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To investigate whether the secular trend for growth in Dutch children still exists, the Oosterwolde I study of 1980 was repeated in 1989. A persisting secular trend was visible for height while the z scores of body proportions show no change during the past 10 years, which suggests that there is no change in the timing of puberty.
In 1993, a cross-sectional study of sexual maturation of normal Chinese schoolgirls was performed in Hong Kong. The aim of the study was to obtain an up-to-date reference for normal pubertal development in Chinese girls. Breast development was assessed in 3749 girls aged 7-19 y, and pubic hair rating was assessed in 3745 girls. Menstrual status was recorded in 6467 girls over 6 y of age. The median age of onset of puberty as indicated by breast stage II or above was 9.78 (95% CI 9.70-9.85) y. The median age of onset of pubic hair development was 11.64 (95% CI 11.56-11.72) y. The median age of menarche was 12.38 (95% CI 11.98-12.78) years. Percentile values for the age at which each puberty staging appeared were constructed and incorporated into the height-for-age charts. When comparison is made with similar studies done in 1962 and 1979, a significant downward secular trend in sexual maturation is observed (p < 0.01). Except for breast development the downward secular trend in sexual maturation appears to be diminishing and may be coming to a halt in the Chinese girls in Hong Kong. Their median ages of sexual maturation are now among one of the earliest medians recorded in the world population studied.
The secular equation for surface acoustic waves propagating on a monoclinic elastic half-space is derived in a direct manner, using the method of first integrals. Although the motion is at first assumed to correspond to generalized plane strain, the analysis shows that only two components of the mechanical displacement and of the tractions on planes parallel to the free surface are nonzero. Using the Stroh formalism, a system of two second order differential equations is found for the remaining tractions. The secular equation is then obtained as a quartic for the squared wave speed. This explicit equation is consistent with that found in the orthorhombic case. The speed of subsonic surface waves is then computed for 12 specific monoclinic crystals.
We have studied changes in the birthweight of Asian babies born alive at this hospital between 1968 and 1978. In 1978 Pakistani babies were 139 g heavier but Indian babies only 25 g heavier than 10 years earlier. Contributing to these changes were significantly fewer short mothers and primiparae among Pakistanis, and non-significant increases in gestational age and intrauterine growth (that is, weight centile after allowing for gestational age, parity, and maternal height). Among Indians there were significant increases in maternal height and gestational age, but parity was reduced and intrauterine growth did not increase. In both groups there were fewer teenage mothers, but whereas among Pakinstanis birth intervals of less than one year were less common, there was no such reduction among Indian mothers. The secular change suggests that genetic factors are unlikely to be the major reason why Pakistani babies born in Birmingham are lighter than European babies, and that environmental factors play an important role. Efforts to increase birthweight need to consider both the mothers' physical environment during pregnancy and prepregnancy factors influencing growth in childhood, age at first pregnancy, and birth interval. The study shows a need to describe an 'Asian' population with details of their sub-ethnic structure. The sub-ethnic and secular differences further suggest that a single 'Asian' standard for birthweight and intrauterine growth may be inappropriate; the use of international reference data with which all infants may be compared is preferable.
AIM: To describe the epidemiology of congenital anomalies in Glasgow with special reference to secular trends. METHODS: The prevalence of congenital anomalies was determined retrospectively in 233 777 births using the Glasgow Register of Congenital Anomalies for the period 1980-97. RESULTS: The total prevalence of congenital anomalies was 324 per 10 000 births, declining by just over a third from 382 per 10 000 births in 1980 to 238 per 10 000 births in 1997. The categories of defects with the highest prevalence were congenital heart disease (50 per 10 000 births), anomalies of limbs (49 per 10 000 births), and digestive system anomalies (47 per 10 000 births). Prevalence in most categories of anomaly declined, including those of the ear (-88%), congenital heart disease (-69%), anomalies of integument (-67%), nervous system anomalies (-61%), anomalies of limb (-54%), and urogenital (including renal) anomalies (-31%). By contrast, there was a significant upward trend for chromosomal anomalies (+50%). CONCLUSIONS: Despite the decline in the prevalence of many types of congenital anomaly, around 2.5% of all births in Glasgow were still associated with these disorders in 1997. In attempting to explain the prevalence and secular trend of congenital anomalies in Glasgow, underlying contributing factors require to be considered. These include changes in case ascertainment, antenatal screening, and diagnostic methods.
