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CHANCE News 2.09
(25 April to 15 May 1993)
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Prepared by Laurie Snell
Please send suggestions for articles or format to
dart.chance@dartmouth.edu
Previous issues of this chance news and other materials for
a chance course are on the chance gopher. Just point your
gopher to chance.dartmouth.edu
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It is interesting having two instructors one of whom likes
numbers and the other is human.
From a student journal in Doyle-Snell chance class.
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ARTICLES ABSTRACTED
>>>>>==========>> In 4/27/93 NY Times, p A14, headline: "1 in 4 of the Elderly Are Ill Fed, Poll says" The survey reported in the article was conducted by Peter D. Hart Research Associates for the Nutrition Screening Initiative, a project whose purpose might be apparent from its name. The data was collected via telephone survey with doctors, nurses, and health care administrators who work with the elderly. The data collected from these sources were described as estimates, not as actual percentages based on testing or on notations in patient charts. The actual estimates reported in the article range from 34% to 50%, but for some reason, left unexplained, the 1 in 4 figure is headlined and also used by Rep. Ron Wyden, Dem of Oregon, who is quoted. Submitted by Rochelle Meyer, Prof at Nassau Community College. <<<========<<
>>>>>==========>> A costlier heart drug also proves better. The New York Times, 1 May, 1993, Sec 1 Page 7 Lawrence K. Altman An account of a large international clinical trial involving 41000 patients to see which of two clotbusting drugs: tissue plasminogen activator, or t-PA a genetically engineered substance that costs $2,400 a dose, or Streptokinase, an older drug derived from bacteria and costing $240 a dose. The study was designed to test four different strategies as they effect the patient up to 30 days after the heart attack. Participants were assigned at random to the four groups. All received aspirin and a blood thinner heparin. Group 1: Rapid infusion of t-PA plus intravenous heparin Death rate 6.3% stroke rate .6% Group 2: Somewhat slower infusion of t-PA plus streptokinase and intravenous heparin. Death rate 7%, stroke rate .6 Group 3: Streptokinase and under the skin injection of heparin : Death rate 7.2% and stroke rate .5 Group 4: Streptokinase and intravenous heparin Death rate 7.4% stroke rate .5% Here death rate means deaths in the first 30 days and stoke means disabling stroke. This study has been released to the newspapers before being reviewed and accepted for publication. Previous studies had suggested that the two drugs were about equally effective. Most accounts of this study reported that the study conclusively settles the issue quoting Dr. Topol director of the study that the study shows a 14 percent reduction in risk with T.P.A. Ethical questions on cost of new drug: Heart treatment has $200,000 price tag for each life saved San Francisco Chronicle, 5 May, 1993, Sec A, Page 2 Sabin Russell A discussion of the question of what effect the study described in the previous article will have. Stanford cardiologist Dr. William Hancock who prefers to use streptokinase is quoted as saying "I don't think I will change my view. The results were not different enough to make a clear-cut case for change." Berkeley medical ethicist John Golensky thinks that a wholesale switch to the more expensive drug is inevitable. Since TPA costs $2,000 more per treatment, the added cost of treating 100 patients ins $200,000 which can be considered the cost of saving one life which turns out to be about $30,000 per year of life saved. Dr. William Elliott, chairman of the committee that determines which drugs will be recommended at Kaiser Permanented hospitals in Northern California says "We've never looked at dollars-per-life-saved statistics." Since we see the two drugs do basically the same thing, we think it makes more sense to use Streptokinase" <<<========<<
>>>>>==========>> New colon cancer gene discovered. Science Vol.260, 7 May 1993 Jean Marx This issue of Science has several articles related to the discovery of a gene that causes colon cancer. This article has a fascinating description of the way that the colon cancer gene was found and how it acts. The gene intself has, in fact, not actually been found, but rather linkage studies have demonstrated its existence. The scientists Albert de la Chapelle from University of Helsinki, Finland and Bert Vogelstein of Johns Hopkins estimate that as many as 1 in 200 people have the gene. Eric Lancer is quoted as saying that the discovery is "the most exciting development in human genetics in the past year". Presumably this is partly because of the novel way that the gene causes it's damage. This is described in the next two articles. <<<========<<
>>>>>==========>> Cancer-causing gene found, with a clue to how it works. The New York Times 6 May, 1993, Sec A, Page 1 Gina Kolata An account of the above science article. Chapelle is quoted as saying that 65 percent of the people who carry the gene will develop colon cancer and de la Chapelle says that 90 to 100 percent will get cancer of some form. Since early detection can lead to successful cures it is hoped that the testing for the gene will reduce cancer deaths. "According to the American Cancer Society colon cancer will be diagnosed in 152,000 Americans this year, and 57,000 will die. It is the third leading cancer in men, after prostate and lung cancer, and the second-leading cancer in women after lung cancer." It is remarked that facilities for testing are far from established and that the test so far is applicable only to people from large families with a history of colon cancer where genes that are associated with the cancer gene can be followed through the generations. <<<========<<
