Effectiveness of nicotine patches in a workplace smoking cessation program. An eleven-month follow-up study.

Transdermal nicotine patches are widely prescribed as part of smoking cessation programs, but their efficacy beyond 6 months is not well established. We evaluated the efficacy of a 70-day treatment regimen among 75 subjects in an industrial setting where follow-up was conducted for 11 months. The median time free of cigarettes was 73 days, and the overall smoking abstinence rate was 9% after 11 months of follow-up. Smoking abstinence was significantly higher among those subjects who completed the full course of treatment than among those who did not (25 vs 6%, respectively). Smoking abstinence was also higher among subjects who started smoking after age 17 than among those who started at younger ages and was higher among male than female subjects. We conclude that transdermal nicotine patches are of limited efficacy in achieving long-term smoking cessation and that the relative costs and benefits of this treatment are not adequately specified.

Wood-dust exposures and cancer of the colon.

Previous studies of workers exposed to wood dusts have shown a decreased risk of cancer of the colon in these workers. However, none of these studies adequately controlled for potential confounders, such as physical activity, diet, and family history of colorectal cancer. The purpose of this case-control study was to evaluate the association between exposure to wood dust and risk for colon cancer after adjusting for potential confounders. Four hundred nineteen male cases of adenocarcinoma of the colon, identified from the Los Angeles County Cancer Surveillance Program, were individually matched to neighborhood controls based on gender and date of birth. Exposure to wood dust was associated with reduced risk of colon cancer that was partially masked before adjustment for confounders, and was limited to workers with frequent exposures that had begun at least 30 years before diagnosis [unadjusted and adjusted ORs, respectively, to exposures 5+ times a week beginning 30+ years before diagnosis = 0.63 (95% CI 0.36-1.13) and 0.39 (95% CI 0.20-0.77)]. This study provides additional evidence that heavy exposure to wood dusts may be associated with reduced risk of colon cancer in males after adjustment for other known causes of colon cancer.

Asbestos and colon cancer: lack of association in a large case-control study.

Previous studies linking exposure to asbestos with human colon cancer have used mortality rather than incidence as their endpoint and have neither assessed nor controlled for confounding by diet, genetic factors, or other risk factors for colon cancer. A case-control study of 746 histologically confirmed cases of colon cancer and 746 matched neighborhood controls was conducted in Los Angeles County, California. In univariate analyses of the 419 male pairs, a weak association was found between asbestos exposure and colon cancer (odds ratio (OR) = 1.16, 95% confidence interval (CI) 0.80-1.69). When confounding by family history of large bowel cancer, diet, body weight, and physical activity was controlled, there was no association between colon cancer and exposure to asbestos among males (OR = 0.99, 95% CI 0.66-1.50). When asbestos exposure was restricted to occurrences preceding diagnosis by more than 15 years, there was no clear association between such exposure and colon cancer, either before (OR = 1.14, 95% CI 0.76-1.70) or after confounding was controlled (OR = 0.93, 95% CI 0.60-1.44). Further analyses by frequency and duration of exposure failed to show any association between asbestos and risk of colon cancer, but did show a consistent pattern of confounding by nonoccupational factors that, when controlled, invariably produced a weak protective effect of asbestos exposure. Among the 327 female pairs, only 6 cases and 11 controls reported asbestos exposure (OR = 0.55, 95% CI 0.20-1.48), and there was no evidence of risk increasing as the frequency or duration of exposure increased. This study suggests not only that occupational exposure to asbestos is not a risk factor for colon cancer in the general population of Los Angeles, but also that observed associations between asbestos and colon cancer should not be interpreted as causal unless confounding by nonoccupational factors has been evaluated and controlled.

A meta-analysis of colorectal cancer and asbestos exposure.

A meta-analysis of the relation between asbestos exposure and colorectal cancer mortality was conducted, using published reports of 20 asbestos-exposed cohorts. Summary standardized mortality ratios (SMRs) for colorectal cancer were examined in relation to asbestos type and estimates of dust exposure (as direct estimators of asbestos exposure) and in relation to lung cancer SMR and the proportion of all deaths due to mesothelioma (as proxy estimators of asbestos exposure). An elevated summary SMR was observed in cohorts exposed to amphibole asbestos (summary SMR = 1.47; 95% confidence interval (CI) 1.09-2.00), but not in cohorts exposed to serpentine asbestos (summary SMR = 1.04; 95% CI 0.81-1.33) or in cohorts exposed to both serpentine and amphibole asbestos (summary SMR = 1.03; 95% CI 0.74-1.42). Cohorts having a lung cancer SMR greater than 2.00 had a summary SMR of 1.51 (95% CI 1.29-1.76), and cohorts in which more than 1% of all deaths were attributed to mesothelioma had a summary SMR of 1.24 (95% CI 0.94-1.64). After stratifying the cohorts based on mortality due to all cancers excluding those known or suspected to be associated with asbestos exposure, lung cancer mortality was not clearly associated with colorectal cancer mortality, suggesting that the crude association between these factors may be due to misdiagnosis of lung cancer as other types of cancer in the reported causes of death. These results suggest that exposure to amphibole asbestos may be associated with colorectal cancer, but these findings may reflect an artifact of miscertification of cause of death. The results also suggest that serpentine asbestos is not associated with colorectal cancer.

