Progress in the battle against hypertension. Changes in blood pressure levels in the United States from 1960 to 1980.

Intensive efforts by practicing physicians and public health workers to identify and treat persons with hypertension have been underway for many years. In this report, changes in blood pressure levels in the United States are assessed based on nationally representative health (and nutrition) examination surveys conducted by the National Center for Health Statistics in 1960 to 1962, 1971 to 1974, and 1976 to 1980. Analysis of age-adjusted data for adults aged 18 to 74 years (including those on antihypertensive medication) indicates that between the first and third surveys for whites and blacks, respectively, mean systolic blood pressure declined 5 and 10 mm Hg; the proportion of persons with systolic blood pressure of 140 mm Hg or higher fell 18 and 31%; the proportion with undiagnosed hypertension decreased 17 and 59%; and the proportion taking antihypertensive medications rose 71 and 31%. These differences between the first and third surveys were all statistically significant (p less than 0.05 or better). Changes in diastolic blood pressure levels were generally not significant among race-sex groups. The proportion of persons with definite hypertension (i.e., systolic blood pressure greater than or equal to 160 mm Hg, and/or diastolic blood pressure greater than or equal to 95 mm Hg, and/or taking antihypertensive medication) declined among blacks but rose slightly among whites. Study results are consistent with the recent decline in cardiovascular disease mortality.

Bicycle helmet use among Maryland children: effect of legislation and education.

Although bicycle helmets are effective in preventing head injuries, use of helmets among children remains infrequent. In response to the bicycling deaths of two children, Howard County, Maryland, became the first US jurisdiction to mandate use of bicycle helmets for children. Schoolchildren were lectured by police about the law before its enactment. Prelaw and postlaw helmet use was observed in Howard County and two control counties: Montgomery (which sponsored a community education program) and Baltimore County (no helmet activities). Prelaw crude helmet use rates for children were 4% (95% confidence interval [CI] 0% to 10%) for Howard, 8% (95% CI 3% to 13%) for Montgomery, and 19% (95% CI 5% to 33%) for Baltimore. Postlaw rates were 47% (95% CI 32% to 62%), 19% (95% CI 11% to 27%), and 4% (95% CI 0 to 11%), respectively. The rate of bicycle helmet use by Howard County children is now the highest documented for US children. A similar increase in helmet use among children younger than 16 years nationwide could prevent about 100 deaths and 56,000 emergency-department-treated head injuries annually. Physicians and other health professionals should consider proposing and supporting the Howard County approach in their communities.

Population implications of electrocardiographic left ventricular hypertrophy.

Left ventricular (LV) hypertrophy on the electrocardiogram is an ominous harbinger of cardiovascular disease in the general population markedly increasing the risk of coronary heart disease, cardiac failure, stroke and peripheral arterial disease. This contribution to risk exceeds that of the often accompanying hypertension. Once overt coronary disease occurs, electrocardiographic LV hypertrophy also further escalates risk of cardiovascular morbidity and mortality. The risk associated with electrocardiographic LV hypertrophy is particularly great when repolarization abnormality is present. Electrocardiographic LV hypertrophy and silent electrocardiographic myocardial infarction are similar in evolution and prognosis. LV hypertrophy is an important predictor of risk of cardiac failure; the electrocardiographic manifestation of LV hypertrophy predisposes to cardiac failure more than x-ray cardiac enlargement. Electrocardiographic LV hypertrophy heralds the onset of serious cardiovascular disease and premature mortality despite lack of associated symptoms. The serious prognosis of this abnormality warrants vigorous preventive management. More prospective data are needed comparing the prognosis of echocardiographic anatomical hypertrophy with that diagnosed by electrocardiography.

Association of echocardiographic left ventricular mass with body size, blood pressure and physical activity (the Framingham Study).

