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PubMed2002

The air-sea equilibrium and time trend of hexachlorocyclohexanes in the Atlantic Ocean between the Arctic and Antarctica.

Hexachlorocyclohexanes (HCHs) were determined simultaneously in air and seawater during two cruises across the Atlantic Ocean between the Arctic Ocean (Ny-Alesund/ Svalbard, 79 degrees N; 12 degrees E) and the Antarctic Continent (Neumayer Station/ Ekstroem Ice Shelf, 70 degrees S; 8.2 degrees W) in 1999/ 2000. The concentrations of alpha-HCH and gamma-HCH in air and surface waters of the Arctic exceeded those in Antarctica by 1-2 orders of magnitude. The gaseous concentrations of gamma-HCH were highest above the North Sea and between 20 degrees N and 30 degrees S. Fugacity fractions were used to estimate the direction of the air-sea gas exchange. These showed for alpha-HCH thatthe measured concentrations in both phases were close to equilibrium in the North Atlantic (78 degrees N-40 degrees N), slightly undersaturated between 30 degrees N and 10 degrees S and again close to equilibrium between 20 degrees S and 50 degrees S. Y-HCH has reached phase equilibrium in the North Atlantic as alpha-HCH, but the surface waters of the tropical and southern Atlantic were strongly undersaturated with y-HCH, especially between 30 degrees N and 20 degrees S. These findings are significantly different from two earlier estimates around 1990 as a result of global emission changes within the past decade. Therefore, we investigated the time trend of the HCHs in the surface waters of the Atlantic between 50 degrees N and 60 degrees S on the basis of archived samples taken in 1987-1997 and those from 1999. A decrease of alpha-HCH by a factor of approximately 4 is observed at all sampling locations. No decrease of gamma-HCH occurred between 30 degrees N and 30 degrees S, but there was a decrease in the North Atlantic, North Sea, and in the South Atlantic south of 40 degrees S. The constant level of gamma-HCH in the tropical Atlantic confirms the conclusion that the tropical Atlantic acts as a sink for y-HCH at present time. The measured alpha-HCH seawater concentrations were compared with results from a global multimedia fate and transport model. Whereas the time trend over 13 years and the latitudinal gradient were well reproduced by the model, the absolute levels were too high by a factor of 4.5. This may be explained by the zonal averaging employed in the model as well as uncertain emissions and degradation rates.

Air Pollutants↗

PubMedDate not supplied

[Geographical distribution and time trends in avoidable mortality in Catalonia, Spain (1986-2001)].

OBJECTIVES: To analyze time trends and geographical variation in avoidable mortality by health areas in Catalonia. MATERIAL AND METHODS: Avoidable mortality was analyzed according to the classification used by the Health Department of the Regional Government of Catalonia from 1986-2001 for health areas and causes were grouped as treatable and preventable. Standardized mortality rates were calculated by the direct and indirect method and the comparative mortality figures were calculated for the treatable and preventable groups and for the 46 health areas. The mean annual change adjusted for age was also calculated using a Poisson regression of avoidable and general mortality. RESULTS: The total number of avoidable deaths was 61,261 (7.3% of overall deaths). 10,623 cases (17.34%) were classified as treatable and 50,638 (82.65%) as preventable. The mean annual change for avoidable causes was -2.43% (95% CI, -2.60 to -2.26), higher than the -1.57% (95% CI, -1.61 to -1.52) change for general mortality. The rates were higher for preventable causes than for treatable causes, although mortality decreased in both groups. The health area of Segrià was notable for its significantly higher mortality from both treatable and preventable causes in both periods. Four health areas showed a significant increase in mortality from preventable causes but none showed an increase in mortality from treatable causes. CONCLUSIONS: In Catalonia, the decrease in avoidable mortality was greater than that in general mortality from 1986 to 2001. The geographical distribution shows wide dispersion but allows areas requiring preventive interventions to be identified.

Adolescent↗

PubMed1990

Declining serum cholesterol levels prior to diagnosis of colon cancer. A time-trend, case-control study.

