PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “secular change”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

Absence of secular changes in the prognosis of patients with an initial myocardial infarction.

A community-based study was conducted in metropolitan Baltimore in which secular trends in the in-hospital and long-term prognosis of 935 male and female patients hospitalized with an initial myocardial infarction were examined for the two periods of 1966-1967 and 1971. The in-hospital case fatality rate among males in both periods remained unchanged (19.0% vs 19.0%), whereas there was a decrease over time among women hospitalized in 1966-1967 as compared to those in 1971 (37.2% vs 26.6%) (p less than 0.10). For patients discharged alive from the hospital and followed up for as long as 10 years, no significant differences in overall survival were observed between male patients discharged in 1966-1967 and 1971 or between female patients discharged in these two periods. These findings may reflect the lack of major therapeutic advances in the care of the acute coronary patient between the two study periods and, therefore, support continuing efforts directed at the primary and secondary prevention of the atherosclerotic process.

Age Factors↗

Secular changes in stature in southern Portugal between 1930 and 1980 according to conscript data.

Stature of conscripts from four regions of southern Portugal was evaluated in a secular perspective. Data were drawn from the draft records for each decade between 1930 and 1980, a period that corresponds to a decisive expansion of industry and urbanization. In each region conscripts were divided into two groups according to their area of birth: urban or rural. A secular shift was apparent in every region, affecting conscripts of both urban and rural extraction. However, gains in stature were greater in the littoral than in the hinterland regions, where agriculture still employs a large percentage of the population. In each region the urban conscripts experienced greater secular gains than their rural counterparts. The secular shift was more pronounced among the short-stature segments of the populations; percentages of conscripts below a height of 160.0 cm dropped in a striking manner throughout the period under investigation. Despite the paucity of reliable information on the anthropometric and biodemographic characteristics of the Portuguese population, the secular gains were found to be associated with infant mortality and total death rate in the four regions. Compared to other Western European populations, the secular growth of the Portuguese proceeds at a slower pace, even when comparisons are made within the group of Latin countries that share a common linguistic and cultural heritage in addition to the shortest statures in Europe.

Body Height↗

Secular changes in early neonatal mortality in Norway, 1967-1981.

Two five-year cohorts, 1967-1971 and 1977-1981, of the Medical Birth Registry of Norway, were utilized to analyze secular trends in early neonatal mortality rates, controlling simultaneously for birth weight, parity, maternal age, and sex. Improvement in the crude early neonatal mortality rate, from 6.5 to 2.9 per 1,000, was partitioned into one portion (18.4%) attributable to changes in the distribution of the birth weight or the other independent variables and another portion (81.6%) attributable to improved survival within each specific subgroup in the multivariate table. The early neonatal mortality rate was found to decrease in all subgroups, the low birth weight groups showing a significantly greater decline than the normal birth weight groups. Women with diabetes, epilepsy, or blood group antibodies were studied in separate analyses. For women with diabetes, the odds ratio of the early neonatal mortality rate between the first and the second periods was found to be three times the odds ratio for women without diabetes, and 2.9% of the total improvement of the crude early neonatal mortality rate was attributable to an improved survival in these infants.

Birth Weight↗

Secular changes in cardiovascular risk factors over 30 years in Swedish men aged 50: the study of men born in 1913, 1923, 1933 and 1943.

OBJECTIVES: To study secular trends in cardiovascular risk factors in men aged 50 over a period of 30 years. DESIGN: Cross-sectional studies of successive cohorts of men from 1963 to 1993. SETTING: City of Göteborg, Sweden. SUBJECTS: Four random population samples of men born in 1913, 1923, 1933 and 1943, aged 50 when they were examined in 1963, 1973, 1983, and 1993 (n = 855, 226, 776, and 798, respectively). MAIN OUTCOME MEASURES: Anthropometric measurements, blood pressure, serum cholesterol and triglycerides and smoking habits over three decades. RESULTS: Over 30 years, men increased in weight from a mean (SD) of 75.9 (11.0) kg to 82.8 (12.1) kg and gained 3.4 cm in height, with a net increase in body mass index from 24.8 (3.2) to 26.0 (3.4) kg m-2 (P < 0.0001), and a concomitant increase in waist circumference. The proportion of men who were overweight but not obese (BMI = 25-30 kg m-2) increased from 38 to 47%, whereas the prevalence of frank obesity (more than 30 kg m-2) increased from 6% in 1963 to 11% in 1993. Despite the increase in weight, mean systolic blood pressure fell by almost 10 mmHg (P < 0.0001). Mean serum cholesterol concentration decreased from 6.42 (1.12) to 5.88 (1.04) (P < 0.0001). Serum triglycerides increased from 1.26 (0.77) to 1.69 (1.04) mmol L-1 (P = 0.001). The proportion of men who smoked decreased from 56% in 1963 to 30% in 1993 (P < 0.0001). This was due more to an increase in smoking cessation rates than to an increase in the proportion of men who had never smoked. In particular, smokers and former smokers are now more obese than the corresponding categories 30 years ago and smokers are no longer leaner than men who have never smoked. CONCLUSIONS: Over a period of 30 years, serum cholesterol as well as systolic blood pressure and the prevalence of smoking decreased. This favourable decline in coronary risk factors was offset by an appreciable increase in body mass index and waist circumference.