Left ventricular (LV) hypertrophy has been found to predispose to increased cardiovascular morbidity and mortality. To assess the clinical correlates and potential determinants of LV mass, the relation of echocardiographically determined LV mass to a variety of clinical parameters was examined in a general population. From 1979 to 1983 Framingham Heart Study participants underwent routine evaluation including medical history, physical examination and M-mode echocardiography. LV mass was determined using an anatomically validated formula that incorporates measurements of LV wall thickness and LV internal diameter. The study population consisted of 2,226 men and 2,746 women (mean age 51 years, range 17 to 90). Age, height, systolic blood pressure and body mass index (a measure of obesity) were statistically significant and independent correlates of LV mass in both sexes (p less than 0.001). In men under age 50, leisure-time physical activity was associated with LV mass (p less than 0.05), but this was not observed in women. Results from multivariate analyses in which body mass index and subscapular skinfold thickness were included suggest that lean body mass is correlated with LV mass. Maintenance of ideal body weight and normal blood pressure, weight reduction in obese persons and blood pressure control in hypertensive patients may contribute to the primary and secondary prevention of LV hypertrophy and its sequelae. Clinical interpretation of echocardiograms should include consideration of the correlates of LV mass to gain better insight into the pathogenesis of LV hypertrophy.

Intentional and unintentional injuries in women. An overview.

Injuries are the leading cause of death for females 1 to 34 years old, and a major source of preventable morbidity and mortality in middle-aged and elderly women. In the United States, 43,000 women die from injuries and approximately 1 million women are hospitalized for injuries annually. The leading causes of injury death in women are motor vehicle-related injuries (34%), suicide (14%), falls (14%), and homicide (12%). Injuries of particular concern include fatal and nonfatal falls in elderly women, homicides among young black women, suicides among young white women, work-related homicides among female convenience store workers, and fatal and nonfatal injuries in pregnant and nonpregnant women associated with domestic violence. Strategies to prevent most types of injuries are either known or being investigated. Increased efforts to develop, implement, and evaluate such interventions would help to reduce the toll of injuries on women's health.

Penetration eye injuries in the workplace. The National Eye Trauma System Registry.

Occupational eye injuries are common and preventable. Between 1985 and 1991, there were 635 work-related penetrating eye injuries among the 2939 cases (22%) reported to the National Eye Trauma System Registry by 48 collaborating centers in 28 states and Washington, DC. The median age of the injured workers was 30 years; 75% were younger than 40 years; and 97% were male. The commonest causes of injuries were projectiles (457 cases), sharp objects (166 cases), blunt objects (60 cases), and blasts (22 cases); these terms are not mutually exclusive. Specific objects causing injuries included nails, wire, screwdrivers, and other hand tools. There was evidence of alcohol use by at least 2% of the injured workers. When they were injured, 6% of the workers were wearing safety glasses; 3% were wearing nonsafety eyewear. Posterior segment trauma, which occurred in 63% of the cases, included vitreous hemorrhage (42%), intraocular foreign bodies (35%), and retinal detachment (10%). Hyphema occurred in 35% and traumatic cataract in 32% of the cases. Initial visual acuity after injury was hand motion or worse in 43% of the cases. National Eye Trauma System Registry data are useful to identify strategies to prevent occupational eye injuries such as wider use of safety glasses and improvement in engineering controls.

Penetrating eye injuries related to assault. The National Eye Trauma System Registry.

From 1985 to 1991, 648 cases of assault-related penetrating ocular injury were reported to the National Eye Trauma System Registry. We examined the circumstances surrounding and initial clinical findings related to this case series of injuries. Eighty-three percent of the patients were male. The median age was 28 years; 77% were younger than age 40 years, and 17% were younger than age 20 years. The ocular injury was part of multiple trauma in 34% of cases. There was evidence of alcohol and illicit drug use by at least 48% and 6% of the injured persons, respectively. Seventeen percent of the injuries involved powder or nonpowder firearms. Fists, glass fragments, metal rods or pipes, knives, and scissors were among the other objects causing injury. Posterior segment trauma, which occurred in 70% of cases, included vitreous hemorrhage (40% of cases), retinal detachment (11%), presence of intraocular foreign bodies (6%), and optic nerve damage (4%). The initial visual acuity after injury was hand motion or worse in 74% of the cases. Strategies to prevent such injuries focus on the origins of violence in general and are more difficult to devise than strategies to prevent eye injuries in other settings. Public health efforts to reduce the use of alcohol, drugs, and firearms may reduce the incidence of these injuries.

An elective rotation in applied epidemiology with the Centers for Disease Control and Prevention (CDC), 1975-1997.

