New research shows small increase in hospital mortality rates in the first week of August

New research shows small increase in hospital mortality rates in the first week of August

Study finds six percent higher mortality rate for people admitted in an emergency on first Wednesday in August, compared with previous week <em> - News Release</em>

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17.00 US Pacific Time/20.00 US Eastern Time, Tuesday 22 September 2009
(01.00 BST, Wednesday 23 September 2009)

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People admitted to English hospitals in an emergency on the first Wednesday in August have, on average, a six percent higher mortality rate than people admitted on the previous Wednesday, according to research published in PLoS One today.

Newly qualified junior doctors start their new positions in NHS hospitals in England on the first Wednesday in August. The authors of the study, from the Dr Foster Unit and the Department of Acute Medicine at Imperial College London, say the excess mortality rates may be linked to this influx of newly qualified doctors but more research is needed before they can draw any firm conclusions.

The study, which was supported by Dr Foster Intelligence and is the biggest study of its kind, looked at data for almost 300,000 patients admitted to hospitals in 175 NHS Trusts between 2000 and 2008. Researchers in the UK and the US have previously carried out smaller studies looking at the effect on mortality rates of junior doctors starting work but the results have often been inconclusive.

Mortality rates fluctuate throughout the year, with higher rates in the winter. However, the researchers behind today's study suggest that although the effect identified in their research is small, it is statistically significant and there appears to be a relatively consistent pattern over the nine years of the study.

The study did not analyse the causes of individual deaths. The researchers say further studies are needed before they can draw firm conclusions about why the apparent increase in mortality rates might be happening.

Dr Paul Aylin, the senior author of the study from the Dr Foster Unit at Imperial College London said: "We wanted to find out whether mortality rates changed on the first Wednesday in August, when junior doctors take up their new posts. What we have found looks like an interesting pattern and we would now like to look at this in more detail to find out what might be causing the increase.

"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," added Dr Aylin.

The researchers looked at data for 299,741 patients who were admitted to hospital in an emergency between 2000 and 2008; over the nine years, a total of 151,844 people were admitted on the last Wednesday in July and 147,897 on the first Wednesday in August. The researchers followed both sets of patients up for a week, and examined the in-hospital death rate in each group with 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.

The researchers found a small, non-significant difference in the mortality rate using these figures. However, after taking into account factors such as age, sex, socio-economic deprivation, year and additional diagnoses, they found a six percent increase in mortality rates for the first Wednesday in August compared to the previous Wednesday.


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Notes to editors:

1. "Early in-hospital mortality following trainee doctors' first day at work" PLoS One, Tuesday 22 September 2009
Corresponding author: Min Hua Jen, Imperial College London
(For full list of authors please see paper)

2. About Imperial College London

Consistently rated amongst the world's best universities, Imperial College London is a science-based institution with a reputation for excellence in teaching and research that attracts 13,000 students and 6,000 staff of the highest international quality.

Innovative research at the College explores the interface between science, medicine, engineering and business, delivering practical solutions that improve quality of life and the environment - underpinned by a dynamic enterprise culture.

Since its foundation in 1907, Imperial's contributions to society have included the discovery of penicillin, the development of holography and the foundations of fibre optics. This commitment to the application of research for the benefit of all continues today, with current focuses including interdisciplinary collaborations to improve health in the UK and globally, tackle climate change and develop clean and sustainable sources of energy.

3. Dr Foster Intelligence is the UK's market-leading provider of information, analysis and targeted communications to health and social care organisations. An independent organisation, Dr Foster Intelligence was launched in 2006 as a joint venture between Dr Foster Holdings LLP and the NHS Information Centre for health and social care.

Dr Foster Intelligence aims to set a new standard in information for health and social care providers and their users and is legally required to follow a code of conduct that prohibits political bias and requires it to act in the public interest. For more information, please visit

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