Aged↗

Secular change in adult stature has come to a halt in northern Europe and Italy.

AIM: To investigate whether the increase in adult stature in European countries is continuing. METHODS: The secular trend in growth after 1990 for various European countries was assessed by national conscript data. RESULTS: In Scandinavia and the Netherlands, the height has reached a plateau at 179-181 cm, and in Italy a plateau at 174 cm. In Belgium, Portugal and Spain, height continued to increase. CONCLUSION: Only in the northern European countries and Italy height has ceased to increase.

Adolescent↗

Secular changes in twinning rates in England and Wales.

The monozygotic twinning rate in England and Wales seems to have increased over the years of 1957-1977. This constitutes evidence against the suggestion that the secular decline in dizygotic twinning rates over the same period has been due to an increase in spontaneous abortion rates.

Birth Rate↗

Secular change in height in Austria: an effect of population stratification?

The records of height on some 700,000 18-year-old Austrian males, called for examination as to their fitness for conscription, were analysed. The data covered 14 conscription years (1980-93), representing males born in the years 1962-75. The sample covered over 90% of the total male population of those cohorts in Austria. The data were analysed by birth year to show the secular trend in 18-year-old stature and its rate, which overall amounted to 0.53 cm/decade. Analysis by urban-rural residence showed that both participated in the trend, but that the urban-rural differences were appreciably less than the differences between the types of school the young men had attended. The rate of increase over the 14 years was less within each of the eight subgroups (urban-rural, four school categories). It is argued that the secular trend in height that has occurred is largely attributable to the change in social stratification, as evidenced by the changed proportion of subjects who attended schools of different types.

Adolescent↗

Secular changes in age at menarche in a sample of US women.

In an epidemiological survey of the reproductive history of a large group of United States women who had given birth to at least one child, there was a secular trend in age at menarche between those born around 1920 and those born around 1940-45. The trend was linear and the increment 3.2 months (+/- 0.36) per decade. The women were White, well nourished, middle-class and resided in all parts of the United States.

Adolescent↗

Secular changes in sleep position during infancy: 1995-1998.

OBJECTIVE: Prone sleeping among infants has been associated with an increased risk of sudden infant death syndrome. The objective of this study was to compare factors associated with sleep position in 1995-1996 and 1997-1998 and to assess secular trends in use of prone infant sleep position from 1995 through 1998 among families stratified by race and education. METHODS: A prospective cohort study was conducted in eastern Massachusetts and northwest Ohio of 12 029 mothers of infants who weighed > or =2500 g at birth. Descriptive statistics and multivariate odds ratios were used to relate maternal and infant characteristics to prone and supine sleeping. RESULTS: A total of 14 206 mothers (25% of those eligible) were enrolled. A total of 12 029 mothers (85% of enrolled) responded to the 1-month and 11 552 mothers (81% of enrolled) responded to the 3-month follow-up questionnaire. A decline in use of the prone sleep position and increase in use of the supine position was observed during the 4 years of the study. Factors associated with prone and supine sleep position were similar in 1995-1996 and 1997-1998. In 1997-1998, use of prone sleeping at 1 month of age reached the goal of < or =10% only among infants of white and Asian women, married women, women who were older than 25 years, women who were college graduates, and women with incomes >$55 000 per year. At 3 months of age, however, prone sleeping increased to 12% to 17% in these groups. These same groups were most likely to use the supine position; 38% to 45% were supine at 1 month, increasing to 56% to 64% by 3 months of age. However, as of the end of 1998, approximately 27% of infants of non-college-educated black and Hispanic mothers were placed to sleep in the prone position and only 20% to 30% were being placed to sleep in the supine position at 3 months of age. CONCLUSIONS: Recommendations to avoid prone sleep position and especially the recommendation that supine sleep position is preferred have not been effectively delivered to black and Hispanic families and to families of low-income and less than a college education.

Chi-Square Distribution↗

Fracture patterns in children. Analysis of 8,682 fractures with special reference to incidence, etiology and secular changes in a Swedish urban population 1950-1979.

