Showing papers in "American Journal of Epidemiology in 1979"
TL;DR: The findings show that people who lacked social and community ties were more likely to die in the follow-up period than those with more extensive contacts.
Abstract: The relationship between social and community ties and mortality was assessed using the 1965 Human Population Laboratory survey of a random sample of 6928 adults in Alameda County, California and a subsequent nine-year mortality follow-up. The findings show that people who lacked social and community ties were more likely to die in the follow-up period than those with more extensive contacts. The age-adjusted relative risks for those most isolated when compared to those with the most social contacts were 2.3 for men and 2.8 for women. The association between social ties and mortality was found to be independent of self-reported physical health status at the time of the 1965 survey, year of death, socioeconomic status, and health practices such as smoking, alcoholic beverage consumption, obesity, physical activity, and utilization of preventive health services as well as a cumulative index of health practices.
4,882 citations
TL;DR: There is little evidence that coronary heart disease (CHD) experience and CHD risk factors differ in parents of those who volunteered for this study and the parents ofThose who did not volunteer.
Abstract: The Framingham Heart Study (FHS) was started in 1948 as a prospective investigation of cardiovascular disease in a cohort of adult men and women. Continuous surveillance of this sample of 5209 subjects has been maintained through biennial physical examinations. In 1971 examinations were begun on the children of the FHS cohort. This study, called the Framingham Offspring Study (FOS), was undertaken to expand upon knowledge of cardiovascular disease, particularly in the area of familial clustering of the disease and its risk factors. This report reviews the sampling design of the FHS and describes the nature of the FOS sample. The FOS families appear to be of typical size and age structure for families with parents born in the late 19th or early 20th century. In addition, there is little evidence that coronary heart disease (CHD) experience and CHD risk factors differ in parents of those who volunteered for this study and the parents of those who did not volunteer.
1,630 citations
TL;DR: An excess of electrical wiring configurations suggestive of high current-flow was noted in Colorado in 1976--1977 near the homes of children who developed cancer, as compared to the homesof control children.
Abstract: An excess of electrical wiring configurations suggestive of high current-flow was noted in Colorado in 1976--1977 near the homes of children who developed cancer, as compared to the homes of control children. The finding was strongest for children who had spent their entire lives at the same address, and it appeared to be dose-related. It did not seem to be an artifact of neighborhood, street congestion, social class, or family structure. The reason for the correlation is uncertain; possible effects of current in the water pipes or of AC magnetic fields are suggested.
1,552 citations
TL;DR: Because of an increase in the number of reports of Guillian-Barre syndrome following A/New Jersey influenza vaccination, the National Influenza Immunization Program was suspended December 16, 1976 and nationwide surveillance for GBS was begun.
Abstract: Because of an increase in the number of reports of Guillian-Barre syndrome (GBS) following A/New Jersey influenza vaccination, the National Influenza Immunization Program was suspended December 16, 1976 and nationwide surveillance for GBS was begun. This surveillance uncovered a total of 1098 patients with onset of GBS from October 1, 1976, to January 31, 1977, from all 50 states, District of Columbia, and Puerto Rico. A total of 532 patients had recently received an A/New Jersey influenza vaccination prior to their onset of GBS (vaccinated cases), and 15 patients received a vaccination after their onset of GBS. Five hundred forty-three patients had not been recently vaccinated with A/New Jersey influenza vaccine and the vaccination status for 8 was unknown. Epidemiologic evidence indicated that many cases of GBS were related to vaccination. When compared to the unvaccinated population, the vaccinated population had a significantly elevated attack rate in every adult age group. The estimated attributable risk of vaccine-related GBS in the adult population was just under one case per 100,000 vaccinations. The period of increased risk was concentrated primarily within the 5-week period after vaccination, although it lasted for approximately 9 or 10 weeks.
698 citations
TL;DR: Virus antigenically similar to A/Texas/1/77(H3N2) was isolated from 8 of 31 passengers cultured, and 20 of 22 ill persons tested had serologic evidence of infection with this virus.