OBJECTIVE: To formulate and evaluate a new method to measure secular trends in child growth based on the cross sectional collection of heights of children and young adults. DESIGN: Trends in child growth obtained from comparison of two national surveys made with an interval of 15 years were compared with estimates obtained from comparison of height deficits of children and young adults in the more recent survey. SETTING: Brazil. SUBJECTS: Random sample of children (6 and 7 years old) and young adults (21 and 22 years old) living in Brazil in 1974 and 1989 (a total of 23,271 subjects in 1974 and 5479 in 1989). MAIN OUTCOME MEASURES: Increments in average heights of 6 and 7 year old children in a 15 year period. RESULTS: Mean height of 6 year old children increased 4.0 cm (boys) and 3.3 cm (girls) from 1974 to 1989. Similar results were obtained by subtracting, in the 1989 survey, mean height deficits found at ages 21 and 6 (3.8 cm for males and 3.5 cm for females). Positive changes in the mean height of 7 year old children could also be predicted by subtracting, in the 1989 survey, height deficits found at ages 7 and 22. CONCLUSIONS: Findings of this study support the hypothesis that secular trends in child growth can be estimated by comparing height deficits observed in children and young adults.
OBJECTIVE: To investigate secular trends in resting heart rate in young adults. DESIGN, SETTING, AND PARTICIPANTS: A series of cross sectional cohorts of first year undergraduates (5562) aged 16-24 years who attended Queen's University Belfast from 1949 to 2004 and underwent health checks at the university health centre. MAIN OUTCOME MEASURE: Resting heart rate. RESULTS: Crude aggregate data for 1949-59 showed a secular decline in heart rate in male and female students. Both unadjusted and fully adjusted analyses of data from 1975 onwards-controlled for age, body mass index, height, and smoking-showed a U shaped association between heart rate and year of entry to university in both sexes (p < 0.001): heart rate initially declined and then increased from the mid 1980s. Trends were similar in smokers and non-smokers and in students with normal body size and those who were overweight. However, heart rate in the 693 (28%) male students reporting the most physical activity remained stable and lower than that of men who participated in less physical activity over the period of the study. Similarly in female students, heart rate was generally lower in the 210 (10%) who participated in the most physical activity than in those who engaged in less physical activity. CONCLUSIONS: The decline in heart rate in young adults occurring at least 50 years ago and continuing until the 1980s is consistent with other favourable findings on cardiovascular health in this age group and with observed long term declines in cardiovascular mortality. The more recent rise in heart rate, not accounted for by increases in overweight, prompts concern that recent favourable trends in cardiovascular disease risk may not be maintained. Among students who took part in the highest levels of physical activity the finding of low and stable heart rates points to the importance of exercise in maintaining cardiovascular health. Measurement of heart rate in population surveys would provide a simple tool to assist monitoring cardiovascular health.
BACKGROUND: Although recent research has reported an evolution in the level of medical care, little is known about secular trends in the medical discharge summary. METHODS: The audit evaluated the evolution of discharge summary abstract over a decade in an acute medicine hospital among three successive periods of 1994, 2000, and 2005. RESULTS: Of the 140 random samples of discharge summaries, significant between-cohort difference existed in the logarithm transformed length of discharge summary; the median length of discharge summary increased from 11 lines in 1994 to 26 lines in 2005 (p<0.001 corrected for multiple comparison). The closest univariate associations of discharge summary length were positively with the year of hospitalisation, length of stay, length of wordings about discharge plan and duplication of previous discharge summary, and negatively with clinical or planned admission (all p<0.01). In a multiple linear regression analysis, the year of patient admission correlated significantly with the length of discharge summary (p<0.001). CONCLUSIONS: Over the 10 year study period, significant secular trends were seen in the discharge summary length and discharge plan documentation. The causes and implications for these trends deserve further investigation.
Available summaries of radiology reports were examined among 899 primary brain cancer cases (age 40 years and older) diagnosed in Connecticut residents in selected years from 1965 to 1988 and reported to the population-based Connecticut Tumor Registry. Adjustment for the lower sensitivities of radiologic tests used before the advent of computerized tomography (CT) suggested that the introduction of CT (by itself) could account for little of the secular increase in brain cancer rates. Examination of trends in age-standardized rates for histologically confirmed brain cancers in the elderly, after excluding those diagnosed only by radiologic tests, did not support the idea that the secular trend in the elderly was largely artifactual.
