The relation between smokeless tobacco and cancer in Northern Europe and North America. A commentary on differences between the conclusions reached by two recent reviews

<p>Abstract</p> <p>Background</p> <p>Smokeless tobacco is an alternative for smokers who want to quit but require nicotine. Reliable evidence on its effects is needed. Boffetta et al. and ourselves recently reviewed the evidence on cancer, based on Scandinavian and US studies. Boffetta et al. claimed a significant 60–80% increase for oropharyngeal, oesophageal and pancreatic cancer, and a non-significant 20% increase for lung cancer, data for other cancers being "too sparse". We found increases less than 15% for oesophageal, pancreatic and lung cancer, and a significant 36% increase for oropharyngeal cancer, which disappeared in recent studies. We found no association with stomach, bladder and all cancers combined, using data as extensive as that for oesophageal, pancreatic and lung cancer. We explain these differences.</p> <p>Methods</p> <p>For those cancers Boffetta et al. considered, we compared the methods, studies and risk estimates used in the two reviews.</p> <p>Results</p> <p>One major reason for the difference is our more consistent approach in choosing between study-specific never smoker and combined smoker/non-smoker estimates. Another is our use of derived as well as published estimates. We included more studies, and avoided estimates for data subsets. Boffetta et al. also included some clearly biased or not smoking-adjusted estimates. For pancreatic cancer, their review included significantly increased never smoker estimates in one study and combined smoker/non-smoker estimates in another, omitting a combined estimate in the first study and a never smoker estimate in the second showing no increase. For oesophageal cancer, never smoker results from one study showing a marked increase for squamous cell carcinoma were included, but corresponding results for adenocarcinoma and combined smoker/non-smoker results for both cell types showing no increase were excluded. For oropharyngeal cancer, Boffetta et al. included a markedly elevated estimate that was not smoking-adjusted, and overlooked the lack of association in recent studies.</p> <p>Conclusion</p> <p>When conducting meta-analyses, all relevant data should be used, with clear rules governing the choice between alternative estimates. A systematic meta-analysis using pre-defined procedures and all relevant data gives a lower estimate of cancer risk from smokeless tobacco (probably 1–2% of that from smoking) than does the previous review by Boffetta et al.</p

Risks of serious complications and death from smallpox vaccination: A systematic review of the United States experience, 1963–1968

BACKGROUND: The United States (US) has re-instituted smallpox vaccinations to prepare for an intentional release of the smallpox virus into the civilian population. In an outbreak, people of all ages will be vaccinated. To prepare for the impact of large-scale ring and mass vaccinations, we conducted a systematic review of the complication and mortality risks of smallpox vaccination. We summarized these risks for post-vaccinial encephalitis, vaccinia necrosum (progressive vaccinia), eczema vaccinatum, generalized vaccinia, and accidental infection (inadvertant autoinoculation). METHODS: Using a MEDLINE search strategy, we identified 348 articles, of which seven studies met our inclusion criteria (the number of primary vaccinations and re-vaccinations were reported, sufficient data were provided to calculate complication or case-fatality risks, and comparable case definitions were used). For each complication, we estimated of the complication, death, and case-fatality risks. RESULTS: The life-threatening complications of post-vaccinial encephalitis and vaccinia necrosum were at least 3 and 1 per million primary vaccinations, respectively. Twenty-nine percent of vaccinees with post-vaccinial encephalitis died and 15% with vaccinia necrosum died. There were no deaths among vaccinees that developed eczema vaccinatum; however, 2.3% of non-vaccinated contacts with eczema vaccinatum died. Among re-vaccinees, the risk of post-vaccinial encephalitis was reduced 26-fold, the risk of generalized vaccinia was reduced 29-fold, and the risk of eczema vaccinatum was reduced 12-fold. However, the risk reductions of accidental infection and vaccinia necrosum were modest (3.8 and 1.5 fold respectively)

Licensing Telemedicine: The Need for a National System

The expansion of information technology has shattered geographic boundaries, allowing for extraordinarily increased access to health information and expanded opportunities for telemedicine practice across state boundaries. But despite its recent growth, telemedicine technology remains embedded in a state-based licensure system that places severe limits on its expansion. The current system of medical licensure is based primarily on statutes written at the turn of the 20th century. This system is inadequate to address the emerging medical practices and future uses of medical technology in the telecommunications age. To respond to the changes offered by the telecommunications revolution, we need to design a new regulatory structure for the 21st century. The purpose of this article is to propose a policy of national telemedicine licensure. The primary goal here is not to simply develop a policy proposal, but to discuss the rationale for national licensure and place it on the policy agenda. A national licensure system will expand the market for telemedicine, promote both the use and development of new technologies, and simultaneously eliminate many of the legal and regulatory ambiguities that plague and constrain the present system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63348/1/15305620050503915.pd