Abstract: A jet airliner with 54 persons aboard was delayed on the ground for three hours because of engine failure during a takeoff attempt. Most passengers stayed on the airplane during the delay. Within 72 hours, 72 per cent of the passengers became ill with symptoms of cough, fever, fatigue, headache, sore throat and myalgia. One passenger, the apparent index case, was ill on the airplane, and the clinical attack rate among the others varied with the amount of time spent aboard. Virus antigenically similar to A/Texas/1/77(H3N2) was isolated from 8 of 31 passengers cultured, and 20 of 22 ill persons tested had serologic evidence of infection with this virus. The airplane ventilation system was inoperative during the delay and this may account for the high attack rate.
554 citations
TL;DR: A retrospective survey of extrapulmonary tuberculosis has shown that it differs from pulmonary tuberculosis with regard to sex and race distribution, diagnosing physician's speciality and proportion of cases bacteriologically confirmed.
Abstract: In recent years, the decrease in reported tuberculosis in the United States has been due almost entirely to a drop in the number of cases of pulmonary disease. There has been little change in the average number of extrapulmonary cases reported. A retrospective survey of extrapulmonary tuberculosis has shown that it differs from pulmonary tuberculosis with regard to sex and race distribution, diagnosing physician's speciality and proportion of cases bacteriologically confirmed. There is variation within extrapulmonary cases according to specific anatomic site with regard to the above characteristics as well as age distribution. These epidemiologic differences in tuberculosis of different sites are unexplained.
511 citations
TL;DR: Findings are encouraging regarding the ability to recall the age when certain menstrual and reproductive events occur, but not for menstrual cycle intervals or patterns.
Abstract: A study was conducted to examine the accuracy of recall of females to questions regarding age at menarche natural and surgical menopause 1st use of oral contraceptives (OC) and mean menstrual cycle length and variance. Prospectively collected data were obtained from a final sample of 160 women aged 25 to 64 years living in the Minneapolis-St. Paul metropolitan area and who had participated in the Menstrual and Reproductive History study (MRH; period covered 1934 to 1974) for at least 5 years. The MRH study was began in 1934 by Dr. Al Treloar by enrolling coeds at the University of Minnesota who agreed to record the dates on onset and cessation of menstrual flow pregnancies lactation contraceptive use and related events. 40 women were randomly selected in the 25 to 34 and 35 to 44 age groups and 80 in the 45 to 64 age group. A structured questionnaire was administered to each woman and the responses compared with the MRH data. Results of analysis show that 75 to 90% of women correctly recalled age at menarche age at natural menopause age at surgical menopause and age of 1st use of OC. However recall of menstrual cycle length and variability appears to be generally unreliable; recall of cycle length is best for women aged 20 to 39 when menstrual cycles are least variable. The data from this study were collected from well-educated women who were able to record their reproductive events. The results may thus be considered optimal.
324 citations
TL;DR: The data presented in this report indicate that in industrialized societies the high degree of intra-individual variability of sodium intake, compared to much smaller inter-individual differences, may obscure potential biological correlations.
Abstract: Despite the finding in cross-cultural comparisons that habitual sodium intake correlates with levels of blood pressure, similar studies from within population groups have yielded inconsistent results. The data presented in this report indicate that in industrialized societies the high degree of intra-individual variability of sodium intake, compared to much smaller inter-individual differences, may obscure potential biological correlations. A quantitative statistical method is presented to assess and minimize the effect of the large intra-individual variation in daily urinary sodium excretion.
269 citations
TL;DR: A relationship, though small, showed a consistent dose-response gradient, appeared in both case-hospital control and case-multiphasic health checkup control comparisons, and could not be accounted for by the effects of other variables.
