Friday, June 29, 2007

Article in Nature Highlights Shoddy Science Behind Helena et al. Conclusions and 30 Minute Claims of Anti-Smoking Groups

An article by Dr. Kris Novak in this week's issue of Nature highlights my questioning of the validity of the conclusion of the Helena, Pueblo, Piedmont, and Bowling Green studies that smoking bans in those towns resulted in immediate, dramatic reductions in heart attacks. The article also highlights my questioning of the claim being made by many anti-smoking groups that 30 minutes of secondhand smoke causes clogged arteries and heart attacks among otherwise healthy nonsmokers.

According to the article:

"In principle, smoking bans provide a unique opportunity to study populations before and after reductions in second-hand smoke exposure. But if research into the incidence of heart attacks is any guide, the results of such studies are often far from clear and can cause more controversy. Glantz reported in 2004 that during a six-month smoking ban in Helena, Montana, the number of heart attacks dropped by 40% compared with the same months in other years. The study, cited in the surgeon general's report, was criticized for the small number of cases studied and the large month-to-month variations in incidence of heart attacks. Since the report, several studies have reported a drop in hospital admissions for heart attacks after smoking bans in the Piedmont region of Italy (11% drop), and in small cities in Colorado (27%) and Ohio (39%)."

"But not all epidemiologists are impressed. 'It's quite common to see major year-to-year changes in heart attacks, sometimes as much as a 50% increase or decrease,' says Michael Siegel, an epidemiologist at Boston University School of Public Health. Attributing such changes to a ban is impossible, he says. Worse, none of the studies recorded whether the changes occurred in non-smokers or in smokers, yet the effects of the ban are frequently attributed to reductions in second-hand smoke exposure. The lead author of the Ohio study agreed that a prospective study that collected data on groups of non-smokers and smokers in advance of a ban — and then followed them up for a few years after — would be ideal, but this would take longer and be costly." ...

Certainly, public-health officials seem convinced. Pechacek says that the general consensus in tobacco researchers is that the drop in heart attacks occurs mainly in non-smokers. Smokefree England suggests that just 30 minutes of breathing in second-hand smoke can raise your risk of having a heart attack. But can you really become ill just by sitting in a bar next to a smoker? 'Saying that just a little exposure is killing people is going overboard,' says Siegel, who worries that when researchers exaggerate their findings, they lose credibility with the public. 'I agree that second-hand smoke is a tremendous health hazard, but no one is going to have a heart attack from 30 minutes of exposure.'"

"Siegel thinks that banning smoking in outdoor places is going too far and risks losing support for smoking bans overall. Smoking has been banned on 25 California beaches, and this week the Beverly Hills City Council approved a ban in nearly all outdoor dining areas. 'We should focus efforts on the remaining areas in which workers are not protected,' he says. 'My biggest concern is for the waiters and bartenders who spend 40 hours each week in very smoky environments.' He's also worried about the health of smoking research itself, which he sees being compromised by methodological flaws and over-interpretation of results. And although prospective studies would be costly, Siegel argues that funding for a large prospective study of the effects of smoking bans on non-smokers is warranted. 'Although I wholeheartedly support smoking bans, I still believe that we must use solid science to advocate for such bans and that a noble end — improving public health — does not justify the compromise of our scientific principles.'"

The Rest of the Story

I don't have much to add to what Dr. Novak wrote. I'm just glad that the misrepresentation of the science by anti-smoking groups and the deterioration of the quality of the scientific conclusions being made in the movement are being highlighted in a scientific journal with the high quality and fine reputation of a journal like Nature. I hope this will force anti-smoking groups to re-examine their decisions to disseminate misleading, if not inaccurate, health information and encourage the tobacco control movement to take stock of the deterioration of its scientific integrity and take steps to restore it.

Unfortunately, I don't think either of these will happen, because frankly, I really don't think that the movement, as an entity, actually cares. As long as its political aims are being met, I don't think that scientific integrity really enters the picture.

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