We report the results of a 10-year, time-trend, case-control study in which serum cholesterol level was determined at several points in time preceding the diagnosis of colon cancer in a population of individuals who sought general checkups at an ambulatory care screening facility. Each of the 69 patients with colon cancer (32 men and 37 women) was matched with a control patient who was randomly selected. At the time of diagnosis, the patients with colon cancer had significantly lower serum cholesterol values than control patients (5.56 +/- 0.31 mmol/L [SEM] vs 6.47 +/- 0.34 mmol/L). This difference did not vary with sex or Dukes' stage of the cancer. The percent of matched pairs in which the cancer patient had a lower serum cholesterol level increased from 42% at 10 years prior to cancer diagnosis to 77% at diagnosis. The ratio of serum cholesterol at each period to the level at time of diagnosis demonstrated an average decline of 13% during the 10 years prior to diagnosis for case patients vs an average rise of 2% in the same period for control patients. We conclude that individuals in whom colorectal cancer develops share the same level of serum cholesterol as the general population initially, but during the 10 years preceding the cancer demonstrate a decline in serum cholesterol level that is opposite to the rising level seen with age in the general population.

Aged↗

PubMed1998

Time trends in mental health care utilization in a Dutch area, 1976-1990.

This paper concerns time trends in mental health care utilization in a Dutch area from 1976 to 1990. In general, there was an increase in the use of psychiatric services during the study period, both in terms of the number of new patients (per 1000 population) and in terms of the amount of care utilized per patient. When only intramural services were taken into account the number of new psychiatric patients remained approximately constant, but the number of patients in care at a certain point in time (point prevalence) showed a rising trend. For most part, the increase in inpatient point prevalence rates could be ascribed to the increase in the elderly population (75 years or more). In addition to the proportional increase of the ageing population, a growing amount of psychosocial problems and broadening of the concept of illness were tentatively assumed to be related to the increase in mental health care utilization. Unlike some other countries, deinstitutionalization hardly occurred in the Netherlands.

Adolescent↗

PubMed2001

Time trends in the incidence of parkinsonism in Olmsted County, Minnesota.

OBJECTIVE: To investigate time trends in the incidence of parkinsonism and PD over a 15-year period (1976 to 1990). METHODS: The authors used the medical records-linkage system of the Rochester Epidemiology Project to identify incidence cases of parkinsonism in Olmsted County, MN, over three 5-year periods, 1976 to 1980, 1981 to 1985, and 1986 to 1990. PD and other types of parkinsonism were classified using defined criteria. Population denominators were derived from census data and were corrected by removing prevalent cases of parkinsonism. RESULTS: Over the 15 years of the study, 364 cases of parkinsonism were identified; 154 (42%) of them had PD. The incidence of parkinsonism remained stable over the three 5-year periods for the age classes 0 to 39, 40 to 59, and 60 to 69 years. For the age class 70 to 99 years, there was some increase over time mainly owing to an increased incidence of drug-induced parkinsonism. The incidence of PD remained stable over the three 5-year periods for all age classes. Results were similar when considering men and women separately. No birth-cohort effect was present for parkinsonism. Comparison with three previous studies in the same population did not reveal any major long-term secular trends in the incidence of parkinsonism. CONCLUSIONS: The findings for PD over 15 years and comparison of the findings with historical data for parkinsonism over half a century suggest that no major environmental risk factors for PD (e.g., environmental toxins, drugs, diet constituents, or infectious agents) were introduced or removed from this population during these periods.

Adolescent↗

PubMedDate not supplied

[Time trends in fatal traumatic occupational injuries in Spain [1992-2002]].

OBJECTIVE: To describe time trends in fatal traumatic occupational injuries by economic activity, type of contract, age, and gender between 1992 and 2002 in Spain. METHODS: The number of fatal traumatic occupational injuries occurring during the study period in salaried workers was 8,510. The annual percentage of change in fatal occupational injury rates was calculated by economic activity, type of employment, age group, and gender assuming a Poisson distribution. The incidence in 2002 was standardized by economic activity to adjust for the potential effect of changes in the labor market from 1992. Economic activities were regrouped according to their percentages of change in employees during the study period. RESULTS: The incidence of fatal traumatic injuries decreased by an annual percentage of -4.3% (95% CI, -5.3 to -3.4%) from a rate of 9.8 per 100,000 in 1992 to 6.1 in 2002, representing an overall reduction of 38% (relative risk = 0.62), particularly in expanding employment industries (-4.4%), women (-7.6%) and permanent employment (-4.3%). In 2002 the incidence was 8.5 after adjusting by economic activity in 1992 (adjusted relative risk = 0.87). CONCLUSIONS: The decreasing trend observed in fatal occupational injuries is similar to that observed in other developed countries. At least two thirds of this decrease can be explained by changes in productive structures. The results indicate the areas in which preventive activities should be concentrated.

