jurek grabowski - Profile on Academia.edu (original) (raw)
Papers by jurek grabowski
Annals of Epidemiology, 2002
laboratory conducted studies at doses of about 35, 7, 1.4, and 0.5 mg/ day and found iodine inhib... more laboratory conducted studies at doses of about 35, 7, 1.4, and 0.5 mg/ day and found iodine inhibition rates of 67%, 45%, 16%, and 2% (not significant) (Greer et al., 2002). Neither free thyroxine index nor free thyroxine levels were affected at any laboratory exposure level. Log-linear extrapolation of the data indicated that an exposure level slightly below 0.5 mg/day perchlorate would be below the threshold level for iodine uptake inhibition in these populations. CONCLUSION: An occupational health study found no adverse effect on thyroid hormone (FTI) at exposures of about 1, 4, 11, and 35 mg/day perchlorate, a chemical known to inhibit iodine uptake. Measurement of iodine uptake inhibition at similar levels showed that the uptake inhibition threshold was just below 0.5 mg/day and that adverse effects on thyroid hormone (FTI) were not seen with exposures equivalent to 67% inhibition. Thus, a range of iodine uptake inhibition at which thyroxine level appears not to be adversely affected is indicated.
Study objective: In recent years, air transport of patients has been associated with disproportio... more Study objective: In recent years, air transport of patients has been associated with disproportionate increases in crashes and deaths. We identify factors related to fatal outcome in air medical helicopter crashes and suggest preventive measures.
Accident Analysis and Prevention, 2001
To examine the secular trends of mortality from motor vehicle crashes, the authors compiled annua... more To examine the secular trends of mortality from motor vehicle crashes, the authors compiled annual population and mortality data for the United States from 1910 to 1994 and performed an age-period-cohort analysis through graphical presentation, median polish, and Poisson regression modeling. During the 85-year study period, death rates from motor vehicle crashes showed two peaks, first in 1935-39 and then in 1965-69. Age and period effects accounted for 94% of the variation in motor vehicle mortality in men and 84% of the variation in women. Age patterns of motor vehicle mortality varied greatly with birth cohorts: for those who were born before 1910, death rates increased with age; for those born after 1910, death rates peaked at age 20-24 years for men and at age 15-19 years for women. A crossover characterized by a downward trend in death rates among the elderly and an upward trend among adolescents and young adults was observed in both sexes. The complex age, period, and cohort patterns of motor vehicle mortality are likely to have been shaped by changes in traffic patterns and driver behavior, and by improvements in safety design and emergency medical service systems.
Annals of Emergency Medicine, 2006
Study objective: In recent years, air transport of patients has been associated with disproportio... more Study objective: In recent years, air transport of patients has been associated with disproportionate increases in crashes and deaths. We identify factors related to fatal outcome in air medical helicopter crashes and suggest preventive measures.
Federal aviation regulations prohibit airline pilots from flying beyond the age of 60 years. Howe... more Federal aviation regulations prohibit airline pilots from flying beyond the age of 60 years. However, the relation between pilot age and flight safety has not been rigorously assessed using empirical data. From 1987 to 1997, the authors followed a cohort of 3,306 commuter air carrier and air taxi pilots who were aged 45-54 years in 1987. During the follow-up period, the pilots accumulated a total of 12.9 million flight hours and 66 aviation crashes, yielding a rate of 5.1 crashes per million pilot flight hours. Crash risk remained fairly stable as the pilots aged from their late forties to their late fifties. Flight experience, as measured by total flight time at baseline, showed a significant protective effect against the risk of crash involvement. With adjustment for age, pilots who had 5,000-9,999 hours of total flight time at baseline had a 57% lower risk of a crash than their less experienced counterparts (relative risk = 0.43, 95% confidence interval: 0.21, 0.87). The protective effect of flight experience leveled off after total flight time reached 10,000 hours. The lack of an association between pilot age and crash risk may reflect a strong "healthy worker effect" stemming from the rigorous medical standards and periodic physical examinations required for professional pilots.
Geographic information systems and exploratory spatial analysis were used to describe the geograp... more Geographic information systems and exploratory spatial analysis were used to describe the geographic characteristics of pilot fatality rates in 1983-1998 general aviation crashes within the continental United States. The authors plotted crash sites on a digital map; rates were computed at regular grid intersections and then interpolated by using geographic information systems. A test for significance was performed by using Monte Carlo simulations. Further analysis compared low-, medium-, and high-rate areas in relation to pilot characteristics, aircraft type, and crash circumstance. Of the 14,051 general aviation crashes studied, 31% were fatal. Seventy-four geographic areas were categorized as having low fatality rates and 53 as having high fatality rates. High-fatality-rate areas tended to be mountainous, such as the Rocky Mountains and the Appalachian region, whereas low-rate areas were relatively flat, such as the Great Plains. Further analysis comparing low-, medium-, and high-fatality-rate areas revealed that crashes in high-fatality-rate areas were more likely than crashes in other areas to have occurred under instrument meteorologic conditions and to involve aircraft fire. This study demonstrates that geographic information systems are a valuable tool for injury prevention and aviation safety research. Am J Epidemiol 2002;155:398-405.
