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Biomedical subjects

C M Haines

Publications and source records attributed to C M Haines.

8 recordsLinked to original sources

Residential exposure to magnetic fields and acute lymphoblastic leukemia in children.

BACKGROUND: Previous studies found associations between childhood leukemia and surrogate indicators of exposure to magnetic fields (the power-line classification since known as "wire coding"), but not between childhood leukemia and measurements of 60-Hz residential magnetic fields. METHODS: We enrolled 638 children with acute lymphoblastic leukemia (ALL) who were under 15 years of age and were registered with the Children's Cancer Group and 620 controls in a study of residential exposure to magnetic fields generated by nearby power lines. In the subjects' current and former homes, data collectors measured magnetic fields for 24 hours in the child's bedroom and for 30 seconds in three or four other rooms and outside the front door. A computer algorithm assigned wire-code categories; based on the distance and configuration of nearby power lines, to the subjects' main residences (for 416 case patients and 416 controls) and to those where the family had lived during the mother's pregnancy with the subject (for 230 case patients and 230 controls). RESULTS: The risk of childhood ALL was not linked to summary time-weighted average residential magnetic-field levels, categorized according to a priori criteria. The odds ratio for ALL was 1.24 (95 percent confidence interval, 0.86 to 1.79) at exposures of 0.200 mu T or greater as compared with less than 0.065 mu T. The risk of ALL was not increased among children whose main residences were in the highest wire-code category (odds ratio as compared with the lowest category, 0.88; 95 percent confidence interval, 0.48 to 1.63). Furthermore, the risk was not significantly associated with either residential magnetic-field levels or the wire codes of the homes mothers resided in when pregnant with the subjects. CONCLUSIONS: Our results provide little evidence that living in homes characterized by high measured time-weighted average magnetic-field levels or by the highest wire-code category increases the risk of ALL in children.

Case-Control Studies↗

Magnetic field exposure assessment in a case-control study of childhood leukemia.

Epidemiologic evaluation of the relation between magnetic field exposures and cancer depends critically on study design, particularly the methods used for exposure assessment. We incorporated a complex magnetic field exposure assessment protocol into a large incident case-control study of childhood leukemia. We measured residential magnetic fields using a standard protocol in current and former homes of 638 cases and 620 controls and determined wire codes for 414 case-control pairs. We chose a time-weighted average of magnetic field measurements in each eligible home, weighted by the time the subject lived in each home as the main exposure metric for each subject. We found that 24-hour bedroom magnetic field measurements adequately characterize children's residential exposure and that measuring other rooms contributes only slightly to the estimate of average residential exposure to magnetic fields. Front door measured fields provide useful exposure information when interior measurements are missing. If feasible, measuring multiple homes in which the subject has resided is preferable to measuring a single home. A similar distribution of wire codes for controls agreeing or refusing to participate in our study implies that risk estimates derived from wire code data will not be influenced by response bias.

Adolescent↗

Change in physician perspective on cholesterol and heart disease. Results from two national surveys.

The National Heart, Lung, and Blood Institute sponsored national telephone surveys of practicing physicians in 1983 (N = 1610) and 1986 (N = 1277) to assess attitudes and practices regarding elevated serum cholesterol levels. The 1983 survey was conducted just before the release of the results of the Lipid Research Clinics Coronary Primary Prevention Trial, which showed that a reduction in the blood cholesterol level reduced coronary heart disease. In 1986, 64% of physicians thought that reducing high blood cholesterol levels would have a large effect on heart disease, up considerably from 39% in 1983. Whereas in 1983, physicians attributed considerably less preventive value to reducing the cholesterol level than to reducing blood pressure or smoking, this disparity was substantially smaller in 1986. The median range of blood cholesterol at which diet therapy was initiated was 6.21 to 6.70 mmol/L (240 to 259 mg/dL) in 1986, down from 6.72 to 7.21 mmol/L (260 to 279 mg/dL) in 1983; the median for drug therapy was 7.76 to 8.25 mmol/L. (300 to 319 mg/dL) in 1986 and 8.79 to 9.28 mmol/L (340 to 359 mg/dL) in 1983. In 1986, 87% of physicians surveyed felt that medical evidence warranted the recommended treatment levels set forth in the 1984 National Institutes of Health Consensus Conference on Lowering Blood Cholesterol. These changes indicate that by 1986, physicians were more convinced of the benefit of lowering high blood cholesterol levels and were treating patients accordingly. The data also suggest areas for continued educational initiatives.

Adult↗

Change in public perspective on cholesterol and heart disease. Results from two national surveys.

The National Heart, Lung and Blood Institute, Bethesda, Md, and the Food and Drug Administration, Washington, DC, sponsored two national probability telephone surveys (N = 4000) of adults to assess attitudes and knowledge about heart disease risk from high blood cholesterol levels and the public's efforts to lower blood cholesterol levels. The first survey was conducted in 1983, before release of the results from the Lipid Research Clinics Coronary Primary Prevention Trial, which showed that a reduction in the blood cholesterol level reduced coronary heart disease; the second survey was conducted in 1986. The percentage of adults who believed that reducing high blood cholesterol levels would have a large effect on heart disease increased from 64% in 1983 to 72% in 1986, so that the importance attached to reducing high blood cholesterol levels approached that attributed to reducing smoking and high blood pressure. In 1983, 35% of adults reported that they had their cholesterol level checked vs 46% in 1986. In both years, diet changes were most frequently chosen (greater than 60%) as ways to control the blood cholesterol level; reducing dietary fat was believed to be as important as reducing dietary cholesterol. By 1986, 23% of adults reported that they made dietary changes specifically to lower their blood cholesterol level, up from 14% in 1983. These comparative data show gains in public awareness and action relating to high blood cholesterol level risk. The data can be used to develop education programs.

Attitude to Health↗

Hypertension control: meeting the 1990 objectives for the nation.

Hypertension (high blood pressure) is 1 of 15 health priorities of the Public Health Service set forth in the report, "Promoting Health/Preventing Disease: Objectives for the Nation." The nine objectives for hypertension include improved health status, reduced risk factors, increased public-professional awareness, improved services and protection, and improved surveillance-evaluation systems. A number of Federal agencies, coordinated by the National Heart, Lung, and Blood Institute, are working to reach the hypertension objectives in cooperation with State, local, and voluntary agencies and organizations. A great deal of progress has been made toward the objectives, as reflected by a variety of indicators. By 1980, for example, 34.1 percent of the population with hypertension had their blood pressure controlled at less than 160/95 mm Hg, but in 1972 only 16.5 percent were so controlled. Since 1972, the age-adjusted death rate has dropped 42 percent for stroke and 27 percent for coronary heart disease. Data indicate that the national goal for sodium ingestion (3-6 grams daily) may already have been met. Fifty-one percent of the population understand that hypertension may lead to stroke, meeting another objective. Public knowledge about hypertension as a "major likely cause of heart trouble" almost doubled in the 6-year period for which data are available. In 1982, 30 percent of processed food in grocery stores had sodium content labeling and almost 50 percent had calorie labeling, according to studies conducted by the Bureau of Foods of the Food and Drug Administration. Efforts are underway to develop a methodology for assessing incidence of hypertension and categories of hypertension control, a need spelled out in another objective.

Health Education↗