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PubMed2001

Time trends in first admissions for schizophrenia and paranoid psychosis in Stockholm County, Sweden.

Several studies have reported decreasing time trends in first diagnosed schizophrenia patients. The aim of this study was to analyze time trends for first admissions with a diagnosis of schizophrenia or a diagnosis of either schizophrenia or paranoid psychosis during 1978-1994 in Stockholm County, Sweden, with a population of around 1.8million. Information about first psychiatric admission with the diagnosis schizophrenia or paranoid psychosis for residents of Stockholm County was obtained from the Swedish population-based psychiatric inpatient register. Age-adjusted average yearly changes in first hospitalization rates were estimated in a Poisson regression model. Time trends in first admission rates were calculated from 1978 to 1994, while admissions during 1971 to 1977 were observed only to eliminate later re-admissions. First admissions for schizophrenia declined by 1.9% annually for females and by 1.3% for males, while first admissions for schizophrenia and paranoid psychosis together were unchanged over the study period for both genders. Our results indicate that the incidence of schizophrenia and paranoid psychosis taken together was essentially the same over the studied time period in Stockholm County, and that the apparent decline in first admission rates for schizophrenia may be an effect of changes in clinical diagnosis over time.

Adolescent↗

PubMed1992

Exploring time trends in cancer incidence.

We examined incidence time-trends for lung, stomach, intestinal, prostate, and breast cancer among Whites diagnosed in the United States between 1973 and 1987. For each sex and five-year age group, we modeled cancer incidence as a log-linear function of diagnosis-year to permit extrapolation over time and simple summarization of trends. Comparisons with nonparametric estimates show that, except for breast cancer, the model performs well. Plots of the annual percent change in incidence cf age illustrate the way in which time trends depend on age. Between 1973 and 1987, stomach cancer incidence decreased by about two percent per year. The annual change in lung cancer incidence progressed from a two to three percent decrease in persons under age 40 to an increase of two percent in men and eight percent in women by age 80. Intestinal cancer incidence decreased annually by as much as three percent in persons under age 50, remained constant in women aged 50 to 74, and otherwise increased about one percent per year. The annual increase in prostate cancer incidence declined from about six percent in men under age 40 to about two percent in men over age 80. After a surge in female breast-cancer diagnoses in 1974, the annual increase in incidence between 1980 and 1987 stabilized at four to six percent.

Adult↗

PubMed1999

Time trends in neural tube defects prevalence in relation to preventive strategies: an international study.

OBJECTIVE: To examine time trends in neural tube defects (NTD) prevalence from 1987 to 1996 in relation to the primary prevention policies for folic acid supplementation strategies in different countries. DESIGN: Retrospective time trends analysis of NTD prevalence. SETTING: 11 birth defect registries of congenital malformations participating in the International Clearinghouse for Birth Defects Monitoring System, in the period from 1 July 1987 to 30 June 1996. SUBJECTS: 8207 live births, stillbirths and terminated pregnancies affected by anencephaly or spina bifida registered by the 11 participating centres 1987-1996. OUTCOME MEASURES: Prevalence rate ratios based on the annual rates, using the Poisson regression model. RESULTS: During the study period a significant fall in prevalence rates for all NTD is present in Atlanta (USA), England and Wales, Hungary and Japan, and a significant rise in Norway and South America. After adjusting for the secular trends observed in the earlier years of the study, no significant trend can be attributed to preventive strategies. Data on NTD prevalence are supplemented with information on folate awareness among some of the populations studied. CONCLUSION: There is no evidence that, up to the middle of 1996, any change in time trend was attributable to the introduction of national folate supplementation policies. The possible effectiveness of folate supplementation policies for the reduction of NTD clearly needs to be tried and studied for several more years. Considering that in the Western world about 50% of pregnancies are unplanned, a policy that rests on action taken before conception can only have limited success. Strategies based on food enrichment, such as was introduced in the USA from the beginning of 1998, may prove to be more successful.

Female↗

PubMed1989

Time-trends in necropsy prevalence and birth prevalence of lung hypoplasia.