Geographic Region, Weather, Pilot Age, and Air Carrier Crashes: A Case-Control Study
Aviation Space and Environmental Medicine, 2009
Information about risk factors of aviation crashes is crucial for developing effective interventi... more Information about risk factors of aviation crashes is crucial for developing effective intervention programs. Previous studies assessing factors associated with crash risk were conducted primarily in general aviation, air taxis, and commuter air carriers. A matched case-control design was used to examine the associations of geographic region, basic weather condition, and pilot age with the risk of air carrier (14 CFR Part 121) crash involvement. Cases (N = 373) were air carrier crashes involving aircraft made by Boeing, McDonnell Douglas, and Airbus recorded in the National Transportation Safety Board's aviation crash database during 1983 through 2002, and controls (N = 746) were air carrier incidents involving aircraft of the same three makes selected at random from the Federal Aviation Administration's aviation incident database. Each case was matched with two controls on the calendar year when the index crash occurred. Conditional logistic regression was used for statistical analysis. With adjustment for basic weather condition, pilot age, and total flight time, the risk of air carrier crashes in Alaska was more than three times the risk for other regions ladjusted odds ratio (OR) 3.18, 95% confidence interval (CI) 1.35-7.49]. Instrument meteorological conditions were associated with an increased risk for air carrier crashes involving pilot error (adjusted OR 2.26, 95% CI 1.15-4.44) and a decreased risk for air carrier crashes without pilot error (adjusted OR 0.60, 95% CI 0.37-0.96). Neither pilot age nor total flight time were significantly associated with the risk of air carrier crashes. The excess risk of air carrier crashes in Alaska and the effect of adverse weather on pilot-error crashes underscore the importance of environmental hazards in flight safety.
Academic Emergency Medicine, 2003
Objectives: Neighborhood environments have been linked to the prevalence and incidence rates of a... more Objectives: Neighborhood environments have been linked to the prevalence and incidence rates of a variety of diseases and injuries. This study assessed the relations between neighborhood demographic and socioeconomic characteristics and emergency department (ED) utilization. Methods: Billing data for the calendar year 2000 for adult patients residing within a one-mile radius of the study ED were geocoded based on home addresses and merged with neighborhood data from the U.S. Census Bureau. Annual ED visit rates per 100 population were computed for each census block within the study area and analyzed in relation to neighborhood characteristics. Results: The study area consisted of 714 census blocks and 42,278 adult residents, with a total of 16,427 visits to the study ED. Annual ED visit rates increased from 17 visits per 100 population for neighborhoods where less than 50% of the population were African American to 51 visits per 100 population for neighborhoods where all residents were African American (p \ 0.001). Annual ED visit rates decreased from 53% for neighborhoods where \20% of housing units were owneroccupied to 27% for neighborhoods with [45% owneroccupied housing units (p \ 0.001). Multivariate linear regression modeling revealed that proportions of African American residents and owner-occupied housing units were significantly associated with ED utilization, independent of age and gender compositions and the distance between residence and the study ED. Conclusions: Even within a small geographic area, ED utilization may vary greatly by neighborhood characteristics. Neighborhood racial composition and housing tenure are independent predictors of ED visit rates in this urban community.
Accident Analysis and Prevention, 2005
The Federal Aviation Administration conducts background checking for driving-while-intoxicated (D... more The Federal Aviation Administration conducts background checking for driving-while-intoxicated (DWI) convictions on all pilots. This study examined the association between DWI history and crash risk in a cohort of 335,672 general aviation pilots. These pilots were followed up from 1994 to 2000 through the aviation crash surveillance system of the National Transportation Safety Board. At baseline, 3.4% of the pilots had a DWI history. DWI history was associated with a 43% increased risk of crash involvement (adjusted relative risk: 1.43; 95% confidence interval: 1.15-1.77). The population-attributable risk fraction for DWI history was estimated as 1.4%. In addition to DWI history, male gender, older age, and inexperience were associated with significantly increased risk of crash involvement. The results of this study support DWI history as a valid risk marker for general aviation pilots. The safety benefit of background checking for DWI history needs to be further evaluated.
