"Statistics are like bikinis. What they conceal is more important than what they reveal."
Are you in favour of large-scale (health) screenings? Does preventive screening for breast and prostate cancer, cardiovascular disease, diabetes and kidney functioning seem like a good idea to you? Think again...
No test is 100 per cent accurate. You may end up with a lot of 'sick' people who are, in fact, healthy. Even an extremely accurate test will still perform badly in very large populations and in populations where only very few people are expected to be sick. Not convinced? Well, find out for yourself. Fill in the numbers and do the math!