Biomedical subjects

David Hemenway

Publications and source records attributed to David Hemenway.

At least 19 recordsLinked to original sources

PubMed2006

State-level homicide victimization rates in the US in relation to survey measures of household firearm ownership, 2001-2003.

Two of every three American homicide victims are killed with firearms, yet little is known about the role played by household firearms in homicide victimization. The present study is the first to examine the cross sectional association between household firearm ownership and homicide victimization across the 50 US states, by age and gender, using nationally representative state-level survey-based estimates of household firearm ownership. Household firearm prevalence for each of the 50 states was obtained from the 2001 Behavioral Risk Factor Surveillance System. Homicide mortality data for each state were aggregated over the three-year study period, 2001-2003. Analyses controlled for state-level rates of aggravated assault, robbery, unemployment, urbanization, per capita alcohol consumption, and a resource deprivation index (a construct that includes median family income, the percentage of families living beneath the poverty line, the Gini index of family income inequality, the percentage of the population that is black and the percentage of families headed by a single female parent). Multivariate analyses found that states with higher rates of household firearm ownership had significantly higher homicide victimization rates of men, women and children. The association between firearm prevalence and homicide victimization in our study was driven by gun-related homicide victimization rates; non-gun-related victimization rates were not significantly associated with rates of firearm ownership. Although causal inference is not warranted on the basis of the present study alone, our findings suggest that the household may be an important source of firearms used to kill men, women and children in the United States.

Adolescent↗

PubMed2006

Is an armed society a polite society? Guns and road rage.

BACKGROUND: While concerns about road rage have grown over the past decade, states have made it easier for motorists to carry firearms in their vehicles. Are motorists with guns in the car more or less likely to engage in hostile and aggressive behavior? METHODS: Data come from a 2004 national random digit dial survey of over 2,400 licensed drivers. Respondents were asked whether, in the past year, they (1) made obscene or rude gestures at another motorist, (2) aggressively followed another vehicle too closely, and (3) were victims of such hostile behaviors. RESULTS: Seventeen percent admitted making obscene or rude gestures, and 9% had aggressively followed too closely. Forty-six percent reported victimization by each of these behaviors in the past year. Males, young adults, binge drinkers, those who do not believe most people can be trusted, those ever arrested for a non-traffic violation, and motorists who had been in a vehicle in which there was a gun were more likely to engage in such forms of road rage. CONCLUSION: Similar to a survey of Arizona motorists, in our survey, riding with a firearm in the vehicle was a marker for aggressive and dangerous driver behavior.

Adolescent↗

PubMed2006

Are household firearms stored less safely in homes with adolescents?: Analysis of a national random sample of parents.

OBJECTIVE: To examine whether firearms are more frequently stored loaded, unlocked, or both in households with adolescents only (aged 13-17 years) compared with households with younger children only (aged 0-12 years). DESIGN: Random-digit-dial survey on firearms (n = 2770). We computed bivariate associations between the presence of adolescents and firearm storage practices. Statistical significance was assessed using prevalence ratios with 95% confidence intervals. SETTING: United States. PARTICIPANTS: Survey respondents with children (aged <18 years) who reported the presence of a household firearm. MAIN OUTCOME MEASURES: Prevalence of firearms in the home stored loaded and/or unlocked. RESULTS: Of the 392 respondents, 22% had a loaded firearm, 32% had an unlocked firearm, and 8% had a firearm stored loaded and unlocked. Compared with households with younger children, households with adolescents only were somewhat more likely to store a firearm unlocked (42% vs 29%; prevalence ratio, 1.48; 95% confidence interval, 1.04-2.02), loaded (26% vs 20%; prevalence ratio, 1.25; 95% confidence interval, 0.82-1.91), or both (10% vs 8%; prevalence ratio, 1.43; 95% confidence interval, 0.64-3.19). CONCLUSIONS: Parents of adolescents appear to be more likely to keep household firearms stored unsafely, especially with regard to keeping firearms unlocked. This is of concern because most youth firearm injuries happen to adolescents. Firearm injury prevention programs should directly target parents of adolescents to promote safe firearm storage.

Adolescent↗

PubMed2006

Gun carrying and drug selling among young incarcerated men and women.