Japan has been experiencing ever more rapid socioeconomic development and changes in eating habit, especially in children, since the end of the Second World War. These occurrences (westernized life style) have greatly affected the growth of Japanese. Nutrition is the most important factor in promoting the physical growth in childhood during food supply shortage, and for a relatively short term the secular trend in linear growth will reach a plateau if the food supply is adequate, but the secular trend is also limited. Since the condition for this limitation should be comprised by genetic factors, we are most interested in investigating and analyzing these genetic factors in the near future. Overeating adversely affects growth in childhood, with most common representatives of these ill effects being atherogenic risk factors such as obesity, hypertension and hypercholesterolaemia.
BACKGROUND: The reduction in US stroke mortality has been attributed to declining stroke incidence. However, evidence is accumulating of a trend in declining stroke severity. METHODS: We examined secular trends in stroke incidence, prevalence, and fatality in Framingham Study subjects aged 55-64 years in three successive decades beginning in 1953, 1963, and 1973. RESULTS: No significant decline in overall stroke and transient ischemic attack incidence or prevalence occurred. In women, but not men, incidence of completed ischemic stroke declined significantly. Stroke severity, however, decreased significantly over time. Stroke with severe neurological deficit decreased in later decades, with a fall in rates of severe stroke cases in which patients were unconscious on admission to the hospital. There was no substantial change in the case mix of infarcts and hemorrhages and no decline in hemorrhage to account for the decline in severity. The proportion of isolated transient ischemic attacks increased significantly over the 30 years studied, yielding an apparent and significant decline in case-fatality rates in men only. CONCLUSIONS: Secular trends in stroke incidence and fatality did not follow a clear or definite pattern of decline. While a significant decline in stroke severity occurred over three decades, incidence of infarction fell only in women. The decline in total case fatality rates occurred only in men and resulted largely from an increased incidence of isolated transient ischemic attacks. The severity of completed stroke was significantly lower in the later decades under study.
BACKGROUND AND PURPOSE: Pathological patterns of stroke are different in various races, with the predominant stroke type in the Chinese being intracerebral hemorrhage. A total of 31,078 deaths from cerebral infarction and 77,773 deaths from cerebral hemorrhage in Taiwan were reported for groups of subjects aged 40-79 years during the period 1974-1988 to elucidate their secular trends. METHODS: Vital statistics and demographic data were collected for analyzing the truncated age-adjusted mortality rates. Poisson regression analysis was used to estimate the relative risk and 95% confidence interval. RESULTS: The mortality rates for cerebral hemorrhage were greater than those for cerebral infarction. The mortality rates increased exponentially with age for both subtypes. The decline in age-specific mortality for the period 1974-1983 was much more striking for cerebral hemorrhage than for cerebral infarction. Mortality from cerebral infarction and hemorrhage increased with age for all birth cohorts except the cerebral hemorrhage mortality of the oldest cohort. Male/female ratios for both cerebral infarction and hemorrhage were greater in the younger age groups. The cerebral hemorrhage/infarction ratio during the period 1984-1988 was highest for the younger age groups and lowest for the oldest age groups. CONCLUSIONS: The different secular trends of mortality from cerebral infarction and hemorrhage imply that these two patterns of stroke may be associated with some different risk factors.
This study examined the community intervention practice of grouping children on the basis of religious attitudes for analysing community fear responses. The study examined the differences of responses between religious and secular school populations to the Israeli Fear Survey Schedule for Children (IFSSC), an adaptation of the Wolpe and Lang (1964) Fear Survey Schedule. 283 children from secular-trend schools in Israel. 18 of the 99 items of the IFSSC (Klingman & Wiesner, 1982) showed significant differences. The study supported the continuation of the community intervention practice of grouping children on the basis of religious attitude for analyzing IFSSC responses. Religious group affiliation was found to be an influential factor in certain fear responses. The findings point to the need for investigating normative differences among subpopulations with FSS-like instruments. Pre-knowledge and the understanding of the fear level in a community is of great value for emergency-oriented consultation during a crisis. When facing an anxiety-producing situation, the focus of primary as well as early secondary prevention is reaching individuals, as well as groups, of high psychological risk (Caplan, 1964; Klingman & Ben-Eli, 1981; Ollendick & Offman, 1982; Poser & Hartmen, 1979; Shippee, Bradford & Gregory, 1982). The utilization of appropriate classification variables enhances the ability to assess the quality and the degree of reaction to stress within a community.(ABSTRACT TRUNCATED AT 250 WORDS)
BACKGROUND: Evaluating the incidence of nonmelanocytic skin cancers in white populations and assessing the direction and strength of secular trends in these cancers have become important issues to dermatologists, oncologists, health policy analysts, and health care funders. OBJECTIVE: The objective of this paper is to evaluate the three principal methods used to assess incidence rates and secular trends. CONCLUSIONS: Each of the three methods has strengths and weaknesses. An understanding of these will enable proper assessment of the value and significance of findings presented in the literature.