Abstract: Ninety-nine black colorectal cancer patients and 280 matched controls from hospitals and multiphasic health checkup clinics were interviewed about past dietary habits and other traits. The colon cancer cases tended to report less frequent use of foods with at least 0.5% fiber content than did their controls. This relationship, though small, showed a consistent dose-response gradient, appeared in both case-hospital control and case-multiphasic health checkup control comparisons, and could not be accounted for by the effects of other variables. Colon and rectosigmoid junction cancer patients tended to have eaten foods with at least 5% saturated fat somewhat more often than controls. When consumption of these two groups of foods was considered in combination, significantly more colon cancer patients than controls reported a high saturated fat foods-low fibrous foods eating pattern, as opposed to a low saturated fat foods-high fibrous foods diet. Statistically significant excesses of the following traits were also reported by the colorectal cancer patients: prolonged cigar smoking in men, nulliparity in women, and history of colorectal polyps.
269 citations
TL;DR: It is suggested that HDL cholesterol is an independent risk factor for CHD, especially in males over 50, and the implication is that increased HDL cholesterol might play a protective role in the pathogenesis of CHD.
Abstract: Using univariate and multivariate analyses, the association between high density lipoprotein (HDL) cholesterol and coronary heart disease (CHD) incidence was investigated. Over 150 cases of myocardial infarction (MI) occurred among 6500 Israeli adult males in a five-year prospective study. At age 50 years and over, there is a significant inverse association between MI incidence and HDL cholesterol. This relationship persists when controlling for risk factors such as age, other cholesterol components, smoking, blood pressure, weight, and diabetes mellitus. Unlike hypercholesterolemia and smoking, the relative risk with HDL cholesterol increases with age above 50. Similar patterns of association occur between HDL cholesterol and angina pectoris incidence, sudden unexpected death and deaths from MI. It is suggested that HDL cholesterol is an independent risk factor for CHD, especially in males over 50, and the implication of this study is that increased HDL cholesterol might play a protective role in the pathogenesis of CHD.
266 citations
TL;DR: The findings of this investigation are consistent with tumor inhibition by retinoids in animal studies and the low risk associated with vitamin A in epidemiologic studies of lung cancer.
Abstract: Retrospective data on dietary habits, employment history and tobacco use were obtained from 569 bladder cancer patients and 1025 age-matched controls admitted to Roswell Park Memorial Institute. Sex-adjusted relative risks revealed increases in risk for lower levels of an index of vitamin A intake. A similar pattern of risk elevation was associated with infrequent milk and carrot intake. Some elevation of risk was found for heavy coffee drinking but the apparent protective effect for milk consumption was not found to be a spurious result of lower coffee intake. Neither was the role of vitamin A explained by its relationship with smoking or employment in high risk occupations. Some association of bladder cancer with infrequent consumption of cruciferous vegetables was also observed. The findings of this investigation are consistent with tumor inhibition by retinoids in animal studies and the low risk associated with vitamin A in epidemiologic studies of lung cancer.
TL;DR: The eradication of poliomyelitis in spite of the fact that no more than 90% of US children have been reached indicates that either vaccine virus has spread to the unimmunized or a herd immunity effect is operating and the resultant disappearance of wild poliovirus prevents exposure of the unim immunized.
Abstract: The emergence of a debate in the US regarding poliomyelitis immunization practices makes it important to examine unresolved issues about the epidemiology of this disease. The literature suggests that poliomyelitis initially appears as a disease of preschool children but then there is a trend toward increasing age of cases. Age differences in the case: infection ratio do not appear to have a consistent predictable impact on overall incidence. The appearance of epidemic poliomyelitis is assumed to have resulted from a reduction in levels of maternal antibodies as booster reinfections became less common a reduction in the frequency of antibody levels sufficient to produce cross-protection between virus types and an increase in the average age of primary infections. The relative importance of virus virulence and of elevated infection rate in the production of epidemics remains unknown. The use of poliovirus vaccine in the US has reduced paralytic disease from an annual incidence of about 10000 cases to 10 cases. The eradication of poliomyelitis in spite of the fact that no more than 90% of US children have been reached indicates that either vaccine virus has spread to the unimmunized or a herd immunity effect is operating and the resultant disappearance of wild poliovirus prevents exposure of the unimmunized. The unexpected eradication of natural poliomyelitis in the US has raised the problem of vaccine-associated disease when oral vaccine is used. Since oral poliovirus vaccine appears to have provided protection through herd immunity any change in immunization practices that might increase the exposure of susceptibles should be undertaken with great caution. Evidence of repeated importations of wild poliovirus emphasizes this concern. If inactivated vaccine is seriously considered for primary immunization it should be followed by reimmunization with oral vaccine.
