Space travelers are exposed to unique forms of ionizing radiation that pose potentially serious h... more Space travelers are exposed to unique forms of ionizing radiation that pose potentially serious health hazards. Prior analyses have attempted to quantify excess mortality risk for astronauts exposed to space radiation, but low statistical power has frustrated inferences. If exposure to deep space radiation were causally linked to deaths due to two particular causes, e.g., cancer and cardiovascular disease, then those cause-specific deaths would not be statistically independent. In this case, a Kaplan-Meier survival curve for a specific cause that treats deaths due to competing causes as uninformative censored events would result in biased estimates of survival probabilities. Here we look for evidence of a deleterious effect of historical exposure to space radiation by assessing whether or not there is evidence for such bias in Kaplan-Meier estimates of survival probabilities for cardiovascular disease and cancer. Evidence of such bias may implicate space radiation as a common causal...
Background: Cancer incidence and mortality are important outcomes in the surveillance of long-ter... more Background: Cancer incidence and mortality are important outcomes in the surveillance of long-term astronaut health. In this research, we compare cancer incidence rates, cancer-specific mortality rates, and cancer case fatality ratios in US astronauts with those in the US general population.Methods: We use standardized incidence ratios and standardized mortality ratios to index the incidence and mortality of various cancers against rates in the US general population, from the US astronaut cohort inception in April 1959 through 31 December 2017. We also compare the lethality of these cancers in astronauts and the general population using the relative case fatality ratio.Results: The astronaut cohort included 338 individuals and over 9600 person-years of follow-up time. The counts of most cancers were under 3, though there were 11 cases of melanoma and 30 cases of prostate cancer. Both prostate and melanoma had statistically significant increases in incidence, though only melanoma had...
Cerebral palsy (CP) is a heterogenous condition, with level of disability ranging from immaterial... more Cerebral palsy (CP) is a heterogenous condition, with level of disability ranging from immaterial to profound. In concert with the continuum of level of severity of disability/ independent functioning, health care needs, therapies, medications, surgical interventions, costs of care, daily demands on parents and other family members, and expectations for the future in terms of education, employment, and other milestones of life all vary widely. Similarly, life expectancy in CP follows a continuum, from far lower than to potentially as high as general population life expectancy, that parallels the continuum of levels of disability. Here we review the literature documenting this, and examine the specific factors that are known to be strongly associated with mortality and longevity in CP. We also examine the evidence regarding causes of death in CP, and present some new findings related to this. Finally, we outline important methodological considerations for future research in this area.
ObjectivesCancer incidence and mortality are important outcomes in the surveillance of long-term ... more ObjectivesCancer incidence and mortality are important outcomes in the surveillance of long-term astronaut health. We compare cancer incidence rates, cancer-specific mortality rates, and cancer case-fatality ratios in US astronauts with those in the US general population.MethodsWe use standardised incidence ratios (SIRs) and standardised mortality ratios (SMRs) to index the incidence and mortality of various cancers against rates in the US general population, from the US astronaut cohort inception in April 1959 through 31 December 2017. We compare the lethality of these cancers using the relative case-fatality ratio.ResultsOverall cancer incidence and mortality were slightly lower than expected from national rates with SIR 82 (95% CI 63 to 104) and SMR 72 (95% CI 44 to 111) with a modest 14% reduction in case-fatality ratio. Prostate cancer and melanoma skin cancer had significant increases in incidence, with SIR of 162 (95% CI 109 to 232) and 252 (95% CI 126 to 452), respectively, ...
Objectives To compare the mortality experience of 112 justices of the US Supreme Court with that ... more Objectives To compare the mortality experience of 112 justices of the US Supreme Court with that expected in the general population. To identify variables associated with mortality within this cohort. Background Supreme Court justices are a select occupational cohort. High socio-economic status, advanced education, lifetime appointment, and the healthy worker effect suggest lower mortality. Sedentary work, stress, and a tendency to work beyond typical retirement age may attenuate this. Methods Standardized mortality ratios compare the observed mortality rates of justices with those expected in age- and sex-matched contemporary general populations. Poisson regression analyzes variables associated with mortality within the cohort. Results From 1789 to 2013, 112 justices (108 male) contributed 2,355 person-years of exposure. Mean age (standard deviation) at appointment was 53.1 years (6.7); at retirement 69.7 years (9.9); at death (n = 100) 74.4 years (10.3); and at end of the study fo...