This paper examines the relationship between illegal drug economy involvement, gun-related victimization, and recent gun carrying among young men and women incarcerated in a state prison in the United States. Interviews were conducted with 18- to 25-year old incarcerated men (n = 135) and women (n = 69) between July 1999 and October 2000. Forty-five percent of men and 16% of women reported carrying a gun in the year prior to incarceration. Respondents who sold crack cocaine or other drugs were more likely to have carried guns than those not selling drugs. However, hard drug use was not associated with gun carrying among men. All ten women who carried guns had used hard drugs. Sixty-seven percent of men and 28% of women had been shot at. Respondents who sold crack cocaine were at elevated risk of being shot at. Among men, selling crack (OR = 10.2, 95% CI = 2.5, 42.1) and ever being shot at (OR = 4.6, 95% CI = 1.7, 12.2), were associated with carrying guns. These findings provide further evidence of a link between crack selling (but not necessarily drug using) and gun carrying.

Adolescent↗

PubMed2006

The effect of child access prevention laws on unintentional child firearm fatalities, 1979-2000.

OBJECTIVE: Unintentional firearm deaths among children have been declining steadily in the United States. This study investigates whether Child Access Prevention (CAP) laws are associated with this decline. METHODS: Pooled cross-sectional time- series data (1979-2000) for 50 states and negative binomial regression methods were used to estimate the effect of Child Access Prevention laws on unintentional firearm deaths among children. RESULTS: Most states that enacted CAP laws experienced greater subsequent declines in the rate of unintentional firearm deaths for children age 0 to 14 compared with states not enacting the laws; however when adjusted for firearm prevalence and state and national effects the laws were associated with statistically significant declines only in Florida and California. In a comparison group of adults age 55 to 74, a group less likely to have young children in the home and thus less likely to be influenced by CAP laws, there was no indication that CAP laws affected unintentional firearm death rates. CONCLUSIONS: Unintentional firearm deaths are declining in the United States, with the rate for children under age 15 declining faster than adults. States that allowed felony prosecution of offenders experienced a greater effect of CAP laws than states that did not. CAP laws may have had some influence on the continued reduction in national death rates.

Accident Prevention↗

PubMed2006

Gun possession among Massachusetts batterer intervention program enrollees.

Batterers with access to firearms present a serious lethal threat to their partners. The purpose of this exploratory study is to estimate the prevalence of and risk markers for gun possession among Massachusetts men enrolled in batterer intervention programs. The authors found that 1.8% of the men reported having a gun in or around their home. Those most likely to report having a gun were White, earned 25,000 US dollars or more per year, had served in the military, engaged in problem gambling, and had attempted homicide or threatened their partner with a firearm. Recommendations for strengthening relevant gun laws both within and outside of Massachusetts are discussed.

Adolescent↗

PubMed2006

Belief in the inevitability of suicide: results from a national survey.

To examine public opinion regarding the effectiveness of means restriction as an approach to preventing suicide we asked a national sample of 2,770 respondents a hypothetical question about what effect a suicide barrier might have had on the ultimate fate of the more than 1,000 people who have jumped to their death from the Golden Gate Bridge. Thirty-four percent of respondents believed that every single jumper would have found another way to complete suicide and an additional 40% believed that "most" would have completed suicide using other means. The strongest predictors of belief in complete substitution were firearm ownership and cigarette smoking. Belief in the inevitability of suicide may be a political impediment to adopting potentially effective suicide prevention efforts.

Adult↗

PubMed2005

Asbestos-induced lung inflammation and epithelial cell proliferation are altered in myeloperoxidase-null mice.

Asbestos fibers are carcinogens causing oxidative stress and inflammation, but the sources and ramifications of oxidant production by asbestos are poorly understood. Here, we show that inhaled chrysotile asbestos fibers cause increased myeloperoxidase activity in bronchoalveolar lavage fluids (BALF) and myeloperoxidase immunoreactivity in epithelial cells lining distal bronchioles and alveolar ducts, sites of initial lung deposition of asbestos fibers. In comparison with sham mice, asbestos-exposed myeloperoxidase-null (MPO-/-) and normal (MPO+/+) mice exhibited comparable increases in polymorphonuclear leukocytes, predominately neutrophils, in BALF after 9 days of asbestos inhalation. Differential cell counts on BALF revealed decreased proportions of macrophages and increased lymphocytes in all mice exposed to asbestos, but numbers were decreased overall in asbestos-exposed myeloperoxidase-null versus normal mice. Asbestos-associated lung inflammation in myeloperoxidase-null mice was reduced (P < or = 0.05) in comparison with normal asbestos-exposed mice at 9 days. Decreased lung inflammation in asbestos-exposed myeloperoxidase-null mice at 9 days was accompanied by increases (P < or = 0.05) in Ki-67- and cyclin D1-positive immunoreactive cells, markers of cell cycle reentry, in the distal bronchiolar epithelium. Asbestos-induced epithelial cell proliferation in myeloperoxidase-null mice at 30 days was comparable to that found at 9 days. In contrast, inflammation and epithelial cell proliferation in asbestos-exposed normal mice increased over time. These results support the hypothesis that myeloperoxidase status modulates early asbestos-induced oxidative stress, epithelial cell proliferation, and inflammation.

