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OVERDIAGNOSIS, OVERTREATMENT FAR TOO COMMON

Published: 
Tuesday, January 10, 2017

The basis of good medical care is diagnosis. Tell your symptoms to the doctor and in most cases she can make a diagnosis 90 per cent of the time. Follow up with a physical exam and she reaches diagnostic certainty in the high 90’s. Occasionally, lab testing may be necessary especially for the more esoteric symptoms: fever lasting more than a week; a large mass in the neck or abdomen; a cough with weight loss; memory loss and so on. Serious stuff. Not “meh back hurting me since Friday night lime” or “I have a rash and an inside fever” or the October to March annual “flu.”

This of course is news to most people who believe that the lab test comes first or is the most important part of the medical consultation. How many times have I had people coming in, scared out of their wits because they went to their friendly neighbourhood lab, conveniently situated over the local rumshop or grocery, and requested a test for their child that comes back “abnormal.”

Most of these “tests” are interpreted by a lab technician who has no training in laboratory medicine interpretation or by a computer whose default mode is for adult values. Normal or abnormal adult lab values are different to children’s lab values. What is an abnormal lab result in an adult may be normal in a child.

A common mistake made is the interpretation of the haemoglobin level. Haemoglobin is an indirect measurement of the amount of red blood cells you have in your body. It measures whether you are anaemic or not. Adults normal values are much higher than children’s. Too many children come into my office saying that the lab technician or worse, the GP, said that the child is anaemic. Anaemia usually forms part of the cancer scenario. Most people with cancer have some degree of anaemia. Stress!

The most common cause of anaemia in the world, not to mention the Caribbean, is iron deficiency. Up to one quarter of Caribbean women and children have some degree of iron deficiency, due to poor diet (think fast food) yet everyone, lab technician, doctor and patient immediately say “cancer!”

The danger of this is that this iron deficiency is not treated, with all the possible consequences: tiredness, weakness, lack of concentration, depression, breakup of marriages and in the case of children, delayed development, school failure and delinquency. Overused medical care that is not properly evaluated, is not only wasteful, it is harmful.

The scenario about people requesting lab tests, is not only one form of overdiagnosis abuse but of overuse of medical care, in this case people-driven, using up money unnecessarily, wasting foreign exchange (lab reagents have to be imported) and causing stress.

The doctor-driven one, however, is just as common especially in an environment where medical litigation is increasing. “Defensive” medicine, common in the USA, is increasing in the Caribbean as people return from the USA where you do a test, “in case” and “to make sure” (as if all tests are conclusive and really help cover your back), and as local lawyers realise that local doctors do make mistakes, honest or otherwise.

Once you diagnose something, treatment should be easy. Get a book, Google treatment and move on. Or so it would seem. In fact there is a lot of discrepancy in treatment especially if the doctor is inexperienced or immature or poorly trained or afraid of making a mistake. This is a well known problem in adult medicine. There’s now talk that for children, overdiagnosis and overtreatment too, is far too common.

In a January article entitled Update on Pediatric Overuse by Eric R Coon et al, mention was made of unnecessary measurements of head circumference in infants. Head circumferences are supposed to indirectly assess brain growth which was thought to be related to brain function. According to the American Academy of Pediatrics, it’s should be done eight times before the child is two years old, ie at every health maintenance visit. This is totally unnecessary.

WHO recommends it be done twice, once at birth and then at eight weeks of age. Why? Because head circumference screening does not identify anything after two months and is specifically not related to low IQ or need for a special education later in life.

However it is related to parental stress and unnecessary lab investigations. If you check things too frequently, whether they be head circumferences or not, you will find minor “abnormalities” that are of no major consequence to children but that can lead to further investigations which then show that nothing is wrong and all you have done is hurt the child, stress out the parents and waste time and money.

Another rather startling one is the finding that two commonly used antidepressants for adolescents, paroxetine and imipramine, were no better than placebo and had potential harms not reported in the original study. The original study showing an advantage was re-examined last year in view of increasing evidence that antidepressant use in adolescents was associated with suicidal thoughts and behaviour.

Turns out that the original findings were false. The study had been ghost-written for the researchers. As one of the authors of the Update on Pediatric Overuse said: “This really gets at the importance of transparent reporting of data and how powerful the influence of industry can be.”

But that’s for another column. For now, it’s sufficient to know that medical knowledge is not static, it is continually evolving, with difficulty, with zig zags, with flashback and under pressure from various points, which ultimately affect you.