The present study examines secular changes in the rate of twinning in Denmark during the period of 1931-77. Total twinning (i.e., mono- and dizygotic twinning combined) declined from a crude rate of 15.0 twin births per 100 deliveries in 1931 to 9.6 twin births per 100 deliveries at the end of the period. After direct adjustment for maternal age and parity (between the years 1935 and 1965), a 22% decline in total twinning rates was noted. Estimates of the rates of dizygotic twinning over the same period, again adjusted for maternal age and parity, show a decline of 20%. Thus there is evidence of a real decline in twinning, independent of the effects of changing patterns of maternal age and parity. These findings are consistent with reports of a general decline in twinning rates from a number of other countries. The interpretation of such secular changes is a matter for speculation.
In our previous study we reported that the secular change of the mean birth weight (MBW) of Okinawa was different from that of Japan as a whole, that is, the MBW of Okinawa was lower, but the annual increase rate of the MBW of Okinawa was larger than that of Japan as a whole. Through analyses using birth records of several obstetric facilities in Naha, we concluded that this phenomenon must be due to the remarkable improvement of the socioeconomical environment of Okinawa. In this report we analyzed secular changes of mean birth weight (MBW) and mean gestational day (MGD) of 15,847 singleton babies born at an obstetric clinic in the city of Naha for the 33 years from 1955 to 1987. To avoid fluctuations of annual changes in MBW and MGD caused by a small number of babies born in a single year, we also used the moving average of three years. In analyzing birth weight we stratified birth weight by sex, parity and the number of gestational weeks. It is considered that birth weight stratified by the number of gestational weeks reflects the intrauterine growth rate of infants. According to our results, both the MBW of infants with 40 gestational weeks, which reflects the intrauterine growth rate, and the MGD increased during the period from the 1950s to the early 1970s in this clinic. On the basis of these results we concluded that the increase of birth weight in this clinic until the early 1970s was due to increases in both the intrauterine growth rate and the gestational period. Our results also show that the mean height of mothers who delivered at this clinic also increased, which might reflect the development of the socioeconomical environment during their childhood. During the period when MBW increased, the economic growth rate of Okinawa was higher than that of other prefectures. From these results we concluded that the MBW can be used as a community health indicator reflecting the total health condition in a given community.
The aims of this study were to describe secular changes in body size in Shanghai infants, to compare the growth pattern between Shanghai children and Swedish children, and to explore the association of growth rate with parental body size, feeding practice and child health status. The study series consisted of 6,018 longitudinally followed full-term children, born between 1st January 1980 and 31st December 1990 in Fenglin Community, Shanghai. The data clearly show a positive secular trend in growth in Shanghai over the decade of observation; at 12 months, the mean increase in weight and length were 0.32 kg and 0.64 cm, and at 24 months they were 0.54 kg and 1.29 cm. The general growth pattern observed in the children in comparison with the Swedish reference was of fast growth in the first few months of life, and faltering between 9 and 24 months of age. Age at introduction of solid food, weaning age and parental body size were related to growth velocity in the first two years. There was little cumulative effect of diarrhoea on growth in the first two years of life.
OBJECTIVE: It is a common experience among pediatricians in the industrialized countries that many girls-but many fewer boys-present with secondary sex characteristics at a younger age than normal. This study examines whether there are sex differences in the secular changes toward earlier pubertal maturation. METHODS: The author collected the growth data from various studies performed in Greece in the 20th century (from 1928 to 1995) and estimated the age at peak annual height increment in each study by calculating mean increase in height in each successive year. RESULTS: In all studies, boys presented peak mean annual height increment at 13 to 14 years of age. Girls did not present a discernible peak height increment until the late 1960s; however, thereafter they presented a peak height increment at 11 to 12 years of age. CONCLUSIONS: The data suggest sex differences in the secular changes in pubertal maturation, girls being affected more intensely than boys.