IELTS Academic Reading Practice Test 390

Before the nineteenth century, a physician had no instrument for measuring a patient's temperature. Fever was judged by the hand, the pulse and the appearance of the tongue, and the results were recorded in words such as 'hectic' or 'low'. In the eighteenth century fever was often treated as a disease in its own right, and much medical effort went into distinguishing one kind of fever from another. A reliable measurement would have given physicians something words could not: a number that could be compared from one day to the next, and from one patient to another.

Thermometers themselves were nothing new. The thermoscope, which showed changes in temperature without measuring them, had been described around 1600, and by the early eighteenth century Daniel Gabriel Fahrenheit was making mercury thermometers with fixed and reproducible scales. Mercury was a sensible choice, because it expands steadily when heated. Yet these instruments were laboratory apparatus: long, fragile and slow, and each maker's scale differed from the next, so that a reading taken in one city meant little in another. Physicians who owned a thermometer generally used it for experiment rather than for the routine care of patients.

The decisive work came from Leipzig, where Carl Reinhold August Wunderlich began systematic measurements in 1851. Placing thermometers in the armpit, he and his assistants recorded the temperatures of thousands of patients over nearly two decades, and in 1868 he published a book on body heat in disease. Wunderlich established that a healthy body stays close to 37 degrees Celsius, and he showed that particular fevers followed characteristic patterns of rise and fall. But the thermometers he relied on were about thirty centimetres long and had to stay in place for some twenty minutes, which made them impractical on a busy ward.

Thomas Clifford Allbutt approached the problem from a different direction. Born in 1836 in Dewsbury, in the West Riding of Yorkshire, he was educated at St Peter's School in York and at Gonville and Caius College, Cambridge, before completing his clinical training in Paris. He then returned to Leeds, where he worked as a physician at the General Infirmary and became known both for his teaching and for his interest in new instruments. He was among the first physicians in Britain to use the ophthalmoscope, and in 1871 he published a book on the subject.

His contribution to the thermometer was a matter of size. Around 1867 Allbutt had an instrument made that was only about fifteen centimetres long, small enough to be carried in a pocket case. It reached a steady reading in roughly five minutes, rather than the twenty required by the thermometers used in Leipzig. The scale was marked in fifths of a degree, fine enough to reveal changes that no hand could detect. The instrument also allowed a physician to take a temperature during an ordinary visit and to compare the result with a reading recorded days earlier.

Adoption was not instant. Some physicians doubted that a number on a glass tube could add anything to trained judgement, and the instruments were expensive and easily broken. Within a decade, however, the clinical thermometer had become standard equipment in British and American hospitals. Temperature charts appeared at the end of patients' beds, where nurses recorded readings at fixed intervals. The thermometer did something few instruments had done before. It moved a measurement out of the physician's hands and into the routine of the ward, where it was taken by nursing staff, written down and read by anyone who could follow a chart.

Allbutt's career continued long after the thermometer. He had served as a commissioner in lunacy before moving to Cambridge. In 1892 he was appointed Regius Professor of Physic there, a post he held until his death in 1925, and he was knighted in 1907. He wrote extensively on diseases of the heart and of the nervous system. He also became uneasy about the direction medicine was taking. In a book published late in life he warned that the specialist, however valuable, risked knowing more and more about an ever narrower field.

Museum collections still hold examples of Allbutt's thermometer, usually in a slim metal case with a clip. The maker's name is stamped on the scale plate. Such an object shows the physics on which it depended. Mercury expands far more than the glass that contains it when both are warmed. At the base of the instrument a thin glass bulb holds a small reservoir of the metal.

Heat drives the mercury up a bore finer than a hair, so that a modest rise in temperature produces a visible movement along the scale. Just above the bulb a narrow constriction breaks the column when the instrument is removed from the mouth. The reading then stays where it was until the mercury is shaken back down.

The modern ward has moved on. Glass thermometers have largely been replaced by electronic probes and infrared devices, which give a reading in seconds, cannot break into a patient's skin and pass the figure straight to a computer. Yet the principle Allbutt helped to establish is unchanged. A measurement taken in the same way at the same intervals and written down is what turns an impression into a record, and it is on such records that the comparison of treatments depends.

