Homogeneity Of Trends Research Articles

Medical Misadventures as Errors and Mistakes and Motor Vehicular Accidents in the Disproportionate Burden of Childhood Mortality among Blacks/African Americans in the United States: CDC Dataset, 1968-2015.

Racial disparities in infant mortality in the United States persist after adjustment for known confounders of race and mortality association, as well as heterogeneity assessment. Epidemiologic and clinical data continue to show the survival disadvantages of Black/AA children: when Black/AAs are compared to whites, they are three times as likely to die from all-cause mortality. The persistent inability to remove the variance in race-mortality association is partly due to unobserved, unmeasured, and residual confounding, as well as implicit biases in public health and clinical medicine in health equity transformation. This current epidemiologic-perspective explanatory model study aimed to examine the possible explanation of racial differences in U.S. infant mortality using medical misadventures as errors and mistakes, and infants' involvement in motor vehicular traffic accidents. Using CDC WONDER ecologic data from 1968 to 2015, we assessed the infant mortality-rate ratio and percent change associated with medical misadventures as well as motor vehicular accidents or trauma. The rate ratio and percent change were estimated using stratification analysis and trend homogeneity, respectively. There was a Black-white racial difference in medical misadventures during the study period. Relative to the years 1968-1978 (rate ratio [RR], 1.43), there was a steady increase in the mortality-rate ratio in 1979-1998 (52%, RR = 1.52), and mortality was more than two times as likely in 1999-2015 (RR = 2.37). However, with respect to motor vehicular accident/trauma mortality, the mortality ratio, although lower among Blacks in 1968-1978 (RR, 0.92), increased in 1979-1998 by 27% (RR = 1.27) but decreased in 1999-2015 (RR, 1.17), though there was still an excess of 17% mortality among Black/AAs. The percent change for medical misadventures indicated an increasing trend from 9.3% in 1998 to 52% in 2015. However, motor vehicular-related mortality indicated a positive trend in 1998 (38.5%) but a negative trend in 2015 (-8.4%). There were substantial race differentials or variances in infant mortality associated with medical misadventures compared to traffic accidents, and Black/AA children relative to whites experienced a survival disadvantage. These comparative findings are suggestive of medical misadventures and motor vehicular trauma as potential explanations for some of the persistent Black-white disparities in overall infant mortality in the U.S. From these findings, we recommend a national effort to address these issues, thus narrowing the observed disparities in the U.S. infant mortality burden among Black/AAs.

Analysis of the Inhomogeneous Effect of Different Meteorological Trends on Drought: An Example from Continental Croatia

The majority of central Europe has a transitional climate type as a result of interactions between maritime and continental climates. This study focuses on the appearance and severity of drought in continental Croatia, which is part of the transitional climate area. It is situated between 15° E and 19° E. The altitude declines from west (167 m a.s.l) to east (88 m a.s.l.). The time period analysed is 1981–2018. Air temperature and precipitation data series from 13 meteorological stations were analysed. The analysis was done on an annual basis to define the spatio-temporal variability in air temperature and precipitation and their impact on drought episodes using the standardised evapotranspiration precipitation index. Different statistical methods (e.g., the nonparametric Mann–Kendall test and agglomerative hierarchical clustering) were used to examine the trend homogeneity of the analysed region. The analysis indicated inhomogeneity across the study area in terms of what significantly impacted the occurrence and severity of droughts. Drought occurrence is influenced more strongly by increasing trends in air temperature as compared with increasing or decreasing precipitation trends. The probability of severe drought occurrence was estimated using a copula function, and the results demonstrated that areas with higher precipitation could be more exposed to drought. Furthermore, the results demonstrated the impacts of specific regional characteristics on drought occurrence, severity, and duration, which indicates that small-scale research on droughts is more reliable.

