34 research outputs found
Minimum Responsiveness and the Political Exclusion of the Poor
Sweden received about 5 % of the total release of Cs-137 from the Chernobyl nuclear power plant accident in 1986. The distribution of the fallout mainly affected northern Sweden, where some parts of the population could have received an estimated annual effective dose of 1-2 mSv per year. It is disputed whether an increased incidence of cancer can be detected in epidemiological studies after the Chernobyl nuclear power plant accident outside the former Union of Soviet Socialist Republics. In the present paper, a possible exposure-response pattern between deposition of Cs-137 and cancer incidence after the Chernobyl nuclear power plant accident was investigated in the nine northernmost counties of Sweden (2.2 million inhabitants in 1986). The activity of Cs-137 from the fallout maps at 1986 was used as a proxy for the received dose of ionizing radiation. Diagnoses of cancer (ICD-7 code 140-209) from 1980 to 2009 were received from the Swedish Cancer Registry (273,222 cases). Age-adjusted incidence rate ratios, stratified by gender, were calculated with Poisson regression in two closed cohorts of the population in the nine counties 1980 and 1986, respectively. The follow-up periods were 1980-1985 and 1986-2009, respectively. The average surface-weighted deposition of Cs-137 at three geographical levels; county (n = 9), municipality (n = 95) and parish level (n = 612) was applied for the two cohorts to study the pre- and the post-Chernobyl periods separately. To analyze time trends, the age-standardized total cancer incidence was calculated for the general Swedish population and the population in the nine counties. Joinpoint regression was used to compare the average annual percent change in the general population and the study population within each gender. No obvious exposure-response pattern was seen in the age-adjusted total cancer incidence rate ratios. A spurious association between fallout and cancer incidence was present, where areas with the lowest incidence of cancer before the accident coincidentally had the lowest fallout of Cs-137. Increasing the geographical resolution of exposure from nine county averages to 612 parish averages resulted in a two to three times higher value of variance in the regression model. There was a secular trend with an increase in age-standardized incidence of cancer in both genders from 1980 to 2009, but significant only in females. This trend was stronger and statistically significant for both genders in the general Swedish population compared to the nine counties. In conclusion, using both high quality cancer registry data and high resolution exposure maps of Cs-137 deposition, it was not possible to distinguish an effect of Cs-137 on cancer incidence after the Chernobyl nuclear power plant accident in Sweden
Inflammatory parameters after pleurodesis in recurrent malignant pleural effusions and their predictive value
AbstractRecurrent pleural malignant effusion is a common problem which can be treated by inducing symphysis of the pleural sheets. Many different drugs administered into the pleural space can be used to achieve this. The drugs cause an inflammatory response, which in turn is believed to cause the symphysis. Comparatively little has been published on the degree of pleural inflammation and the systemic response and whether this will affect the outcome.The aim of this study was to describe the systemic inflammatory reaction following instillation of a chemical agent into the pleura and to investigate whether this had any predictive value for the outcome (i.e. the pleurodesis). The markers investigated were simple ones: erythrocyte sedimentation rate, C-reactive protein, and leukocyte count from venous blood samples, and the fever reaction.Eighty-nine prospective patients with malignant pleural effusion who underwent pleurodesis with either talc (48 patients) or quinacrine (41 patients) were included in the study. Symphysis was achieved in 82 patients (92 per cent) and all had a prominent transitional elevation of the inflammatory parameters. The unsuccessful attempts caused negligible or very small elevations, but due to the small numbers only the degree of fever after 8 and 48h showed a statistically significant difference.In conclusion, pleurodesis causes a systemic inflammation and there is a tendency to a correlation between the success of pleurodesis and the degree of inflammation. High fever and high inflammatory parameters including CRP are due to this inflammatory response and do not indicate infection
Radioactive fall-out from the Chernobyl nuclear power plant accident in 1986 and cancer rates in Sweden, a 25-year follow up