TL;DR: This exploratory study is one of the first case-control studies of the epidemiology of brain tumors in children, and the results suggest directions for future epidemiologic studies in this relatively uncharted field.
Abstract: An exploratory case-control study was conducted in 15 hospitals in the Baltimore, MD, SMSA of possible etiologic factors associated with brain tumors in children. Eighty-four children with brain tumors were compared to normal children and to children with other malignancies. Parents of these children were interviewed about a variety of possible etiologic factors. The findings included: 1) children with brain tumors as well as children with other cancers had a greater tendency than normal children to have been first births and to have had higher birth weights; 2) more children with brain tumors had a sibling with epilepsy or seizures than did normal children, and several of the mothers of children with brain tumors had themselves had epilepsy or a stroke at a relatively young age; 3) there were no significant differences between the groups with regard to several maternal characteristics, including smoking during pregnancy and prior radiation exposure; 4) more children with brain tumors and children with other cancers were found to have had exposures to insecticides than had normal children; 5) fewer children with brain tumors or with other cancers were reported to have had tonsillectomies than normal children; and 6) more of the children with brain tumors as well as the children with other malignancies were reported to have been exposed to farm animals and to sick pets. This exploratory study is one of the first case-control studies of the epidemiology of brain tumors in children, and the results suggest directions for future epidemiologic studies in this relatively uncharted field.
TL;DR: The data confirm that cigarette smoking by young children and teenagers has direct measurable effects on their pulmonary function, but show thatcigarette smoking by parents has a measurable effect on the pulmonary function of their children which is independent of any direct use of cigarettes by the children.
Abstract: The authors have investigated the effects of parental smoking patterns on the pulmonary function of children in East Boston, Massachusetts. A crude inverse dose-response relationship was observed between the level of FEF25--75% predicted of children who never smoked and the number of smoking parents in the household. Compared to children with two non-smoking parents, the level of FEF25--75% predicted was 0.156 and 0.355 standard deviation units lower for children with one and two currently smoking parents, respectively. An additional decline in level of FEF25--75% predicted was observed for children who themselves had smoked. Smoking children with two smoking parents had an average FEF25--75% predicted level which was 0.355 standard deviation units lower than non-smoking children with two smoking parents. These data not only confirm that cigarette smoking by young children and teenagers has direct measurable effects on their pulmonary function, but also show that cigarette smoking by parents has a measurable effect on the pulmonary function of their children which is independent of any direct use of cigarettes by the children.
TL;DR: It is argued that the population size of 500,000 for measles persistence (described by Bartlett) is primarily a consequence of seasonal variation, and computer modelling can be used to examine the effect of changes in parameters which determine the seasonal cycle of virus perpetuation and fadeout.