Spatial and temporal patterns of climate variables in Iraq

Temporal and spatial changes in Iraq total precipitations, maximum and minimum temperatures in the period of 1980–2011 are analyzed using 28 meteorological stations data distributed throughout the country. The Mann–Kendall and Spearman’s Rho test statistics for annual and seasonal Kendall and Sen’s T tests for monthly total precipitation and temperature series are calculated and plotted on maps to display any spatial trend patterns. Serial correlation structure in the data series and homogeneity of trends in monthly series were tested before applying the methods. Non-parametric methods using annual and monthly data over 32 years show almost same temporal and spatial patterns in trends of precipitation (P), maximum and minimum temperature (Tmax, Tmin) but some are not statistically significant at the 5 % level. While observation shows decreasing trends in precipitation except for two stations when using monthly data, increasing trend is detected in both temperature series. The Sen’s and seasonal Kendall slope estimator are also used to estimate linear trend magnitudes for annual and monthly data to determine the change per unit time in a time series, respectively. The six tests provide the same results about trend in most cases. As a conclusion, all of the study results show that there are not differences in the geographic location of trends (statistically significant or not) in the meteorological variables implying that climatic impacts are spatially uniform in this region. The effect of the North Atlantic Oscillation (NAO) on temporal patterns of climate data in Iraq is also investigated, since it has been suggested that it affects the northern hemisphere climate system. Our study shows that NAO has no detectable influences on climate of this region. This paper is the first comprehensive studies for evidence of climate change with applying tests in this region.

Evaluating long-term trends in littoral benthic macroinvertebrate communities of lakes recovering from acid deposition

The Mann-Kendall test has been proposed as a nonparametric method to evaluate trends in long-term water quality datasets with missing values, serial correlation, and non-normality. However, this test has rarely been used to evaluate long-term trends in biological data. In this study, we used the Mann-Kendall test to evaluate trends in 15 years of data on benthic macroinvertebrate communities from 17 Precambrian Shield lakes. We also used the van Belle and Hughes test of trend homogeneity to assess whether common among-lake temporal trends existed. We assumed that evidence of a common regional trend among lakes would support the hypothesis of long-term biological recovery from past acidification. We found decreasing proportions of Chironomidae and increasing proportions of Ephemeroptera, Plecoptera, and Trichoptera (EPT) in both single-lake and multi-lake trend analysis. Moreover, six of the nine lakes with significant trends in more than one benthos metric displayed a significant decrease in Chironomidae and increase in EPT concurrently, indicating a shift towards more acid-sensitive taxa. Weak trends in several of the biological metrics indicated that recovery in these lakes has been impeded. Results of this study indicate that the Mann-Kendall and van Belle and Hughes trend tests are useful statistical tools to evaluate long-term patterns in biological data.

Antacid Drug Use and Risk of Esophageal and Gastric Adenocarcinomas in Los Angeles County

Concern has been expressed that antacid drugs increase the risk of esophageal and gastric adenocarcinomas. This population-based case-control study recruited patients with incident esophageal adenocarcinoma (n = 220), gastric cardiac adenocarcinoma (n = 277), or distal gastric adenocarcinoma (n = 441) diagnosed between 1992 and 1997, and 1,356 control participants in Los Angeles County. Unconditional polychotomous multivariable logistic regression analyses were done to evaluate the association between antacid drug use and these cancers. Among participants who took nonprescription acid neutralizing agents for >3 years, the odds ratio for esophageal adenocarcinoma was 6.32 compared with never users (95% confidence interval, 3.14-12.69; P(trend) < 0.01). Analyses stratified by history of physician diagnosed upper gastrointestinal (UGI) disorders revealed a greater increase in esophageal adenocarcinoma risk associated with nonprescription antacid use among persons with no UGI disorder than among those with an UGI disorder (homogeneity of trends P = 0.07). Regular use of nonprescription acid neutralizing agents was not associated with risk of adenocarcinomas of the gastric cardia or distal stomach. Regular use of prescription acid suppressive drugs was not associated with risk for any of these cancers. We found risk of esophageal adenocarcinoma was greater among long-term nonprescription acid neutralizing drugs in participants without physician-diagnosed UGI conditions than among those with these conditions; this may represent self medication for undiagnosed precursor conditions or it may be that nonprescription acid neutralizing drugs, taken without limitation on amount used when symptoms are most intense, may permit alkaline bile reflux into the lower esophagus, thereby increasing esophageal adenocarcinoma risk.

