Hmm, what could have happened in the early 90s to explain the significant decrease in incidence of acute hepatitis B? Urkel?
For those of you new to Science-Based Medicine, I am a pediatric hospitalist and spend the majority of my time caring for newborns. It’s an extremely rewarding experience on most days. The babies are usually healthy, the parents are usually happy and appreciative, and I get to give a lot of good news. I also get to dispel a lot of myths and misconceptions regarding the care of infants, which as you can probably imagine, I take great pleasure in.
Parents ask a lot of questions, which I appreciate and encourage, but they also make a lot of claims about the care of children based on their prior experience, advice from well-meaning friends and family, or their evaluation of the online “literature.” Some of these claims I will challenge, nicely of course, when they are demonstrably wrong or increase the risk for a bad outcome. (“We read that babies should sleep inverted like a bat in order to increase blood flow to the brain.”) Some of these claims I acknowledge as an acceptable approach, even if I don’t agree with them myself, if there is low risk or a lack of available quality evidence to guide me. (“We burped our last baby every five minutes during feeds to prevent colic.”) Sometimes I even learn a thing or two from parents.
It is a triumph of marketing over evidence that millions take supplements every day. There is no question we need vitamins in our diet to live. But do we need vitamin supplements? It’s not so clear. There is evidence that our diets, even in developed countries, can be deficient in some micronutrients. But there’s also a lack of evidence to demonstrate that routine supplementation is beneficial. And there’s no convincing evidence that supplementing vitamins in the absence of deficiency is beneficial. Studies of supplements suggest that most vitamins are useless at best and harmful at worst. Yet the sales of vitamins seem completely immune to negative publicity. One negative clinical trial can kill a drug, but vitamins retain an aura of wellness, even as the evidence accumulates that they may not offer any meaningful health benefits. So why do so many buy supplements? As I’ve said before, vitamins are magic. Or more accurately, we believe this to be the case.
There can be many reasons for taking vitamins but one of the most popular I hear is “insurance” which is effectively primary prevention – taking a supplement in the absence of a confirmed deficiency or medical need with the belief we’re better off for taking it. A survey backs this up – 48% reported “to improve overall health” as the primary reason for taking vitamins. Yes, there is some vitamin and supplement use that is appropriate and science-based: Vitamin D deficiencies can occur, particularly in northern climates. Folic acid supplements during pregnancy can reduce the risk of neural tube defects. Vitamin B12 supplementation is often justified in the elderly. But what about in the absence of any clear medical need? (more…)
A November letter to the editor in American Family Physician chastises that publication for misusing the term “secondary prevention,” even using it in the title of an article that was actually about tertiary prevention.
I am guilty of the same sin. I had been influenced by simplistic explanations that distinguished only two kinds of prevention: primary and secondary. I thought primary prevention was for those who didn’t yet have a disease, and secondary prevention was for those who already had the disease, to prevent recurrence or exacerbation. For example, vaccinations would be primary prevention and treatment of risk factors to prevent a second myocardial infarct would be secondary prevention.
No, there are three kinds of prevention: primary, secondary and tertiary. Primary prevention aims to prevent disease from developing in the first place. Secondary prevention aims to detect and treat disease that has not yet become symptomatic. Tertiary prevention is directed at those who already have symptomatic disease, in an attempt to prevent further deterioration, recurrent symptoms and subsequent events. (more…)