Incidence and survival rates of children and young adults with osteogenic sarcoma.

Gender-specific and race-specific incidence and survival rates of osteogenic sarcoma over a 14-year period are presented for persons aged 0 to 24 years from eight Surveillance, Epidemiology, and End Results (SEER) registries. They were no significant gender or racial differences in age at diagnosis. There was no significant gender difference in overall incidence. Although incidence rates were slightly higher in blacks compared with whites, the difference was not significant after controlling for multiple comparisons. Females (median, 74 months) survived longer than males (median, 29 months), although this difference weakened after controlling for stage. No racial differences in survival were observed. White females survived the longest (median, 94 months), followed by black females (median, 41 months), black males (median, 34 months), and white males (median, 29 months). This striking difference in survival should be explored more fully.

Asthma mortality in U.S. Hispanics of Mexican, Puerto Rican, and Cuban heritage, 1990-1995.

We used national vital statistics data for 1990 through 1995 to examine both national and regional age-adjusted asthma mortality rates for U.S. Hispanics of Mexican, Cuban, and Puerto Rican heritage, as well as for non-Hispanic whites and non-Hispanic blacks. Nationally, Puerto Ricans had an age-adjusted annual asthma mortality rate of 40.9 per million, followed by Cuban-Americans (15. 8 per million) and Mexican-Americans (9.2 per million). In comparison, non-Hispanic whites had an age-adjusted annual asthma mortality rate of 14.7 per million and non-Hispanic blacks had a rate of 38.1 per million. Age-adjusted asthma mortality for Puerto Ricans was highest in the Northeast (47.8 per million); this region accounted for 81% of all asthma deaths among Puerto Ricans in the United States. In the U.S., Puerto Ricans had the highest asthma mortality rates among Hispanics, followed by Cuban-Americans and Mexican-Americans. In addition, among Hispanic national groups, mortality rates were consistently higher in the Northeast than the Midwest, South, or West regions. These results further support that Hispanics do not represent a uniform, discrete group in terms of health outcomes, and that further public health research and interventions should take Hispanic national origin into account.

Surveillance for asthma--United States, 1960-1995.

PROBLEM/CONDITION: Asthma is one of the most common chronic diseases in the United States, and it has increased in importance during the preceding 20 years. Despite its importance, no comprehensive surveillance system has been established that measures asthma trends at the state or local level. REPORTING PERIOD: This report summarizes and reviews national data for specific end-points: self-reported asthma prevalence (1980-1994), asthma office visits (1975-1995), asthma emergency room visits (1992-1995), asthma hospitalizations (1979-1994), and asthma deaths (1960-1995). DESCRIPTION OF SYSTEM: The National Center for Health Statistics (NCHS) annually conducts the National Health Interview Survey, which asks about self-reported asthma in a subset of the sample. NCHS collects physician office visit data with the National Ambulatory Medical Care Survey, emergency room visit data with the National Hospital Ambulatory Medical Care Survey, and hospitalization data with the National Hospital Discharge Survey. NCHS also collects mortality data annually from each state and produces computerized files from these data. We used these datasets to determine self-reported asthma prevalence, asthma office visits, asthma emergency room visits, asthma hospitalizations, and asthma deaths nationwide and in four geographic regions of the United States (i.e., Northeast, Midwest, South, and West). RESULTS: We found an increase in self-reported asthma prevalence rates and asthma death rates in recent years both nationally and regionally. Asthma hospitalization rates have increased in some regions and decreased in others. At the state level, only death data are available for asthma; death rates varied substantially among states within the same region. INTERPRETATION: Both asthma prevalence rates and asthma death rates are increasing nationally. Available surveillance information are inadequate for fully assessing asthma trends at the state or local level. Implementation of better state and local surveillance can increase understanding of this disease and contribute to more effective treatment and prevention strategies.