Long-Term Trends in Biochemical Data Obtained from Two Population Surveys

1986 ◽  
Vol 23 (4) ◽  
pp. 474-486 ◽  
Author(s):  
P M G Broughton ◽  
Roger Holder ◽  
Deborah Ashby
Keyword(s):  
Quality Control ◽  
Mean Value ◽  
Population Surveys ◽  
Men And Women ◽  
Mean Values ◽  
Epidemiological Surveys ◽  
Abrupt Changes ◽  
Control Procedures ◽  
Long Term Trends

A study has been made of the variations in monthly mean values of 10 serum constituents in subjects participating in two partly-concurrent long-term epidemiological surveys. Closely similar patterns of variation were found in men in both surveys and in men and women in one survey. During the 6 years of the study, four types of variation of the monthly mean concentrations were identified in varying combinations: (i) abrupt changes of less than 2% not detected by quality control procedures; (ii) a gradual drift in mean value; (iii) haphazard variations in mean values; and (iv) seasonal variations in bilirubin and urea, identical in men and women. The implications of these findings for the design of long-term epidemiological surveys, and the criteria for designating variations as seasonal, are discussed.

Feasibility of centralized measurements of glycated hemoglobin in the Diabetes Control and Complications Trial: a multicenter study. The DCCT Research Group.

1987 ◽  
Vol 33 (12) ◽  
pp. 2267-2271 ◽  
Keyword(s):  
Quality Control ◽  
High Performance ◽  
Glycated Hemoglobin ◽  
Multicenter Trial ◽  
Diabetes Control ◽  
Mean Values ◽  
Hb A1c ◽  
Control Procedures ◽  
Over Time

Abstract A method for measuring glycated hemoglobin (Hb A1c) and an accompanying method of specimen transport to a central laboratory were developed for the multicenter Diabetes Control and Complications Trial (DCCT). In the DCCT, results for Hb A1c are used to assess chronic glycemic control for data collection and patient management. During the feasibility phase of the trial, central (CHL) and backup laboratories using automated, "high-performance" ion-exchange liquid-chromatographic methods were established. Whole-blood samples were stored (4 degrees C) at each of the 21 clinical centers for up to 72 h before air-express shipment to the CHL. Quality-control procedures included daily analyses of three calibration specimens. A pooled hemolysate was assayed frequently over time as a long-term quality control (LTQC). After 18 months, within- and between-run CVs were less than 6%. Mean values for split duplicate samples assayed in a masked fashion at the CHL were nearly identical. LTQC results indicated no significant assay drift over time. More than 6000 samples were assayed (mean interval between obtaining the blood sample and completing the assay: less than six days). Hb A1c evidently can be precisely and reliably measured in the context of a long-term, multicenter trial such as the DCCT.

LONG-TERM TRENDS IN MARITAL STATUS MORTALITY DIFFERENCES IN THE NETHERLANDS 1850–1970

2001 ◽  
Vol 33 (2) ◽  
pp. 279-303 ◽  
Author(s):  
FRANS VAN POPPEL ◽  
INEZ JOUNG
Keyword(s):  
World War Ii ◽  
The Netherlands ◽  
Marital Status ◽  
Cause Of Death ◽  
Relative Increase ◽  
World War ◽  
Men And Women ◽  
Married Men ◽  
Long Term Trends

This article describes the long-term trends in marital status mortality differences in the Netherlands using a unique dataset relating to the period 1850–1970. Poisson regression analysis was applied to calculate relative mortality risks by marital status. For two periods, cause-of-death by marital status could be used. Clear differences in mortality by marital status were observed, with strongly increasing advantages for married men and women and a relative increase in the mortality of widowed compared with non-married people. Excess mortality among single and formerly married men and women was visible in many cause-of-death categories, and this became more widespread during the last decades of the nineteenth century. Hypotheses are formulated that might explain why married men and women underwent a stronger decrease in mortality up until the end of World War II.