Abstract: Perpetuation of a virus in a population is distinct from the ability to persist in a cell culture or individual host. Parameters which determine perpetuation include: 1) the size of the population; 2) the turnover of the population; 3) the proportion of immunes in the population; 4) the transmissibility of the infection; and 5) the generation time between sequential infections. These parameters may be grouped into two composite factors which most directly affect transmission dynamics and perpetuation: (a) population turnover per generation period, and (b) transmissibility or the fraction of susceptibles infected per existing infection. Perpetuation in small populations usually requires either the ability to persist in individuals or rapid population turnover. Conversely, human viruses which initiate only acute infections require larger populations to persist. Seasonal variation in transmissibility can greatly increase the minimum population size in which persistence is possible, and we argue that the population size of 500,000 for measles persistence (described by Bartlett) is primarily a consequence of seasonal variation. Computer modelling can be used to examine the effect of changes in parameters which determine the seasonal cycle of virus perpetuation and fadeout. Finally, human infections are reviewed to indicate those which have been eradicated (smallpox), are on the threshold of eradication (poliomyelitis), are possibly eradicable (measles), or could be candidates for future efforts (hepatitis A and hepatitis B). In developing a strategy for eradication two points are of great potential utility: first, the seasonal trough should be exploited as a time for effective intervention; and, second, containment efforts should be directed at epidemiologically important population groupings such as schools.
TL;DR: Calculation of the age-specific incidence of HAV infections suggests a remarkable decline in the exposure rate in the last few decades, and antibody was found more frequently in rural than in urban populations in Greece and Switzerland.
Abstract: Using a solid phase radioimmunoassay, antibody to hepatitis A virus (anti-HAV) was determined in 3890 sera from populations in seven European countries. Prevalence of anti-HAV was lowest in Scandinavian countries and highest in Greece and France. Antibodies were found in 77 (13%) of 602 blood donors in Sweden, in 29 (17%) of 175 blood donors and women taking birth control pills in Norway, in 273 (39%) of 700 blood donors in Switzerland, in 262 (52%) of 505 blood donors in Holland, in 365 (55%) of 661 accident patients in West Germany, in 452 (75%) of 600 blood donors in France and in 530 (82%) of 647 persons in Greece. Prevalence of anti-HAV increased with age in all populations tested, indicating nearly total exposure to HAV in persons over 19 years of age in Greece and in persons over 39 years of age in West Germany, Holland and France. Antibody was found more frequently in rural than in urban populations in Greece and Switzerland. Calculation of the age-specific incidence of HAV infections suggests a remarkable decline in the exposure rate in the last few decades.
TL;DR: It is shown, using both a mathematical model and referring to empirical data, that if certain variances are sufficiently great, even when there is cause and effect, correlation coefficients close to zero would be expected from the actual data of a cross-sectional study.
Abstract: The confounding that results from the uncontrolled conditions under which most epidemiologic observations are made is sufficient to undermine their validity with respect to investigation of the relationship between diet and serum cholesterol. In this paper, the authors show, using both a mathematical model and referring to empirical data, that if certain variances are sufficiently great, even when there is cause and effect, correlation coefficients close to zero would be expected from the actual data of a cross-sectional study. Cross-sectional designs are therefore not suitable for studying this relationship.
TL;DR: It is suggested that low levels of HDL cholesterol are important risk factors for the development of atherosclerosis and that they may be useful for identifying patients at high risk of certain anatomic patterns of coronary artery disease.
Abstract: Epidemiologic studies have found associations between low levels of high density lipoprotein (HDL) cholesterol and increased risk of coronary artery disease, using myocardial infarction or angina pectoris as endpoints. However, since most studies have not correlated HDL cholesterol with the presence, severity, or location of anatomically proven coronary disease, the present study measured HDL cholesterol levels in 483 men and women undergoing coronary arteriography. Consistent and statistically significant trends of decreasing mean HDL cholesterol levels with increasing numbers of diseased coronary arteries were observed in both men and women and in younger and older age groups. Although women without coronary disease had much higher levels of HDL cholesterol than men without coronary disease, the differences between men and women with similar degrees of coronary disease were small. Low levels of HDL cholesterol were associated with left main coronary disease; patients with both triple vessel disease and left main disease had lower levels of HDL cholesterol than did patients with triple vessel disease without left main disease. These results were not explained by the possible associations of low density lipoprotein cholesterol or triglycerides with HDL cholesterol. These findings suggest that low levels of HDL cholesterol are important risk factors for the development of atherosclerosis and that they may be useful for identifying patients at high risk of certain anatomic patterns of coronary artery disease.