Aim: The current research aimed to study the association between exposure to low-dose radiation fallout after the Chernobyl accident in 1986 and the incidence of cancer in Sweden. Methods: A nationwide study population, selecting information from nine counties out of 21 in Sweden for the period from 1980 – 2010. In the first study, an ecological design was defined for two closed cohorts from 1980 and 1986. A possible exposure response pattern between the exposure to 137Cs on the ground and the cancer incidence after the Chernobyl nuclear power plant accident was investigated in the nine northernmost counties of Sweden (n=2.2 million). The activity of 137Cs at the county, municipality and parish level in 1986 was retrieved from the Swedish Radiation Safety Authority (SSI) and used as a proxy for received dose of ionizing radiation. Information about diagnoses of cancer (ICD-7 code 140-209) from 1958 – 2009 were received from the Swedish Cancer Registry, National Board of Health and Welfare (368,244 cases were reported for the period 1958 to 2009). The incidence rate ratios were calculated by using Poisson Regression for pre-Chernobyl (1980 – 1986) and post-Chernobyl (1986 – 2009) using average deposition of 137Cs at three geographical levels: county (n=9), municipality (n=95), and parish level (n=612). Also, a time trend analysis with age standardized cancer incidence in the study population and in the general Swedish population was drawn from 1980 – 2009. In the second study, a closed cohort was defined as all individuals living in the three most contaminated counties in mid-Sweden in 1986. Fallout of 137Cs was retrieved as a digital map from the Geological Survey of Sweden, demographic data from Statistics Sweden, and cancer diagnosis from the Swedish Cancer Registry, National Board of Health and Welfare. Individuals were assigned an annual 137Cs exposure based on their place of residence (1986 through 1990), from which 5-year cumulative 137Cs exposures were calculated, accounting for the physical decay of 137Cs and changing residencies. Hazard ratios for having cancer during the follow-up period, adjusted for age, sex, rural/non-rural residence, and pre-Chernobyl total cancer incidence, were calculated. Results: No obvious exposure-response pattern in the age-standardized total cancer incidence rate ratios could be seen in the first study. However, a spurious association between the fallout and cancer incidence was present, where areas with the lowest incidence of cancer before the accident coincidentally had the lowest fallout of cesium-137. Increasing the geographical resolution of exposure from the average values of nine counties to the average values of 612 parishes resulted in two to three times higher degree of variance explanation by regression model. There was a secular trend, with an increase in age standardized incidence of cancer from 1980 – 2009. This trend was stronger in the general Swedish population compared to the nine counties of the present study. In the second study, 734,537 people identified were divided into three exposure categories: the first quartile was low exposure (0.0 to 45.4 kBq/m2), the second and third quartiles were intermediate exposure (45.41 to 118.8 kBq/m2), and the fourth quartile was highest exposure (118.81 to 564.71 kBq/m2). Between 1991 and 2010, 82,495 cancer cases were registered in the three counties. Adjusted HRs (95% CI) were 1.03 (1.01 to 1.05) for intermediate exposure, and 1.05 (1.03 to 1.07) for the highest exposure, when comparing to the reference exposure. Conclusion: Using the ecological data, there was no exposure response trend; however, after refining the data to the individual level of exposure, there was an overall exposure response pattern. Nonetheless, due to the time dependency, these results were restricted to the age group of 25 – 49 among males. Using register-based data only, for determining the association between low-dose exposure to radiation and the risk of developing cancer, is difficult since we cannot control for other significant factors that are associated with cancer
Radioactive fall-out from the Chernobyl nuclear power plant accident in 1986 and cancer rates in Sweden, a 25-year follow up