Congenital lung hypoplasia (LH) has been identified with increasing frequency in perinatal and neonatal necropsy reviews. The available prevalence figures have been derived using various diagnostic criteria in different populations and at various times. We therefore reviewed our experience in 15 years of consecutive early neonatal necropsies using one constant set of diagnostic criteria for LH and looked for a time-trend. We determined the necropsy prevalence (no. of cases of LH/no. of necropsies) and the birth prevalence (no. of cases of LH documented at necropsy per 1000 livebirths for inborn patients, and per 1000 referrals for outborn patients) between 1971 and 1985. We then divided this 15-year period into five consecutive 3-year periods to determine if a time-trend was discernible. Whereas early neonatal mortality for neonatal intensive care unit (NICU) admissions progressively decreased from 11.4% to 4.0% between the first and the last 3-year periods, the number of cases of LH per 3-year period did not vary appreciably. As a result, the prevalence of LH at necropsy showed a slight upward trend with time. The overall prevalence was 18%; it was 13% during the first and 23% during the last 3-year period. We found no time-trend in birth or referral prevalence for this lesion, which averaged 1.1 per 1000 livebirths and 9.8 per 1000 referrals. We conclude that lung hypoplasia appears to be emerging as an increasingly prevalent necropsy finding as a result of a shift in proportionate mortality, with the number of patients dying of other causes (denominator) decreasing, and the number of patients dying with lung hypoplasia remaining constant.

Cause of Death↗

PubMed2006

[Mortality of gastric cancer in Catalonia, Spain: geographical distribution and time trends from 1986 to 2000].

BACKGROUND AND OBJECTIVE: The aims of this study are to describe the time trends and the changes in the spatial distribution of stomach cancer mortality by gender, in Catalonia, Spain, in the period 1986-2000. MATERIAL AND METHOD: The mortality data comes from the Mortality Register for Catalonia at the Health Department and the population data from the Institute of Statistics for Catalonia. To analyze time trends, a Poisson regression model was adjusted for each gender. To analyze the geographical distribution, a Bayesian hierarchical model was used. RESULTS: During the period 1986-2000 the number of deaths from stomach cancer was 8,627 for males and 5,831 for females. During this period the estimated decrease in mortality was 3.13% for males and 3.91% for females. The spatial analysis showed the lowest mortality risk areas along the coast while the mortality risk increased toward the zones in the interior. This geographical pattern is very similar for both sexes but in the lasts years of the period it has been fading. CONCLUSIONS: The time trends and the geographical pattern of stomach cancer mortality in Catalonia is similar for both sexes and it is consistent with the trends observed in other developed countries. This suggests a relationship with improved food habits and a better accessibility to health care in the areas of higher risk.

Catchment Area, Health↗

PubMed2005

Comparative levels and time trends in blood pressure, total cholesterol, body mass index and smoking among Caucasian and South-Asian participants of a UK primary-care based cardiovascular risk factor screening programme.

BACKGROUND: Individuals of South-Asian origin have a comparatively higher cardiovascular disease burden, but there is uncertainty about whether this is due to differences in risk factor levels and trends. We therefore studied comparative levels and time trends in blood pressure (BP), total cholesterol, body mass index (BMI) and current smoking among UK Caucasian and South-Asian individuals. METHODS: Repeatable cross-sectional survey of men and women aged 35-60 attending for first screening as part of a primary-care based cardiovascular risk factor screening programme 1989 and 1999. RESULTS: Of 34,122 men and 37,294 women participants, 499 men (1.5%)and 381 women (1%) were of South-Asian origin. South-Asian men had lower systolic [(-4.91 mmHg (95% Confidence Iterval (CI): -3.58 to -6.23)] and diastolic BP [-2.87 mmHg (-2.02 to -3.72)], with no significant differences in cholesterol and BMI. South-Asian women had lower systolic BP [-1.77 mmHg, 95% (-0.21 to -3.33)], diastolic BP [-1.87 mmHg (-0.92 to -2.82)], cholesterol [-0.24 mmol/l (-0.08 to -0.39)]; and higher BMI [+0.78 kg/m2 (0.25 to 1.3)]. South-Asian men and women had significantly lower prevalence of self-reported current smoking (29.0% and 1.8% respectively). With the exception of self-reported current smoking, between ethnic group risk factor trends were not converging. CONCLUSION: With the exception of women's BMI, South-Asian individuals had either lower or similar levels of the examined cardiovascular risk factor levels, compared with Caucasian individuals. Although time trends in smoking were converging, other risk factors trends were similar between the two ethnic groups. Overall the findings do not support the hypothesis that the relatively high cardiovascular disease burden in UK South-Asians is due to higher levels exposure to the examined risk factors. Other hypotheses, such as higher frequency of diabetes and increased genetic predisposition, require further exploration.

