Map of life expectancy at birth from Global Education Project.

Wednesday, August 12, 2009

Public health roundup from today's JAMA

. . .with influenza in appropriate perspective. Some of it is open access, some of it is subscription only, as usual, but at least I can do a service by telling you uncredentialed rabble what's in it.

I have not neglected to tell you that the prevalence of dementia is almost 14% among people 70 and older in the U.S., and that means as the population continues to age we'll have more and more of it. It's a huge problem, not only because of the destruction of quality of life in what ought to be the harvest years, and the distress and burden on loved ones, but also because of the enormous expense, much of which is ultimately borne by Medicaid after life's savings are wiped out.

That's why it's so important that a study by Scarmeas et al finds that older people who stay physically active have a sharply lower risk for Alzheimer's disease. They found that this effect was additive with adherence to a so-called "Mediterranean" diet, with lots of olive oil and veggies and stuff, an effect which was not supported by a separate study by Féart et al, so the jury's out on that one, but the physical activity prescription looks pretty good.

That's why an essay by Michael Katz (sorry, you don't even get an abstract for this one) is so important. Katz points out that interventions focused on individuals to get them to do things like exercise more, eat right, not smoke, etc. are expensive and usually only mildly effective. However, so-called "structural interventions" can be very cost-effective. These are modifications of the social and built environment. Sewer systems and safe drinking water, for example, are responsible for much of the increase in longevity in the first part of the 20th Century. Today we can encourage physical activity by land use planning so that people live in neighborhoods where they can walk to shopping, school, and public transportation (a favorite cause of Atrios); safe parks; and even wider sidewalks. Other examples are workplace smoking bans, removing soda machines from schools, offering phys-ed in schools, designing schoolyards to encourage physical play, and so on. We already know these are ways of combating the obesity epidemic, diabetes and heart disease, but now we know they're good for combating dementia as well.

It turns out, as reporter Bridget Kuehn tells us, that stimulants given to kids to treat Attention Deficit disorder can kill them, specifically by causing sudden cardiac death. It's rare, but it happens. We already know they stunt growth and do other long-term damage. I think these drugs are grossly overprescribed and we really need to do something about it. But that's a longer story for another day.

Samet and Wipfli discuss "unfinished business in tobacco control." We've cut the prevalence of smoking in half in this country, but the goal needs to be to drive it to zero. Tobacco is still killing more Americans than any cause. Structural interventions have been the most effective here as well -- banning smoking on airplanes, in workplaces (especially restaurants and bars) and oh yeah, hospitals, actually encourages and helps people to quit. We've eliminated TV advertising and limited other forms of advertising and promotion. And we've raised tobacco taxes. But we haven't done all of that everywhere -- 39 states still don't mandate smoke-free restaurants. Insurance needs to pay for smoking cessation products, and we need to fund anti-tobacco advertising.

Oh yeah, influenza. Morens and Taubenberger review what is known of historical influenza epidemics and pandemics conclude that in fact, the widespread belief that there is a standard or typical pattern in which new strains of influenza first circulate in a mild form, then come back in a killer "second wave," is illusory. That has not been a pattern with most previous events, and it's not even clear that it really happened in the 1918 "Spanish flu" event which is the one that has people's knickers in a twist. They conclude:

Considering the long and confusing track record of pandemic influenza, it is difficult to predict the future course of the present H1N1 pandemic. The virus' modest transmission efficiency, the possibility of a degree of pre-existing population immunity due to prior cross-reactive viruses and vaccines, and its arrival in the Northern Hemisphere as summer approaches, all give reason to hope for a more indolent pandemic course and fewer deaths than in many past pandemics. . . . [P]andemic history suggests that changes neither in transmissibility nor in pathogenicity are inevitable.

Amen. This is no big deal folks. We have much bigger fish to fry in public health.

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