Accidents, Occupational↗

PubMed2001

Time trends in exposure measurements from OSHA compliance inspections of the pulp and paper industry.

Time trends in employee exposures to the air contaminants measured by the Occupational Safety and Health Administration (OSHA) during compliance inspections of pulp and paper manufacturing facilities conducted between 1979 and 1997 were evaluated based on the measurement results stored in the OSHA Integrated Management Information System (IMIS) database. The IMIS database is among the largest sources of occupational exposure measurements available for occupational health research in the United States. The IMIS database contains the results of 3,568 personal time-weighted average (TWA) measurements for 171 air contaminants made at 524 establishments in Standard Industrial Classification (SIC) 26. An analysis of these measurements revealed an overall decrease in the total number of measurements made per year since 1991, and a decrease in the percentage of measurements by year that exceeded the OSHA permissible exposure limits (PELs). Linear regression analyses detected decreasing trends in the geometric mean concentrations by year for 33 of the 36 agents analyzed.

Air Pollutants, Occupational↗

PubMed2005

Time trends in eating disturbances in young Greek migrants.

OBJECTIVE: The study intends to measure time trends in eating disorder psychopathology in Greek adolescents in Veria (Greece) and migrant Greek adolescents in Munich (Germany). For this purpose, large samples of students were assessed at both locations in the 1980s and about two decades later. Our research question was whether the frequency of eating disorder-related psychopathology had changed over time and that there were differences between migrants and nonmigrants. The present-day prevalence of eating disorders in the Greek population was established. METHOD: Greek adolescents were assessed in Munich and Veria in the 1980s (N = 2,631) and almost two decades later (N = 2,920). At both times, the Anorexia Nervosa Inventory for Self-Rating (ANIS) was used to assess eating disorder pathology and the General Health Questionnaire (GHQ-28) was used to assess mental health status. In the second wave, persons at risk for an eating disorder were interviewed using the Structured Interview for Anorexic and Bulimic Syndromes (SIAB-EX). RESULTS: At both times and both locations, adolescent girls in comparison to boys had higher, more pathologic scores on the GHQ-28 and on all ANIS self-rating subscales. Females in Munich reported an increase over time in figure consciousness and their fear of negative effects of meals. In the 1980s, significantly higher scores of bulimic behavior were found in Veria as compared with Munich. In the second wave, bulimic behavior was considerably decreased in Veria for both girls and boys, and for bulimic behavior no significant differences were found between locations. The percentage of girls with a low body weight (<5th percentile) increased significantly over time in Veria and Munich. In the second wave, the current prevalence for girls with anorexia nervosa was 0.00% in Munich and 0.59% in Veria (lifetime 1.26% and 1.18%, respectively). For bulimia nervosa, current prevalence was 1.89% in Munich and 1.18% in Veria. CONCLUSION: Differences between locations diminished over time. Bulimic syndromes are prevalent in both locations.

Acculturation↗

PubMed2002

Advanced detection of time trends in long-term cancer patient survival: experience from 50 years of cancer registration in Finland.

Timely monitoring of trends in long-term patient survival is an important task of cancer registries. Recently, a new method, denoted period analysis, has been proposed to enhance up-to-date monitoring of survival. The authors assessed the use of period analysis for advanced detection of time trends in long-term cancer patient survival based on data from the nationwide Finnish Cancer Registry by comparing estimates of 10-, 15-, and 20-year relative survival rates obtained by period analysis and by traditional (cohort) analysis of survival at various points of time between 1953 and 1997. Time trends are graphically displayed for the 15 most common forms of cancer. Long-term survival rates strongly improved over time for most forms of cancer. The slope and shape of trend curves obtained by period analysis are very similar to those obtained by traditional survival analysis. However, detection of progress in 10-, 15-, and 20-year survival rates of newly diagnosed patients could have been advanced by 5-10 years, 10-15 years, and 15-20 years, respectively, with the use of period analysis rather than traditional cohort survival analysis. The authors conclude that period analysis should be routinely used to advance detection of progress in long-term cancer patient survival.