Analysis of the Trend and Seasonal Cycle of Carbon Monoxide Concentrations in an Urban Area (4 pp)

Air quality is an field of major concern in large cities. This problem has led administrations to introduce plans and regulations to reduce pollutant emissions. The analysis of variations in the concentration of pollutants is useful when evaluating the effectiveness of these plans. However, such an analysis cannot be undertaken using standard statistical techniques, due to the fact that concentrations of atmospheric pollutants often exhibit a lack of normality and are autocorrelated. On the other hand, if long-term trends of any pollutant's emissions are to be detected, meteorological effects must be removed from the time series analysed, due to their strong masking effects. The application of statistical methods to analyse temporal variations is illustrated using monthly carbon monoxide (CO) concentrations observed at an urban site. The sampling site is located at a street intersection in central Valencia (Spain) with a high traffic density. Valencia is the third largest city in Spain. It is a typical Mediterranean city in terms of its urban structure and climatology. The sampling site started operation in January 1994 and monitored CO ground level concentrations until February 2002. Its geographic coordinates are W0º22'52\ N39º28'05\ and its altitude is 11 m. Two nonparametric trend tests are applied. One of these is robust against serial correlation with regards to the false rejection rate, when observations have a strong persistence or when the sample size per month is small. A nonparametric analysis of the homogeneity of trends between seasons is also discussed. A multiple linear regression model is used with the transformed data, including the effect of meteorological variables. The method of generalized least squares is applied to estimate the model parameters to take into account the serial dependence of the residuals of this model. This study also assesses temporal changes using the Kolmogorov-Zurbenko (KZ) filter. The KZ filter has been shown to be an effective way to remove the influence of meteorological conditions on O3 and PM to examine underlying trends. The nonparametric tests indicate a decreasing, significant trend in the sampled site. The application of the linear model yields a significant decrease every twelve months of 15.8% for the average monthly CO concentration. The 95% confidence interval for the trend ranges from 13.9% to 17.7%. The seasonal cycle also provides significant results. There are no differences in trends throughout the months. The percentage of CO variance explained by the linear model is 90.3%. The KZ filter separates out long, short-term and seasonal variations in the CO series. The estimated, significant, long-term trend every year results in 10.3% with this method. The 95% confidence interval ranges from 8.8% to 11.9%. This approach explains 89.9% of the CO temporal variations. The differences between the linear model and KZ filter trend estimations are due to the fact that the KZ filter performs the analysis on the smoothed data rather than the original data. In the KZ filter trend estimation, the effect of meteorological conditions has been removed. The CO short-term component is attributable to weather and short-term fluctuations in emissions. There is a significant seasonal cycle. This component is a result of changes in the traffic, the yearly meteorological cycle and the interactions between these two factors. There are peaks during the autumn and winter months, which have more traffic density in the sampled site. There is a minimum during the month of August, reflecting the very low level of vehicle emissions which is a direct consequence of the holiday period. The significant, decreasing trend implies to a certain extent that the urban environment in the area is improving. This trend results from changes in overall emissions, pollutant transport, climate, policy and economics. It is also due to the effect of introducing reformulated gasoline. The additives enable vehicles to burn fuel with a higher air/fuel ratio, thereby lowering the emission of CO. The KZ filter has been the most effective method to separate the CO series components and to obtain an estimate of the long-term trend due to changes in emissions, removing the effect of meteorological conditions. . Air quality managers and policy-makers must understand the link between climate and pollutants to select optimal pollutant reduction strategies and avoid exceeding emission directives. This paper analyses eight years of ambient CO data at a site with a high traffic density, and provides results that are useful for decision-making. The assessment of long-term changes in air pollutants to evaluate reduction strategies has to be done while taking into account meteorological variability.