Effectiveness of Long-term Heparin-induced Extracorporeal LDL Precipitation (HELP) in Improving Coronary Calcifications

2003 ◽  
Vol 26 (3) ◽  
pp. 252-255 ◽  
Author(s):  
A. Ramunni ◽  
L.F. Morrone ◽  
G. Baldassarre ◽  
E. Montagna ◽  
A. Saracino ◽  
...  
Keyword(s):  
Coronary Heart Disease ◽  
Heart Disease ◽  
Clinical Evidence ◽  
Ldl Cholesterol ◽  
Clinical Manifestations ◽  
Mean Value ◽  
Mean Values ◽  
Plasma Pool ◽  
Before And After

There is clear clinical evidence that a drastic lowering of plasma LDL- Cholesterol (LDL) concentrations significantly reduces the rate of total and coronary mortality as well as the incidence of cardiovascular events in high risk hypercholesterolemic patients. We describe the case of a 51-year-old woman with coronary heart disease (CHD) who presented with increasing angina on exertion in 1995, at the age of 45. She suffered from a heterozygous familial hypercholesterolemia and in 1985 her total cholesterol (TCHO) was 328±62 mg/dl (mean value of ten analysis). After ten years of statins her mean values (20 analysis, 2 per year) were: TCHO 259±71, LDL 209±47, HDL 35±7 mg/dl. Coronary angiography (CA) performed in 1995 disclosed three vessel coronary heart disease with significant stenoses of the distal right coronary artery, multiple calcifications of the interventricularis artery and multiple plaques with significant stenoses in the ramus circumflexus. The woman underwent coronary by-pass surgery. Thereafter the patient was treated for six years with HELP in biweekly intervals, in combination with statins. TCHO, LDL, HDL and fibrinogen (fb) levels were measured before and after each treatment. Their mean values for an amount of 120 sessions were: TCHO pre 216±23, post 111±18 LDL pre 152±16 post 67±18, HDL pre 42±5 post 35±4 fb pre 306±48 post 125±31. In 2001 a new CA was performed. Calcifications disappeared and stenoses were identical to the previous CA or reduced. There were no further clinical manifestations of CHD. We trust that the clinical benefit of the HELP procedure will be substantial for those patients who have problems in clearing LDL from their plasma pool and who are at the same time sensitive to elevated LDL levels by the development of premature coronary sclerosis.

scholarly journals Long-Term Trends in Unintentional Fall Mortality in China: A Population-Based Age-Period-Cohort Study

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhenkun Wang ◽  
Youzhen Hu ◽  
Fang Peng
Keyword(s):  
Public Health Problem ◽  
Mortality Rates ◽  
Population Based ◽  
Mortality Data ◽  
Major Public Health Problem ◽  
Age Group ◽  
Men And Women ◽  
Long Term Trends ◽  
Unintentional Falls

Background: Unintentional falls seriously threaten the life and health of people in China. This study aimed to assess the long-term trends of mortality from unintentional falls in China and to examine the age-, period-, and cohort-specific effects behind them.Methods: This population-based multiyear cross-sectional study of Chinese people aged 0–84 years was a secondary analysis of the mortality data of fall injuries from 1990 to 2019, derived from the Global Burden of Disease Study 2019. Age-standardized mortality rates of unintentional falls by year, sex, and age group were used as the main outcomes and were analyzed within the age-period-cohort framework.Results: Although the crude mortality rates of unintentional falls for men and women showed a significant upward trend, the age-standardized mortality rates for both sexes only increased slightly. The net drift of unintentional fall mortality was 0.13% (95% CI, −0.04 to 0.3%) per year for men and −0.71% (95% CI, −0.96 to −0.46%) per year for women. The local drift values for both sexes increased with age group. Significant age, cohort, and period effects were found behind the mortality trends of the unintentional falls for both sexes in China.Conclusions: Unintentional falls are still a major public health problem that disproportionately threatens the lives of men and women in China. Efforts should be put in place urgently to prevent the growing number of fall-related mortality for men over 40 years old and women over 70 years old. Gains observed in the recent period, relative risks (RRs), and cohort RRs may be related to improved healthcare and better education.

scholarly journals Implementation of Real-Time Quality Control Procedures by Means of a Probabilistic Estimate of Seawater Temperature and Its Temporal Evolution

2013 ◽  
Vol 30 (3) ◽  
pp. 609-625 ◽  
Author(s):  
Giuseppe M. R. Manzella ◽  
Marco Gambetta
Keyword(s):  
Quality Control ◽  
Real Time ◽  
Position Control ◽  
Seawater Temperature ◽  
Likelihood Method ◽  
Temperature Profiles ◽  
Quality Of Data ◽  
Control Procedures ◽  
The Mediterranean