INTRODUCTION: To increase awareness of and interest in public health and epidemiology, CDC initiated an elective in epidemiology and public health for senior medical students in 1975 and for veterinary students in 1982. METHODS: A review of CDC records to describe participation in the elective, to assess whether students subsequently enrolled in another CDC training program, the Epidemic Intelligence Service (EIS), and, if enrolled, employment status following EIS. A review of documentation of board certification in preventive medicine to determine how many participants later chose this specialty, one indicator of public health and prevention as a career choice. RESULTS: From 1975 through 1997, 632 students participated in the elective. Of these, 438 (69%) were assigned to infectious disease areas, 95 (15%) to environmental health, 59 (9%) to chronic disease, and 40 (7%) to other areas. Students participated in at least 278 official investigations of important public health problems including infectious disease outbreaks, natural disasters, chronic disease problems and access to health care. Of 530 students who had completed the elective through June 1995, 91 (17%) were enrolled in EIS by July 1997. Of 83 completing EIS by July 1997, 65 (78%) had continued in public health careers: 35 with CDC; 17 with local or state health departments; 7 with other federal agencies; 4 in academic public health; and 2 in international health. Of those not enrolling in EIS, at least 5% were certified by the American Board of Preventive Medicine, compared with 34% of those completing EIS. CONCLUSION: An elective rotation in public health and applied epidemiology is valuable in introducing future physicians and veterinarians to the practice of public health, and can provide important role models for encouragement to pursue careers in public health.

Hospitalization due to injuries in the military. Evaluation of current data and recommendations on their use for injury prevention.

INTRODUCTION: Injuries inflict the largest health impact on military populations in terms of hospitalization. Hospitalized injuries result in the largest direct costs of medical care and the most lost workdays, include the largest proportion of disabling injuries, and have the largest impact on troop readiness. Efforts are now beginning to focus on how injury surveillance data can be used to reduce the burden of injuries. This article examines the value of administrative hospital discharge databases in the military for routine injury surveillance, as well as investigation of specific injury problems, including musculoskeletal conditions that are frequently sequelae of old injuries. METHODS: Data on hospitalizations for injuries and musculoskeletal conditions were obtained from separate administrative agencies for the Army, Navy, and Air Force. Since 1989, a Standard Inpatient Data Record (SIDR) has been used to ensure uniformity in data collection across the services utilizing standard ICD-9 codes. Cause of injury was coded using special military cause codes (STANAG codes) developed by NATO. Data were analyzed on both nature and cause of injury. Denominator data on troop strength were obtained from the Defense Manpower Data Center (DMDC). RESULTS: Hospital records data indicate that injuries and musculoskeletal conditions have a bigger impact on the health of service members and military/combat readiness than any other ICD-9 Principal Diagnostic Group (higher incidence and higher noneffective rate or days not available for duty). Hospitalization rates for injury appeared to decline for all services from 1980 to 1992. In 1992, service-specific injury hospitalization rates per 1000 person-years were 15.6 for the Army, 8.3 for the Navy (enlisted only), and 7.7 for the Air Force, while the corresponding hospitalization rate for musculoskeletal conditions was higher in all three services: 28.1, 9.7, and 12.0, respectively. CONCLUSIONS: Military hospital discharge databases are an important source of information on severe injuries and are more comprehensive than civilian databases. They include detailed injury information that can be useful for injury prevention and surveillance purposes. Specifically, it can be used to identify high-risk groups or hazards for targeting prevention resources. These may vary widely by service, rank, and job tasks. Hospital discharge data can also be used to evaluate the effectiveness of interventions for reducing injury rates. Recommendations were submitted to further improve data collection and the use of hospital data for research and injury prevention.

Incidence of hospitalized injuries among pregnant women in Maryland, 1979-1990.