Lifetime Recreational Exercise Activity and Breast Cancer Risk Among Black Women and White Women

Physical inactivity is a potentially modifiable breast cancer risk factor. Because few data on this relationship exist for black women, we examined the relationship between breast cancer risk and lifetime and time- or age-specific measures of recreational exercise activity among white women and among black women. The Women's Contraceptive and Reproductive Experiences Study was a multicenter population-based case-control study of black women and white women aged 35-64 years with newly diagnosed invasive breast cancer. We collected detailed histories of lifetime recreational exercise activity during in-person interviews with 4538 case patients with breast cancer (1605 black and 2933 white) and 4649 control subjects (1646 black and 3033 white). Control subjects were frequency-matched to case patients on age, race, and study site. We examined associations between exercise activity measures (metabolic equivalents of energy expenditure [MET]-hours per week per year) and breast cancer risk overall and among subgroups defined by race, other breast cancer risk factors, and tumor characteristics by use of unconditional logistic regression. All statistical tests were two-sided. Among all women, decreased breast cancer risk was associated with increased levels of lifetime exercise activity (e.g., average MET-hours per week per year, P(trend) = .002). An average annual lifetime exercise activity that was greater than the median level for active control subjects was associated with an approximately 20% lower risk of breast cancer, compared with that for inactivity (for 6.7-15.1 MET-hours/week/year, odds ratio [OR] = 0.82, 95% confidence interval [CI] = 0.71 to 0.93; for > or =15.2 MET-hours/week/year, OR = 0.80, 95% CI = 0.70 to 0.92). The inverse associations did not differ between black and white women (for MET-hours/week/year, P(trend) = .003 and P(trend) = .09, respectively; homogeneity of trends P = .16). No modification of risk was observed by disease stage, estrogen receptor status, or any breast cancer risk factor other than first-degree family history of breast cancer. This study supports an inverse association between physical activity and breast cancer among black women and among white women.

Incidence Trends of Adenocarcinoma of the Cervix in 13 European Countries

Rapid increases in cervical adenocarcinoma incidence have been observed in Western countries in recent decades. Postulated explanations include an increasing specificity of subtype-the capability to diagnose the disease, an inability of cytologic screening to reduce adenocarcinoma, and heterogeneity in cofactors related to persistent human papillomavirus infection. This study examines the possible contribution of these factors in relation with trends observed in Europe. Age-period-cohort models were fitted to cervical adenocarcinoma incidence trends in women ages <75 in 13 European countries. Age-adjusted adenocarcinoma incidence rates increased throughout Europe, the rate of increase ranging from around 0.5% per annum in Denmark, Sweden, and Switzerland to >/=3% in Finland, Slovakia, and Slovenia. The increases first affected generations born in the early 1930s through the mid-1940s, with risk invariably higher in women born in the mid-1960s relative to those born 20 years earlier. The magnitude of this risk ratio varied considerably from around 7 in Slovenia to almost unity in France. Declines in period-specific risk were observed in United Kingdom, Denmark, and Sweden, primarily among women ages >30. Whereas increasing specificity of subtype with time may be responsible for some of the increases in several countries, the changing distribution and prevalence of persistent infection with high-risk human papillomavirus types, alongside an inability to detect cervical adenocarcinoma within screening programs, would accord with the temporal profile observed in Europe. The homogeneity of trends in adenocarcinoma and squamous cell carcinoma in birth cohort is consistent with the notion that they share a similar etiology irrespective of the differential capability of screen detection. Screening may have had at least some impact in reducing cervical adenocarcinoma incidence in several countries during the 1990s.

Lifetime recreational exercise activity and risk of breast carcinoma in situ.

