Yesterday the NHS Atlas of Variation in Healthcare was launched. It aims to “address variations in activity and spend within the NHS” and “search for un-warranted variation”. Unwarranted variation is defined as “Variation in the utilization of health care services that cannot be explained by variation in patient or patient preferences”, and addressing it may “maximise health outcome and minimise inequalities”. The media coverage, as expected, has focused on the shocking “postcode lottery” of NHS healthcare with a 14-fold difference in hip replacement rates and a three- to four-fold variation in the percentage of patients getting the best possible stroke care. Across countries and across disease areas, there has been a flurry of research to show both VARIATION and INEQUALITIES. What do these words mean?

Variation, variability and statistical dispersion are terms often used interchangeably, but they all describe the spread of a variable. Variation can be described using measures such as the standard deviation, the range and the coefficient of variation (CV). For example, the CV is defined as the ratio of the standard deviation to the mean. CV, unlike the standard deviation or the range, does not have units-ie. It is dimensionless.

Variability can occur due to random measurement errors. For example if we assume the outdoor temperature to be fixed, the variation between measurements is due to observational error. With people, such assumptions are false: observed variation is because distinct members of a population differ greatly. For example, the way we measure blood pressure has been called into question by recent research about blood pressure variability

The Longman’s dictionary defines “inequality” as “an unfair situation, in which some groups in society have more money, opportunities, power etc than others”. So “inequalities” are “unwarranted variation”. Probably the most famous recent studies of health inequalities are Sir Michael Marmot’s Whitehall Studies, first started in 1967, showing that men in the lowest employment grades in the civil service were much more likely to die prematurely than men in the highest grades, and led to the study of “socioeconomic inequalities in health”. The WHO set up a Commission for Social Determinants of Health, led by Marmot, which has published several reports on how to address social health inequalities. Another example of health inequalities research is the Global Burden of Disease project of the WHO has studied variations and inequalities in global disease distribution.

But the difficult part is characterising what causes these variations. The Right Care programme, led by Sir Muir Gray, has for the first time attempted to aggregate what the NHS spends on particular groups of disease. Perhaps surprisingly, this list is topped by more than £10bn spent on mental health in England, £7.5bn on circulatory diseases, and £5bn on cancers. The unpacking of this kind of data is where the real inequalities will get tackled.

There are few surgeons who are as passionate as Atul Gawande about improving the desperate state of surgery in the poorest parts of the world. I met him a few years back at the launch of his bestselling book, “Complications”. He is a surgeon, academic, author, public health guru and heads Safe Surgery Saves Lives, a WHO group, formed to improve patient safety within surgical specialities. You cannot help but be impressed by the simplicity and the far-reaching consequences of research coming from the group. For example, a 19-point surgical checklist was introduced in eight hospitals in eight cities (Toronto, Canada; New Delhi, India; Amman, Jordan; Auckland, New Zealand; Manila, Philippines; Ifakara, Tanzania; London, England; and Seattle, WA) for 1 year. Use of the checklist reduced death rate from 1.5% to 0.8% and reduced complications occurring in hospital from 11% to 7%.

The Lancet Online First includes the latest study from Gawande’s group. Apparently, 11% of the world's disability-adjusted life years (a measure of the disability caused by diseases) are due to diseases that are often treated with surgery, whether coronary artery bypass graft surgery in coronary heart disease, carotid surgery in the setting of stroke, cancer surgery, or trauma surgery following road traffic accidents. There are huge global inequalities in terms of the operations performed. Out of 234 million surgical procedures done every year, the richest third of the world’s population has three-quarters of the operations, whereas the poorest third has only 4%. The latest study looks at how much of that inequality is due to two integral parts of surgery. One is the operating theatre, and the other is pulse oximetry, the simple process by which a patient’s blood oxygen levels are monitored during an operation. The study used WHO data from 769 hospitals in 92 countries. Importantly there were no differences in patients, health systems or wealth between countries that did have data about operating theatres and pulse oximetry and those which did not. Therefore, these factors are unlikely to be confounders.

The results make sombre reading. Rich countries like the UK had at least 14 operating theatres per 100 000 people, while all poor regions of the world (accounting for more than 2 billion people, or a third of the world’s population) had fewer than two operating theatres per 100 000 people. This is in spite of having more surgically treated diseases per head than do rich countries. As the authors state, “People in such regions are effectively without access to surgical care”. The fact that over half of operating theatres in sub-Saharan Africa did not have the facility to measure oxygen levels and therefore could not monitor a patient’s breathing during anaesthetic is horrifying and is probably the tip of the iceberg in terms of lack of other essential surgical and anaesthetic equipment. Whilst showing these inequalities does not solve them, it does the vital job of highlighting where global health initiatives need to focus.

Over the last few days, the Prime Minister has led a large, high-powered delegation to India promoting greater collaboration between the UK and India in areas as diverse as health and science to trade and climate change and education. Vince Cable, the Business Secretary, was very impressed by what he saw in the Narayana Health City (one of the largest medical facilities in the world) in Bangalore (one of the top four technological hubs in the world). The Narayana Hospitals (between Bangalore and Kolkata) currently have 5000 beds in India and aim to have 30,000 beds in the next 5 years in India. In terms of cardiac care they are doing some amazing work there against the odds: treating patients from 73 countries with complex heart disease and doing the largest number of heart surgeries on children in the world. No wonder Vince Cable was impressed.

In countries such as India, patients can have a massive array of procedures from cataract surgery to coronary artery bypass graft surgery at a fraction of the cost in the Western world. The massive growth of the private health sector in India has increased efficiency and quality. In the UK, medical tourism has been authorised for certain procedures as a way of reducing costs and waiting lists, and increasing consumer choice. This trend is set to increase after the European Court of Justice established the right of European citizens to seek treatment abroad if they are entitled to it in their own country but have suffered an unreasonable delay. There are now a massive number of medical tourism companies which will organise all aspects of healthcare abroad and a relaxing holiday afterwards. The Confederation of Indian Industry estimated that 150,000 medical tourists came to India in 2005, and the health care market, which includes health insurance, is set to expand by 2012 from US$22.2 billion (5.2% of GDP) to US$69 billion (8.5% of GDP).

There is another side to this coin. India has probably the worst health and wealth inequalities of any country in the world. The new “multidimensional poverty index” designed by the Oxford Poverty and Human Development Initiative showed that Bihar, the poorest state in India, has more poor people (95 million) living there than do nine of ten poorest countries in Africa. In 2001, India had only 35 well-equipped centres for modern diagnosis and treatment, mostly located in the six metropolitan cities; this is grossly inadequate for a vast country with an immense population such as India. The Narayana Hospitals currently do 12% of all cardiac surgery in India. That probably tells us that across the population there is not that much heart surgery going on.

The problem of inadequate resources is compounded by the fact that despite being one of the world’s major sources of medical staffing, the number of physicians per 100,000 population is less than 50. To plug the “brain drain”, the Indian government is starting a shortened, rural medical training programme to train and retain doctors in the poorest areas of the country. This is an innovative scheme which other developing countries will be watching closely.

So what can we learn from Indian healthcare? Firstly, sophisticated, world-class healthcare can be performed at a fraction of the cost of healthcare in the US and the UK with equal if not superior quality in the private sector of developing countries. Secondly, private healthcare does not at all reflect the health of the nation and often broadens health inequalities. On this point, the Narayana Hospitals are truly remarkable as they incorporate many societal initiatives such as microfinance and education. Thirdly, as flows of patients, doctors, and resources across country borders are all likely to increase in the future, improvements in the planning of our own healthcare resources and the way we interact with other countries (such as India) are a necessity.