Research has shown that hospital deaths see a small but significant rise during early August when newly qualified junior doctors start work.

Research from Imperial College London has found that hospital deaths see a small but significant rise during early August when newly qualified junior doctors start work.

Every August more than 50,000 medics start work or swap to new jobs as part of a huge training rotation of a third of all doctors in the NHS.

Drawing from the commonly held assumption that early August is hence an unsafe period to be admitted to hospital, having been coined the “killing season” in the past, researchers from the Dr Foster Unit and the Department of Acute Medicine at Imperial undertook a retrospective study of data from nearly 300,000 patients in 175 hospital trusts in England between 2000 and 2008.

Published in the Public Library of Science One journal (PLoS One), it compared death rates of all emergency patients admitted on the last Wednesday in July and the first Wednesday in August for 2000 to 2008, each followed up for one week.

The researchers found that, on average, the odds of death for patients admitted on the first Wednesday in August was 6% higher after controlling for year, gender, age, socio-economic deprivation and co-morbidity.

Furthermore, the difference was most marked in medical cases, such as heart attacks and strokes, where there was an 8% increase in deaths; there was no difference in surgical cases.

There were 2,182 deaths in patients admitted on the last Wednesday in July and 2,227 deaths in patients who had been admitted on the first Wednesday in August – this correlated to “12 to 14 deaths”.

Dr Paul Aylin, the lead researcher, said: “The death rate does appear to be higher. It is a small increase but we think it is statistically significant. It is not necessarily because of the change over but we are saying it warrants further investigation. It is worth looking at in greater detail.”

He continued: “Our study does not mean that people should avoid going into hospital that week. This is a relatively small difference in mortality rates, and the numbers of excess deaths are very low. It’s too early to say what might be causing it. It might simply be the result of differences between the patients who were admitted.”

Dr Shree Datta, Chair of the British Medical Association’s Junior Doctor Committee, said: “This study has to be judged alongside many previous studies looking at mortality rates before and after junior doctors start their new jobs, which have not shown any differences.

“Clearly even a small increase in death rates is of great concern and we need further research to see whether this is a real effect or an anomaly.”

For more information and to read the research, click here.