The human hip is a ball-and-socket joint, built for both stability and a wide range of movement. The rounded head of the thigh bone, the femur, sits inside a cup-shaped cavity in the pelvis called the acetabulum. Both surfaces are covered with a smooth layer of cartilage, lubricated by a small quantity of fluid, so that a healthy hip moves with almost no friction. When the cartilage is worn away, by osteoarthritis, by inflammatory disease or by injury, bone begins to rub on bone, and the result is pain, stiffness and a limp.

Replacement is offered when other measures — weight loss, physiotherapy, painkillers and injections — no longer control the symptoms. It is now one of the most frequently performed elective operations in the world; in the United Kingdom alone, surgeons carry out more than 100,000 hip replacements each year. Most patients are over sixty, but younger adults whose joints have been damaged by injury or by disease such as rheumatoid arthritis also receive them. It is this group that places the greatest demands on the materials involved. Patients are assessed beforehand for heart and lung disease, which raise the risks of anaesthesia.

Under a general or spinal anaesthetic, the surgeon reaches the joint through an incision in the side or front of the hip. The damaged head of the femur is cut away, and the hollow centre of the bone is opened up with a reamer to accept the stem of the implant. The acetabulum is cleaned and shaped so that a metal shell can be pressed into it.

A liner is then fixed inside the metal shell. Finally a rounded head, mounted on top of the stem, is placed within the liner, and the joint is tested through its full range of movement before the soft tissues are repaired. Most patients are helped to stand within a day of the operation.

Each part is chosen from a small range of materials. Stems and shells are usually made of titanium alloys, which are strong, relatively light and tolerated well by the body, or of cobalt-chromium alloys, which are harder and more resistant to scratching. The head may be metal or ceramic; ceramic is extremely smooth and hard-wearing, though it is brittle and in rare cases can fracture. The liner is almost always made of polyethylene, a tough plastic, and the pairing of a hard head with a plastic liner is known as a bearing couple.

Implants are held in place in one of two ways. The traditional method uses bone cement, a dough-like polymer that sets hard within minutes and grips both bone and metal. The alternative is a cementless implant, whose surface carries a porous coating of tiny beads or a roughened texture. Bone grows into these irregularities over the following weeks, so that the implant becomes fixed by living tissue rather than by glue. Cemented implants are more common in older patients, whose bone may regrow slowly, while cementless designs are often preferred for younger, more active people.

Modern replacement owes much to the work of John Charnley, an orthopaedic surgeon who experimented at Wrightington Hospital in Lancashire in the late 1950s and 1960s. Earlier implants had often failed because the surfaces wore each other away, or because metal rubbed against bone. Charnley combined a small metal head, a socket lined with high-density polyethylene and acrylic cement, an arrangement he called low-friction arthroplasty. The results were good enough to turn an experimental operation into a routine one, and his design has been refined rather than replaced ever since.

An artificial joint does not last forever. Every step produces microscopic particles, mainly of polyethylene, and these are not inert. The immune system treats them as foreign bodies: cells called macrophages engulf them and release signals that activate other cells, which break down bone, a process known as osteolysis. Bone loss around the implant loosens it, and a loose implant becomes painful and may eventually need a second operation, known as a revision. National joint registries, which record every implant and every revision, exist precisely to measure how long different designs survive, and they can reveal a poorly performing implant sooner than any single hospital could.

Some difficulties have proved harder to predict. Metal-on-metal bearings, widely used around 2000 in the belief that they would last longer, were found to shed metallic debris. In a small minority of patients this provoked a destructive reaction in the surrounding tissue, and their use has since declined sharply. Regulators advised that some patients with these implants should be monitored. Ceramic components can squeak, and although fracture is rare it has not been eliminated. Nor is it understood why a minority of patients still report pain after an operation that appears successful on an X-ray.

Current research therefore concentrates on materials and on precision. Highly cross-linked polyethylene, treated so that its molecular chains are more tightly bound, wears at a much lower rate than the older plastic. Surgeons use computer navigation and robotic arms to place components within a few degrees of the planned position, and three-dimensional printing allows implants to be shaped to an individual's anatomy. Whether these refinements will produce joints that last appreciably longer in young patients is not yet known, because the evidence will take decades to collect, and registry results are watched closely for any sign that a new material is underperforming.

