Calendar Decade Research Articles

Twenty-seven-year time trends in dementia incidence in Europe and the United States: The Alzheimer Cohorts Consortium.

ObjectiveTo determine changes in the incidence of dementia between 1988 and 2015.MethodsThis analysis was performed in aggregated data from individuals >65 years of age in 7 population-based cohort studies in the United States and Europe from the Alzheimer Cohort Consortium. First, we calculated age- and sex-specific incidence rates for all-cause dementia, and then defined nonoverlapping 5-year epochs within each study to determine trends in incidence. Estimates of change per 10-year interval were pooled and results are presented combined and stratified by sex.ResultsOf 49,202 individuals, 4,253 (8.6%) developed dementia. The incidence rate of dementia increased with age, similarly for women and men, ranging from about 4 per 1,000 person-years in individuals aged 65–69 years to 65 per 1,000 person-years for those aged 85–89 years. The incidence rate of dementia declined by 13% per calendar decade (95% confidence interval [CI], 7%–19%), consistently across studies, and somewhat more pronouncedly in men than in women (24% [95% CI 14%–32%] vs 8% [0%–15%]).ConclusionThe incidence rate of dementia in Europe and North America has declined by 13% per decade over the past 25 years, consistently across studies. Incidence is similar for men and women, although declines were somewhat more profound in men. These observations call for sustained efforts to finding the causes for this decline, as well as determining their validity in geographically and ethnically diverse populations.

Does the Energy-Food Nexus still exist: Empirical Evidence from the Indian Agriculture Sector post food crisis of 2006

The present study made an attempt to empirically investigate the impact of crude oil prices on agricultural prices for India during the calendar decade 2010-19. The bio-fuels which were considered in the present study included soy-oil, rapeseed oil, sunflower oil and palm-oil. The study covered a period of post food crisis of 2006 and after three years of stabilization of these prices to get an insight into the current scenario. The econometric tools used to examine the relationship included Johansen Co-integration, Gregory Hansen Co-integration with structural breaks, Toda and Yamamoto Causality and GARCH (1,1) Method. The results of our study did not give sufficient evidence to prove that crude oils impacted any of the bio-fuel prices in current scenario. The long run inter-linkages between crude oil and energy crops was not established which brought us to the conclusion that the energy-food nexus was a temporary phenomenon that existed during food crisis (2006) only and crude prices were no longer a guiding force to determine the price of bio-fuels

Does the Energy-Food Nexus Still Exist: Empirical Evidence from the Indian Agriculture Sector Post Food Crisis of 2006

The present study made an attempt to empirically investigate the impact of crude oil prices on agricultural prices for India during the calendar decade 2010-19. The bio-fuels which were considered in the present study included soy-oil, rapeseed oil, sunflower oil and palm-oil. The study covered a period of post food crisis of 2006 and after three years of stabilization of these prices to get an insight into the current scenario. The econometric tools used to examine the relationship included Johansen Co-integration, Gregory Hansen Co-integration with structural breaks, Toda and Yamamoto Causality and GARCH (1,1) Method. The results of our study did not give sufficient evidence to prove that crude oils impacted any of the bio-fuel prices in current scenario. The long run inter-linkages between crude oil and energy crops was not established which brought us to the conclusion that the energy-food nexus was a temporary phenomenon that existed during food crisis (2006) only and crude prices were no longer a guiding force to determine the price of bio-fuels

Portfolio Allocation: An Empirical Analysis of Ten American Stocks for the Period 2010-2015

We invest in order to obtain excess returns on the investment. The excess return is calculated with respect to the risk free rate and implies taking on risk. It is necessary to quantify both return and risk on the portfolio level. Asset returns are correlated, and for this reason the correlation matrix is estimated to quantify precisely the correlation among the returns on portfolio assets. These coefficients will then enable us to describe the combined returns on the portfolio’s assets, and the risk of the portfolio. The basis of all quantitative portfolio management and theory today are given by the well-known Modern Portfolio Theory. We analyze in this paper ten American stocks from completely different industry sectors, part of the Standard & Poor’s 500 index. The period is from December 2010 to December 2015, monthly observations. Since the end of 1999, the S&P’s 500 stock index has lost an average of 3.3% a year on an inflation adjusted basis, compared with a 1.8% average annual gain during the 1930s when deflation afflicted the economy. In nearly 200 years of recorded stock-market history, no calendar decade has seen such a bad performance as the 2000s. The computer programs used in this work are MATLAB and Microsoft Excel. For optimization problems we mainly use the Excel Solver.

The Rate of Development of Complicated Crohnʼs Disease (Penetrating or Stricturing) Increases with Calendar Decade of Diagnosis: Reality or Bias?

