Second-hand Smoke Study Sparks Controversy

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Second-hand Smoke Study Sparks Controversy

• By Mike WendlingCNSNews.com London Bureau
  ChiefMay 16, 2003

http//www.cnsnews.com/ViewForeignBureaus.asp?Page
5CForeignBureaus5Carchive5C2003055CFOR2003051
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The Study

• A study about to be published in this week's
  British Medical Journal indicates that
  second-hand smoke doesn't increase the risk of
  heart disease or lung cancer, but the publication
  and the study's authors have come under attack by
  anti-smoking groups.
• http//bmj.bmjjournals.com/cgi/content/full/326/73
  98/1057
• Two American researchers analyzed data from an
  American Cancer Society survey that followed more
  than 118,000 Californians from 1960 until 1998.
• James E. Enstrom, of the University of California
  at Los Angeles and Geoffrey C. Kabat of the SUNY
  at Stony Brook concluded that "the results do not
  support a causal relation between environmental
  tobacco smoke (second-hand smoke) and tobacco
  related mortality, although they do not rule out
  a small effect."
• "The association between exposure to
  environmental tobacco smoke and coronary heart
  disease and lung cancer may be considerably
  weaker than generally believed," the researchers
  wrote.
• Study was funded from tobacco industry-related
  sources

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Response (1)

• The data and design of the Enstrom and Kabat
  secondhand smoke study has been widely
  criticized. Even the British Medical Association,
  the publisher of the journal that printed the
  study, described the research as being
  "fundamentally flawed." The misuse of data and
  flawed methodology are two very significant
  faults in the study.
• Enstrom and Kabat did not gather original data
  for their study. Instead, it drew on data from
  the American Cancer Society's Cancer Prevention
  Study I (CPS-I), and used only a small subset
  (approximately 10) of the total CPS-I data.
  Researchers at the American Cancer Society
  repeatedly warned Enstrom that the data from
  CPS-I could not be used to determine the health
  effects of secondhand smoke, and they spoke out
  against the study upon its release, stating that
  their data had been misused.

http//www.no-smoke.org/Responding_EnstromandKabat
.html
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Response (2)

• The study used cohort methodology to look at the
  rate of mortality from heart disease and lung
  cancer in nonsmokers who were married to smokers,
  covering a time period from 1959 to 1998.
• A severe error in the study was the failure to
  establish a control group of nonsmokers who were
  unexposed to secondhand smoke.
• Other critical methodological flaws include not
  measuring for secondhand smoke exposure from any
  source other than the spouse, including the
  workplace (where smoking was extremely prevalent
  at the time) not taking into account either
  spouse's smoking status after 1972, though the
  study continued for 26 more years and
  classifying the non-smoking spouse as still
  exposed to secondhand smoke in that 26 year
  period, during which time the "smoking spouse"
  could have quit smoking or died, not to mention
  that they could have divorced or separated.

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Study and Responses

• Original Study
• http//bmj.bmjjournals.com/cgi/content/full/326/73
  98/1057
• Rapid Responses
• http//bmj.bmjjournals.com/cgi/eletters/326/7398/1
  05732297