Age, sex, type of fracture and the circumstances causing the injury were studied in altogether 8,682 fractures in children, aged 0 - 16, which had occurred 1950, 1955, 1960, 1965, 1970 and 1975 - 1979. For studies of incidence, the years 1975 - 1979 were chosen and for secular trend studies 1950, 1955, 1960, 1965, 1970 and 1975 - 1979. The following conclusions may be drawn: 1. The risk of fracture increased with age up to age 11 - 12 in girls and 13 - 14 in boys. 2. The accumulated risk of fracture was 27 per cent in girls and 42 per cent in boys. 3. Fractures were more common in boys of all age groups. 4. Over the last three decades the risk of fracture was doubled in boys as well as in girls. 5. Over the years more and more fractures were caused by slight trauma whereas the more severe trauma - even if increasing somewhat in risk - contributed a smaller fraction of the injuries. 6. For the various types of fracture the pattern of change could differ - some increased in incidence, whereas some remained unchanged or even decreased. 7. All types of trauma - horse riding accidents excluded - were more frequent in boys. 8. The most commonly fractured region was the distal end of the forearm followed by the phalanges of the hand and the bones of the carpal-metacarpal region. 9. Playing, sports and traffic, in that order contributed 24, 21 and 12 per cent of those fractures in which the circumstances of the accident could be analysed. 10. Traffic accidents increased with one third in boys as well as in girls. 11. The passive participants in traffic - pedestrians and passengers in motor vehicles - were not more frequently injured during the latter part of the period under observation - a tendency of increase in girls was compensated for by a decrease in boys. 12. Sports and various playing activities as a cause of fracture increased with a factor of five. 13. In the upper limb, the left side was most frequently fractured. 14. The occurrence of fractures varied with the seasons with peak values in May and August and low values in July and December. 15. No fracture type in children could completely meet the criteria of a fragility fracture such as seen in old age. 16. Sustaining one fracture carried an increased risk of an additional fracture especially in the very young children. 17. Fractures not requiring reduction increased the most over the years. 18. The subset of children with various diseases suspected to interfere with skeletal development carried an increased risk of fracture. 19. Some age-related fracture patterns could be traced but they were not very distinct.

Accidents↗

Evidence for secular change in Paget's disease.

Death certification data has shown that death rates due to Paget's disease of bone and osteosarcoma in older people (assumed to be attributable to Paget's) declined in the latter part of the 19th and in the early 20th century, suggesting that there may be a secular trend toward less severe disease. We have reviewed a 21 year experience in a clinic specializing in Paget's disease. Data from all 1041 patients attending the clinic in this period were reviewed. Despite an increase in the susceptible population and an increased rate of referral to the clinic over this time (p = 0.012), there was a fall in the absolute numbers of patients referred with severe disease, as judged by the initial plasma alkaline phosphatase activity at presentation. In the years 1973-1978 the initial plasma alkaline phosphatase was > 500 U/L in an average of 22 new patients per year and > 1000 U/L in 12 per year. In the years 1988-1993, the figures were 12 and 3 per year, respectively. During this period, there were no other facilities offering scintigraphy or intravenous treatment for Paget's disease in the Auckland region, making it unlikely that patients with severe disease were being seen and treated elsewhere. The average age of newly referred patients rose steadily from a mean 62 years, in 1971-1973 to 71 years in 1991-1993 (p < 0.001). 534 subjects had scintiscans (52%) from which the extent of skeletal involvement was calculated. Skeletal involvement showed a significant negative correlation with year of birth (p < 0.01) but not with age or year of presentation. The proportion of patients with > 20% skeletal involvement had fallen by a third in the cohort born after 1926, compared to the cohort born before 1915. Our data demonstrate that, on average, newly referred patients with Paget's disease have less severe disease and are significantly older at diagnosis than was the case two decades ago.

Aged↗

An early hand-wrist atlas and its implications for secular change in bone age.

A little-known 'Skiagraphic Atlas' documenting radiographic changes in the bones of the hand and wrist was published by Poland in 1898. Nineteen skiagrams of British children, 1-17 years of age, were included. Tanner-Whitehouse-2 bone ages were assessed for 15 individuals in this series and differences from chronological ages were calculated. Mean differences for 20-bone, RUS and carpal bone ages are significantly larger than zero. Hence, these children were relatively advanced compared to present children. Comparisons of Poland's expected ages for onset and fusion of secondary ossification centres in the hand and wrist with more recent reference data indicated a secular increase in the rates of skeletal maturation of approximately 0.22-0.66 year/decade, with relatively greater change in expected ages of fusion.

Adolescent↗

Social background and age at menarche in Portuguese university students: a note on the secular changes in Portugal.