Aim: The current research aimed to study the association between exposure to low-dose radiation fallout after the Chernobyl accident in 1986 and the incidence of cancer in Sweden. Methods: A nationwide study population, selecting information from nine counties out of 21 in Sweden for the period from 1980 – 2010. In the first study, an ecological design was defined for two closed cohorts from 1980 and 1986. A possible exposure response pattern between the exposure to 137Cs on the ground and the cancer incidence after the Chernobyl nuclear power plant accident was investigated in the nine northernmost counties of Sweden (n=2.2 million). The activity of 137Cs at the county, municipality and parish level in 1986 was retrieved from the Swedish Radiation Safety Authority (SSI) and used as a proxy for received dose of ionizing radiation. Information about diagnoses of cancer (ICD-7 code 140-209) from 1958 – 2009 were received from the Swedish Cancer Registry, National Board of Health and Welfare (368,244 cases were reported for the period 1958 to 2009). The incidence rate ratios were calculated by using Poisson Regression for pre-Chernobyl (1980 – 1986) and post-Chernobyl (1986 – 2009) using average deposition of 137Cs at three geographical levels: county (n=9), municipality (n=95), and parish level (n=612). Also, a time trend analysis with age standardized cancer incidence in the study population and in the general Swedish population was drawn from 1980 – 2009. In the second study, a closed cohort was defined as all individuals living in the three most contaminated counties in mid-Sweden in 1986. Fallout of 137Cs was retrieved as a digital map from the Geological Survey of Sweden, demographic data from Statistics Sweden, and cancer diagnosis from the Swedish Cancer Registry, National Board of Health and Welfare. Individuals were assigned an annual 137Cs exposure based on their place of residence (1986 through 1990), from which 5-year cumulative 137Cs exposures were calculated, accounting for the physical decay of 137Cs and changing residencies. Hazard ratios for having cancer during the follow-up period, adjusted for age, sex, rural/non-rural residence, and pre-Chernobyl total cancer incidence, were calculated. Results: No obvious exposure-response pattern in the age-standardized total cancer incidence rate ratios could be seen in the first study. However, a spurious association between the fallout and cancer incidence was present, where areas with the lowest incidence of cancer before the accident coincidentally had the lowest fallout of cesium-137. Increasing the geographical resolution of exposure from the average values of nine counties to the average values of 612 parishes resulted in two to three times higher degree of variance explanation by regression model. There was a secular trend, with an increase in age standardized incidence of cancer from 1980 – 2009. This trend was stronger in the general Swedish population compared to the nine counties of the present study. In the second study, 734,537 people identified were divided into three exposure categories: the first quartile was low exposure (0.0 to 45.4 kBq/m2), the second and third quartiles were intermediate exposure (45.41 to 118.8 kBq/m2), and the fourth quartile was highest exposure (118.81 to 564.71 kBq/m2). Between 1991 and 2010, 82,495 cancer cases were registered in the three counties. Adjusted HRs (95% CI) were 1.03 (1.01 to 1.05) for intermediate exposure, and 1.05 (1.03 to 1.07) for the highest exposure, when comparing to the reference exposure. Conclusion: Using the ecological data, there was no exposure response trend; however, after refining the data to the individual level of exposure, there was an overall exposure response pattern. Nonetheless, due to the time dependency, these results were restricted to the age group of 25 – 49 among males. Using register-based data only, for determining the association between low-dose exposure to radiation and the risk of developing cancer, is difficult since we cannot control for other significant factors that are associated with cancer
Principal Components Regression
"Principal Components Regression" (PCREG), also sometimes called "biased regression methods" is used to model data with highly correlated explanatory variables. This well-known method has been discussed by multiple previous authors (Marquardt 1970, Hoerl and Kennard 1970, Lott 1973, Hawkins 1973, Webster, Grace and Mason 1974, Hoerl, Kennard and Baldwin 1975, Marquardt and Snee 1975, Hocking, Speed and Lynn 1976 Smith and Campbell 1980, Park 1981). In recent decades, when modeling data with highly correlated explanatory variables, statisticians and researchers have frequently used multiple regression models that are related to the "Partial Least Squares regression (PLSREG) and SIMPLE algorithm to avoid multicollinearity in the data. PCREG uses the estimated components in the same way as PLSREG to estimate the regression coefficients. Both of these biased regression methods are discussed in detail by Wold 1966, Horel and Kennard 1970, Dijkstra 1983, 1985, de Jong 1993 SIMPLE algorithm, gutters et al. 1994, van der Voet 1994. Most available software; however, only gives users the opportunity to run PLSREG analyses. Examples include SAS, Minitab, Statistica and SPSS (although SPSS require that a special component be downloaded and installed to run PLSREG analyses). All these programs are under development and each provides slightly different output. All programs that run PLSREG analyses automatically rank principal