INTRODUCTION: Injuries are a leading cause of morbidity among pregnant women. We compared injuries among pregnant women and all women of reproductive age in a large defined population. METHODS: Maryland hospital discharge data files from 1979-1990 were used to identify injuries in pregnant women and in all women 15-44 years of age. Injured pregnant women were defined as those hospitalized with concurrent ICD-9-CM discharge codes for injury and pregnancy. RESULTS: The 80,311 hospitalizations with injury of women 15-44 years old included 2,185 hospitalizations of pregnant women. The incidence of hospitalized injury per 100,000 person-years was 460 for pregnant women and 608 for all women 15-44 years old. Median length of stay and cost per hospitalization were 3.0 days and $1,478 for pregnant women and 4.0 days and $1,666 for all women 15-44 years old. Leading causes of hospitalized injury in pregnant women were poisonings (16.9%), fractures (14.7%), sprains (10.9%), and contusions (8.0%). Compared to all women 15-44 years of age, pregnant women had significantly fewer hospitalizations for dislocations, fractures, poisoning, sprains, and intracranial injuries, and more hospitalizations for contusions and internal injuries. Based on limited information about external causes of injury, pregnant women had significantly fewer hospitalizations for poisoning, drowning/suffocation, and suicide attempts than all women 15-44 years of age. CONCLUSIONS: Many hospitalizations of pregnant women are for relatively minor injuries requiring a short duration of stay, possibly to gauge the impact of the injury on the mother and the fetus. Since most pregnant women receive at least some medical care during pregnancy, prenatal visits represent an ideal time to implement strategies to prevent injuries.

The epidemiology of varicose veins: the Framingham Study.

The epidemiology of varicose veins was examined in 3,822 adults in the Framingham Study. Findings indicate that the incidence of varicose veins is higher among women than men, with no clear age differences. Compared to women without varicose veins, women with varicose veins were more often obese (p less than .01), had lower levels of physical activity (p less than .001) and higher systolic blood pressure (p less than .001), and were older at menopause (p less than .001). Women who reported spending eight or more hours in an average day in sedentary activities (sitting or standing) also had a significantly higher incidence of varicose veins than those who spent four or fewer hours a day in such activities (p less than .05). For men, varicose veins coexisted with lower levels of physical activity (p less than .05) and higher smoking rates (p less than .05). While men and women with varicose veins had a higher incidence of atherosclerotic cardiovascular disease than those without varicose veins, only the excess risk of coronary heart disease in women was statistically significant (p less than .05). However, this finding was not significant after controlling for body mass and systolic blood pressure. These results suggest that increased physical activity and weight control may help prevent varicose veins among adults at high risk, and reduce the overall risk of atherosclerotic cardiovascular disease as well.

When children have children: the teen pregnancy predicament.

Despite developments in contraceptive technology and changes in societal norms, adolescent pregnancy remains a key issue for politicians, social scientists, health care providers, and educators. The adolescent's access to contraception and abortion services continues to spark legal debate. The implications of research call for the development of innovative programs to address larger issues, such as poverty and limited access to health care, in the management and prevention of adolescent pregnancies. Clinical interventions, such as school-linked clinics to provide contraception and prenatal care programs to reduce perinatal morbidity, have varied in their approaches and their subsequent success.

PIP: The birthrate among both white and African-American US young women 15-19 years old declined steadily from 89.1 live births per 1000 women (LB/1000) in 1960 to 51.3 LB/1000 in 1985, as a result of the availability of contraception and abortion. The rate has since risen to 62.1 LB/1000 in 1991. In contrast, the birthrate among unmarried young women 15-19 years old increased from 15.3 LB/1000 in 1960 to 42.5 LB/1000 in 1990. The birthrate among white unmarried adolescents more than tripled over the past three decades. The Johns Hopkins University School of Public Health revealed a rise in overall sexual activity from 28% in 1972 to 50% in 1979 in interviews of a national sample of 15-19 year olds. After the Supreme Court decision in Roe v. Wade, 232,440 abortions were performed in 1973 to 15-19 year olds and that number rose to 444,780 by 1980. Title IX of the Civil Rights Act prohibited the exclusion of girls from schools on the basis of pregnancy. In 1977 the Supreme Court struck down a statute that prohibited the sale of nonprescription contraceptives to minors under 16. Reports by the Centers for Disease Control and Prevention identified 1,559,110 legal abortions in 1987, of which 26.1% were to women younger than 20 years old. The adolescent seeking an abortion faces clinical disclosure and parental consent. According to a 1985 poll, 85% of Americans approve of sex education. Nearly 60% of 12-17 year olds surveyed in 1986 said that they had taken a course or had a class on sex education. However, in a 1988 survey of over 4000 public school teachers, only 84% of teachers were in programs that included sexual decision making, abstinence, and birth control methods. Adolescent childbearing may represent normative behavior for those coping with the stress of poverty. Adolescent pregnancy is associated with low birthweight, preterm labor and delivery, poor maternal weight gain, hypertension, anemia, and sexually transmitted diseases.

