Agricultural injuries among operation household members: RRIS-II 1999.

The purpose of this study was to determine the magnitude and consequences of agricultural injuries, and to reveal potential risk factors among agricultural household members. The Regional Rural Injury Study (RRIS-II) collected injury and exposure data on agricultural households of 16,538 people in Minnesota, Wisconsin, North Dakota, South Dakota, and Nebraska for each six-month period of 1999. Adjusted injury rates, consequences, and potential risk factors were identified through analyses. Selection of variables for multivariate analyses was based on a causal model. Injuries reported here occurred while the individuals were involved in activities associated with their own farm or ranch, unless otherwise stated. Estimates of injury rates and the effects of various exposures were derived by Poisson and logistic regression. These models accounted for correlation within both subject and household, and were adjusted for non-response. The rate of agricultural injury to household members on their own operation was 74.5 injuries per 1,000 persons per year. Differences in rates due to age and gender diminished when rates were calculated according to hours worked. Although only 5% of injured persons required in-patient hospitalization, 28% required emergency department treatment, and 84% required some type of professional health care. Moreover, 47% of all injuries required time off from agricultural work, and 7% required time off from non-agricultural work. In multivariate analyses, decreased risks were associated with Minnesota, and increased risks were identified for those with prior injuries and for males.This study provides a basis for further research on agricultural injuries and their prevention.

An epidemiological study of the magnitude and consequences of work related violence: the Minnesota Nurses' Study.

AIMS: To identify the magnitude of and potential risk factors for violence within a major occupational population. METHODS: Comprehensive surveys were sent to 6300 Minnesota licensed registered (RNs) and practical (LPNs) nurses to collect data on physical and non-physical violence for the prior 12 months. Re-weighting enabled adjustment for potential biases associated with non-response, accounting for unknown eligibility. RESULTS: From the 78% responding, combined with non-response rate information, respective adjusted rates per 100 persons per year (95% CI) for physical and non-physical violence were 13.2 (12.2 to 14.3) and 38.8 (37.4 to 40.4); assault rates were increased, respectively, for LPNs versus RNs (16.4 and 12.0) and males versus females (19.4 and 12.9). Perpetrators of physical and non-physical events were patients/clients (97% and 67%, respectively). Consequences appeared greater for non-physical than physical violence. Multivariate modelling identified increased rates for both physical and non-physical violence for working: in a nursing home/long term care facility; in intensive care, psychiatric/behavioural or emergency departments; and with geriatric patients. CONCLUSIONS: Results show that non-fatal physical assault and non-physical forms of violence, and relevant consequences, are frequent among both RNs and LPNs; such violence is mostly perpetrated by patients or clients; and certain environmental factors appear to affect the risk of violence. This serves as the basis for further analytical studies that can enable the development of appropriate prevention and control efforts.

Metabolites of a tobacco-specific lung carcinogen in the urine of elementary school-aged children.

Limited data are available in the literature on carcinogen uptake by children exposed to environmental tobacco smoke (ETS). In this study, we quantified metabolites of the tobacco-specific lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in the urine of elementary school-aged children participating in the School Health Initiative: Environment, Learning, Disease study, a school-based investigation of the environmental health of children. The metabolites of NNK are 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its glucuronide (NNAL-Gluc). We also measured cotinine and its glucuronide (total cotinine). Urine samples were collected from 204 children. Seventy (34.3%) of these had total cotinine > or =5 ng/ml. NNAL or NNAL-Gluc was detected in 52 of 54 samples with total cotinine > or =5 ng/ml and in 10 of 20 samples with total cotinine < 5 ng/ml. Levels of NNAL plus NNAL-Gluc and total cotinine were significantly higher when exposure to ETS was reported than when no exposure was reported. However, even when no exposure to ETS was reported, levels of NNAL, NNAL-Gluc, and NNAL plus NNAL-Gluc were higher than in children with documented low exposure to ETS, as determined by cotinine levels < 5 ng/ml. Levels of NNAL, NNAL-Gluc, and cotinine were not significantly different in samples collected twice from the same children at 3-month intervals. Levels of NNAL plus NNAL-Gluc in this study were comparable with those observed in our previous field studies of adults exposed to ETS. There was a 93-fold range of NNAL plus NNAL-Gluc values in the exposed children. The results of this study demonstrate widespread and considerable uptake of the tobacco-specific lung carcinogen NNK in this group of elementary school-aged children, raising important questions about potential health risks. Our data indicate that objective biomarkers of carcinogen uptake are important in studies of childhood exposure to ETS and cancer later in life.