Annals of Epidemiology, 2002
laboratory conducted studies at doses of about 35, 7, 1.4, and 0.5 mg/ day and found iodine inhib... more laboratory conducted studies at doses of about 35, 7, 1.4, and 0.5 mg/ day and found iodine inhibition rates of 67%, 45%, 16%, and 2% (not significant) (Greer et al., 2002). Neither free thyroxine index nor free thyroxine levels were affected at any laboratory exposure level. Log-linear extrapolation of the data indicated that an exposure level slightly below 0.5 mg/day perchlorate would be below the threshold level for iodine uptake inhibition in these populations. CONCLUSION: An occupational health study found no adverse effect on thyroid hormone (FTI) at exposures of about 1, 4, 11, and 35 mg/day perchlorate, a chemical known to inhibit iodine uptake. Measurement of iodine uptake inhibition at similar levels showed that the uptake inhibition threshold was just below 0.5 mg/day and that adverse effects on thyroid hormone (FTI) were not seen with exposures equivalent to 67% inhibition. Thus, a range of iodine uptake inhibition at which thyroxine level appears not to be adversely affected is indicated.
Study objective: In recent years, air transport of patients has been associated with disproportio... more Study objective: In recent years, air transport of patients has been associated with disproportionate increases in crashes and deaths. We identify factors related to fatal outcome in air medical helicopter crashes and suggest preventive measures.
Accident Analysis and Prevention, 2001
To examine the secular trends of mortality from motor vehicle crashes, the authors compiled annua... more To examine the secular trends of mortality from motor vehicle crashes, the authors compiled annual population and mortality data for the United States from 1910 to 1994 and performed an age-period-cohort analysis through graphical presentation, median polish, and Poisson regression modeling. During the 85-year study period, death rates from motor vehicle crashes showed two peaks, first in 1935-39 and then in 1965-69. Age and period effects accounted for 94% of the variation in motor vehicle mortality in men and 84% of the variation in women. Age patterns of motor vehicle mortality varied greatly with birth cohorts: for those who were born before 1910, death rates increased with age; for those born after 1910, death rates peaked at age 20-24 years for men and at age 15-19 years for women. A crossover characterized by a downward trend in death rates among the elderly and an upward trend among adolescents and young adults was observed in both sexes. The complex age, period, and cohort patterns of motor vehicle mortality are likely to have been shaped by changes in traffic patterns and driver behavior, and by improvements in safety design and emergency medical service systems.
Annals of Emergency Medicine, 2006
Study objective: In recent years, air transport of patients has been associated with disproportio... more Study objective: In recent years, air transport of patients has been associated with disproportionate increases in crashes and deaths. We identify factors related to fatal outcome in air medical helicopter crashes and suggest preventive measures.
Federal aviation regulations prohibit airline pilots from flying beyond the age of 60 years. Howe... more Federal aviation regulations prohibit airline pilots from flying beyond the age of 60 years. However, the relation between pilot age and flight safety has not been rigorously assessed using empirical data. From 1987 to 1997, the authors followed a cohort of 3,306 commuter air carrier and air taxi pilots who were aged 45-54 years in 1987. During the follow-up period, the pilots accumulated a total of 12.9 million flight hours and 66 aviation crashes, yielding a rate of 5.1 crashes per million pilot flight hours. Crash risk remained fairly stable as the pilots aged from their late forties to their late fifties. Flight experience, as measured by total flight time at baseline, showed a significant protective effect against the risk of crash involvement. With adjustment for age, pilots who had 5,000-9,999 hours of total flight time at baseline had a 57% lower risk of a crash than their less experienced counterparts (relative risk = 0.43, 95% confidence interval: 0.21, 0.87). The protective effect of flight experience leveled off after total flight time reached 10,000 hours. The lack of an association between pilot age and crash risk may reflect a strong "healthy worker effect" stemming from the rigorous medical standards and periodic physical examinations required for professional pilots.
Geographic information systems and exploratory spatial analysis were used to describe the geograp... more Geographic information systems and exploratory spatial analysis were used to describe the geographic characteristics of pilot fatality rates in 1983-1998 general aviation crashes within the continental United States. The authors plotted crash sites on a digital map; rates were computed at regular grid intersections and then interpolated by using geographic information systems. A test for significance was performed by using Monte Carlo simulations. Further analysis compared low-, medium-, and high-rate areas in relation to pilot characteristics, aircraft type, and crash circumstance. Of the 14,051 general aviation crashes studied, 31% were fatal. Seventy-four geographic areas were categorized as having low fatality rates and 53 as having high fatality rates. High-fatality-rate areas tended to be mountainous, such as the Rocky Mountains and the Appalachian region, whereas low-rate areas were relatively flat, such as the Great Plains. Further analysis comparing low-, medium-, and high-fatality-rate areas revealed that crashes in high-fatality-rate areas were more likely than crashes in other areas to have occurred under instrument meteorologic conditions and to involve aircraft fire. This study demonstrates that geographic information systems are a valuable tool for injury prevention and aviation safety research. Am J Epidemiol 2002;155:398-405.