Animals↗

PubMed2005

Nitrogen dioxide enhances allergic airway inflammation and hyperresponsiveness in the mouse.

In addition to being an air pollutant, NO2 is a potent inflammatory oxidant generated endogenously by myeloperoxidase and eosinophil peroxidase. In these studies, we sought to determine the effects of NO2 exposure on mice with ongoing allergic airway disease pathology. Mice were sensitized and challenged with the antigen ovalbumin (OVA) to generate airway inflammation and subsequently exposed to 5 or 25 ppm NO2 for 3 days or 5 days followed by a 20-day recovery period. Whereas 5 ppm NO2 elicited no pathological changes, inhalation of 25 ppm NO2 alone induced acute lung injury, which peaked after 3 days and was characterized by increases in protein, LDH, and neutrophils recovered by BAL, as well as lesions within terminal bronchioles. Importantly, 25 ppm NO2 was also sufficient to cause AHR in mice, a cardinal feature of asthma. The inflammatory changes were ameliorated after 5 days of inhalation and completely resolved after 20 days of recovery after the 5-day inhalation. In contrast, in mice immunized and challenged with OVA, inhalation of 25 ppm NO2 caused a marked augmentation of eosinophilic inflammation and terminal bronchiolar lesions, which extended significantly into the alveoli. Moreover, 20 days postcessation of the 5-day 25 ppm NO2 inhalation regimen, eosinophilic and neutrophilic inflammation, pulmonary lesions, and AHR were still present in mice immunized and challenged with OVA. Collectively, these observations suggest an important role for NO2 in airway pathologies associated with asthma, both in modulation of degree and duration of inflammatory response, as well as in induction of AHR.

Animals↗

PubMed2005

Firearm storage practices and rates of unintentional firearm deaths in the United States.

BACKGROUND: The American Academy of Pediatrics and the American Medical Association recommend storing firearms unloaded and locked up to minimize the chance of injury. Although these recommendations appeal to common sense, no study has yet addressed whether firearm storage practices influence the risk of unintentional firearm injury. METHODS: Negative binomial regression analyses were used to assess the cross sectional relation between firearm storage practices and rates of unintentional firearm death in the United States, controlling for rates of firearm prevalence, poverty and urbanization. Recently available state-level measures of household firearm prevalence and firearm storage practices were obtained from the 2002 Behavioral Risk Factor Surveillance System. Unintentional firearm death counts and population data came from the National Center for Health Statistics. RESULTS: Independent of firearm prevalence, urbanization, and poverty, a disproportionately large share of unintentional firearm fatalities occurred in states where gun owners were more likely to store their firearms loaded, the greatest risk occurring in states where loaded firearms were more likely to be stored unlocked. CONCLUSION: Our findings provide empirical support for recommendations issued by the AMA and the AAP that firearms should be stored unloaded and locked, and suggest that promoting safer storage practices could save many lives.

Accidents, Home↗

PubMed2005

Intimate partner violence: homicides followed by suicides in Kentucky.

Homicides followed by suicides are rare yet devastating events. This study, for the first time, details the problem in Kentucky by linking coroner, medical examiner, vital statistics and administrative judicial data. In the three-year period 1998-2000, there were 492 firearm homicides in Kentucky, of which 32 (6.5%) were followed by a firearm suicide. All perpetrators who followed their homicide by killing themselves were males. Just or 9% of firearm homicides (46/492) were intimate partner-related but the majority of these (54%) were followed by a suicide. Although we found that only a small percentage of firearm homicides a followed by firearm suicide, when women were shot and killed by their intimate partners, the perpetrator shot himself in two thirds of cases. Continued research about violent deaths might provide a better understanding of homicides followed by suicides--critical for surveillance and prevention efforts.

Crime Victims↗

PubMed2005

Batterers' use of guns to threaten intimate partners.