Adolescent↗

PubMed1997

Time trend and age-period-cohort effects on gastric cancer incidence in Zaragoza and Navarre, Spain.

STUDY OBJECTIVE: To describe time trends in gastric cancer incidence in Zaragoza and Navarre, and to investigate time period and birth cohort as determinants of such trends. DESIGN: Cases from two registries were grouped into five year intervals and the following were calculated: age specific and sex specific incidence rates, and the male to female ratio. Log linear models including age, period of diagnosis, and birth cohort were fitted. SETTING: The Zaragoza Cancer Registry covers the province of Zaragoza, which has a population of 824,776 (403,755 men and 421,021 women). The Navarre Cancer Registry covers the province of Navarre which has 512,512 inhabitants (254,786 men and 257,726 women). In both cases population figures were based on the late census. PATIENTS: These comprised incident cases of gastric cancer reported to the Zaragoza Cancer Registry in 1963-87 and to the Navarre Cancer Registry in 1973-87. MAIN RESULTS: Navarre registered higher adjusted and cumulative rates than Zaragoza for both sexes. In both provinces, there were relative declines in the rates for men and women of 3% and 4% respectively per year. In Zaragoza, the risk of developing stomach cancer fell in generations born between 1888 and 1933, and rose in subsequent birth cohorts in both sexes, while in Navarre the cohort effect showed an approximately linear risk for both sexes. Both provinces recorded increases in risk associated with cohorts born between 1933 and 1943. CONCLUSION: The incidence rates of gastric cancer fell in both Zaragoza and Navarre. The reason for the greater incidence of gastric cancer in Navarre remains unknown. Trends in rates seem to be mainly linked to birth cohort. Increases in risk in generations born after 1933 may be ascribable to nutritional deficiencies in the early years of life.

Adolescent↗

PubMedDate not supplied

[Time trends in infectious disease mortality in Italy: 1969-1999].

OBJECTIVE: To describe the global impact of infectious diseases on mortality in Italy from 1969 to 1999. DESIGN: Statistical analysis of routinely collected mortality data, using a revised definition of infectious causes of death based on target organs. SETTING: The present paper summarizes time trends of infectious disease mortality widely discussed in the Atlas "30 Anni di Malattie Infettive in Italia: Atlante di Mortalità". MAIN OUTCOME MEASURES: Age standardized mortality rates (/100,000); standardized mortality ratios (SMR); percentage of deaths attributable to infectious diseases. RESULTS: Apart from HIV infection and AIDS, infectious diseases were responsible of 1.7% of the overall mortality that occurred in Italy in the study period: 57.5% of such deaths were not included in the ICD8 and ICD9 codes for infectious diseases. The mortality for all infectious diseases showed a very strong downward trend up to 1994, (with a 6-fold decline). Thereafter, a slight increase in deaths for septicaemias, heart infections and hepatitis was recorded. Over time, an increasing proportions of deaths due to infections occurred in the elderly (i. e., > or = 65 years of age), from 48.1% in 1969-1979 to 77.3% in 1990-1999. Mortality rates were consistently higher in men than in women, and showed a substantial geographic heterogeneity. In newborns, from 1969 thru 1999 mortality rates declined 10-fold all over the country, but an inverse north-south geographic gradient persisted during the whole study period. The spread of HIV infection and AIDS epidemic in the first '80s dramatically interrupted the downward trend in infectious disease mortality outlined above. Between 1993 and 1996, HIV/AIDS was the main cause of death among Italian men aged 30 to 39 years. CONCLUSIONS: This statistical analysis allowed to better quantify the impact of infectious diseases on overall mortality in Italy. Observed time trends were in accordance to the picture recorded in other western Countries, whereas the higher newborn mortality in southern Italy reflects the persistence of geographical inequalities in the health care organization.

