Changes to trends in disease-related deaths

‘Cancer overtakes heart disease as number one killer’, is the news in The Daily Telegraph.

The Telegraph, and other papers, report that a third of people now die from some form of cancer, according to 2011 statistics.

Taking a more glass half-full approach, The Guardian reports that heart deaths have been halved by healthier lifestyles, while conceding that cancers have become the biggest group of killers and that Alzheimer’s disease-related deaths are on the increase.

This media barrage of fatal statistics was prompted by the publication of the Office for National Statistics’ (ONS) annual report into the number, and causes of, registered deaths in England and Wales during 2011. They also include demographic information on how these statistics break down in terms of age and sex.

During 2011 there were 484,367 deaths registered in England and Wales, which is a fall of 1.8% compared with 2010. It is also the third consecutive year that annual death registrations have been below half a million.

Cancers were the largest cause of death, accounting for 30% of all registered deaths – 2,023 deaths per million of the male population, and 1,478 deaths per million of the female population. The leading cause of cancer-related deaths in both sexes were cancers affecting the airways, such as lung cancer.

Following very closely behind cancers, are what the ONS refers to as circulatory diseases (usually referred to as cardiovascular disease), such as heart attacks, which accounted for 29% of all deaths. Next came respiratory diseases (such as pneumonia), accounting for 14% of deaths.

The study also highlights a rise in deaths associated with dementia and Alzheimer's disease, which are now the second most common cause of death in women, and the fifth most common in men.

Over the past decade, there has been a gradual decline in mortality from all three of the main disease groups, with deaths from cardiovascular disease showing the most dramatic decline.

The statistics confirm what is already known – that cancers and cardiovascular diseases remain the most common causes of death in England and Wales.

The decline in deaths from these diseases year by year – and in particular circulatory diseases – may be a reflection of general improvements to population health, individual lifestyles, and improved treatment of disease.

What are the main findings of the report?

The ONS reports the number of deaths registered in England and Wales in 2011 by age, sex and underlying cause of death. It has also ranked the 10 leading causes of death for both men and women.

The main findings of the report are:

• There were 484,367 deaths registered in England and Wales in 2011 compared with 493,242 in 2010, which is a fall of 1.8% since 2010.
• There were 234,660 deaths in males, representing a fall of 1.4% from the previous year, and 249,707 deaths in females, representing a 2.2% fall from the previous year.
• The age-standardised mortality rates in 2011 were, 6,236 deaths per million men and 4,458 deaths per million women, which are the lowest mortality rates since records began, between 2001 and 2011 these rates fell by 24% for men and 20% for women.

By cause of death:

• cancers accounted for 30% of all deaths in 2011
• circulatory diseases (for example, deaths from heart attack and strokes) accounted for 29% of all deaths
• respiratory diseases (such as deaths from pneumonia) accounted for 14% of all deaths
• no overall statistic for the proportion of all deaths due to dementia and Alzheimer’s is given, but they accounted for 5.1% of deaths in men and 10.3% of deaths in women

What are the differences between the leading causes of death for men and women?

As can be seen, heart diseases are the leading cause of death for both men and women. Male gender is a well-established risk factor for heart disease, so the much higher mortality rate for men from this cause, compared to women, is partly explained.

Similarly, in the 20th century, smoking rates were higher in men than women, and therefore this may explain why male deaths from lung cancers and chronic respiratory diseases are greater for men than for women.

Looking at other cancers; for men, prostate cancer comes next-down on the list at number 7, accounting for 4.1% of male deaths in 2011. For women, breast cancer comes next, also at position 7 and also accounting for 4.1% of female deaths.

What changing trends have been detected and what are the reasons for this?

The ONS reports that 2011 is the third consecutive year in which mortality rates have fallen below half a million.

Over the course of the 20th century, mortality rates have been steadily falling (although up until the 1970s more fluctuations in mortality were still seen as a result of flu epidemics and vulnerable people dying during cold winters).

Just looking at the past decade alone, between 2001 and 2011, the age-standardised mortality rate for men fell by 24% (from 8,230 deaths per million in 2001), and fell by 20% for women (from 5,566 deaths per million in 2001).
 
When looking at the three main causes of death – cancers, circulatory diseases and respiratory diseases – there have also been fairly steady annual decreases in mortality rates for each of these
disease groups. However, the main difference noted is that deaths from circulatory diseases have fallen the most dramatically.

In 2001, circulatory diseases accounted for the most deaths, followed by cancer, and then respiratory diseases, but by 2011 there has been a much greater drop in deaths from circulatory diseases than there has been for the other two disease groups, such that cancer deaths now exceed circulatory deaths. For example, between 2001 and 2011, there was a 44% decline in male deaths from circulatory diseases, compared to a 14% decline in male deaths from cancer.

Therefore, it is important to be aware that these statistics do not show an increase in cancer deaths – only a greater decline in circulatory deaths. Put simply, it’s not the case that more people of dying of cancer, in fact each year fewer people are dying from cancer. It’s just that the fall in circulatory deaths has been greater than the fall in cancer deaths.

The reasons for these changes are unclear and it is always difficult to extrapolate conclusive evidence just from pure statistics (though they can often point towards wider trends).

Improvements in public health messages, population health and individual lifestyles (such as eating a healthier diet, exercising more and smoking less), delivery of health services, and new treatments may all have had a part to play.

The ONS do refer to a recent Department of Health study, ‘Improving Outcomes: A Strategy for Cancer’ (2011). This stated that, although improvements have been made in the quality of cancer services in England, a significant gap remains in mortality rates compared with the European average.

The study sets out how the Department of Health aims to improve outcomes for all people with cancer and improve cancer survival rates, with the aim of saving an additional 5,000 lives every year by 2014/15. The strategies discussed included:

• providing high-quality patient information
• enhanced screening
• standardising treatment protocols so a national ‘best practice approach’ is adopted

Cancers and circulatory diseases remain the main causes of death in England and Wales. A decline in mortality rates is encouraging and shows that the trend is in the right direction.

However, one cloud on the horizon is the notable example of a disease where mortality rates have increased – deaths related to dementia and Alzheimer’s disease. These rose between 2001 and 2011 by around 6% for both men and women.

The reasons for this are not explored by the ONS, but in the future, the increase in health and ageing of the population may mean that the prevalence of these age-related conditions increases as more people live into older age.