A life care plan often analyzes needs up to a person's life expectancy. Expected present valu... more A life care plan often analyzes needs up to a person's life expectancy. Expected present value of necessary funding for such a plan is likewise based on the fixed survival time. If a client should live beyond or die before the life expectancy, a shortfall or excess of funding may seem inevitable. The life table, of which life expectancy is a summary measure, clarifies these issues. We explain life expectancy and how it is used in tort litigation, economic calculations, and life care planning. We examine the life table, of which life expectancy is one output. We illustrate how a life table provides age-specific probabilities of death and survival, life expectancies, and median survival times, and other information and that every life expectancy must be associated with a life table. We consider the implications for life care planners, forensic economists, and others. Life expectancy is a summary of more detailed information provided in a life table. The full life table provides be...
Developmental medicine and child neurology, Jan 15, 2015
Studies reporting long-term survival probabilities for cohorts of persons with cerebral palsy pro... more Studies reporting long-term survival probabilities for cohorts of persons with cerebral palsy provide evidence-based information on the life expectancy of those cohorts. Some studies have provided estimates of life expectancy based on extrapolation of such evidence, whereas many others have opted not to do so. Here we review the basic methods of life table analysis necessary for performing such extrapolations, and apply these methods to obtain evidence-based estimates of life expectancy from several studies that do not report such estimates themselves.
Several studies have documented increased life expectancy and improved mortality for Major League... more Several studies have documented increased life expectancy and improved mortality for Major League Baseball players, but none has yet provided a complete analysis of baseball player mortality patterns over time. We selected all baseball players who debuted between 1900 and 1999, modeled numbers of deaths, calculated SMRs with 95% confidence intervals, and calculated life expectancies for baseball players and the general population in each decade from 1930-1939 and 1990-1999. Mortality risk for MLB players increased with age and decreased over time except in the 1950-1969 and 1980-1999 periods. Ballplayers had greater life expectancy in all periods compared to the general population, though the differences were small in the 1950s and 1960s. SMRs revealed that baseball players experienced fewer deaths than expected based on general population rates in most decades from 1930 onward. This research shows that baseball players experienced lower rates of mortality than the general populatio...
Professional baseball players have lower mortality rates than the US general population, but whet... more Professional baseball players have lower mortality rates than the US general population, but whether this is true of foreign-born players is not known. Using data on ballplayers from six nations, we compare mortality rates with those of US players via standardized mortality ratios. After controlling for confounders, four countries had statistically insignificant SMRs while two nations had significantly elevated SMRs. In the two nations with elevated SMRs, low average ages at death and high crime rates suggest the increased mortality may be linked to violent crime. A full understanding of the causes of disparity in mortality will require further research.
Is the customary care and treatment provided for children with cerebral palsy (CP) in California ... more Is the customary care and treatment provided for children with cerebral palsy (CP) in California better than that provided to such children in England? Are children with CP in Sweden more likely to receive hip surveillance than those in Australia? Is a child with severe CP and failure to thrive more likely to undergo a gastrostomy procedure in Merseyside, England than in Ontario, Canada? I’ve long wondered about such questions and the obvious follow-up: do any differences that might be found make any difference in terms of outcomes? I have also given considerable thought to the difficulties that would arise in trying to answer such questions. Take the gastrostomy question, for example. To get at any real meaningful differences in the proportions, one would have to control for level of disability, swallow study parameters, weight and height, and more. If you pause to consider the many complications that would be involved in trying to answer some of these questions you may appreciate the work that Horridge et al. report in this issue as much as I do. These authors have compared the care provided for children with CP across 15 districts in the north of England, over time from 1995 to 2002, and by an area-based measure of socio-economic status. Focusing on four evidence-based standards of health care for CP, the authors found significant differences in provision across the 15 districts while controlling for level of disability and other important factors. Extending such comparisons to wider regions of England or to disparate settings throughout the world will be challenging. As Horridge et al. note, even the relatively small set of variables upon which they rely for the present comparison are not routinely collected throughout England. However, the study makes an important contribution to my dream of more expansive comparisons: it begins to set parameters for the kinds of data that ought to be collected and the variables that ought to be controlled for in order to make such comparisons meaningful. The study has a number of important limitations, as the authors acknowledge. Small convenience samples of data, high numbers of missing values for some variables, and no information on many potentially important functional variables make the results less robust than we might like. Nevertheless, the study takes an important and courageous step, shining a light on differences in care provision for CP within different settings, and blazing a trail for future research of this type. More ought to be done in this area, and eventually a connection with outcomes may lead to the dissemination of best practices of care for CP from many different regions and facilities.