Menarcheal age of a sample of Portuguese university students (n = 3366), born between 1972 and 1983, age 18-23 years, was analyzed. The influence of parents' educational level and occupation, family size, birth order, and degree of urbanization of girl's locality of residence during childhood and adolescence were analyzed as well as secular trend in the Portuguese population. Mean age at menarche for girls born in 1983 was 12.32 years. Parents' educational level and occupation did not show any significant influence on mean age at menarche. Place of residence during childhood years and adolescence showed a significant effect on mean age at menarche, with girls from rural places with a later age at menarche than those who spent their childhood or adolescence in urban areas (P <or= 0.01 and P <or= 0.05 for childhood and adolescence, respectively). Family size and birth order showed the highest effect. Girls born in small families, with one child, matured earlier (12.32 years) than those born in large families with four or more children (12.67 years), (P <or= 0.01). Also, girls that were first-born had an earlier menarche (12.41 years) than those who were third or later (12.58 years, P <or= 0.01). Regression analysis selected family size and place of residence in childhood as the most important determinants of mean age at menarche in our university students. In this sample, from 1972 to 1983, mean age at menarche remained stable. When we considered published data from all the Portuguese population we found a decrease in mean age at menarche from 15 years for girls born in 1880 to 12.44 for those born in the 1980s. This decrease was the result of great improvements in the social and economic living conditions that occurred in Portugal especially after the 1970s concerning nutrition and health care, among many other environmental factors.

Adolescent↗

Secular change in growth of native children and adolescents at high altitude I. Puno, Peru (3800 meters).

A cross sectional sample of 969 native males from Puno (Peru), altitude 3800 m, ranging in age from 7-20 years, and studied for body height, weight, sitting height, leg length, and chest circumference in 1980, were compared, from the point of view of secular trend, with another cross sectional sample of 992 native males from the same place, which were investigated in 1945. In addition, similar observations were carried out in 1980, in a group of 112 females. The data indicate that in Puno there has been no secular increment in the adult body size. However for all ages between 7 and 19 years, body weight and height were significantly greater in 1980 than in 1945. This may be due to earlier sexual maturation in the present generation.

Adolescent↗

Ageing and secular changes in adult stature of Jat-Sikh and Bania females of Punjab (India).

Stature, sitting height and subischial length in a cross-sectional sample of 502 Jat-Sikh and 510 Bania females of Punjab ranging in age from 20 to 80 years, have been studied. It has been possible to separate out statural decrease due to ageing from secular effects by taking into consideration the subischial length, which is least affected by ageing. The rate of loss in stature obtained due to ageing is 0.0997 +/- 0.012 cm/yr in Jat-Sikh females and 0.127 +/- 0.012 cm/yr in Bania females. After adjusting the stature for ageing, the secular estimate obtained is 0.051 +/- 0.022 cm/yr in Jat-Sikh and 0.047 +/- 0.021 cm/yr in Bania females. The ageing and secular estimates obtained per year in both the communities are significantly different from zero at 5% level. The ageing estimate obtained per year is more in Bania females, whereas the secular estimate per year is larger in Jat-Sikh females, although non-significant.

Adult↗

Lack of secular change in male adult stature in rural Mali (West Africa).

A study has been carried out on a sample of 2,158 male subjects between 20 and 50 years old representative of the rural Malian population (West Africa), and the results are compared with historic data obtained since 1885. This comparison suggests that there has been no modification in stature during this century. The analysis of each ethnic group does not show any disparity. Our results are in agreement with the theory that certain factors lead to the secular increase of stature in developed countries. These etiologic factors are not found in our West African population.

Adult↗

Aging and secular change in adult stature in rural Colombia.

Age-associated changes in adult stature of a cross-sectional sample of 634 adults from rural Colombia were estimated by multiple regression of stature and age controlling for subischial length, and from equations predicting maximum attained stature from subischial length. From these analyses the estimated rate of loss in stature due to aging per se for men was 0.12 cm/yr, while for women it was 0.03 cm/yr. When corrected for aging, several secular trends in adult stature were evident, although none were statistically significant.

Adult↗

Secular changes in published clinical trials of second-line agents in rheumatoid arthritis.

The present investigation was undertaken to explore changes over time in the design and reporting of trials of second-line drugs in rheumatoid arthritis, in the characteristics of patients included in the trials, and in the sources of funding. We studied 105 trials of second-line agents for the treatment of rheumatoid arthritis, including placebo-controlled and comparative trials involving 8 different agents. Three time periods, 1945-1969, 1970-1979, and 1980-1989, were compared. We found little change in the standards for reporting on the design of trials or for reporting information on patient dropout and drug side effects, some increase in the complexity of the statistical methods used, but no increase in the use of power analysis (reported in only 13% of trials). The average age of patients in clinical trials has increased. In recent years, there has been a substantial shift from placebo-controlled to comparative trials, and it is increasingly common for trials to be financially supported by pharmaceutical companies. The possible effects of secular trends should be considered when combining or comparing results of trials conducted in different years.

Age Factors↗