Adult↗

PubMed2006

[Time trend of breast cancer incidence in Catalonia].

BACKGROUND AND OBJECTIVE: Time trend of breast cancer incidence in Catalonia in the last 20 years is evaluated by a age-period-cohort model. POPULATION AND METHOD: Women older than 25 years diagnosed with breast cancer between 1980 and 1999 in the population covered by Tarragona and Girona population-based cancer registries. To investigate the age, period and birth cohort effect in the time trends of breast cancer incidence, Decarli and La Vecchia and Holdford's methods were used. RESULTS: The world age-standardized rate (25 to > or = 85 years old) has increased from 53.9 cases per 100,000 women-year in the period 1980-1984 to 83.9 per 100,000 women-year in the period 1995-1999. The annual percentage change was 2.2% (95% confidence interval, 1.8-2.6). According to age-period-cohort model an increment of the incidence exists depending on age and birth cohort, being the period effect less important. CONCLUSIONS: Breast cancer incidence has significantly increased in Catalonia. The birth cohort seems to be more important than the period effect in this increment, which supposes a change on the prevalence of the risk factor, although the use of screening diagnosis techniques might explain a part of the period effect.

Adult↗

PubMed1999

Time trends in the concentrations of lead in wet precipitation from rural and urban sites in Austria.

Trend and time series analysis of concentrations of lead in wet precipitation at different rural and urban sampling sites in Austria, collected during intervals of 6-12 years (between 1984 and 1995) is performed. A substantial decrease of the lead concentrations for all sites in consideration is observed similar to observations in Germany, Sweden and North sea and western Atlantic regions. Reductions in rural sites between 60 and 80% in 10 years and around 90% in 10 years in urban areas are found. This trend correlates with the reduction of lead emissions from combustion of gasoline. The seasonal deconvolution model of the data set reveals a typical seasonality with lead concentration peaks in summer and spring for the rural sites and winter peaks for urban sites. The average annual lead concentration in the rural region for 1995 was 1.25 micrograms/l, in the urban region 2.25 micrograms/l.

Austria↗

PubMed1990

Hospital discharges for inflammatory bowel disease. Time trends from England and the United States.

The present study analyzes time trends of inflammatory bowel disease (IBD) in England-Wales and the United States based on nationwide hospitalization statistics. Because these statistics cover the total population of each country, they may give a more representative picture of the true trends than previous analyses concerning only one region or health center. The Hospital In-patient Enquiry was used to evaluate time trends in England-Wales from 1962 to 1985, data from the National Hospital Discharge Survey and the Commission on Professional Activities were used for trends in the United States from 1970 to 1987. A rise of Crohn's disease persisted unabated in the old age groups throughout the observation period. It was less marked in those aged under 35 and reached a plateau during the most recent decade. In ulcerative colitis, discharge rates increased in the older age groups, but remained constant or declined in the middle or younger age groups, respectively. Similar trends were observed in all three surveys. The hospitalization data confirm similar age-specific trends of mortality. The difference between younger and older age groups suggests that generations born 60-80 years ago have become more likely to be affected by IBD leading to hospitalization and mortality. As these high-risk generations grow older, there is a relative rise of hospitalization and mortality from IBD in these subjects.