Geographic Region, Weather, Pilot Age, and Air Carrier Crashes: A Case-Control Study
Aviation Space and Environmental Medicine, 2009
Information about risk factors of aviation crashes is crucial for developing effective interventi... more Information about risk factors of aviation crashes is crucial for developing effective intervention programs. Previous studies assessing factors associated with crash risk were conducted primarily in general aviation, air taxis, and commuter air carriers. A matched case-control design was used to examine the associations of geographic region, basic weather condition, and pilot age with the risk of air carrier (14 CFR Part 121) crash involvement. Cases (N = 373) were air carrier crashes involving aircraft made by Boeing, McDonnell Douglas, and Airbus recorded in the National Transportation Safety Board's aviation crash database during 1983 through 2002, and controls (N = 746) were air carrier incidents involving aircraft of the same three makes selected at random from the Federal Aviation Administration's aviation incident database. Each case was matched with two controls on the calendar year when the index crash occurred. Conditional logistic regression was used for statistical analysis. With adjustment for basic weather condition, pilot age, and total flight time, the risk of air carrier crashes in Alaska was more than three times the risk for other regions ladjusted odds ratio (OR) 3.18, 95% confidence interval (CI) 1.35-7.49]. Instrument meteorological conditions were associated with an increased risk for air carrier crashes involving pilot error (adjusted OR 2.26, 95% CI 1.15-4.44) and a decreased risk for air carrier crashes without pilot error (adjusted OR 0.60, 95% CI 0.37-0.96). Neither pilot age nor total flight time were significantly associated with the risk of air carrier crashes. The excess risk of air carrier crashes in Alaska and the effect of adverse weather on pilot-error crashes underscore the importance of environmental hazards in flight safety.
Academic Emergency Medicine, 2003
Objectives: Neighborhood environments have been linked to the prevalence and incidence rates of a... more Objectives: Neighborhood environments have been linked to the prevalence and incidence rates of a variety of diseases and injuries. This study assessed the relations between neighborhood demographic and socioeconomic characteristics and emergency department (ED) utilization. Methods: Billing data for the calendar year 2000 for adult patients residing within a one-mile radius of the study ED were geocoded based on home addresses and merged with neighborhood data from the U.S. Census Bureau. Annual ED visit rates per 100 population were computed for each census block within the study area and analyzed in relation to neighborhood characteristics. Results: The study area consisted of 714 census blocks and 42,278 adult residents, with a total of 16,427 visits to the study ED. Annual ED visit rates increased from 17 visits per 100 population for neighborhoods where less than 50% of the population were African American to 51 visits per 100 population for neighborhoods where all residents were African American (p \ 0.001). Annual ED visit rates decreased from 53% for neighborhoods where \20% of housing units were owneroccupied to 27% for neighborhoods with [45% owneroccupied housing units (p \ 0.001). Multivariate linear regression modeling revealed that proportions of African American residents and owner-occupied housing units were significantly associated with ED utilization, independent of age and gender compositions and the distance between residence and the study ED. Conclusions: Even within a small geographic area, ED utilization may vary greatly by neighborhood characteristics. Neighborhood racial composition and housing tenure are independent predictors of ED visit rates in this urban community.
Accident Analysis and Prevention, 2005
The Federal Aviation Administration conducts background checking for driving-while-intoxicated (D... more The Federal Aviation Administration conducts background checking for driving-while-intoxicated (DWI) convictions on all pilots. This study examined the association between DWI history and crash risk in a cohort of 335,672 general aviation pilots. These pilots were followed up from 1994 to 2000 through the aviation crash surveillance system of the National Transportation Safety Board. At baseline, 3.4% of the pilots had a DWI history. DWI history was associated with a 43% increased risk of crash involvement (adjusted relative risk: 1.43; 95% confidence interval: 1.15-1.77). The population-attributable risk fraction for DWI history was estimated as 1.4%. In addition to DWI history, male gender, older age, and inexperience were associated with significantly increased risk of crash involvement. The results of this study support DWI history as a valid risk marker for general aviation pilots. The safety benefit of background checking for DWI history needs to be further evaluated.