Space travelers are exposed to unique forms of ionizing radiation that pose potentially serious h... more Space travelers are exposed to unique forms of ionizing radiation that pose potentially serious health hazards. Prior analyses have attempted to quantify excess mortality risk for astronauts exposed to space radiation, but low statistical power has frustrated inferences. If exposure to deep space radiation were causally linked to deaths due to two particular causes, e.g., cancer and cardiovascular disease, then those cause-specific deaths would not be statistically independent. In this case, a Kaplan-Meier survival curve for a specific cause that treats deaths due to competing causes as uninformative censored events would result in biased estimates of survival probabilities. Here we look for evidence of a deleterious effect of historical exposure to space radiation by assessing whether or not there is evidence for such bias in Kaplan-Meier estimates of survival probabilities for cardiovascular disease and cancer. Evidence of such bias may implicate space radiation as a common causal...
Background: Cancer incidence and mortality are important outcomes in the surveillance of long-ter... more Background: Cancer incidence and mortality are important outcomes in the surveillance of long-term astronaut health. In this research, we compare cancer incidence rates, cancer-specific mortality rates, and cancer case fatality ratios in US astronauts with those in the US general population.Methods: We use standardized incidence ratios and standardized mortality ratios to index the incidence and mortality of various cancers against rates in the US general population, from the US astronaut cohort inception in April 1959 through 31 December 2017. We also compare the lethality of these cancers in astronauts and the general population using the relative case fatality ratio.Results: The astronaut cohort included 338 individuals and over 9600 person-years of follow-up time. The counts of most cancers were under 3, though there were 11 cases of melanoma and 30 cases of prostate cancer. Both prostate and melanoma had statistically significant increases in incidence, though only melanoma had...
Cerebral palsy (CP) is a heterogenous condition, with level of disability ranging from immaterial... more Cerebral palsy (CP) is a heterogenous condition, with level of disability ranging from immaterial to profound. In concert with the continuum of level of severity of disability/ independent functioning, health care needs, therapies, medications, surgical interventions, costs of care, daily demands on parents and other family members, and expectations for the future in terms of education, employment, and other milestones of life all vary widely. Similarly, life expectancy in CP follows a continuum, from far lower than to potentially as high as general population life expectancy, that parallels the continuum of levels of disability. Here we review the literature documenting this, and examine the specific factors that are known to be strongly associated with mortality and longevity in CP. We also examine the evidence regarding causes of death in CP, and present some new findings related to this. Finally, we outline important methodological considerations for future research in this area.
ObjectivesCancer incidence and mortality are important outcomes in the surveillance of long-term ... more ObjectivesCancer incidence and mortality are important outcomes in the surveillance of long-term astronaut health. We compare cancer incidence rates, cancer-specific mortality rates, and cancer case-fatality ratios in US astronauts with those in the US general population.MethodsWe use standardised incidence ratios (SIRs) and standardised mortality ratios (SMRs) to index the incidence and mortality of various cancers against rates in the US general population, from the US astronaut cohort inception in April 1959 through 31 December 2017. We compare the lethality of these cancers using the relative case-fatality ratio.ResultsOverall cancer incidence and mortality were slightly lower than expected from national rates with SIR 82 (95% CI 63 to 104) and SMR 72 (95% CI 44 to 111) with a modest 14% reduction in case-fatality ratio. Prostate cancer and melanoma skin cancer had significant increases in incidence, with SIR of 162 (95% CI 109 to 232) and 252 (95% CI 126 to 452), respectively, ...
Objectives To compare the mortality experience of 112 justices of the US Supreme Court with that ... more Objectives To compare the mortality experience of 112 justices of the US Supreme Court with that expected in the general population. To identify variables associated with mortality within this cohort. Background Supreme Court justices are a select occupational cohort. High socio-economic status, advanced education, lifetime appointment, and the healthy worker effect suggest lower mortality. Sedentary work, stress, and a tendency to work beyond typical retirement age may attenuate this. Methods Standardized mortality ratios compare the observed mortality rates of justices with those expected in age- and sex-matched contemporary general populations. Poisson regression analyzes variables associated with mortality within the cohort. Results From 1789 to 2013, 112 justices (108 male) contributed 2,355 person-years of exposure. Mean age (standard deviation) at appointment was 53.1 years (6.7); at retirement 69.7 years (9.9); at death (n = 100) 74.4 years (10.3); and at end of the study fo...