Purpose: The rate of development of complicated (penetrating or stricturing) Crohn's disease (CD) may be influenced by patient characteristics but also bias of patient selection or inaccurate classification in historical cohort studies. We determined if calendar decade of diagnosis influenced rate of development of complicated disease. Methods: 207 patients with non-stricturing non-penetrating CD were followed from diagnosis to development of complications or last clinic follow-up. The influences of decade of diagnosis and patient specific characteristics including Montreal classification and medication use on the rate of development of complicated disease in a historical cohort were determined. Results: Duration of disease was far longer in patients diagnosed before 1990 compared to after 1990 (24.6 vs. 6.8 years; p<0.001). The proportion diagnosed before age 40 was lower (30 vs. 48%, p=0.02) and surgery rates higher (68 vs. 30%; p<0.001) in the earlier diagnosis group. Immunomodulator use was equal in both groups (34%) yet time to first immunomodulator prescription was significantly longer in the earlier group (17.6 vs. 3.5 yrs; p<0.001). Kaplan Meier analysis was performed to study the rate of development of complications by decade of diagnosis (Figure). Rates of development of complicated disease were unusually low among patients diagnosed before 1990. In a Cox proportional hazards model, only calendar decade of diagnosis (HR 6.9; p<0.001) and age at diagnosis after age 40 (HR 0.29; p=0.006) influenced the hazard of development of complications. Conclusion: Earlier calendar decade of diagnosis of CD is associated with a lower rate of progression to complicated disease. While this might reflect changes in disease course with calendar time, it likely represents a bias in patient selection (survival bias) or inaccurate behavior classification because of differences in technology to detect and define disease complications. Such biases must be taken into account in historical cohort studies.Figure

PRS1 TOBACCO AND INCOME LEVEL: A SYSTEMATIC REVIEW AND META-ANALYSIS

To quantify the association between tobacco consumption, tobacco expenditures and morbi-mortality attributed to tobacco, and income level. Specifically, to compare high-income versus lower income groups in terms of smoking prevalence, quantity of tobacco consumption, disease incidence and mortality attributed to AIM assessment of IL. We searched in the main literature databases, conferences index, tobacco control agencies, and contacted experts. Two independent researchers by register screened titles and abstracts (agreement >0.9). The full text of selected studies and its risk of bias (using a STROBE-based checklist) were assessed by two researches. One reviewer extracted data, and a second one checked it. Disagreements were solved by consensus. We conducted a random effects meta-analysis based on adjusted OR using Stata 9.0. We performed pre-planned subgroup and sensitivity analysis to evaluate heterogeneity (I2>50%) by calendar decade, continent, WHO region, country standardized mortality rate, risk of bias, gender, and age.

Moving with the beat: changing fetal monitoring practices in low-risk labour

In current practice electronic fetal monitoring is used extensively to assess fetal well-being in normal or low-risk labour. Within this clinical context there are a number of issues concerning the comparative benefits or problems of this practice when compared with intermittent auscultation. The purpose of this study was to explore factors influencing current practice by systematically investigating and describing changes in practice, encompassing the period of time prior to and following, the introduction of electronic fetal monitoring, and up to the present day. To do this text from the 13 editions of Margaret Myles's ‘Text Book for Midwives’, was subjected to a qualitative content analysis. The data revealed five distinct patterns of practice, each correlating loosely to a calendar decade and each reflecting different norms for childbirth and midwifery practice. The findings suggest that there is a significant shift in the skills and context associated with fetal monitoring, changes that require reflection and debate.

USING ESTIMATED DATE OF INFECTION TO ASSESS HEALTH EFFECTS OF HTLV-II INFECTION

P176 Background. Health effects of infectious agents such as HTLV tend to increase with duration of infection. A method for estimating date of infection based on a personal history questionnaire is presented. Methods. 298 HTLB-II infected subjects in the REDS cohort were evaluated for low, moderate and high risks reported at enrollment in 1991-93. An infection date estimation algorithm was developed using the weighted average of risk intervals. Subjects were stratified by calendar decade of infection and coded for HAM and for any of ten HAM-associated symptoms. Results. The table presents the infection date distribution in the cohort (row 1), definite and probable HAM diagnosis as of 1997 (row 2-3), and average (mean/median) number of HAM-associated symptoms as of that date (row 4).TableHAM prevalence rates and average number of symptoms increase with estimated duration of infection. Conclusion. The HAM data presented suggest that this infection date estimation algorithm may prove useful in evaluating other adverse health outcomes in the cohort.

Preventive Efficacy of Nutritional Counseling

THERE IS now incontrovertible evidence that dyslipidemia is fundamental to the atherosclerotic process and that correction of the disorder slows atherogenesis, stabilizes lesions, and reduces the morbidity and mortality of coronary heart disease (CHD). 1,2 There is also ample evidence that faulty nutrition, ie, a diet consisting of too much saturated fat and cholesterol, too little fiber, and too many calories for the level of activity, is the chief determinant of blood lipid values in the general population. 3 The average serum total cholesterol level of the general population has declined over the years. 4 In the Framingham Study cohort it has declined each calendar decade, almost certainly as a result of changes in fat and cholesterol intake. 5 Migrants from low to high CHD areas of the world raise their cholesterol level, and along with this, their CHD mortality rate. 6 Thus, for the general population, attention to nutrition