OBJECTIVES: To present the prevalence of gun ownership among batterers and describe their self-reported use of guns to threaten intimate partners. METHODS: We used multivariate methods to analyze data from 8529 men enrolled in Massachusetts certified batterer intervention programs between 1999 and 2003. RESULTS: Seven percent of the sample reported owning guns during the past 3 years. Recent gun owners were 7.8 times more likely than non-gun-owners to have threatened their partners with guns. Gun owners and non-gun-owners were equally likely to have threatened their partners with knives. Batterers reported using guns to threaten their partners in 4 ways, including 1) threatening to shoot them; 2) cleaning, holding, or loading a gun during an argument; 3) threatening to shoot a pet or person the victim cared about; and 4) shooting a gun during an argument with a victim. Identified risk markers for threatening an intimate partner with a gun included substance abuse, homicidal behavior, making knife threats, and gun ownership in the 3 years preceding assessment. CONCLUSION: Among batterers, owning a gun is highly correlated with using a gun to threaten an intimate partner. Legal restrictions that prohibit batterers from owning and possessing firearms should be enforced consistently. Detailed contextual information about the circumstances in which batterers use guns to threaten intimate partners and potential protective and risk factors relevant to firearm use by batterers should be explored.

Coercion↗

PubMed2004

Gun threats against and self-defense gun use by California adolescents.

OBJECTIVE: To assess hostile gun use against and self-defense gun use by adolescents. DESIGN, SETTING, AND PARTICIPANTS: We use random-digit-dial telephone survey data collected from approximately 5800 California adolescents, aged 12 through 17 years, between November 1, 2000, and October 31, 2001. MAIN OUTCOME MEASURES: The prevalence and correlates of reported hostile gun use against and self-defense gun use by adolescents, as well as qualitative information about these 2 types of gun uses. Correlates include age, sex, ethnicity, smoking, alcoholic binge drinking, threatening others, parents knowing their adolescent's whereabouts in the afternoon after school, attending school, area urbanization and poverty level, and living in a household with a gun. RESULTS: Approximately 4% of the adolescents reported ever having been threatened with a gun; only 0.3% reported using a gun in self-defense. Boys, smokers, adolescents who threatened others, and adolescents whose parents knew little about their whereabouts in the afternoon after school were more likely to report being threatened with a gun. Most episodes of self-defense gun use seem to be hostile interactions between adolescents with weapons. CONCLUSIONS: Far more California adolescents are threatened with a gun than use a gun in self-defense. Self-defense gun use is rare; many of the reported self-defense gun uses seem to be armed confrontations.

Adolescent↗

PubMed2004

The epidemiology of case fatality rates for suicide in the northeast.

STUDY OBJECTIVE: We examine how method-specific case fatality rates for suicide differ by age and sex. METHODS: Seven northeastern states provided mortality and hospital discharge data (1996 to 2000). Suicide acts were divided into 8 categories according to the method used. For each method, the fraction of acts resulting in death (the method-specific case fatality rate) was calculated. Only suicide acts that resulted in hospitalization or death were included. RESULTS: Overall, 13% of all suicide acts proved lethal (23% for males compared with 5% for females; 7% for people aged 15 to 24 years compared with 34% for individuals aged > or =65 years). Poisoning with drugs accounted for 74% of acts but only 14% of fatalities; firearms and hanging accounted for only 10% of acts but 67% of fatalities. Firearms were the most lethal means (91% resulted in death), followed by drowning (84%) and hanging (82%). For every means, method-specific case fatality rates were higher for male victims and older individuals. Age and sex were associated with overall case fatality rates primarily because of their association with the distribution of methods chosen. CONCLUSION: Our findings are based on suicide acts that result in hospitalization or death and therefore underestimate the actual incidence of suicide acts and overestimate case fatality rates. Nevertheless, we find that age and sex influence overall case fatality rates primarily through their association with methods used, rather than because of variation in method-specific case fatality rates.

Adolescent↗

PubMed2004

Medical malpractice as an epidemiological problem.

