested older doctors might do better on other performance measures such as communication with patients, and in decisions informed by experience, ‘leading perhaps to fewer invasive medical procedures at the end of life’.

They added it was not all about individual doctors – with ‘evidence that institutional resource priorities, processes, and culture create the possibility of good patient outcomes despite variation in education, training, and clinical performance of the individuals who comprise the hospital workforce’.