Adult↗

PubMed2004

Time trends (1993-1997) and seasonal variation in body mass index and waist circumference in the Netherlands.

OBJECTIVE: To compare the time trend and seasonal variation in body mass index (BMI) and waist circumference. DESIGN: Continuous monitoring health survey carried out between 1 June 1993 and 31 May 1997. SUBJECTS: A total of 8,186 men and 9,638 women aged 20-59 y from three towns in the Netherlands. MEASUREMENTS: BMI and waist circumference. Obesity was defined as BMI > or =30 kg/m(2), abdominal obesity as waist circumference > or =102 cm for men and > or =88 cm for women. RESULTS: Levels of BMI and waist circumference increased between 1 June 1993 and 31 May 1997. Among women, the time trend in abdominal obesity was stronger than that in obesity. Further, levels of BMI and waist circumference were higher in winter than in summer seasons. The seasonal variation was larger for abdominal obesity than for obesity, among both men and women. CONCLUSIONS: The time trend in women and the seasonal differences in both men and women were stronger for abdominal obesity than for obesity. Surveys on BMI and waist circumference are only comparable if season is taken into account. Furthermore, the waist circumference is a more sensitive indicator of variations in lifestyle and body composition than is body mass index.

Abdomen↗

PubMed1990

Magnitude and time trends of the life-time risk of developing cancer in Saarland, Germany.

The probability of developing cancer within defined age-intervals or during life-time was assessed for the population of Saarland, Germany in 1970-1972 and 1980-1985 based on life-tables and age-specific cancer incidence rates. As a result of increasing life expectancy and, for some forms of cancer, increasing age-specific incidence rates, the probability at birth of eventually developing a malignant neoplasm (ICD-9 140-208) increased from 24.12% in 1970-1972 to 32.35% in 1980-1985 in men, and from 24.76 to 29.72%, respectively, in women. Comparable calculations are presented and discussed for all of the most common malignancies in women and men. The relation to common measures of descriptive epidemiology, mainly the cumulative rate and the cumulative risk, is numerically illustrated.

Adolescent↗

PubMed2006

Time trends of mercury in feathers of West Greenland birds of prey during 1851-2003.

Temporal trends of mercury (Hg) in West Greenland gyrfalcons, peregrine falcons, and white-tailed eagles were determined over 150 years from 1851 to 2003. Hg was measured in the fifth primary feather. Results showed that Hg increased in the order gyrfalcon (lowest) < peregrine falcon (intermediate) < white-tailed eagle (highest). All species showed significant age accumulations, which were taken into account in the temporal trend analysis. Of eight time trend analyses (three species and three age groups of which one was missing), seven showed an increase in primary feather concentrations. Of these, four were significant at the 5% level, two were close to being significant, and one was not significant. The linear regressions of which three out of four showed significant increases were for juvenile and immature gyrfalcon and juvenile peregrine falcon, which covered only periods prior to 1960, owing to limited data from the last half-century. The two sample comparisons of Hg 10-year medians for adult peregrine falcons and juvenile and adult white-tailed eagles indicated a continued increase during recent decades. However, low levels of Hg in a few recent collections among gyrfalcons and peregrines could indicate a change in the increasing trend.

Animals↗

PubMed1986

Time trends in the US racial difference in hypertension.

This paper explores time trends in racial differences in hypertension and in mortality from complications from hypertension in the United States. Mortality data were derived from death certificate data compiled by the National Center for Health Statistics and presented in the 1981 Report of the Working Group on Arteriosclerosis. Prevalence data were obtained from five populations--6,672 people screened in 1960-1962 by the National Health Examination Survey (NHES); 20,749 screened in 1971-1975 by the Health and Nutrition Examination Survey (HANES I); 158,539 screened in 1973-1974 by the Hypertension Detection and Followup Program (HDFP); 1 million persons screened in 1973-1975 by the Community Hypertension Evaluation Clinics (CHEC); and 20,325 screened in 1976-1980 by the second Health and Nutrition Examination Survey (HANES II). Mortality data indicate that the nonwhite/white ratios for mortality from complications of hypertension increased between 1940 and 1967 and decreased between 1968 and 1978. Prevalence data show a corresponding recent decrease in black minus white mean blood pressure. Some of the decrease appears to be due to a greater improvement in hypertension control for blacks than for whites. Time trends in the black/white ratio in prevalence of hypertension were examined with differential treatment effects controlled by inclusion as hypertensive those on drug therapy. The results indicate that in addition to differential changes in therapy, the ratio of black/white prevalence of hypertension may also be decreasing. Additional studies are needed to confirm this finding and to explore time changes in racial patterns of risk factors for hypertension.