Annals of Epidemiology, 2002
laboratory conducted studies at doses of about 35, 7, 1.4, and 0.5 mg/ day and found iodine inhib... more laboratory conducted studies at doses of about 35, 7, 1.4, and 0.5 mg/ day and found iodine inhibition rates of 67%, 45%, 16%, and 2% (not significant) (Greer et al., 2002). Neither free thyroxine index nor free thyroxine levels were affected at any laboratory exposure level. Log-linear extrapolation of the data indicated that an exposure level slightly below 0.5 mg/day perchlorate would be below the threshold level for iodine uptake inhibition in these populations. CONCLUSION: An occupational health study found no adverse effect on thyroid hormone (FTI) at exposures of about 1, 4, 11, and 35 mg/day perchlorate, a chemical known to inhibit iodine uptake. Measurement of iodine uptake inhibition at similar levels showed that the uptake inhibition threshold was just below 0.5 mg/day and that adverse effects on thyroid hormone (FTI) were not seen with exposures equivalent to 67% inhibition. Thus, a range of iodine uptake inhibition at which thyroxine level appears not to be adversely affected is indicated.
Study objective: In recent years, air transport of patients has been associated with disproportio... more Study objective: In recent years, air transport of patients has been associated with disproportionate increases in crashes and deaths. We identify factors related to fatal outcome in air medical helicopter crashes and suggest preventive measures.
Accident Analysis and Prevention, 2001
To examine the secular trends of mortality from motor vehicle crashes, the authors compiled annua... more To examine the secular trends of mortality from motor vehicle crashes, the authors compiled annual population and mortality data for the United States from 1910 to 1994 and performed an age-period-cohort analysis through graphical presentation, median polish, and Poisson regression modeling. During the 85-year study period, death rates from motor vehicle crashes showed two peaks, first in 1935-39 and then in 1965-69. Age and period effects accounted for 94% of the variation in motor vehicle mortality in men and 84% of the variation in women. Age patterns of motor vehicle mortality varied greatly with birth cohorts: for those who were born before 1910, death rates increased with age; for those born after 1910, death rates peaked at age 20-24 years for men and at age 15-19 years for women. A crossover characterized by a downward trend in death rates among the elderly and an upward trend among adolescents and young adults was observed in both sexes. The complex age, period, and cohort patterns of motor vehicle mortality are likely to have been shaped by changes in traffic patterns and driver behavior, and by improvements in safety design and emergency medical service systems.
Annals of Emergency Medicine, 2006
Study objective: In recent years, air transport of patients has been associated with disproportio... more Study objective: In recent years, air transport of patients has been associated with disproportionate increases in crashes and deaths. We identify factors related to fatal outcome in air medical helicopter crashes and suggest preventive measures.
Federal aviation regulations prohibit airline pilots from flying beyond the age of 60 years. Howe... more Federal aviation regulations prohibit airline pilots from flying beyond the age of 60 years. However, the relation between pilot age and flight safety has not been rigorously assessed using empirical data. From 1987 to 1997, the authors followed a cohort of 3,306 commuter air carrier and air taxi pilots who were aged 45-54 years in 1987. During the follow-up period, the pilots accumulated a total of 12.9 million flight hours and 66 aviation crashes, yielding a rate of 5.1 crashes per million pilot flight hours. Crash risk remained fairly stable as the pilots aged from their late forties to their late fifties. Flight experience, as measured by total flight time at baseline, showed a significant protective effect against the risk of crash involvement. With adjustment for age, pilots who had 5,000-9,999 hours of total flight time at baseline had a 57% lower risk of a crash than their less experienced counterparts (relative risk = 0.43, 95% confidence interval: 0.21, 0.87). The protective effect of flight experience leveled off after total flight time reached 10,000 hours. The lack of an association between pilot age and crash risk may reflect a strong "healthy worker effect" stemming from the rigorous medical standards and periodic physical examinations required for professional pilots.
Geographic information systems and exploratory spatial analysis were used to describe the geograp... more Geographic information systems and exploratory spatial analysis were used to describe the geographic characteristics of pilot fatality rates in 1983-1998 general aviation crashes within the continental United States. The authors plotted crash sites on a digital map; rates were computed at regular grid intersections and then interpolated by using geographic information systems. A test for significance was performed by using Monte Carlo simulations. Further analysis compared low-, medium-, and high-rate areas in relation to pilot characteristics, aircraft type, and crash circumstance. Of the 14,051 general aviation crashes studied, 31% were fatal. Seventy-four geographic areas were categorized as having low fatality rates and 53 as having high fatality rates. High-fatality-rate areas tended to be mountainous, such as the Rocky Mountains and the Appalachian region, whereas low-rate areas were relatively flat, such as the Great Plains. Further analysis comparing low-, medium-, and high-fatality-rate areas revealed that crashes in high-fatality-rate areas were more likely than crashes in other areas to have occurred under instrument meteorologic conditions and to involve aircraft fire. This study demonstrates that geographic information systems are a valuable tool for injury prevention and aviation safety research. Am J Epidemiol 2002;155:398-405.
