Chronic disease worldwide

2007-08-20

in Economics, Science

People tend to think of heart disease and cancer as the diseases of the rich world, while AIDS, malaria, and tuberculosis afflict the poor. The latter idea is certainly true: among those, only AIDS kills an appreciable number of people in rich states (though antibiotic resistant tuberculosis may start changing that).

Just because infectious diseases tend to kill a lot more people in poor states than in rich ones, it does not follow that infectious diseases are the greatest health threat there. According to the World Health Organization, heart disease and cancer kill more people in poor states, as well, and together cause 45.9% of all global deaths. Add in diabetes and other chronic diseases, and you find that 63.5% of all deaths are caused by chronic diseases, compared with 29.7% for all infectious diseases (injuries kill 9.3%).

A forecast for the period between 2006 and 2015 predicts that deaths from infectious diseases will fall by about 4% in poor countries, while deaths from chronic illnesses will rise by about 20%. Partly, this is the result of growing affluence – particularly the ability to afford cigarettes. People in China, Russia, and Indonesia already spend between five and six percent of total household income on cigarettes.

The Millennium Development Goals include two targets relating to infectious diseases:

  1. Halt and begin to reverse the spread of HIV/AIDS
  2. Halt and begin to reverse the incidence of malaria and other major diseases

While these are obviously worthy and important goals, there is a danger of funds not being well matched to where they can do the most good. Shedding a few misconceptions about the relative health challenges of rich and poor states may help avoid that. So too, the further recognition that lifestyle factors like diet, exercise, and smoking have an enormous influence on overall morbidity and mortality.

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{ 7 comments… read them below or add one }

Kerrie August 21, 2007 at 1:54 pm

I think that cost of preventing, treating and curing these illnesses should also be taken into account. One of the reasons why people focus on malaria as one of the world’s biggest killers is that the medication is available and cheap, and with some basic health prevention and care there is no reason for this kind of mortality. Many other prominent diseases common in Third World countries would be prevented with access to clean water, another relatively simple measure which is a right anyway.

Discouraging smoking seems like a simple and cheap way to reduce huge numbers of mortalities from cancer, especially in India and China. But the prevention, awareness and cures for heart diseases and cancers are much more costly relative to malaria, diarrhea, TB, and others. I am not suggesting that therefore, it is not worthwhile to put funds into stopping these mortalities, just that a dollar spent on malaria prevention is likely to have a higher return than a dollar spent on heart diseas.

AIDS is more complicated so it stands out as an exception. However, heart disease and cancers are not transmitted from person to person the way AIDS is, and so the urgency of preventing AIDS transmission, not just in individuals but in entire populations, does seem like a reason to view it differently.

Milan August 22, 2007 at 8:03 am

Kerrie,

Well put. It may well be that the present focus on infectious diseases is justified by exactly the kind of issues you raise. That said, it still seems worthwhile to scrutinize the statistics a bit.

. August 22, 2007 at 1:18 pm

CANCER patients’ chances of survival vary widely among European countries. Franco Berrino and a team of researchers from Eurocare studied the outcome of 2.7m new cases diagnosed between 1995 and 1999 in 23 countries. Five years after diagnosis, survival rates were highest overall in the Nordic region (except Denmark) and lowest in central Europe. Health spending is a factor, with higher national expenditure usually correlating with higher survival rates. Denmark and Britain are exceptions. They have lower rates than those in countries with similar levels of spending, perhaps suggesting ineffective use of resources.

Source

Aman August 27, 2007 at 8:24 pm

Hi Milan,

I found your blog when I ran into your post on chronic diseases:

http://www.sindark.com/2007/08/20/chronic-disease-worldwide/

Along with some other students I run a blog dedicated to global health
solutions and we are looking to get others involved. We generally are
focused on how technology can be used to solve global health problems,
but blog about anything global health related.

We are searching for more contributors/guest authors and I was
wondering if you could send our blog to anyone you might know who is
interested in these issues and folks who would just be interested in
reading the blog. You can check out our blog at:

http://thdblog.wordpress.com/

Thanks very much!!
Aman

. September 10, 2007 at 4:56 pm

Westerners tend to assume that most people in tropical countries die of malaria, AIDS, worm diseases and unpronounceable ills. But as vaccines, antibiotics and AIDS drugs become more common, more and more are surviving past measles, infections, birth complications and other sources of a quick death. They grow old enough to die slowly of cancer.