The incidence rates of breast carcinoma in situ (BCIS) have increased dramatically over the past two decades, primarily because of increased mammography screening. Ductal carcinoma in situ, which accounts for approximately 85% of BCIS and 10-20% of all breast carcinomas, is generally recognized as the final step in the progression to invasive disease. To the authors' knowledge, few studies have been conducted to date to evaluate BCIS risk factors. Because of its potential effects on circulating sex hormones, physical activity has been proposed as a modifiable risk factor for invasive breast carcinoma. However, the relation to BCIS risk is poorly understood. The authors analyzed data from a population-based case-control study conducted in Los Angeles County. Personal interviews were conducted with 567 white and black women (age range, 35-64 years) who had been newly diagnosed with BCIS between March 1, 1995 and May 31, 1998 and with 1026 control subjects, of whom 616 were screened within 2 years of identification. After excluding unscreened control subjects (n = 410) and adjusting for potential confounding factors, the risk of BCIS was approximately 35% lower among women with any exercise activity compared with inactive women, although no significant trend was observed. The association between exercise activity and the risk of BCIS was modified by a family history of breast carcinoma. No reduction in risk was observed among women reporting a first-degree family history of breast carcinoma (homogeneity of trends P value = 0.02). The findings of the current study suggest that exercise activity may modify the risk of BCIS, particularly among women without a family history of breast carcinoma.

Effect of family history, obesity and exercise on breast cancer risk among postmenopausal women.

We examined effects of obesity and lifetime exercise patterns on postmenopausal breast cancer risk according to family history in a large population-based case control study conducted in Los Angeles County, California, because we hypothesized that both factors would affect risk through similar mechanistic pathways, and that their effects would be stronger among women with a family history. We studied 1883 postmenopausal breast cancer case subjects and 1628 postmenopausal control subjects ranging in age from 55-72 years. Cases were diagnosed with incident breast cancer in the late 1980s and 1990s. Controls were individually matched to case subjects on age, ethnic origin and neighborhood. In-person interviews determined known breast cancer risk factors including: height, weight, lifetime exercise, and family history of breast and other cancers. Breast cancer risk was raised among women who had at least 1 first-degree relative with breast cancer (odds ratio [OR] = 1.68; 95% confidence interval [CI] = 1.36-2.08). Risk increased with increasing levels of body-mass index (wt-kg/ht-m(2)) (p-trend = 0.005). Breast cancer risk was reduced among women who maintained, on average, 17.6 metabolic equivalent of energy expenditure (MET)-hr of activity/week from menarche onward (OR = 0.66; 95% CI = 0.48-0.90). Body-mass index, adjusted for lifetime exercise, was strongly associated with breast cancer risk among women with a positive family history of breast cancer (p-trend < 0.0001), but only weakly associated among women with no family history (p-trend = 0.08; homogeneity of trends p = 0.0005). In contrast, the risk reduction associated with exercise activity, adjusting for body-mass index, was limited to women without a family history of breast cancer (p-trend = 0.001; homogeneity of trends p = 0.005). Body-mass index and exercise activity, both modifiable risk factors for breast cancer, seem to have differential effects depending on a woman's family history of breast cancer, and may impact risk through different biological mechanisms.

Estimation of contribution of changes in classic risk factors to trends in coronary-event rates across the WHO MONICA Project populations

From the mid-1980s to mid-1990s, the WHO MONICA Project monitored coronary events and classic risk factors for coronary heart disease (CHD) in 38 populations from 21 countries. We assessed the extent to which changes in these risk factors explain the variation in the trends in coronary-event rates across the populations. In men and women aged 35-64 years, non-fatal myocardial infarction and coronary deaths were registered continuously to assess trends in rates of coronary events. We carried out population surveys to estimate trends in risk factors. Trends in event rates were regressed on trends in risk score and in individual risk factors. Smoking rates decreased in most male populations but trends were mixed in women; mean blood pressures and cholesterol concentrations decreased, bodymass index increased, and overall risk scores and coronary-event rates decreased. The model of trends in 10-year coronary-event rates against risk scores and single risk factors showed a poor fit, but this was improved with a 4-year time lag for coronary events. The explanatory power of the analyses was limited by imprecision of the estimates and homogeneity of trends in the study populations. Changes in the classic risk factors seem to partly explain the variation in population trends in CHD. Residual variance is attributable to difficulties in measurement and analysis, including time lag, and to factors that were not included, such as medical interventions. The results support prevention policies based on the classic risk factors but suggest potential for prevention beyond these.