This week the Insights blog will be focusing on health care issues. In this second post, we introduce evidence-based care.
My grandmother believed that tar fumes stopped kids catching colds, so if she saw road menders at work, she’d march me, my sisters and brothers and our friends over to breathe in the vapours.
We’d then have to huddle around a steaming dollop of bitumen, arms flapping to help the lungs pump the goodness into our ventricles, like a flock of baby seagulls stuck in an oil slick.
A woman who thought that pigs could see the wind probably wasn’t the best source of advice on health (or anything else), and a carcinogenic mixture of 10,000 chemicals, half of them unidentified, probably not the best prophylactic around, but the wisdom of the ancients is not the only knowledge that seems bonkers in retrospect. Mainstream medicine has had its share of dubious treatments too.
Not just dubious. The aptly named To Err is Human report from the US Institute of Medicine in 2000 estimated that medical errors killed more people than traffic accidents in the US.
Of course, with millions going to see the doctor every day, even a tiny fraction of mistakes soon adds up to a startling sum, but the problem isn’t just a slip of the scalpel or an illegible prescription. Another report estimated that up to a third of treatments had no real clinical effectiveness.
To the layperson, this is astonishing. How on Earth were the doctors deciding on treatments? Rolling dice? In fact, they were applying what they’d learned at medical school and best practice as it evolved.
The first clinical trial of a drug using properly randomised treatment, control groups and blind assessment (neither researcher nor patient knew which group the patient was in) dates from 1948 when the UK Medical Research Council tested streptomycin to treat pulmonary TB.
In 1972, epidemiologist Archie Cochrane published Effectiveness and Efficiency: Random Reflections on Health Services, and in 1979 he wrote, “It is surely a great criticism of our profession that we have not organised a critical summary, by specialty or subspecialty, adapted periodically, of all relevant randomised controlled trials.”
This led to the creation of an international collaboration to develop the Oxford Database of Perinatal Trials in the 1980s. Iain Chalmers showed that there was no evidence to support many common practices in obstetrics. Chalmers was appointed director of the UK Cochrane Collaboration, founded in 1993 and now a world leader in evidence-based health care.
Evidence-based medicine and its complement, health technology assessment, focus on two simple questions: does it work, and is it worth it? Answering these questions is more difficult than you might expect though. You need comparable data for a start.
In the past, this came down to mortality rates and life expectancy. Today, many interventions are designed to improve quality of life, for example a hip joint replacement, and this is much harder to measure. Moreover, treatments that work extremely well may be very expensive, so are they the best use of limited resources?
In 2002, the OECD launched the Health Care Quality Indicators project to develop indicators measuring the quality of care in various domains ranging from cancer care to mental health care. With economic pressure on health spending rising, measuring the quality of care has become even more relevant, and the OECD Forum on Quality of Care will review the state-of-the art in measuring quality in health systems.
And if you’re wondering: we still caught colds.
Health Technologies and Decision Making from the OECD’s Directorate for Science, Technology and Industry analyses what encourages or hinders evidence-based decision making in OECD health-care systems.
Meeting of OECD Health Ministers, October 2010
NHS Evidence from the UK National Health Service provides free access to clinical and non-clinical information including evidence, guidance and government policy.
The April 2010 IOM report Bridging the evidence gap in obesity prevention shows how EBM contributes to a major health issue