See this NY Times article

. November 12, 2010 at 3:21 pm

Aging bodies with chronic diseases are not the same as young bodies with independently acquired infectious diseases. Yet medicine continues to act as if the diseases of aging are separate from the consequences of aging itself. It’s true that modern medicine has produced miracle treatments for some chronic diseases, such as dialysis for kidney failure, stents and bypass surgery for coronary artery disease, and new diagnostic procedures for detecting and successfully treating disease early. And we are learning how modifying behavioral risk factors can postpone the onset and progression of chronic diseases, such as keeping cholesterol in check to help prevent heart disease, losing weight to help prevent Type II diabetes, and quitting smoking to lower the risk of cancer.

However, while the risk of many infectious diseases can theoretically be reduced to zero through human interventions, even a complete control of behavioral risk factors for chronic degenerative diseases still leaves a population vulnerable to the destructive biological processes of aging. Humanity is paying a heavy price for the privilege of living extended lives—a new and much more complicated relationship with disease.

While eliminating smallpox and curtailing cholera added decades of life to vast populations, cures for the chronic diseases of old age cannot have the same effect on life expectancy. A cure for cancer would be miraculous and welcome, but it would lead to only a three-year increase in life expectancy at birth. A cure for heart disease would be equally welcome, but we would gain only four-and-a-half years as a result. Gains in longevity from cures for diseases are much smaller today than one might expect because aging bodies face multiple lethal conditions—an effect known as competing causes. Competing causes in aging bodies means that those saved from dying from one condition will eventually face an elevated risk of dying from something else. Death is a zero sum game for which there is no cure.

While we can extend life in aging bodies through behavioral improvements and medical treatments, the time has arrived to acknowledge that our current model of reactive medicine, of trying to treat each separate disease of old age as it occurs, is reaching a point of diminishing returns.

. September 9, 2017 at 6:11 pm

Why developing countries must improve primary care

The poor state of primary care will matter even more as the burden of disease in poor countries comes to resemble that in rich ones, shifting from infectious diseases to chronic conditions (see article). By 2020 non-communicable diseases will account for about 70% of deaths in developing countries. But the majority of people with high blood pressure, diabetes or depression do not get effective treatment—and may not even know they have a problem. They deserve better.

A third important change is to design better incentives. Even when clinicians know how to deal with patients properly, they may not do so. Sometimes pressure from patients leads them to overprescribe antibiotics. The problem is made worse when doctors profit from the drugs they prescribe or the tests they order. Better to follow Rwanda, where health workers are rewarded for following clinical guidelines, not for the prescriptions they issue.

In poor countries it is easier than ever to see a medic

But it is still hard to find one who will make you better

For the past two decades policymakers and donors have mostly focused on specific diseases. Fully 86% of children are now immunised against diphtheria, tetanus and pertussis (whooping cough). The Global Fund, a multi-billion-dollar philanthropic effort, reckons it has helped save 22m lives from HIV/AIDS, malaria and tuberculosis since 2002.

Yet health experts worry about the failure to build on that success and create primary-care systems to deal with the growing burden of chronic illness in poor countries. Primary care is “not flashy”, says Dr Asaf Bitton of Ariadne Labs, a research group, so it gets less attention. The result is a big gap between the care people need and what they get.

How big a gap is hard to quantify. Researchers have tended to estimate the number of people who cannot get access to any of a list of “essential health services”, such as contraception, antenatal visits or treatment for tuberculosis. Using this measure the World Health Organisation (WHO) thinks 400m people globally lack access to primary care.

But this definition is unsatisfactory for two reasons. The first is that it ignores non-communicable diseases such as cardiovascular disease and diabetes. By 2020 these will account for about 70% of deaths in developing countries. The World Bank and WHO reckon that in most countries outside the OECD, a club that contains nearly all the developed ones, more than half of people with hypertension are unaware of their condition. The share receiving treatment to manage their blood pressure varies by country, and ranges from 7% to 31%. Between 24% and 62% of diabetics are undiagnosed and untreated—as are an estimated 82% of people with mental illnesses in the developing world.

In India the average consultation lasted three minutes, a quarter as long as in OECD countries. A third lasted less than a minute and involved no examination and just one question from the clinician: “What’s wrong with you?” The correct treatment was given in 30% of cases, and unnecessary or harmful treatment in 42%.

Patients fare little better in China. A team led by Sean Sylvia of Renmin University of China sent standardised patients to clinics in Shaanxi province. Health workers spent an average of 96 seconds with patients. They gave a correct diagnosis in just 26% of cases, and an outright wrong one in 41%. Inept treatment is not because providers are too busy. According to the World Bank, in India, Kenya, Senegal and Tanzania each one sees just eight to ten patients a day. Those in India spent just 40 minutes a day on average seeing patients.

A better explanation starts with the fact that many clinicians have received little training and do not know what they are doing. In India and China more medical training is (reassuringly) associated with making fewer mistakes. And a recent Kenyan study using standardised patients found that clinicians in Nairobi made “significantly better” diagnoses than Indian and Chinese ones, who had less training.

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