The notion that the tort liability system deters negligence in health care has been invoked to make the "business case for patient safety." However, existing data on the relationship between hospital adverse events and malpractice claims typically are interpreted as evidence that the tort system does not deter negligence because of the poor fit between those who are negligently injured and those who sue. Using a familiar analogy from epidemiology--the problem of false positives in screening tests for rare diseases--and data from two large studies of medical injuries and malpractice claims in the United States, this paper presents an argument that the standard interpretation overlooks a complexity in the data. Although most malpractice claims do not actually involve a negligent injury, a patient who suffers a negligent injury is more than 20 times more likely, on average, to file a claim than a patient who does not. However, because malpractice claiming is a rare event with many false positives, for the average hospital or group practice, even substantial improvements in rates of negligent injury will not lead to a large reduction in claims rates. These findings suggest that the strength of the business case for patient safety depends on the perspective from which one views the data.

Humans↗

PubMed2004

Factors associated with rear seating of children in motor vehicles: a study in two low-income, predominantly Hispanic communities.

This study examined child seating patterns in two predominantly low-income, Hispanic communities in Massachusetts. The purpose was to determine the factors associated with child rear seating in the community as a whole and for a subset of Hispanic motorists. Five hundred and five vehicles carrying child passengers and no adult other than the driver were observed in parking lots of fast food restaurants and grocery stores. Four hundred and thirty-two vehicle drivers agreed to be interviewed. A child was defined as a passenger younger than age 12 as determined by appearance and height (head below the vehicle headrest when seated). Variables under study included driver gender, age, ethnicity, and educational attainment; driver shoulder belt use; driver perception of passenger-side airbag presence; and the number and ages of children in the car. Overall, 51% of vehicles were observed with all children seated in the rear. In a bivariate analysis, child rear seating was strongly associated with female drivers ( P = 0.01), younger drivers ( P = 0.02) driver shoulder belt use ( P < 0.00), perceived presence of a passenger-side airbag ( P < 0.00), all children in the vehicle <or=6 years old (P < 0.00), and fewer than three children in the vehicle ( P 0.01). Non-Hispanic ethnicity was weakly associated with child rear seating ( P = 0.09). In the multivariate analysis, only the association between child rear seating and all children in the vehicle <or=6 years old remained strong (RR 2.4, 95% CI 1.7-3.3). Factors associated with rear seating were similar between Hispanic and non-Hispanic motorists. Controlling for other factors, the presence of a passenger-side airbag appeared to be more strongly associated with rear seating among non-Hispanics compared to Hispanics (RR 1.5 versus 1.1). Fewer Hispanic motorists drove vehicles with all children in the rear compared with the non-Hispanic motorists (48% versus 56%); this difference appears to be associated with the finding that fewer Hispanic drivers wore their seat belt. For both Hispanic and non-Hispanic motorists, efforts to increase child rear seating should focus on older children, male drivers, and on increasing general motor vehicle safety behavior (e.g. seat belt use). Messages should be culturally appropriate and should emphasize driver seat belt use in conjunction with rear seating and the importance of rear seating regardless of the presence of a passenger-side airbag.

Adult↗

PubMed2004

The effect of nondiscretionary concealed weapon carrying laws on homicide.

BACKGROUND: Historically, the carrying of concealed firearms has been either substantially restricted or prohibited outright. Over the past two decades, laws making it easier for civilians to obtain permits allowing them to carry concealed weapons legally have proliferated throughout the United States. This study investigates the effect of such changes in state laws on state homicide rates. METHODS: Pooled cross-sectional time-series data (1979-1998) for 50 states and Poisson regression methods were used to estimate the effect of changes in state laws on homicide rates. RESULTS: No statistically significant association exists between changes in concealed weapon laws and state homicide rates. This finding is consistent across all models. CONCLUSIONS: The current findings are consistent with those of other published studies indicating that nondiscretionary concealed weapon laws are not associated with significant increases or decreases in homicide.

Adolescent↗

PubMed2004

Firearms and suicide in the northeast.

BACKGROUND: A central question in suicide research is whether firearm availability increases the overall number of suicides rather than the proportion of suicides from guns. METHODS: Seven state health departments supplied mortality and hospital discharge data for all suicides and nonfatal hospitalized suicide attempts between 1996 and 2000. Firearm prevalence measures came from the Behavioral Risk Factor Survey Surveillance. Pearson correlation coefficients and associated chi statistics were used to quantify the relation between firearm prevalence and rates of suicide; ordinary least squares regression was used to explore whether the relation could be explained by differences across states in attempt rates or method-specific case fatality rates. RESULTS: Firearm prevalence was positively related to the suicide rate, even after controlling for rates of attempted suicide, and could not be accounted for by differences in method-specific case fatality rates. CONCLUSION: When it comes to suicide, the availability of household firearms matters-a lot.

Adolescent↗