Geographic Region, Weather, Pilot Age, and Air Carrier Crashes: A Case-Control Study
Aviation Space and Environmental Medicine, 2009
Information about risk factors of aviation crashes is crucial for developing effective interventi... more Information about risk factors of aviation crashes is crucial for developing effective intervention programs. Previous studies assessing factors associated with crash risk were conducted primarily in general aviation, air taxis, and commuter air carriers. A matched case-control design was used to examine the associations of geographic region, basic weather condition, and pilot age with the risk of air carrier (14 CFR Part 121) crash involvement. Cases (N = 373) were air carrier crashes involving aircraft made by Boeing, McDonnell Douglas, and Airbus recorded in the National Transportation Safety Board's aviation crash database during 1983 through 2002, and controls (N = 746) were air carrier incidents involving aircraft of the same three makes selected at random from the Federal Aviation Administration's aviation incident database. Each case was matched with two controls on the calendar year when the index crash occurred. Conditional logistic regression was used for statistical analysis. With adjustment for basic weather condition, pilot age, and total flight time, the risk of air carrier crashes in Alaska was more than three times the risk for other regions ladjusted odds ratio (OR) 3.18, 95% confidence interval (CI) 1.35-7.49]. Instrument meteorological conditions were associated with an increased risk for air carrier crashes involving pilot error (adjusted OR 2.26, 95% CI 1.15-4.44) and a decreased risk for air carrier crashes without pilot error (adjusted OR 0.60, 95% CI 0.37-0.96). Neither pilot age nor total flight time were significantly associated with the risk of air carrier crashes. The excess risk of air carrier crashes in Alaska and the effect of adverse weather on pilot-error crashes underscore the importance of environmental hazards in flight safety.
Academic Emergency Medicine, 2003
Objectives: Neighborhood environments have been linked to the prevalence and incidence rates of a... more Objectives: Neighborhood environments have been linked to the prevalence and incidence rates of a variety of diseases and injuries. This study assessed the relations between neighborhood demographic and socioeconomic characteristics and emergency department (ED) utilization. Methods: Billing data for the calendar year 2000 for adult patients residing within a one-mile radius of the study ED were geocoded based on home addresses and merged with neighborhood data from the U.S. Census Bureau. Annual ED visit rates per 100 population were computed for each census block within the study area and analyzed in relation to neighborhood characteristics. Results: The study area consisted of 714 census blocks and 42,278 adult residents, with a total of 16,427 visits to the study ED. Annual ED visit rates increased from 17 visits per 100 population for neighborhoods where less than 50% of the population were African American to 51 visits per 100 population for neighborhoods where all residents were African American (p \ 0.001). Annual ED visit rates decreased from 53% for neighborhoods where \20% of housing units were owneroccupied to 27% for neighborhoods with [45% owneroccupied housing units (p \ 0.001). Multivariate linear regression modeling revealed that proportions of African American residents and owner-occupied housing units were significantly associated with ED utilization, independent of age and gender compositions and the distance between residence and the study ED. Conclusions: Even within a small geographic area, ED utilization may vary greatly by neighborhood characteristics. Neighborhood racial composition and housing tenure are independent predictors of ED visit rates in this urban community.
Accident Analysis and Prevention, 2005
The Federal Aviation Administration conducts background checking for driving-while-intoxicated (D... more The Federal Aviation Administration conducts background checking for driving-while-intoxicated (DWI) convictions on all pilots. This study examined the association between DWI history and crash risk in a cohort of 335,672 general aviation pilots. These pilots were followed up from 1994 to 2000 through the aviation crash surveillance system of the National Transportation Safety Board. At baseline, 3.4% of the pilots had a DWI history. DWI history was associated with a 43% increased risk of crash involvement (adjusted relative risk: 1.43; 95% confidence interval: 1.15-1.77). The population-attributable risk fraction for DWI history was estimated as 1.4%. In addition to DWI history, male gender, older age, and inexperience were associated with significantly increased risk of crash involvement. The results of this study support DWI history as a valid risk marker for general aviation pilots. The safety benefit of background checking for DWI history needs to be further evaluated.