Abstract Near-real-time quality control procedures for temperature profiles collected from ships of opportunity were implemented during the 1980s in oceans across the world and from the 1990s in the Mediterranean. In this sea, the procedures were originally based on seven steps (detection of end of profile, gross range check, position control, elimination of spikes, Gaussian smoothing and resampling at 1-m intervals, general malfunction control, and comparison with climatology), complemented with initial and final visual checks. The quality of data derived from a comparison with historical data (namely, climatology) depends on the availability of a huge amount of data that can statistically represent the mean characteristics of the seawater. A significant amount of data has been collected, and the existing temperature database in the Mediterranean can now provide more information on temporal and spatial variability at monthly and mesoscales, and an improved procedure for data quality control has now been adopted. New “best” estimates of monthly temperature profiles are calculated by using a maximum likelihood method. It has been found that more than one “best estimate” temperature can be defined in particular areas and depths, as a consequence of climate variability. Additional near-real-time control procedures have been included in order to provide information on long-term variability associated with data. This information is included in metafiles to be used for reanalysis and studies on long-term variability and changes.

scholarly journals Long-Term Variations of Temperature and Precipitation in the Megacity of Istanbul for the Development of Adaptation Strategies to Climate Change

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Hüseyin Toros ◽  
Mohsen Abbasnia ◽  
Mustafa Sagdic ◽  
Mete Tayanç
Keyword(s):  
Climate Change ◽  
Mean Value ◽  
Daily Maximum ◽  
Precipitation Series ◽  
Mean Values ◽  
Temperature And Precipitation ◽  
Average Annual Temperature ◽  
Notable Increase ◽  
Total Study Period

Istanbul, as one of the four anchor megacities of Europe, has shown a rise of 0.94°C in average annual temperature over the long period of 1912–2016 under impacts of anthropogenic climate change. A notable increase in temperatures has started after the 1940s, which is in parallel with the beginning of industrialization era in Istanbul. This warming is associated with an extensive population growth and accompanied the decrease in vegetation cover. Increasing in minimum series of temperature is more evident than maximum values and the rising rate of temperature values has been more pronounced during recent decades. The first significant upward trend in precipitation series has periodically started in 1920s, while there has been a stable trend from 2001 till today. The daily average of rainfall amount increased with a mean value of 58 mm during the total study period. Rising rate of daily maximum precipitation has been more evident in the last 3 decades, which is shown by the increased frequency of heavy rainfall. In this regard, both of the temperature and precipitation series had higher mean values (13.9°C and 878 mm) for the final period (1965–2016) compared to the mean values (13.6°C and 799 mm) belonging to the first period (1912–1964).

scholarly journals Evaluation of Respiratory Muscular Strength Compared to Predicted Values in Patients with Stroke

2020 ◽  
Vol 17 (3) ◽  
pp. 1091 ◽  
Author(s):  
Sarah Maria Ramos ◽  
Daniela Maciel da Silva ◽  
Daniela Vieira Buchaim ◽  
Rogério Leone Buchaim ◽  
Mauro Audi
Keyword(s):  
Statistical Analysis ◽  
Muscle Strength ◽  
Respiratory Muscles ◽  
Mean Value ◽  
P Value ◽  
Men And Women ◽  
Mean Values ◽  
Significant Difference ◽  
The Mean ◽  
Predicted Values

The purpose of this study was to evaluate the inspiratory and expiratory muscle strength of individuals affected by stroke and to compare it with the predicted values in the literature considering their corresponding age. Respiratory muscle strength was evaluated in 22 elderly people who had sequels of stroke, four with right hemiparesis, 16 with left hemiparesis and two with bilateral, of ages ranging from 34 to 82 years. The collected data were submitted to statistical analysis using a Mann–Whitney test to evaluate if there was a significant difference in the average data collected when compared with a mean of the predicted data in the literature. Fourteen men and eight women were evaluated, who obtained mean values of 71.85 cmH2O and 57.75 cmH2O, respectively, for a maximal inspiratory pressure (MIP), and when compared to the predicted values for men and women, 105.41 cmH2O (p-value 0.0019) and 80.57 cmH2O (p-value 0.00464) were significantly lower. For a maximal expiratory pressure (MEP), the mean value obtained for men was 62.28 cmH2O and 49.5 cmH2O for women, whereas the predicted values in the literature were 114.79 cmH2O (p-value < 0.0001) and 78, 46 cmH2O (p-value 0.0059), respectively. In the statistical analysis, it was possible to notice that the studied population did not reach the predicted age indexes and that there was a significant difference between the median columns. In conclusion, there is a weakness in the respiratory muscles of hemiparetic men and women due to stroke.