TL;DR: Patients with a non-localized tumor at diagnosis had a two-fold risk of suicide and the rate was higher among patients undergoing no treatment, or treatment with chemotherapy or hormones only, than the rate in the general population.
Abstract: Of the 28,857 cancer cases registered by the Finnish Cancer Registry in 1955, 1960 and 1965, 63 patients had committed suicide by the end of 1970. The suicide rate among males was 1.3 times higher (p less than 0.01) and among females 1.9 times higher (p less than 0.05) than the rate in the general population. The highest suicide risk (relative risk 2.5, p less than 0.001) was associated with gastrointestinal cancer. Patients with a non-localized tumor at diagnosis had a two-fold risk of suicide and the rate was higher among patients undergoing no treatment, or treatment with chemotherapy or hormones only. It was estimated that 23% of all suicides among male cancer patients and 46% among female cancer patients was associated with the patients having cancer.
TL;DR: There is a small positive association between estrogen/progesterone exposure and cardiac malformation, but no association was evident between hormones and trunco-conal or any other class of defect among the cases, an observation which casts doubt on a causal relationship betweem hormones and cardiovascular malformations.
Abstract: A history of oral contraceptive use, hormonal pregnancy tests, prescribed hormones and other drugs was obtained from 390 mothers of infants with congenital heart disease and 1254 mothers of normal infants in Massachusetts. The data show a small positive association between estrogen/progesterone exposure and cardiac malformation, the prevalence ratio estimate of exposed to non-exposed being 1.5 (90 per cent confidence limits are 1.0, 2.1). No association was evident, however, between hormones and trunco-conal or any other class of defect among the cases, an observation which casts doubt on a causal relationship betweem hormones and cardiovascular malformations. Several other drugs were reported more frequently by cases' mothers. These include: ampicillin; aspirin; a combined anti-nausea agent (doxylamine succinate, dicyclomine hydrochloride and pyridoxine hydrochloride); chlordiazopoxide, codeine, diazepam, diphenylhydantoin; insulin; phenobarbital; phenothiazine; phenylephrine; and tetracycline.
TL;DR: Observations may indicate that any effect on the incidence of acute coronary events that is caused by walking, cycling, or gardening is neutralized if these activities are interrupted for several months of the year.
Abstract: The case-referent study reported here investigates the relationship between acute coronary events (ACE) and sustained light physical exercise, mainly leisure-time walking, cycling, or gardening (WCG). These activities are classified as habitual WCG (greater than 8 months/year), seasonal WCG (4--8 months), or occasional WCG (less than 4 months), each category being further subdivided according to the number of hours a week: less than 4 hours, 4--7 hours, or greater than 7 hours. A significant negative association is found between ACE and habitual WCG. No such relationship is evident between ACE and seasonal WCG, however, seasonal WCG being equally frequent (27%) in both cases and referents. These observations may indicate that any effect on the incidence of acute coronary events that is caused by walking, cycling, or gardening is neutralized if these activities are interrupted for several months of the year. The negative association between habitual WCG and ACE does not depend on the number of hours a week devoted to SCG and is not enhanced by more vigorous additional exercise. The fatality of ACE (death rate within 4 weeks) is significantly higher in the least active group (WCG less than 4 months/year).
TL;DR: Lower socioeconomic status or greater crowding appeared to be associated with the occurrence of rotavirus infection earlier in life and earlier in the epidemic year, suggesting that these viruses played a role in acute enteric disease.