Black People↗

PubMed2005

No evidence of time trends in the urban-rural differences in schizophrenia risk among five million people born in Denmark from 1910 to 1986.

BACKGROUND: There have been conflicting reports on time trends in urban-rural differences in the incidence of schizophrenia. This study explored the potential time trends in these differences with regard to birth cohort and age at onset. METHOD: Linking data from the Danish Civil Registration system with data from the Danish Psychiatric Central Register, a cohort born in Denmark from 1910 to 1986 was established (5.05 million people). Overall, 23051 people were classified with schizophrenia in 1970-2001. RESULTS: Urban-rural differences in schizophrenia risk may have existed for people born in Denmark since 1910, and have existed at a constant level for people born from 1945 to 1986. Males aged <20 years had a risk of 3.90 [95% confidence interval (CI) 3.28-4.65] associated with urban birth while males >or=20 years had a risk of 2.12 (1.98-2.27). Females <20 years had a risk of 2.49 (95% CI 2.01-3.09) associated with urban birth while females >or=20 years had a risk of 1.90 (95% CI 1.74-2.08). At age 46, 1.84% (95% CI 1.76-1.93) of males and 1.05% (95% CI 0.99-1.12) of females born in the capital area had developed schizophrenia, while 0.81% (95% CI 0.75-0.86) of males and 0.56% (95% CI 0.51-0.60) of females born in the rural area had developed schizophrenia. CONCLUSIONS: There was no evidence of time trends in the urban-rural differences in the incidence of schizophrenia in Denmark, suggesting that the cause(s) responsible for these differences were not related to exposures that became more prevalent in urban areas over time. This finding is in contrast to findings from Finland and The Netherlands.

Adolescent↗

PubMed2003

Time trends in cancer mortality in China: 1987-1999.

A first analysis of time trends in cancer mortality in China at the national level is presented. Using a joinpoint regression model, based on data from a national mortality routine reporting system in China (CHIS), time trends in mortality for 9 major cancers are analyzed. Between 1987 and 1999, the age-standardized mortality rates for all cancers combined declined slightly in rural areas but have increased since 1996 in urban areas. The mortality rates for cancers in oesophagus, stomach, cervix uteri, leukaemia (except for urban males after 1996) and nasopharynx declined, while lung cancer and female breast cancer showed significant increasing trends in both urban and rural areas and for both sexes. Cancers of the colon-rectum and liver had different trends in mortality in urban and rural populations. The trends in age-specific mortality rates suggest some different trends in the younger population, which may presage future overall trends, for example, increasing mortality from cancer of the cervix. The observed trends primarily reflect the dramatic changes in socioeconomic circumstances and lifestyles in China in the last 2 decades. Tobacco smoking remains a major problem, with increases in mortality from lung cancer. The improvements in socioeconomic status, diet and nutrition may be responsible for the declining risk of some cancers (oesophagus, stomach and nasopharynx), while increasing the risk for others (breast and colon-rectum). Screening programs (especially for cervix cancer), and more available and better facilities for cancer therapy, may have helped to reduce mortality for several cancers. The large increases in the absolute number of deaths that resulted from the increasing and aging population are much more important in determining the future cancer burden than any changes due to change in risk, emphasizing the increasing importance of cancer as a health problem in the 21st century in China.

