February 8th, 2011 by Harriet Hall, M.D. in Better Health Network, Research
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Ear infections used to be a devastating problem. In 1932, acute otitis media (AOM) and its suppurative complications accounted for 27 percent of all pediatric admissions to Bellevue Hospital. Since the introduction of antibiotics, it has become a much less serious problem. For decades it was taken for granted that all children with AOM should be given antibiotics, not only to treat the disease itself but to prevent complications like mastoiditis and meningitis.
In the 1980s, that consensus began to change. We realized that as many as 80 percent of uncomplicated ear infections resolve without treatment in three days. Many infections are caused by viruses that don’t respond to antibiotics. Overuse of antibiotics leads to the emergence of resistant strains of bacteria. Antibiotics cause side effects. A new strategy of watchful waiting was developed.
Current Medical Guidelines
In 2004, the American Academy of Pediatrics (AAP) and the American Academy of Family Physicians (AAFP) collaborated to issue evidence-based guidelines based on a review of the published evidence. Something was lost in the transmission: The guidelines have been over-simplified and misrepresented, so it’s useful to look at what they actually said. There were six parts:
1. Criteria were specified for accurate diagnosis.
- History of acute onset of signs and symptoms
- Presence of middle ear effusion (ear drum bulging, lack of mobility, air-fluid level)
- Signs and symptoms of middle ear inflammation: Either red ear drum or ear pain interfering with normal activity or sleep
They stressed that AOM must be distinguished from otitis media with effusion (OME). OME is more common, occurs with the common cold, can be a precursor or a consequence of AOM, and is not an indication for antibiotic treatment. Read more »
*This blog post was originally published at Science-Based Medicine*
February 2nd, 2011 by Harriet Hall, M.D. in Book Reviews, Opinion
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Journalist Gary Taubes created a stir in 2007 with his impressive but daunting 640-page tome Good Calories, Bad Calories. Now he has written a shorter, more accessible book Why We Get Fat: And What to Do About It to take his message to a wider audience. His basic thesis is that:
– The calories-in/calories-out model is wrong.
– Carbohydrates are the cause of obesity and are also important causes of heart disease, type 2 diabetes, cancer, Alzheimer’s, and most of the so-called diseases of civilization.
– A low-fat diet is not healthy.
– A low-carb diet is essential both for weight loss and for health.
– Dieters can satisfy their hunger pangs and eat as much as they want and still lose weight as long as they restrict carbohydrates.
He supports his thesis with data from the scientific literature and with persuasive theoretical arguments about insulin, blood sugar levels, glycemic index, insulin resistance, fat storage, inflammation, the metabolic syndrome, and other details of metabolism. Many readers will come away convinced that all we need to do to eliminate obesity, heart disease and many other diseases is to get people to limit carbohydrates in their diet. I’m not convinced, because I can see some flaws in his reasoning. Read more »
*This blog post was originally published at Science-Based Medicine*
January 26th, 2011 by Mark Crislip, M.D. in Opinion, Research
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It always somewhat surprises me how some interventions never seem to die. One therapy that refuses to be put to rest, or even to be clarified, is the use of cranberry juice for urinary tract infections (UTIs). PubMed references go back to 1962, and there are over 100 references. Firm conclusions are still lacking.
There is a reasonable, but incomplete, basic science behind the use of the cranberry juice for UTIs. E. coli , the most common cause of UTIs, causes infection in the bladder by binding to the uroepithelial cells. To do this, they make fimbriae, proteinaceous fibers on the bacterial cell wall. Fimbriae are adhesins that attach to specific sugar based receptors on uroepithelial cells. Think Velcro. Being able to stick to cells is an important virulence factor for bacteria, but not a critical one — it is not the sine qua non of bladder infections.
Are all E. coli causing UTIs fimbriated? No. It is the minority of E. coli that cause UTI that have fimbria, and the presence of fimbriae may be more important for the development of pyelonephritis (kidney infection) than cystitis (bladder infection). Read more »
*This blog post was originally published at Science-Based Medicine*
January 20th, 2011 by Harriet Hall, M.D. in Better Health Network, Opinion
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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.
Some have suggested a fourth kind, quaternary prevention, to describe “… the set of health activities that mitigate or avoid the consequences of unnecessary or excessive interventions in the health system.” Another version is “Action taken to identify patient at risk of overmedicalisation, to protect him from new medical invasion, and to suggest to him interventions, which are ethically acceptable.” But this is not a generally accepted category. Read more »
*This blog post was originally published at Science-Based Medicine*
January 13th, 2011 by Harriet Hall, M.D. in Book Reviews, Research
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One of our readers suggested that I review the book The Great Influenza: The Epic Story of the Deadliest Plague in History, by John M. Barry. It’s not a new book (it was published in 2004) but it is very pertinent to several of the issues that we have been discussing on this blog, especially in regards to the current anti-vaccine movement. It’s well worth reading for its historical insights, for its illumination of the scientific method, and for its accurate reporting of what science has learned about influenza.
In the great flu epidemic of 1918, influenza killed as many people in 24 weeks as AIDS has killed in 24 years. It’s hard to even imagine what that must have been like, but this book helps us imagine it. It tells horror stories: Children found alone and starving beside the corpses of their parents in homes where all the adults had died, decomposing bodies piling up because there was no one left who was healthy enough to bury them.
Sometimes the disease developed with stunning rapidity: During one three-mile streetcar trip, the conductor, three passengers, and the driver died. In another incident, apparently healthy soldiers were being transferred to a new post by train: During the trip, men started coughing, bleeding, and collapsing; and by the time it arrived at its destination, 25 percent of the soldiers were so sick they had to be taken directly from train to hospital. Two-thirds of them were eventually hospitalized in all, and 10 percent of them died. The mind boggles. Read more »
*This blog post was originally published at Science-Based Medicine*