The effect of fecal occult-blood screening on the incidence of colorectal cancer.

BACKGROUND: Both annual testing for fecal occult blood and biennial testing significantly reduce mortality from colorectal cancer. However, the effect of screening on the incidence of colorectal cancer remains uncertain, despite the diagnosis and removal of precancerous lesions in many persons who undergo screening. METHODS: We followed the participants in the Minnesota Colon Cancer Control Study for 18 years. A total of 46,551 people, most of whom were 50 to 80 years old, were enrolled between 1975 and 1978 and randomly assigned to annual screening, biennial screening, or usual care (the control group). Those assigned to the screening groups were asked to prepare and submit two samples from each of three consecutive stools for guaiac-based testing. Those with at least one positive slide in the set of six were offered a diagnostic examination that included colonoscopy. Screening was conducted between 1976 and 1982 and again between 1986 and 1992. Study participants have been followed with respect to newly diagnosed cases of colorectal cancer and deaths. Follow-up has been more than 90 percent complete. RESULTS: During the 18-year follow-up period, we identified 1359 new cases of colorectal cancer: 417 in the annual-screening group, 435 in the biennial-screening group, and 507 in the control group. The cumulative incidence ratios for colorectal cancer in the screening groups as compared with the control group were 0.80 (95 percent confidence interval, 0.70 to 0.90) and 0.83 (95 percent confidence interval, 0.73 to 0.94) for the annual-screening and biennial-screening groups, respectively. For both screening groups, the number of positive slides was associated with the positive predictive value both for colorectal cancer and for adenomatous polyps at least 1 cm in diameter. CONCLUSIONS: The use of either annual or biennial fecal occult-blood testing significantly reduces the incidence of colorectal cancer.

Colorectal cancer deaths as determined by expert committee and from death certificate: a comparison. The Minnesota Study.

For deaths during the first 13 years of follow-up of the Minnesota Colon Cancer Control Study, an expert committee using numerous medical documents, and a nosologist using only the death certificate independently determined whether colorectal cancer caused the death and, if not, whether the disease was present at death. Deaths due to colorectal cancer numbered 318 according to the nosologist and 323 according to the committee, a discrepancy of 1.5%, which is similar in magnitude to that in three previous studies. The nosologist and committee agreed that colorectal cancer caused the death in each of 290 individual cases; they disagreed widely on the number of deaths from other causes but with colorectal cancer. If it is important to know only the gross number of deaths from colorectal cancer, then the death certificate alone appears to be sufficiently accurate; if it is important to know the cause of death of individual subjects or the number dying from other causes but with colorectal cancer, then the expert committee method provides more accurate information.

Application of a quantitative model to differentiate benign from malignant breast lesions detected by dynamic, gadolinium-enhanced MRI.

Both benign and malignant breast lesions may exhibit intense contrast enhancement when imaged using gadolinium-enhanced MRI. We propose a quantitative approach for fitting dynamic signal intensity (SI) data that may distinguish benign from malignant lesions. We studied 78 lesions in 75 women (18 malignancies, 16 fibroadenomas, and 44 other benign breast lesions) to determine the potential of this model for decreasing false-positive MR results. Twenty-eight lesions showed no enhancement; all were benign. One lesion showed a complex pattern not amenable to region-of-interest analysis and was considered a false positive. SI versus time data for the remaining 49 lesions were fit to the proposed model. We found that one parameter, M, the normalized slope of the SI enhancement profile evaluated at half the maximal signal intensity, seemed to be highly correlated with malignancy and offered improved discrimination between malignant and benign lesions compared to a previously published two-point slope method.