Annals of Epidemiology, 2002
laboratory conducted studies at doses of about 35, 7, 1.4, and 0.5 mg/ day and found iodine inhib... more laboratory conducted studies at doses of about 35, 7, 1.4, and 0.5 mg/ day and found iodine inhibition rates of 67%, 45%, 16%, and 2% (not significant) (Greer et al., 2002). Neither free thyroxine index nor free thyroxine levels were affected at any laboratory exposure level. Log-linear extrapolation of the data indicated that an exposure level slightly below 0.5 mg/day perchlorate would be below the threshold level for iodine uptake inhibition in these populations. CONCLUSION: An occupational health study found no adverse effect on thyroid hormone (FTI) at exposures of about 1, 4, 11, and 35 mg/day perchlorate, a chemical known to inhibit iodine uptake. Measurement of iodine uptake inhibition at similar levels showed that the uptake inhibition threshold was just below 0.5 mg/day and that adverse effects on thyroid hormone (FTI) were not seen with exposures equivalent to 67% inhibition. Thus, a range of iodine uptake inhibition at which thyroxine level appears not to be adversely affected is indicated.
Study objective: In recent years, air transport of patients has been associated with disproportio... more Study objective: In recent years, air transport of patients has been associated with disproportionate increases in crashes and deaths. We identify factors related to fatal outcome in air medical helicopter crashes and suggest preventive measures.
Accident Analysis and Prevention, 2001
To examine the secular trends of mortality from motor vehicle crashes, the authors compiled annua... more To examine the secular trends of mortality from motor vehicle crashes, the authors compiled annual population and mortality data for the United States from 1910 to 1994 and performed an age-period-cohort analysis through graphical presentation, median polish, and Poisson regression modeling. During the 85-year study period, death rates from motor vehicle crashes showed two peaks, first in 1935-39 and then in 1965-69. Age and period effects accounted for 94% of the variation in motor vehicle mortality in men and 84% of the variation in women. Age patterns of motor vehicle mortality varied greatly with birth cohorts: for those who were born before 1910, death rates increased with age; for those born after 1910, death rates peaked at age 20-24 years for men and at age 15-19 years for women. A crossover characterized by a downward trend in death rates among the elderly and an upward trend among adolescents and young adults was observed in both sexes. The complex age, period, and cohort patterns of motor vehicle mortality are likely to have been shaped by changes in traffic patterns and driver behavior, and by improvements in safety design and emergency medical service systems.
Annals of Emergency Medicine, 2006
Study objective: In recent years, air transport of patients has been associated with disproportio... more Study objective: In recent years, air transport of patients has been associated with disproportionate increases in crashes and deaths. We identify factors related to fatal outcome in air medical helicopter crashes and suggest preventive measures.
Federal aviation regulations prohibit airline pilots from flying beyond the age of 60 years. Howe... more Federal aviation regulations prohibit airline pilots from flying beyond the age of 60 years. However, the relation between pilot age and flight safety has not been rigorously assessed using empirical data. From 1987 to 1997, the authors followed a cohort of 3,306 commuter air carrier and air taxi pilots who were aged 45-54 years in 1987. During the follow-up period, the pilots accumulated a total of 12.9 million flight hours and 66 aviation crashes, yielding a rate of 5.1 crashes per million pilot flight hours. Crash risk remained fairly stable as the pilots aged from their late forties to their late fifties. Flight experience, as measured by total flight time at baseline, showed a significant protective effect against the risk of crash involvement. With adjustment for age, pilots who had 5,000-9,999 hours of total flight time at baseline had a 57% lower risk of a crash than their less experienced counterparts (relative risk = 0.43, 95% confidence interval: 0.21, 0.87). The protective effect of flight experience leveled off after total flight time reached 10,000 hours. The lack of an association between pilot age and crash risk may reflect a strong "healthy worker effect" stemming from the rigorous medical standards and periodic physical examinations required for professional pilots.
Geographic information systems and exploratory spatial analysis were used to describe the geograp... more Geographic information systems and exploratory spatial analysis were used to describe the geographic characteristics of pilot fatality rates in 1983-1998 general aviation crashes within the continental United States. The authors plotted crash sites on a digital map; rates were computed at regular grid intersections and then interpolated by using geographic information systems. A test for significance was performed by using Monte Carlo simulations. Further analysis compared low-, medium-, and high-rate areas in relation to pilot characteristics, aircraft type, and crash circumstance. Of the 14,051 general aviation crashes studied, 31% were fatal. Seventy-four geographic areas were categorized as having low fatality rates and 53 as having high fatality rates. High-fatality-rate areas tended to be mountainous, such as the Rocky Mountains and the Appalachian region, whereas low-rate areas were relatively flat, such as the Great Plains. Further analysis comparing low-, medium-, and high-fatality-rate areas revealed that crashes in high-fatality-rate areas were more likely than crashes in other areas to have occurred under instrument meteorologic conditions and to involve aircraft fire. This study demonstrates that geographic information systems are a valuable tool for injury prevention and aviation safety research. Am J Epidemiol 2002;155:398-405.