A life care plan often analyzes needs up to a person's life expectancy. Expected present valu... more A life care plan often analyzes needs up to a person's life expectancy. Expected present value of necessary funding for such a plan is likewise based on the fixed survival time. If a client should live beyond or die before the life expectancy, a shortfall or excess of funding may seem inevitable. The life table, of which life expectancy is a summary measure, clarifies these issues. We explain life expectancy and how it is used in tort litigation, economic calculations, and life care planning. We examine the life table, of which life expectancy is one output. We illustrate how a life table provides age-specific probabilities of death and survival, life expectancies, and median survival times, and other information and that every life expectancy must be associated with a life table. We consider the implications for life care planners, forensic economists, and others. Life expectancy is a summary of more detailed information provided in a life table. The full life table provides be...
Developmental medicine and child neurology, Jan 15, 2015
Studies reporting long-term survival probabilities for cohorts of persons with cerebral palsy pro... more Studies reporting long-term survival probabilities for cohorts of persons with cerebral palsy provide evidence-based information on the life expectancy of those cohorts. Some studies have provided estimates of life expectancy based on extrapolation of such evidence, whereas many others have opted not to do so. Here we review the basic methods of life table analysis necessary for performing such extrapolations, and apply these methods to obtain evidence-based estimates of life expectancy from several studies that do not report such estimates themselves.
Several studies have documented increased life expectancy and improved mortality for Major League... more Several studies have documented increased life expectancy and improved mortality for Major League Baseball players, but none has yet provided a complete analysis of baseball player mortality patterns over time. We selected all baseball players who debuted between 1900 and 1999, modeled numbers of deaths, calculated SMRs with 95% confidence intervals, and calculated life expectancies for baseball players and the general population in each decade from 1930-1939 and 1990-1999. Mortality risk for MLB players increased with age and decreased over time except in the 1950-1969 and 1980-1999 periods. Ballplayers had greater life expectancy in all periods compared to the general population, though the differences were small in the 1950s and 1960s. SMRs revealed that baseball players experienced fewer deaths than expected based on general population rates in most decades from 1930 onward. This research shows that baseball players experienced lower rates of mortality than the general populatio...
Professional baseball players have lower mortality rates than the US general population, but whet... more Professional baseball players have lower mortality rates than the US general population, but whether this is true of foreign-born players is not known. Using data on ballplayers from six nations, we compare mortality rates with those of US players via standardized mortality ratios. After controlling for confounders, four countries had statistically insignificant SMRs while two nations had significantly elevated SMRs. In the two nations with elevated SMRs, low average ages at death and high crime rates suggest the increased mortality may be linked to violent crime. A full understanding of the causes of disparity in mortality will require further research.
Is the customary care and treatment provided for children with cerebral palsy (CP) in California ... more Is the customary care and treatment provided for children with cerebral palsy (CP) in California better than that provided to such children in England? Are children with CP in Sweden more likely to receive hip surveillance than those in Australia? Is a child with severe CP and failure to thrive more likely to undergo a gastrostomy procedure in Merseyside, England than in Ontario, Canada? I’ve long wondered about such questions and the obvious follow-up: do any differences that might be found make any difference in terms of outcomes? I have also given considerable thought to the difficulties that would arise in trying to answer such questions. Take the gastrostomy question, for example. To get at any real meaningful differences in the proportions, one would have to control for level of disability, swallow study parameters, weight and height, and more. If you pause to consider the many complications that would be involved in trying to answer some of these questions you may appreciate the work that Horridge et al. report in this issue as much as I do. These authors have compared the care provided for children with CP across 15 districts in the north of England, over time from 1995 to 2002, and by an area-based measure of socio-economic status. Focusing on four evidence-based standards of health care for CP, the authors found significant differences in provision across the 15 districts while controlling for level of disability and other important factors. Extending such comparisons to wider regions of England or to disparate settings throughout the world will be challenging. As Horridge et al. note, even the relatively small set of variables upon which they rely for the present comparison are not routinely collected throughout England. However, the study makes an important contribution to my dream of more expansive comparisons: it begins to set parameters for the kinds of data that ought to be collected and the variables that ought to be controlled for in order to make such comparisons meaningful. The study has a number of important limitations, as the authors acknowledge. Small convenience samples of data, high numbers of missing values for some variables, and no information on many potentially important functional variables make the results less robust than we might like. Nevertheless, the study takes an important and courageous step, shining a light on differences in care provision for CP within different settings, and blazing a trail for future research of this type. More ought to be done in this area, and eventually a connection with outcomes may lead to the dissemination of best practices of care for CP from many different regions and facilities.
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