>>>>>==========>> Coincidence or link between cancer and hereditary diseases. The New York Times, 11 May 1993, Sec C, Page 3 Gina Kolata Four genetic diseases including Huntington's disease have been associated with genes with three units of DNA which get repeated to a variable number of triplets causing a novel form of mutation. The process has been compared to a copying machine that gets jammed and produces more copies than it should. These multiple triplets lengthen with each generation and the longer they are the more severe the disease. The new colon cancer gene announced this week shows that a very similar miscopying occurs in the tumor cells of individuals who inherit the gene though apparently in a less regular manner. Other known cancer genes are simply mutations of normal genes that control cell proferation which effectively take off the brakes, and the cells to divide out of control. This article is an interesting discussion of the speculation on the possible connection between the new colon cancer gene and diseases like Huntington's disease. It includes quotes from well know geneticists some of whom say it may be just chance and others who say it must be more than chance and we should look for a deeper connections between the behaviors of these genes. <<<========<<
>>>>>==========>> Power lines didn't cause girl's rare cancer, jury finds. Los Angeles Times, 1 May, 1993, Sec A, Page 4 Michael Granberry The first United States case in which a public utility was charged of negligence stemming from electromagnetic fields resulted in the jury siding with the utility. They rejected the claim of a couple whose 5 1/2 year old daughter incurred a rare form of cancer that they claimed was caused by high-voltage power lines within 15 feet of the couples former San Diego home. <<<========<<
>>>>>==========>> Playing the market; stocks chosen by throwing darts. outperforming experts' selection. The Ottawa Citizen, 3 May, 1993, Sec C Page 4 Jade Hemeon A first quarter result of the contest sponsored by the between a portfolio of five stocks picked by tossing darts at the Toronto Stock Exchange listing tacked up on the wall and those chosen by five professional stock advisors who also each chose five stocks. In the first quarter the stocks chosen by tossing darts gained 49 percent and which was 20 percentage points better than the best of the picks made by the five professionals. The experts have nine-months to catch up. Everyone beat the Toronto Stock Exchange 300 index, which gained 7.5% in this period. <<<========<<
>>>>>==========>> The probability of unpleasant facts. Washington Post, 11 May, 1993, A18 Paul Glewwe --letter to the editor A previous letter (May 1) suggested that China has more boys than girls because if they have a boy for the first child they tend not to have a second child. The author of this letter points out the elementary probability calculations show that this will not cause more boys than girls and concludes with "Let's not mangle probability theory to hide unpleasant facts" <<<========<<
>>>>>==========>> Big science enters the clinic. Science Vol. 260 7 May 1993 Eliot Marshall An analysis of a very large Women's Health Initiative that is to be started in September. This study is several studies combined in one. The study has three main elements. The first is a clinical trials study to test the effects of a low-fat diet on incidence of breast and colon cancer. The second is an epidemiological study that will follow for 9 years about 100,000 women to get a better idea of how factors such as lipid levels, blood pressure, smoking habits, and hormone levels effect risks for heart disease, cancer and bone fracture. The third part is a community trial which will give special education programs in certain communities aimed at improving health -- stopping smoking, reducing fat in diet etc. The purpose of this is to see the effect of education. The article describes some of the debate over whether it is a good idea to have such a large overlapping study rather than smaller individual studies. <<<========<<
>>>>>==========>> Research challenges angioplasty risk in women. Star Tribune, 28 April 1993. Sec 1 Page 1 Gordon Slovut A summary of a study in the current Journal of American Medical Association that contradicts several previous studies that claim that a woman's risk of during or immediately after angioplasty is up to 10 times greater than that for men. In angioplasty a tube is inserted in the blood vessel in the leg and a small balloon is inflated to widen the blocked area in the coronary artery to restore blood flow in the hart. The author of the current study, Dr. Malcomn Bell of Mayo Clinic said that the articles that found big differences were relying on outdated data and that methods have been much improved in recent years. The study showed that the best predictors of risk of death during or immediately after angioplasty were the severity of symptoms, having other diseases that contribute to heart problems, being over 70, and being physically small. Risks of men and women who are the same with respect to these factors is almost identical. <<<========<<
>>>>>==========>> !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! CHANCE News 2.09 (25 April to 15 May 1993) !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Please send suggestions to: jlsnell@dartmouth.edu >>>==========>>|<<==========<<<
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