Geographic Region, Weather, Pilot Age, and Air Carrier Crashes: A Case-Control Study
Aviation Space and Environmental Medicine, 2009
Information about risk factors of aviation crashes is crucial for developing effective interventi... more Information about risk factors of aviation crashes is crucial for developing effective intervention programs. Previous studies assessing factors associated with crash risk were conducted primarily in general aviation, air taxis, and commuter air carriers. A matched case-control design was used to examine the associations of geographic region, basic weather condition, and pilot age with the risk of air carrier (14 CFR Part 121) crash involvement. Cases (N = 373) were air carrier crashes involving aircraft made by Boeing, McDonnell Douglas, and Airbus recorded in the National Transportation Safety Board's aviation crash database during 1983 through 2002, and controls (N = 746) were air carrier incidents involving aircraft of the same three makes selected at random from the Federal Aviation Administration's aviation incident database. Each case was matched with two controls on the calendar year when the index crash occurred. Conditional logistic regression was used for statistical analysis. With adjustment for basic weather condition, pilot age, and total flight time, the risk of air carrier crashes in Alaska was more than three times the risk for other regions ladjusted odds ratio (OR) 3.18, 95% confidence interval (CI) 1.35-7.49]. Instrument meteorological conditions were associated with an increased risk for air carrier crashes involving pilot error (adjusted OR 2.26, 95% CI 1.15-4.44) and a decreased risk for air carrier crashes without pilot error (adjusted OR 0.60, 95% CI 0.37-0.96). Neither pilot age nor total flight time were significantly associated with the risk of air carrier crashes. The excess risk of air carrier crashes in Alaska and the effect of adverse weather on pilot-error crashes underscore the importance of environmental hazards in flight safety.
Academic Emergency Medicine, 2003
Objectives: Neighborhood environments have been linked to the prevalence and incidence rates of a... more Objectives: Neighborhood environments have been linked to the prevalence and incidence rates of a variety of diseases and injuries. This study assessed the relations between neighborhood demographic and socioeconomic characteristics and emergency department (ED) utilization. Methods: Billing data for the calendar year 2000 for adult patients residing within a one-mile radius of the study ED were geocoded based on home addresses and merged with neighborhood data from the U.S. Census Bureau. Annual ED visit rates per 100 population were computed for each census block within the study area and analyzed in relation to neighborhood characteristics. Results: The study area consisted of 714 census blocks and 42,278 adult residents, with a total of 16,427 visits to the study ED. Annual ED visit rates increased from 17 visits per 100 population for neighborhoods where less than 50% of the population were African American to 51 visits per 100 population for neighborhoods where all residents were African American (p \ 0.001). Annual ED visit rates decreased from 53% for neighborhoods where \20% of housing units were owneroccupied to 27% for neighborhoods with [45% owneroccupied housing units (p \ 0.001). Multivariate linear regression modeling revealed that proportions of African American residents and owner-occupied housing units were significantly associated with ED utilization, independent of age and gender compositions and the distance between residence and the study ED. Conclusions: Even within a small geographic area, ED utilization may vary greatly by neighborhood characteristics. Neighborhood racial composition and housing tenure are independent predictors of ED visit rates in this urban community.
Accident Analysis and Prevention, 2005
The Federal Aviation Administration conducts background checking for driving-while-intoxicated (D... more The Federal Aviation Administration conducts background checking for driving-while-intoxicated (DWI) convictions on all pilots. This study examined the association between DWI history and crash risk in a cohort of 335,672 general aviation pilots. These pilots were followed up from 1994 to 2000 through the aviation crash surveillance system of the National Transportation Safety Board. At baseline, 3.4% of the pilots had a DWI history. DWI history was associated with a 43% increased risk of crash involvement (adjusted relative risk: 1.43; 95% confidence interval: 1.15-1.77). The population-attributable risk fraction for DWI history was estimated as 1.4%. In addition to DWI history, male gender, older age, and inexperience were associated with significantly increased risk of crash involvement. The results of this study support DWI history as a valid risk marker for general aviation pilots. The safety benefit of background checking for DWI history needs to be further evaluated.