Board certification among preventive medicine residency graduates: characteristics, advantages, and barriers.

In 1991, a mail survey was conducted of graduates (1979-1989) of general preventive medicine/public health (GPM/PH) residency programs to obtain information about the graduates' demographic characteristics, training, and present professional work. Specifically, we evaluated the survey data for percentage of graduates with board certification, advantages of board certification, and barriers to board certification in preventive medicine (PM). The survey response rate was 74% (797 of 1,070 graduates). Only 45% of the respondents were board certified in PM as of 1991. The percentage of respondents board certified in PM was highest among military PM residency graduates and lowest among those from the Centers for Disease Control (CDC) PM residency. Reasons for not taking the board examination included the perception of limited benefit of board certification in current employment or professional endeavors, previous board certification in a clinical specialty, lack of a master of public health (MPH) degree, high cost and time commitment for the examination, and uncertainty about examination admission requirements. PM residency graduates with board certification in PM were more likely to be involved in public health and preventive medicine programs, devoted more time to administration and management, and earned more income than those PM residency graduates without PM board certification. Increasing the percentage of residency graduates who pursue PM board certification will require increasing the advantages of certification for practice, encouraging all residents to identify themselves as practicing the specialty of PM, and addressing the unique concerns of physicians who train both in PM and in a purely or primarily clinical specialty.

Predictors of injury among 1638 riders in a recreational long-distance bicycle tour: Cycle Across Maryland.

To assess the incidence of and risk factors for injuries in a group of bicyclists with a well-defined exposure to bicycling, we conducted a prospective study of 1638 recreational bicyclists who rode in the 6-day 339-mile Cycle Across Maryland tour in 1994. The mean age of participants was 39 years (range, 7 to 79), and two-thirds were male. All riders wore helmets. During the tour there were 85 acute traumatic injuries (15.4 per 100,000 person-miles), 76 overuse injuries (13.7 per 100,000 person-miles), and 37 other medical problems (6.7 per 100,000 person-miles). Acute traumatic injuries were associated with a history of racing versus none (relative risk = 2.2, 95% confidence limits = 1.3, 3.7) and with inexperience, no previous Cycle Across Maryland tours versus one or more (relative risk = 1.7, 95% confidence limits = 1.04, 2.8), but not with sex, training, or prior injuries. Inexperience and lack of preride conditioning were risk factors for overuse injuries. The most common overuse injuries and medical problems were knee pain, hand or wrist numbness, foot blisters, insect stings and bites, and heat and dehydration. Study results provide exposure-based incidence rates of bicyclist injuries and suggest overuse injuries may be reduced by increased preride conditioning.

Injuries associated with snowmobiles, Alaska, 1993-1994.

OBJECTIVE: To characterize the nature and burden of snowmobile injuries in Alaska by examining injury deaths and hospitalizations associated with snowmobiles and comparing these with injury deaths and hospitalizations associated with on-road motor vehicles. METHODS: The authors used vital statistics, medical examiner, Department of Public Safety, and Department of Transportation records to identify snowmobile injury deaths, and used vital statistics mortality files to identify on-road motor vehicle injury deaths. The Alaska Trauma Registry provided data on hospitalizations. The number of vehicles in use in 1993-1994 was estimated from snowmobile sales and on-road motor vehicle registrations. RESULTS: For 1993-1994, injury death and hospitalization rates were greater for snowmobiles than for on-road motor vehicles. In northern Alaska, snowmobile injuries outnumbered on-road motor vehicle injuries. A total of 26 snowmobile injury deaths were reported; 7 decedents drowned after breaking through ice and 8 were ejected from vehicles. More than half (58%) of the snowmobile injury deaths involved a natural object such as a boulder, ravine, or river. Of the 17 decedents for whom blood alcohol concentrations were available, 11 (65%) had blood alcohol concentrations > or = 100 mg/dL. CONCLUSIONS: Natural obstacles and alcohol intoxication contribute to the high risk of injury death associated with snowmobile use. Injury control strategies, including trail development and improvement, should be evaluated.