scholarly journals Long-term trends in smoking prevalence and its socioeconomic inequalities in Korea, 1992–2016

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Youngs Chang ◽  
Hee-Yeon Kang ◽  
Dohee Lim ◽  
Hong-Jun Cho ◽  
Young-Ho Khang
Keyword(s):  
Smoking Prevalence ◽  
Prevalence Ratio ◽  
Socioeconomic Inequalities ◽  
Occupational Class ◽  
Men And Women ◽  
Tobacco Control Policies ◽  
Prevalence Difference ◽  
Long Term Trends ◽  
Index Of Inequality

Abstract Background The aim of this study was to investigate long-term trends in smoking prevalence and its socioeconomic inequalities in Korea. Methods Data were collected from 10 rounds of the Social Survey of Statistics Korea between 1992 and 2016. A total of 524,866 men and women aged 19 or over were analyzed. Age-adjusted smoking prevalence was calculated according to three major socioeconomic position indicators: education, occupational class, and income. The prevalence difference, prevalence ratio, slope index of inequality (SII), and relative index of inequality (RII) were calculated to examine the magnitude of inequality in smoking. Results Smoking prevalence among men decreased from 71.7% in 1992 to 39.7% in 2016, while smoking prevalence among women decreased from 6.5% in 1992 to 3.3% in 2016. Socioeconomic inequalities in smoking prevalence according to the three socioeconomic position indicators were found in both men and women throughout the study period. In general, absolute and relative socioeconomic inequalities in smoking, measured by prevalence difference and prevalence ratio for education and occupational class, widened during the study period among Korean men and women. In men, the SII for income increased from 7.6% in 1999 to 10.8% in 2016 and the RII for income also increased from 1.11 in 1999 to 1.31 in 2016. In women, the SII for income increased from 0.1% in 1999 to 2.4% in 2016 and the RII for income increased from 1.39 in 1999 to 2.25 in 2016. Conclusion Pro-rich socioeconomic inequalities in smoking prevalence were found in men and women. Socioeconomic inequalities in smoking have increased in parallel with the implementation of tobacco control policies. Tobacco control policies should be developed to decrease socioeconomic inequalities in cigarette use in Korea.

Analytical performance and comparability of the determination of triglycerides by 12 Lipid Research Clinic laboratories.

1978 ◽  
Vol 24 (2) ◽  
pp. 330-338 ◽  
Author(s):  
S Ahmed ◽  
K Lippel ◽  
P Bachorik ◽  
J Albers ◽  
J Williams ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Lipid Research Clinic ◽  
Entire Group ◽  
Lipid Research ◽  
Collaborative Studies ◽  
Control Serum ◽  
Control Procedures ◽  
Long Term Trends ◽  
And Control

Abstract Twelve Lipid Research Clinic laboratories performed automated fluorometric triglyceride analyses on four control serum pools of known concentration by a modified Hantzsch reaction. The analyses were done during a two-year period, with use of common standards, methodology, and quality-control procedures. Estimates of analytical bias, variability, and short- and long-term trends for each instrument and for the entire group of LRC instruments are presented. High accuracy, precision, and interlaboratory comparability were achieved through rigorous standardization and control of the entire analytical procedure. Individual instrument biases varied from an average of 4.9% below to 1.0% above reference values. Between-run variability was often less than within-run variability and interlaboratory variation was substantially less than intralaboratory variation. The total standard deviation for all instruments ranged from 37 to 63 mg/liter. Only 5 to 14% of this variation was due to differences among instruments. The among-instruments standard deviation ranged from 12 to 17 mg/liter; the between-run, within-instrument standard deviation ranged from 29 to 46 mg/liter, and within-run standard deviation from 27 to 40 mg/liter. The significance of the results for long-term collaborative studies is discussed.

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