the fact that much of standard medical practice may not work very well. It makes dangerous drugs look safe and effective. It makes it seem like people who don’t need drugs should take them. It justifies a lot of useless surgery that may very well kill you, and certainly isn’t going to make you better. It explains away many promising treatments that don’t require dangerous drugs or surgery. Despite the very best of intentions, it sometimes causes untold pain and suffering, rather than contributing to your health. In fact, you are in grave danger from the moment you walk into your doctor’s surgery, particularly at the point when he tells you he’d like to take a few tests.
Your modern-day doctor has at his disposal an array of high-tech gadgetry that allows him to monitor and measure virtually every nook and cranny of your body. He and his fellow doctors are now completely reliant upon these tests to diagnose disease. As patients, we trust tests so implicitly to provide us with a definitive view of our state of health, even to predict when we’re going to get ill at some distant point in the future, that most of our children begin having tests as soon as they’ve been conceived.
At last count, there were more than 1,400 of these, ranging from the simple blood-pressure cuff to the most sophisticated computerized nuclear magnetic imaging devices. Back in the relatively dark ages of 1987, some 19 billion tests were performed on Americans that year alone, which works out to be 80 tests for each man, woman and child.1
Despite the kind of gadgetry that would put NASA to shame, the problem is that the technology doesn’t really work very well. Most tests are grossly unreliable, giving wrong readings a good deal of the time. A false-positive test sets in motion the juggernaut of aggressive treatments at your doctor’s disposal, with all their attendant risks. But the tests themselves can be as risky as some of the most dangerous drugs and surgery, risks that are magnified because so many of these tests are patently unnecessary. In many cases (more so in the United States), doctors protect themselves against potential lawsuits by ordering every test they can. In fact, in the US, many orders for tests are motivated by a doctor’s own self-interest, since so many physicians either own or have substantial shareholdings in the facilities to which they refer their own patients.
Another problem is that, these days, technology has replaced the fine art of diagnostics – of examining a patient’s clinical history and having a good look at his eyes and the state of his tongue. The problem often comes down to trainee doctors, who often order tests under the mistaken notion that their consultant superiors desire such ‘just-in-case’ medicine. But in many cases senior doctors do flog their juniors if they fail to request particular tests, engendering the view that more is better and that massive test-taking is what constitutes good doctoring.2
Tests also make the fundamental error of assuming not only that all people are alike, but that people (and their measurements) always stay the same.
The other problem is that, unless your doctor has a particular feeling for taking apart computers in his spare time, he can get a bit muddled by this gee-whizz technology. One study found that virtually all doctors and nurses don’t know how to work a pulse oximeter, a monitoring system which is vital for monitoring patients recovering from anaesthesia and recording potential life-threatening situations.3 Consequently, they make serious errors in evaluating readings. The medics reported not being ‘particularly worried’ when patients had levels indicating that they were seriously deprived of oxygen and needed immediate attention if they were to live.4
BLOOD-PRESSURE READINGS
Your problems can start even when your doctor brandishes his blood-pressure cuff to record your blood pressure. Professor William White, chief of Hypertension and Vascular Diseases at the University of Connecticut, refers to this gizmo, known in medicalese as the ‘sphygmomanometer’, as ‘medicine’s crudest investigation’. Blood pressure, he says, can vary tremendously – as much as 30 mm Hg over the course of any day.5 In fact, the time it’s most likely to rise is in your doctor’s surgery, when you’re waiting to have the test – a phenomenon known as ‘white-coat hypertension’. A recent study comparing blood-pressure readings taken at home, at work and at the doctor’s surgery found that the most inaccurate were those performed in the doctor’s surgery.6 Such an artificially high test reading at the doctor’s surgery can launch a patient onto a lifetime of blood-pressure medication.7 The latest studies into blood pressure and hypertension have concluded that true high blood pressure is more related to average levels over 24 hours and also the degree of fluctuation between day and night than any particular or casually-made blood-pressure readings.8
These days, your doctor is more likely to give you a home-monitoring device or even to strap you up with a portable electronic device, which will measure your blood pressure at pre-set intervals over 24 hours. This is now thought to be the more accurate way of assessing your average blood pressure, although there is still a great deal of evidence that this system, called ‘ambulatory monitoring’, likewise doesn’t provide accurate enough information for doctors to decide whether a patient needs treatment for high blood pressure.9
Even the World Health Organization recommends that ambulatory monitoring is best conducted with multiple readings over six months. But because no one has yet bothered to do proper large-scale scientific studies, no one can agree over how long you should go on doing the ambulatory monitoring before making a diagnosis, or what actually constitutes high blood pressure over this period, or even how much blood pressure should be lowered by to make it ‘normal’.10
The values used today are still hypothetical, gleaned from studies of populations with normal blood pressure.11 With home-monitoring systems, accuracy also remains a large problem. Only about a fifth of self-recording devices evaluated in recent studies have met acceptable criteria.12
In the US, the Food and Drug Administration mandates that any hypertension medication must be shown to lower blood pressure over 24 hours through ambulatory monitoring. Nevertheless, neither doctors nor drug companies really understand which reading – morning average, evening average, ambulatory reading, difference between day and night, degree of variation – shows that things are finally under control. Furthermore, many patients have different degrees of variability, depending on the nature of the stress they confront on the job.13 Older patients also have more exaggerated differences in day and night readings – the significance of which is anyone’s guess.14
A task force of participants at the 1999 Consensus Conference on ABP monitoring, sponsored by the International Society of Hypertension, recommended against using ambulatory monitoring for routine screening purposes.15 The latest recommendations are that patients use ambulatory monitoring for initial diagnoses of hypertension, and self-monitoring for long-term follow-up.16
Even the variation between the arms influences a blood-pressure reading. One doctor from City General Hospital in Staffordshire,