Thursday February 17 2011
The north experienced one-fifth more premature deaths than the south
“People in the north of England are 20% more likely to die before they reach 75 than those in the south”, The Guardian reported. It said research has revealed that the gap in life expectancy is the widest for 40 years.
This study compared mortality rates between the north and south of England from 1965 to 2008. In particular, it looked at the proportion of premature deaths (before the age of 75). Overall, mortality in England has improved since 1965. However, the risk of dying early is one-fifth higher in the north than the south, only changing slightly between 1965 and 2008. Overall, premature deaths were 14% higher in the north during these four decades, with the inequality higher in men (15%) than women (13%). Inequality also varied with age, with premature mortality rates in the 20-34-year-old age group noticeably growing since 1996 (22% higher in the north).
There are some limitations to these statistics, including the fact that the location of the north and south divide is an arbitrary one. However, these results clearly indicate that mortality rates in the north have been higher than in the south for the past four decades, despite various government policies. As the authors say, more research is needed, possibly looking at socioeconomic, environmental, educational, genetic and lifestyle factors. The reasons why these previous policies failed to reduce inequalities also needs to be examined, and the findings used to inform future decisions.
Where did the story come from?
The study was carried out by researchers from the University of Manchester and Manchester Joint Health Unit. No additional funding was provided. The study was published in the peer-reviewed British Medical Journal (BMJ).
What kind of research was this?
This was a population-wide observational study. The researchers compared death rates between the north and south of England for over four decades, from 1965 to 2008. In particular, they looked at the proportion of excess deaths in the north compared with the south. The authors point out that the north-south divide in health has a long history, and has posed a challenge for successive governments. They say that in recent years, policymakers have set performance targets to reduce geographical inequalities in health at a local level. Also, many statistics on health inequalities are published regionally and little is known about variations between larger populations. There has also been little research on how the divide has developed over time.
The researchers say that looking at premature mortality (deaths before the age of 75) is a reliable measure for comparing the “overall health experience” of large areas over time.
What did the research involve?
The researchers set their dividing line between north and south by splitting the nine government regions of England into the five northernmost (North East, North West, Yorkshire and Humber, East Midlands and West Midlands) and the four southernmost (East, London, South East and South West). Each area’s population is about 25 million. They looked at mortality rates for each year in these regions between 1965 and 2008, using mortality data and population estimates provided by the Office for National Statistics. The data for mortality was provided by region, sex and age, which was categorised into five-year age bands up to the age of 85.
A statistical model was used to calculate the differences in mortality between the north and south of England, after taking into account differences in the age and sex of the two populations. The percentages of excess deaths in the north were then calculated (as incident rate ratios), and the researchers defined this as northern excess mortality.
What were the basic results?
Generally, from 1965 to 2008, the annual number of deaths each year in England decreased from 516,317 to 475,763. The age at which people died gradually shifted upwards. For example, in 1965-67, 33.8% of men and 53.7% of women were living beyond 75 years, compared to 58% of men and 74.2% of women in 2006-08.
Below are the main findings on excess mortality in the north from 1965 to 2008:
- From 1965 to 2008, the average proportion of excess deaths in the north compared to the south (across all ages) was 13.8% (95% confidence interval [CI] 13.7% to 13.9%).
- Excess mortality was significantly greater for men (14.9%, 95% CI 14.7% to 15.0%) than women (12.7%, 95% CI 12.6% to 12.9%).
- The inequality decreased significantly for both sexes from the early 80s to the late 90s.
- That decrease was only temporary, however, and inequality rose steeply from 2000 to 2008.
- Inequality varied with age, with excess northern mortality higher for ages 0-9 years and 40-74 years and lower for ages 10-39 years and over 75 years.
- Time trends also varied with age. The strongest trend over time by age group was in the 20-34 age group, from no significant northern excess mortality in 1965-95 to 22.2% (18.7% to 26.0%) in 1996-2008.
- Overall, the north experienced one-fifth more premature deaths (before the age of 75) than the south. This difference was significant and has increased slightly between 1965 and 2008.
How did the researchers interpret the results?
The authors say their findings point to “a severe, long-term and recently worsening structural health problem in the geography of England”. They say there are many possible causes for the higher rate of premature deaths in the north, including socioeconomic, environmental, educational, genetic and lifestyle factors, such as smoking and alcohol use.
They say that migration of healthier people from poor health areas to better health areas might also contribute to worsening premature mortality rates over time. Unequal distribution of public health and healthcare resources may also play a role, and any attempt to reduce inequalities in healthcare may have been dwarfed by the effects on health of “continuing economic and income disparity between north and south”.
This important study highlights the difference in premature mortality rates between north and south England. The strengths of this study lie in the long period for which death rates were examined and the fact that it covered a national population, so its calculations are likely to be reliable.
As the authors note, one limitation is the “arbitrariness” of the definition of north and south. They divided the country by government office regions, and considered the five northernmost offices as representing the north and the four southernmost offices as the south. As the authors note, this is an arbitrary definition and it is possible that the results might have been different had north and south been defined differently. Despite this, they say their dividing line approximates to the Severn-Wash boundary, which is usually associated with the north-south divide.
Also, the authors combined mortality rates from all five northern and all four southern regions, so the results only give the larger picture of the north-south divide for mortality rates and do not allow us to compare mortality rates between the regions.
However, these results clearly indicate that mortality rates in the north have been higher than in the south for the past four decades, despite various government policies. As the authors say, more research is needed, possibly looking at socioeconomic, environmental, educational, genetic and lifestyle factors. The reasons why these previous policies failed to reduce inequalities also needs to be examined, and the findings used to inform future decisions.
A Department of Health spokesperson said that efforts are being made to redress the balance, focussing on vulnerable groups and deprived areas: "Everyone should have the same opportunity to lead a healthy life, no matter where they live or who they are. The government has made it clear that reducing health inequalities is a priority as part of its commitment to fairness and social justice. This means tackling the wider, social causes of ill health and early death as well as addressing individual healthy lifestyles."