Allergy/the scientific evidence: safety in numbers

ALLERGY/THE SCIENTIFIC EVIDENCE: SAFETY IN NUMBERS
Medical science is never exact, for a variety of reasons. For a start everyone is different, both in the genes that make them what they are, and in the environmental conditions that shape them from birth. Those environmental conditions include childhood and adult illnesses, standard of nutrition, type of work, nature of relationships with other people, past medical treatments and present living conditions. A collection of patients also differ in their age and sex, two very important factors in health and illness. Their response to treatment is bound to differ for these reasons alone.
A second major factor is the imprecise nature of diagnosis. Names may be given to diseases - 'rheumatoid arthritis', for example, or 'migraine' - but this does not mean that they are single, .clearly defined conditions, in the way that infectious diseases such as measles or cholera are. Doctors suspect that, although the symptoms look similar, there are a multitude of different disorders sheltering under such umbrella terms. One of the ways in which medicine advances is by-recognizing different subgroups within such diseases, and giving new names to the symptoms shown by those subgroups - 'classical migraine' and 'common migraine', for example. But in many diseases, there are no obvious subgroups, even though it is clear that the patients are not all the same. This is particularly true in food intolerance.
To overcome these problems in medical trials, it is important to study as large a group of patients as possible. Because the patients suffering from a disease can be so diverse, a new treatment may only be effective for, say, 10 percent of them. A study that only includes 20 patients should, in a perfect world, include two patients who will respond. But when numbers are this small, die laws of chance dictate that there could easily be no patients of this type in the group. So a group of 100 patients may be needed to give a convincing result -but such large-scale trials are costly and difficult to organize.
*103\180\8*

Allergies

ŤMexican Pharmacyť