Abstract: Human rotavirus (HRV) type 1 or 2, adenovirus, or non-cultivatable 27 nm virus-like particles were demonstrated by electron microscopy and/or rotavirus ELISA in fecal samples from 45.5% of 604 gastroenteritis inpatients, 25.0% of 200 gastroenteritis outpatients and 6.0% of 812 control subjects, all sampled at Children's Hospital National Medical Center. Washington, DC. Rotaviruses were the most common pathogens detected as 39% and 22% of gastroenteritis inpatients and outpatients, respectively, shed HRV. About three-fourths of the rotaviruses were type 2, which was prevalent during five successive epidemic years from January, 1974, through June, 1978. HRV type 1 was detected in the last four successive epidemic years and represented nearly half of the HRV infections observed among gastroenteritis inpatients during the year 1977--1978. Both rotavirus serotypes were detected most often in the month of January, when 71% of 123 gastroenteritis inpatients and 62% of 34 gastroenteritis outpatients shed one of these viruses. Uncultivatable adenoviruses were detected significantly more frequently in stools from patients with gastroenteritis (3.9%) than from control subjects (0.6%), suggesting that these viruses played a role in acute enteric disease. The frequency of detection of 27 nm particles was not significantly different in gastroenteritis and control patients. Numerically, HRV infection was detected most often in gastroenteritis inpatients who were 10 through 12 months of age. The group of gastroenteritis inpatients with the highest percentage of HRV infection was 13 through 15 months of age. The excess of type 2 HRV infection relative to type 1 infection was especially large in those aged 7 through 24 months. Lower socioeconomic status or greater crowding appeared to be associated with the occurrence of rotavirus infection earlier in life and earlier in the epidemic year.
TL;DR: Patients with serious influenza A virus infections were especially likely to have croup (particularly during the H3N2 era), to be seen during December through February, and to be black male infants.
Abstract: Influenza A virus activity was demonstrated in infants and young children from metropolitan Washington, DC during each of 19 successive August-July respiratory disease years, and during 17 of these years at least 2% of hospitalized respiratory disease patients yielded an influenza A or B virus and/or showed an influenza A or B serum complement-fixing (CF) antibody response. Between October 1957 and July 1976, 14.3% of 860 croup patients and 5.3% of a total of 5655 hospitalized respiratory patients, including croup patients, showed evidence of influenza A or B infection. The mean period of hospitalization with either virus was about 8 days, though serious infection with influenza A virus was 4.5 times more common than with influenza B virus. Both influenza viruses were detected more frequently in respiratory disease outpatients than in respiratory disease inpatients. Patients with serious influenza A virus infections were especially likely to have croup (particularly during the H3N2 era), to be seen during December through February, and to be black male infants. During the peak month of a composite of 13 consecutive influenza A virus outbreaks, influenza A virus infection was demonstrated in 67.6% of croup patients and in 35.6% of all hospitalized respiratory patients including croup patients. During the peak month of a composite of 6 consecutive influenza B virus outbreaks, influenza B virus infection was demonstrated in 36.0% of croup patients and in 10.8% of all hospitalized respiratory disease patients including croup patients.
TL;DR: The findings, based on reliable, basal-like measurements, point to a degree of persistence which is quite high, the higher the degree of tracking the more likely that primary hypertension begins early in life.
Abstract: Blood pressures (BPs) were taken with a mercury sphygmomanometer and an automatic recorder on 3524 children representative of an entire geographic community. For all children ages 5, 8, 11, and 14 years in the initial examination, age-specific systolic and diastolic (4th phase) selected percentiles were assessed. Of these children, 1101 were reexamined after one year. Observations from a group of 35 fifth-graders examined monthly for eight months were pooled to observe intra-child BP variability. This estimate was used to reduce to zero in a statistical adjustment the regression toward the mean of the BPs for the after-one-year reexamined children. It was found that those children initially in the top ten percentiles had, upon reexamination, on the average only 3 mmHg lower systolic and 1 mmHg lower diastolic levels. In a multiple regression analysis, the previous year's BP contributed a partial correlation coefficient of 0.6--0.7 for each age cohort to the variability of the BP, controlling for other determinants. These findings, based on reliable, basal-like measurements, point to a degree of persistence which is quite high. The higher the degree of tracking the more likely that primary hypertension begins early in life.