Adult↗

PubMedDate not supplied

Time trends in the analysis of incidence rate of leprosy among household contacts.

Analysis of time trends in the Incidence Rates among 9.598 household contacts of 1,614 primary cases of leprosy, showed that the incidence rates (IR) remained high even 10 years after treatment was started in the Primary Case. The IR during the 1st year of follow-up was 3.8 per 1000 person years of risk (PYR) and the IR was 3 per 1000 PYR after 10 or more years of follow-up. The significance of these findings in relationship to the Epidemiology of leprosy among household contacts in an endemic area for leprosy is discussed.

Adolescent↗

PubMed2003

Time trends and familial risks in squamous cell carcinoma of the skin.

OBJECTIVES: To study time trends and familial clustering of invasive and in situ squamous cell skin cancers (SCC), with particular reference to sun-exposed and covered sites of the body. DESIGN: Epidemiologic follow-up study of the whole population. SETTING: The Swedish Family-Cancer Database from the year 2000, to cover individuals born after 1931 with their biological parents, totaling 10.2 million persons. PATIENTS: Cancer data were obtained from the Swedish Cancer Registry from 1961 through 1998 and included 1907 invasive SCCs in offspring and 12,702 and 7167 in fathers and mothers, respectively. The numbers of patients affected by in situ SCC were 2666, 13,739, and 13,321, respectively. MAIN OUTCOME MEASURES: Standardized incidence ratios and 95% confidence intervals were calculated for SCC in offspring when parents had SCC. Incidence rates were calculated for the population in the Database. RESULTS: Incidence trends showed a large increase in reported cases of SCC and particularly of in situ SCC. Among invasive cases, the increase was largest among covered sites. A clear cohort effect was observed particularly for SCC on covered sites. Familial standardized incidence ratios for offspring combining invasive and in situ SCC were 2.25 (95% confidence interval, 1.93-2.59) for concordant exposed sites and 2.60 (95% confidence interval, 1.38-4.20) for concordant covered sites, suggesting no difference between the body parts within the present statistical power. CONCLUSIONS: The higher increase in incidence on covered sites and the strong cohort effect suggest a contribution by intentional tanning. The observed equal increase in the familial effect on exposed and covered sites suggests that familial risk increases proportionately to the background rate.

Adolescent↗

PubMed2005

Time trends and geographic disparities in acute complications of diabetes in Ontario, Canada.

OBJECTIVE: This study examines whether acute diabetes complication rates have fallen in recent years and whether geographic factors influence these trends. RESEARCH DESIGN AND METHODS: A population-based time-trend analysis of acute complications of diabetes was conducted using linked administrative and census data from Ontario, Canada. The study population included all adults identified through a province-wide electronic diabetes registry between 1994 and 1999 (n = 577,659). The primary outcome was hospitalizations for hyper- and hypoglycemia and emergency department visits for diabetes. RESULTS: Between 1994 and 1999, rates of hospitalization for hyper- and hypoglycemic emergencies decreased by 32.5 and 76.9%, respectively; emergency department visits for diabetes fell by 23.9%. On multivariate analysis, fiscal year was an independent predictor of acute diabetes complications, with individuals in our cohort experiencing a decline in risk of approximately 6% per year for either being hospitalized with hyper- or hypoglycemia or requiring an emergency department visit for diabetes. After accounting for variation in physician service use, diabetic individuals living in rural areas or Aboriginal communities were nearly twice as likely to have an acute complication, whereas those residing in remote areas of the province were nearly three times as likely to experience an event. CONCLUSIONS: Although our findings suggest an overall improvement in diabetes care in Ontario, certain subgroups of the population continue to experience higher rates of complications that are potentially preventable through good ambulatory care. Measures to improve access to timely and effective outpatient care may further reduce rates of acute complications among the diabetic population.

Acute Disease↗

PubMed1996

Time trends in lung-cancer mortality rates among men in Lithuania, 1965-1994.