components in descending order of eigenvalues. One purpose of this essay is to clarify why this descending order may not always be the most useful order in all kinds of research. A second purpose is to show that it is possible to use a newly developed program that runs PCREG in SAS to choose components on the basis of their weight and importance in relation to the explanatory variables. Additionally, the general theory of PCREG and “ridge” regression (RREG) will be discussed. Two data sets (one large and one small) will be used to compare the results of analyses run using PCREG, PLSREG, and RREG. Two data sets were necessary because the more variables in a dataset, the more difficult it is to choose how many estimated components must be used in the analysis and the more potentially misleading the automatic eigenvalues choice of the existing software programs can be. The PCREG analyses of the two data sets (run using PROC IML in SAS 9.2) will include an estimation of the regression coefficients, standard errors of the coefficients, and t-test and (p) values. Interpretation of regression coefficients in PCREG is done in exactly the same way as in regression analysis. The numerical results of the PCREG analyses suggest that the PCREG algorithm used to write the new program can also be used to improve PLSREG estimates based on rotated principal components. Although this work has been motivated by the problem of analyzing quantitative variables in socio-economic and demographic data sets, the method is also applicable to problems that involve estimating regression coefficients that are based on highly correlated quantitative explanatory variables. Thus, the method is probably relevant to a wide range of problems in the physical, chemical, medical, financial, and technical sciences
Cancer incidence in northern Sweden before and after the Chernobyl nuclear power plant accident
Sweden received about 5 % of the total release of Cs-137 from the Chernobyl nuclear power plant accident in 1986. The distribution of the fallout mainly affected northern Sweden, where some parts of the population could have received an estimated annual effective dose of 1-2 mSv per year. It is disputed whether an increased incidence of cancer can be detected in epidemiological studies after the Chernobyl nuclear power plant accident outside the former Union of Soviet Socialist Republics. In the present paper, a possible exposure-response pattern between deposition of Cs-137 and cancer incidence after the Chernobyl nuclear power plant accident was investigated in the nine northernmost counties of Sweden (2.2 million inhabitants in 1986). The activity of Cs-137 from the fallout maps at 1986 was used as a proxy for the received dose of ionizing radiation. Diagnoses of cancer (ICD-7 code 140-209) from 1980 to 2009 were received from the Swedish Cancer Registry (273,222 cases). Age-adjusted incidence rate ratios, stratified by gender, were calculated with Poisson regression in two closed cohorts of the population in the nine counties 1980 and 1986, respectively. The follow-up periods were 1980-1985 and 1986-2009, respectively. The average surface-weighted deposition of Cs-137 at three geographical levels; county (n = 9), municipality (n = 95) and parish level (n = 612) was applied for the two cohorts to study the pre- and the post-Chernobyl periods separately. To analyze time trends, the age-standardized total cancer incidence was calculated for the general Swedish population and the population in the nine counties. Joinpoint regression was used to compare the average annual percent change in the general population and the study population within each gender. No obvious exposure-response pattern was seen in the age-adjusted total cancer incidence rate ratios. A spurious association between fallout and cancer incidence was present, where areas with the lowest incidence of cancer before the accident coincidentally had the lowest fallout of Cs-137. Increasing the geographical resolution of exposure from nine county averages to 612 parish averages resulted in a two to three times higher value of variance in the regression model. There was a secular trend with an increase in age-standardized incidence of cancer in both genders from 1980 to 2009, but significant only in females. This trend was stronger and statistically significant for both genders in the general Swedish population compared to the nine counties. In conclusion, using both high quality cancer registry data and high resolution exposure maps of Cs-137 deposition, it was not possible to distinguish an effect of Cs-137 on cancer incidence after the Chernobyl nuclear power plant accident in Sweden
Downton Fall Risk Index during hospitalisation is associated with fall-related injuries after discharge : a longitudinal observational study