Bicycle helmet use by adults: the impact of companionship.

Most of the nearly 1,000 fatal bicycle-related injuries annually could be prevented if riders used safety helmets. Helmet use by adult bicyclists has received relatively little attention because educational campaigns to promote helmet use generally focus on children. Helmet use by adult and child bicyclists at 120 suburban and rural sites in three Maryland counties was observed on two Saturdays in 1990-91 during an evaluation of the impact of a mandatory helmet law. Concordance or discordance of helmet use within various groups of bicyclists--adults only, adults with children, and children only--was recorded. Helmet use among 2,068 adult bicyclists was 49 percent, 51 percent, and 74 percent in the three counties. In two counties combined, 52 percent (365 of 706) of solo adult bicyclists wore helmets compared with only 5 percent (5 of 94) of solo child bicyclists (P < .001). Helmet use or nonuse was concordant among 87 percent of 277 adult-adult pairs, 94 percent of 50 child-child pairs, and 91 percent of 32 adult-child pairs of bicyclists observed. Concordance rates of helmet use or nonuse were similarly high among pairs of adult bicyclists of the same or mixed sexes. These data are consistent with the concept that both adults and children tend to adopt the helmet-wearing behaviors of their companions. Public health efforts focused on adults should encourage helmet use by adult bicyclists both to prevent head injuries and to provide a role model for children.

Characteristics and causes of penetrating eye injuries reported to the National Eye Trauma System Registry, 1985-91.

Ocular trauma is one of the most important preventable causes of visual impairment. The National Eye Trauma System was developed to provide optimal clinical care for severe ocular injuries, to foster research on eye injury, and to increase awareness of ocular trauma as a public health problem. From 1985 through 1991, the National Eye Trauma System Registry collected data on 2,939 cases of penetrating eye injury reported by ophthalmologists at 48 collaborating eye trauma centers in 28 States and Washington, DC. Eighty-three percent of the cases involved men; the median age of the patients was 27 years, ranging from 1 to 92 years of age. Seventy-seven percent of the injuries were unintentional, 22 percent were the result of assault, and 1 percent were self-inflicted. In 62 percent of the cases studied, the injured person's initial best corrected visual acuity in the injured eye was the ability to perceive hand motion, or worse. The settings in which the injuries occurred included the home (28 percent), the worksite (21 percent), at recreation (11 percent), and in transportation (8 percent). At the time of the injury, 1.5 percent of the injured persons were wearing safety glasses and 2.9 percent were wearing nonsafety glasses. There was evidence of definite or possible alcohol use by at least 24 percent of the injured persons and illicit drug use by 8 percent. The most frequent types of tissue damage included corneal or scleral laceration, traumatic cataract, intraocular foreign body, vitreous hemorrhage, and prolapse of intraocular tissue. Analyses of the causes and characteristics of ocular injuries reported to the National Eye Trauma System Registry will help identify high risk settings for such injuries. Results will be used to develop and implement interventions that will reduce the incidence of eye trauma.

Cardiovascular mortality among munitions workers exposed to nitroglycerin and dinitrotoluene.

A retrospective cohort mortality study with 5529 nitroglycerin, 4989 dinitrotoluene, and 5136 unexposed workers compared the mortality of the exposed groups with that of the United States population and that of the unexposed group with life-table analysis and Poisson regression. Mortality from ischemic heart disease was close to that expected, and mortality from cerebrovascular disease was slightly less than that expected, for the workers with both nitroglycerin and dinitrotoluene exposure and for those with dinitrotoluene exposure only. A significant interaction between age and nitroglycerin exposure was detected in the Poisson regression analyses for ischemic heart disease, particularly for workers actively exposed to nitroglycerin. The rate ratio for the workers under 45 years of age and actively exposed to nitroglycerin was 3.30 (95% confidence interval 129-8.48). This study did not show a chronic effect of nitroglycerin or dinitrotoluene exposure on cardiovascular disease risk. Potential biases related to the company's medical screening program may have limited the ability to detect chronic cardiovascular effects.