Adolescent↗

PubMed1994

Malignant melanoma incidence in Connecticut (United States): time trends and age-period-cohort modeling by anatomic site.

This study examined time trends and age-period-cohort patterns in the incidence of cutaneous malignant melanoma (CMM) by gender and anatomic site in Connecticut (United States) between 1950 and 1989, using data from the population-based Connecticut Tumor Registry. A total of 8,249 invasive CMM incident cases were included. Cases were grouped into melanomas of the head and neck, upper limb, lower limb, and trunk. Between 1950 and 1989, rates increased substantially for all sites. The largest relative increases occurred in melanoma of the upper limb for both males and females; the largest absolute increase occurred for melanoma of the trunk in males; and the smallest increase occurred in head and neck melanoma in females. Recent trends for time periods 1970-89 among birth cohorts 1930-69 indicated that the rate of increase of CMM is slowing substantially among males, but not among females. Nevertheless, continued overall increases in CMM incidence are likely in Connecticut in the 1990s in both genders, with a decrease in the male-female ratio. The age-period-cohort patterns were significantly different between the genders and among anatomic sites, suggesting different trends in carcinogenic exposures (mainly ultraviolet radiation from the sun) or etiologic distinctions between males and females and among the sites.

Adult↗

PubMed2004

[Methods for time trend analysis of cancer incidence rates].

OBJECTIVE: To introduce statistical methods of time trend analysis on cancer rates. METHODS: Cancer incidence data collected by the Shanghai Cancer Registry during 1991 to 1999 was used in the analysis to calculate the crude and age-adjusted rates, percent changes (PCs) and annual percent changes (APCs). APCs were estimated by a linear regression of the logarithm on the incidence rates during the nine years. It also introduced a method for partitioning a linear trend in age-adjusted rates into site-specific contributions to the overall floating trend. 95% confidence intervals for the APCs and contributions were described in the paper. RESULTS: A decreasing rates were observed for cancers of stomach and esophagus among both men and women in urban Shanghai from 1991 to 1999. The increasing rates among men would include cancers of colon, rectum, gall bladder, pancreas, prostate, urinary bladder, kidney and leukemia. The rates of cancers among women increased for colon, rectum, lung, breast, gall bladder, endometrium, ovary, urinary bladder and kidney. The changes of above cancers over time were statistically significant (P < 0.05 or P < 0.01), but rates for other cancer sites changed little. The APCs (weighted method) and contributions for the cancers of stomach, esophagus, colon, rectum and prostate were -2.99% and -65.72%, -2.90% and -17.07%, 12.30% and 21.46%, 2.94% and 18.62%, and 3.11% and 15.09% among men, and -6.05% and -39.55%, -1.08% and -35.19%, 2.81% and 28.64%, and 3.69% and 15.70% for the cancers of stomach, esophagus, breast and colon in women, respectively. CONCLUSION: APC, and related statistics could be used to describe and analyze the time trend of cancer rates rather than PC or/and graphical method alone.

Algorithms↗

PubMed2003

Time-trend (1973-2000) of polybrominated diphenyl ethers in Japanese mother's milk.

The time-trend and recent concentrations of polybrominated diphenyl ethers (PBDEs) in Japanese mother's milk were investigated. The time-trend of 16 PBDEs (BDE-28, 37, 47, 66, 71, 75, 77, 85, 99, 100, 119, 153, 154, 138, 183, and 190) in pooled milk samples from mothers living in Osaka between 1973 and 2000 was analyzed. Additionally, PBDE concentrations in individual milk samples collected from 13 mothers living in Kanagawa and Okayama in 1999 were measured. The total concentration of all PBDE congeners (SigmaPBDEs) measured in the pooled samples increased during the period between 1973 (<0.01 ng/g lipid) and 1988 (1.64 ng/g lipid), and remained low afterwards while showing remarkable changes in PBDE congener profiles. The SigmaPBDEs in the 1999 individual milk samples were also low (0.56-3.97 ng/g lipid), except for a single sample (291 ng/g lipid). The source of this exposure could not be identified.

Adult↗