Questions: Among older people who are hospitalised, what is the predictive validity of the Downton Fall Risk Index (DFRI) in relation to fall-related injury after discharge? What is the predictive validity of the DFRI among males and females in this setting? Design: Prospective, longitudinal, observational study. Participants: All hospital admissions during 2012 at three geriatric clinics in the Stockholm County Council were monitored. Patients aged > 65 years who did not die during the admission and who lived in the Stockholm County Council region were included. Outcome measures: The DFRI consists of five modules: previous falls, medication, sensory deficits, mental state, and gait. Three or more points indicate an increased fall risk. Data on DFRI, health status and medications were collected prior to discharge. Data regarding fall-related injuries were collected up to 6 months after discharge. Poisson multivariate regression analyses were conducted to evaluate the association between DFRI and fall-related injuries. Results: In total, 6650 patients were analysed. The cut-off >= 3 points in the DFRI was significantly associated with fall-related injury when confounding variables were controlled for (IRR 1.94, 95% CI 1.60 to 2.38). Among individual modules, only previous falls (IRR 2.58, 95% CI 2.22 to 3.01) and unsafe gait (IRR 1.79, 95% CI 1.53 to 2.09) were associated with fall-related injuries. Stratified analyses showed a higher risk ratio for men compared to women regarding the DFRI, but the test for an interaction effect was not significant. Conclusion: The risk of post-discharge fall-related injury is increased among older hospitalised people with an increased fall risk, according to the DFRI, especially those who had previous falls or unsafe gait. Although the DFRI tool is predictive, previous falls and gait are the measures that are most worthy of focus
Poor physical function, relationship problems and alcohol use are predictors of increased overall mortality in Swedish cancer patients : 27-years follow-up study in Stockholm County
Background: To study the mortality rates among cancer patients and whether these differences are associated with history of poor physical health and socio-economic situation. Method: The relation between overall mortality and 30 questions of life-style and health was investigated in all subjects (n = 3197) who received a diagnosis of cancer (ICD-7 140-209) between 1969 and 1996 from the Rebus-cohort created in 1969 (n = 32186). Results: The overall mortality was increased in both men and women who received a cancer diagnose if they had reported problems with physical function at the beginning of the study. Men who received a cancer diagnose also had higher mortality due to cancer if they had relationship problems (HR = 1.23, 1.02-1.48), and alcohol use problem (HR = 1.35, 1.04-1.74) at baseline. Women who received cancer also had higher risk to die in cardiovascular diseases if they had reported physical function problem (HR = 1.97, 1.25-3.12) at the beginning of the study. Conclusions: Poor physical function is a predictor of increased mortality among subjects with diagnosis of cancer
Total cancer incidence in relation to 137Cs fallout in the most contaminated counties in Sweden after the Chernobyl nuclear power plant accident : a register-based study
OBJECTIVES: To determine the total cancer incidence in relation to a 5-year exposure to caesium-137 ((137)Cs) from the 1986 Chernobyl nuclear power plant accident. METHODS: A closed cohort was defined as all individuals living in the three most contaminated counties in mid-Sweden in 1986. Fallout of (137)Cs was retrieved as a digital map from the Geological Survey of Sweden, demographic data from Statistics Sweden, and cancer diagnosis from the National Board of Health and Welfare. Individuals were assigned an annual (137)Cs exposure based on their place of residence (1986-1990), from which 5-year cumulative (137)Cs exposures were calculated, accounting for the physical decay of (137)Cs and changing residencies. HRs were adjusted for age, sex, rural/non-rural residence and pre-Chernobyl total cancer incidence. RESULTS: The 734 537 people identified were categorised by exposure: the first quartile was low exposure (0.0-45.4 kBq/m(2)), the second and third quartiles were intermediate exposure (45.41-118.8 kBq/m(2)), and the fourth quartile was the highest exposure (118.81-564.71 kBq/m(2)). Between 1991 and 2010, 82 495 cancer cases were registered in the 3 counties. Adjusted HRs (95% CI) were 1.03 (1.01 to 1.05) for intermediate exposure and 1.05 (1.03 to 1.07) for the highest exposure compared to the reference exposure. CONCLUSIONS: We found a small overall exposure-response pattern of the total cancer incidence related to (137)Cs after adjustment for age, sex, rural residence and pre-Chernobyl cancer incidence