This study examines time trends in lung-cancer mortality rates among men in Lithuania during the period 1965-1994. Age-standardized mortality rates increased from 32.5 per 100,000 in 1964-1969 to 62.9 per 100,000 in 1990-1994. Regression analysis indicates that net drift (sum of cohort and period slopes) was positive. Cohort effect was dominant in the trend observed. Mortality in cohorts born before 1945 showed an increase. In younger generations, born after 1945, the risk declined in each subsequent cohort. Higher prevalence of cigarettes with filters and lower tar content of cigarettes may be of importance. This analysis suggests that mortality will rise until cohorts born around 1950 reach middle age or old age. After that some stabilization can be expected if other conditions remain unchanged and previous trends continue.

Adult↗

PubMed2003

Time trends in the consumption of dairy foods in German children and adolescents.

OBJECTIVE: Examination of time trends in the consumption of dairy food and their impact on fat and calcium intakes in German children and adolescents. DESIGN: Dietary records from the DONALD Study (DOrtmund Nutritional and Anthropometric Longitudinally Designed Study). METHODS: A total of 5068 3-day weighed dietary records from 914 1 to 13-y-old children and adolescents collected between 1986 and 2001 were analysed using a mixed linear model, in which the means of the data and the covariance structure specific to the DONALD Study were modelled. RESULTS: During the study period, the consumption of 'milk products' in children and adolescents >/=4 y remained stable, since the reduced consumption of 'fluid milk' (between -2.8 and -7.4 g/day/study year) was compensated for by an increased consumption of 'yoghurt' (between +2.4 and +3.3 g/day/study year). The consumption of 'cheese' increased in subjects >/=4 y (between +0.2 and +0.7 g/day/study year). In 1 to 3-y-old children, the decreased intake of 'fluid milk' (-6.5 g/day/study year) was not compensated for by the increased intake of 'formula' (+3.5 g/day/study year). The percentage of 'low-fat milk products' significantly increased (although not significant in 9-13-y-old boys) to nearly 25% of milk products. The impact of dairy food on fat intake (as percentage of energy intake) remained stable with the exception of a slight reduction in 4-8 y olds, the impact of dairy on calcium (as percentage of US adequate intake) decreased only in 1-3 y olds. CONCLUSIONS: The consumption of dairy food remained widely stable over time in >/=4-y-old children and adolescents, but decreased in 1-3 y olds. A further decline in this age group would be undesirable as is the shift from common milk to formula. The intake of 'low-fat milk products' increased and should be continuously promoted.

Adolescent↗

PubMed1999

Time trends in incidence of cervical cancer in Lithuania from 1983 to 1997.

This report examines time trends in both age-specific and age-standardized cervical cancer (ICD9-180) incidence rates among Lithuanian women. The study covers the period from 1983 to 1997. In case of the age-specific rates Poisson regression revealed the controversial results for the different age groups. The incidence rates increased (beta > 0) for the women below 50 years and decreased (beta < 0) for the women above 50 years. The average annual percentage changes were estimated using the age-drift model. In the age groups from 30 to 49 years old the incidence rate increased by 3.3% per year with the 95% confidence interval (CI) being 2.2-4.4. In the age groups from 50 to 69 years old the incidence rate decreased by 2.9% (95% CI: 1.9-3.8). In case of the age-standardized rates during the last few years some increase was observed, although no strict conclusions could be drawn. This observation together with the results of the age-specific rate studies predicts that in the near future the age-standardized rate will start growing.

Adult↗

PubMed2001

A longitudinal study of time trends in the eruption of permanent teeth in Danish children.

The purpose was: (1) to estimate mean eruption times of permanent teeth in Danish schoolchildren for the birth cohorts from 1969 to 1982; and (2) to determine any time trends in eruption. For teeth with a low proportion of aplasia, the distribution of the eruption time was close to normal. For teeth with a higher proportion of aplasia there was a slight deviation from the normal distribution in the right-hand part of the distribution. For erupted teeth, the time to eruption was, however, again very close to the normal distribution. A small, but statistically significant, increase in mean eruption times was found for both sexes and almost all teeth. Averaged over all teeth the increase was 1.5 days per year (95% CI: 0.9--2.2) for boys and 2.6 days per year (95% CI: 2.2--2.9) for girls.

Adolescent↗