Patterns of Smoking Initiation in Italian Males and Females from 1955 to 1985

Methods. The changes in patterns of smoking initiation in Italian males and females in 1955, 1965, 1975, and 1985 were analyzed using data from the 1990-1991 Italian National Health Survey, based on a sample of 18,483 males and 19,320 females ages 19 to 59. The sample was randomly selected within strata of geographic area and size of place of residence and of household in order to be representative of the general Italian population. The age of each subject was reconstructed for each calendar year of interest (1954 to 1956, centered on 1955, 1964 to 1966, 1974 to 1976, and 1984 to 1986). For each calendar period and year of age of interest (14 to 24), the numerator of the smoking initiation rate was the number of subjects who started smoking and the denominator was the number of subjects at risk, i.e., nonsmokers of the same age. The same procedure was repeated for three separate age groups (14 to 17, 18 to 20, and 21 to 24). Results. Among males, there was a trend toward earlier age at start of smoking and higher initiation rates between 1955 and 1965, and a subsequent decline in initiation rate, particularly at age 18 or over and during the last calendar decade studied. In females, between 1955 and 1975 there was an increase of over fourfold in initiation rates and systematic tendencies toward earlier age at starting; only over the past decade have the starting rates begun to decline. The peak rate was reached at age 18-20 for males in 1965 (53.3%) and for females in 1975 (23.9%). Conclusion. The recent declines in smoking initiation have been relatively limited among the younger age groups, and this reflects an earlier average age at smoking initiation.

The epidemiology of heart failure: The Framingham Study

Congestive heart failure has become an increasingly frequent reason for hospital admission during the last 2 decades and clearly represents a major health problem. Data from the Framingham Heart Study indicate that the incidence of congestive heart failure increases with age and is higher in men than in women. Hypertension and coronary heart disease are the two most common conditions predating its onset. Diabetes mellitus and electrocardiographic left ventricular hypertrophy are also associated with an increased risk of heart failure. During the 1980s, the annual age-adjusted incidence of congestive heart failure among persons aged ≥ 45 years was 7.2 cases/1,000 in men and 4.7 cases/1,000 in women, whereas the age-adjusted prevalence of overt heart failure was 24/1,000 in men and 25/1,000 in women. Despite improved treatments for ischemic heart disease and hypertension, the age-adjusted incidence of heart failure has declined by only 11%/calendar decade in men and by 17%/calendar decade in women during a 40-year period of observation. In addition., congestive heart failure remains highly lethal, with a median survival time of 1.7 years in men and 3.2 years in women and a 5-year survival rate of 25% in men and 38% in women.

Survival after the onset of congestive heart failure in Framingham Heart Study subjects.

Relatively limited epidemiological data are available regarding the prognosis of congestive heart failure (CHF) and temporal changes in survival after its onset in a population-based setting. Proportional hazards models were used to evaluate the effects of selected clinical variables on survival after the onset of CHF among 652 members of the Framingham Heart Study (51% men; mean age, 70.0 +/- 10.8 years) who developed CHF between 1948 and 1988. Subjects were older at the diagnosis of heart failure in the later decades of this study (mean age at heart failure diagnosis, 57.3 +/- 7.6 years in the 1950s, 65.9 +/- 7.9 years in the 1960s, 71.6 +/- 9.4 years in the 1970s, and 76.4 +/- 10.0 years in the 1980s; p < 0.001). Median survival after the onset of heart failure was 1.7 years in men and 3.2 years in women. Overall, 1-year and 5-year survival rates were 57% and 25% in men and 64% and 38% in women, respectively. Survival was better in women than in men (age-adjusted hazards ratio for mortality, 0.64; 95% CI, 0.54-0.77). Mortality increased with advancing age in both sexes (hazards ratio for men, 1.27 per decade of age; 95% CI, 1.09-1.47; hazards ratio for women, 1.61 per decade of age; 95% CI, 1.37-1.90). Adjusting for age, there was no significant temporal change in the prognosis of CHF during the 40 years of observation (hazards ratio for men for mortality, 1.08 per calendar decade; 95% CI, 0.92-1.27; hazards ratio for women for mortality, 1.02 per calendar decade; 95% CI, 0.83-1.26). CHF remains highly lethal, with better prognosis in women and in younger individuals. Advances in the treatment of hypertension, myocardial ischemia, and valvular heart disease during the four decades of observation did not translate into appreciable improvements in overall survival after the onset of CHF in this large, unselected population.

Impact of randomized clinical trials on therapy of primary breast cancer: The NSABP overview

The history of treatment for early breast cancer, particularly as it relates to the most recent calendar decade, exemplifies the contribution that can be made to resolving therapeutic controversies by well-designed prospective randomized clinical trials (RCTs). In this article we provide an overview of the breast cancer clinical trials that have been conducted by the National Surgical Adjuvant Project for Breast and Bowel Cancers (NSABP) since 1971. These trials have had a strong impact in changing the clinical management of breast cancer over the past decade. Emphasis will be given to those aspects of the studies that demonstrate the advantages and/or necessity for RCTs to evaluate alternative therapeutic approaches to the management of breast cancer.