Few changes in modern medicine have been as contentious as the decision to publish the results of individual hospitals and doctors. Twenty-five years ago, in most countries, a patient who wanted to know how well a surgical unit performed had no way of finding out, and often neither did the unit itself. Today, in a growing number of health systems, death rates and complication rates for particular operations appear on public websites, sometimes down to the level of the named surgeon. Supporters call this accountability. Critics call it a beauty parade. The question deserves to be taken seriously, because the way such figures are produced and used affects patients directly.

The case that did most to change British practice concerned children's heart surgery at Bristol Royal Infirmary in the 1980s and 1990s. Clinicians inside the hospital became convinced that mortality among babies undergoing certain operations was higher than it should have been. An anaesthetist who pressed for the figures to be examined found his position increasingly difficult. A public inquiry, which reported in 2001, concluded that the unit's results had indeed been poorer than expected and that concerns had been dismissed too easily. A culture of secrecy, it found, had prevented an honest reckoning. Among its recommendations was far greater openness about outcomes.

Publication has since become routine in several countries. In the United Kingdom, cardiac surgeons have reported their individual results across a whole career since the mid-2000s, and other specialties have followed with varying enthusiasm. In the United States, New York State began publishing risk-adjusted death rates for coronary artery bypass surgery in the late 1980s and early 1990s, first by hospital and then by surgeon. Registries in Scandinavia and elsewhere allow similar comparisons, and some newspapers now compile their own tables from whatever data they can obtain.

For campaigners and for many patients, the argument is simple. Care that is hidden cannot be judged, and care that cannot be judged is rarely improved. Bereaved families who spent years trying to obtain figures have argued that only publication forces an institution to confront its own performance. They argue too that a patient has a right to know what a reasonable person would want to know before agreeing to an operation. Publication has practical effects as well: units that discover they are outliers commonly review their practice, and several documented improvements in cardiac surgery followed the release of comparative data.

Many surgeons, however, remain uneasy, and their objections deserve a fair hearing. The first is that a surgeon who knows every death will be counted may begin to think about the count rather than about the patient. The fear is that difficult cases will be quietly referred elsewhere, or that an operation will be offered to a patient who is likely to survive rather than to one who most needs it. Studies of reporting systems have found signs that this can happen, although the evidence is mixed. A second objection is personal: a run of deaths in a small unit may reflect chance rather than competence, yet the surgeon's name stays attached to it.

Statisticians make a related but sharper point. A hospital that performs forty operations a year and loses four patients has a death rate of ten per cent. One that performs four hundred and loses twenty has the same rate, but the second figure is far more stable. Small numbers fluctuate, and a table that ranks units without showing the uncertainty around each figure will mislead. Risk adjustment, which corrects for how ill patients were before surgery, reduces the distortion but cannot remove it. The data rarely capture frailty, deprivation or the judgement that a patient is too ill to be operated on. Careful analysts therefore prefer funnel plots, which show whether a unit lies outside the range that chance alone would produce.

Hospital managers have a further concern. A poor position in a published table can damage an institution's reputation, deter referrals and, in systems where money follows patients, reduce income. Managers may respond by withdrawing a service altogether, which is not always in the interests of the population served, or by devoting resources to measurement itself rather than to care. That is not an argument for concealment, but for thinking carefully about what happens after a figure is published.

Regulators have come to see the data as a screening tool. Inspection teams increasingly use published outcomes to decide where to look next, treating an unusual result as a reason to ask questions rather than as proof of failure. The most defensible response to a poor result is a review of the whole service — its staffing, its equipment, its selection of patients — carried out by people with the authority to put things right.

My own view is that publication should continue, but in a form that respects the limits of the numbers. Figures should be adjusted for case mix, presented with intervals that show how much they could reasonably vary, and released for teams as well as for individuals. No operation, after all, is the work of one person. They should be a starting point for inquiry, not a verdict. Where publication has been done in this way the results have generally been encouraging. Services have improved, poor performers have been identified, and the argument has moved from whether data should be released to how it should be read.

The alternative, after all, is the world that Bristol exposed, in which those who ask awkward questions are treated as troublemakers and families learn the truth years too late. A league table is a crude instrument, and a single number can never describe a hospital. But the demand behind it — that institutions should be able to show what they achieve — is entirely reasonable.