Testing the Optimality of Two Different Non-Parametric Discriminant Methods

This paper aims at comparing the concept of data depth to classification and classification by projection pursuit using method of linear discriminant function. These two methods allow the extension of univariate concepts to the field of multivariate analysis. In particular they open the possibility of non-parametric methods to be used in multivariate data analysis. In this study, six simulated and one real life data sets were studied and, we observed that projection pursuit method is more optimal in classifying objects into their original groups

Global burden and strength of evidence for 88 risk factors in 204 countries and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

Background: Understanding the health consequences associated with exposure to risk factors is necessary to inform public health policy and practice. To systematically quantify the contributions of risk factor exposures to specific health outcomes, the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 aims to provide comprehensive estimates of exposure levels, relative health risks, and attributable burden of disease for 88 risk factors in 204 countries and territories and 811 subnational locations, from 1990 to 2021. Methods: The GBD 2021 risk factor analysis used data from 54 561 total distinct sources to produce epidemiological estimates for 88 risk factors and their associated health outcomes for a total of 631 risk–outcome pairs. Pairs were included on the basis of data-driven determination of a risk–outcome association. Age-sex-location-year-specific estimates were generated at global, regional, and national levels. Our approach followed the comparative risk assessment framework predicated on a causal web of hierarchically organised, potentially combinative, modifiable risks. Relative risks (RRs) of a given outcome occurring as a function of risk factor exposure were estimated separately for each risk–outcome pair, and summary exposure values (SEVs), representing risk-weighted exposure prevalence, and theoretical minimum risk exposure levels (TMRELs) were estimated for each risk factor. These estimates were used to calculate the population attributable fraction (PAF; ie, the proportional change in health risk that would occur if exposure to a risk factor were reduced to the TMREL). The product of PAFs and disease burden associated with a given outcome, measured in disability-adjusted life-years (DALYs), yielded measures of attributable burden (ie, the proportion of total disease burden attributable to a particular risk factor or combination of risk factors). Adjustments for mediation were applied to account for relationships involving risk factors that act indirectly on outcomes via intermediate risks. Attributable burden estimates were stratified by Socio-demographic Index (SDI) quintile and presented as counts, age-standardised rates, and rankings. To complement estimates of RR and attributable burden, newly developed burden of proof risk function (BPRF) methods were applied to yield supplementary, conservative interpretations of risk–outcome associations based on the consistency of underlying evidence, accounting for unexplained heterogeneity between input data from different studies. Estimates reported represent the mean value across 500 draws from the estimate's distribution, with 95% uncertainty intervals (UIs) calculated as the 2·5th and 97·5th percentile values across the draws. Findings: Among the specific risk factors analysed for this study, particulate matter air pollution was the leading contributor to the global disease burden in 2021, contributing 8·0% (95% UI 6·7–9·4) of total DALYs, followed by high systolic blood pressure (SBP; 7·8% [6·4–9·2]), smoking (5·7% [4·7–6·8]), low birthweight and short gestation (5·6% [4·8–6·3]), and high fasting plasma glucose (FPG; 5·4% [4·8–6·0]). For younger demographics (ie, those aged 0–4 years and 5–14 years), risks such as low birthweight and short gestation and unsafe water, sanitation, and handwashing (WaSH) were among the leading risk factors, while for older age groups, metabolic risks such as high SBP, high body-mass index (BMI), high FPG, and high LDL cholesterol had a greater impact. From 2000 to 2021, there was an observable shift in global health challenges, marked by a decline in the number of all-age DALYs broadly attributable to behavioural risks (decrease of 20·7% [13·9–27·7]) and environmental and occupational risks (decrease of 22·0% [15·5–28·8]), coupled with a 49·4% (42·3–56·9) increase in DALYs attributable to metabolic risks, all reflecting ageing populations and changing lifestyles on a global scale. Age-standardised global DALY rates attributable to high BMI and high FPG rose considerably (15·7% [9·9–21·7] for high BMI and 7·9% [3·3–12·9] for high FPG) over this period, with exposure to these risks increasing annually at rates of 1·8% (1·6–1·9) for high BMI and 1·3% (1·1–1·5) for high FPG. By contrast, the global risk-attributable burden and exposure to many other risk factors declined, notably for risks such as child growth failure and unsafe water source, with age-standardised attributable DALYs decreasing by 71·5% (64·4–78·8) for child growth failure and 66·3% (60·2–72·0) for unsafe water source. We separated risk factors into three groups according to trajectory over time: those with a decreasing attributable burden, due largely to declining risk exposure (eg, diet high in trans-fat and household air pollution) but also to proportionally smaller child and youth populations (eg, child and maternal malnutrition); those for which the burden increased moderately in spite of declining risk exposure, due largely to population ageing (eg, smoking); and those for which the burden increased considerably due to both increasing risk exposure and population ageing (eg, ambient particulate matter air pollution, high BMI, high FPG, and high SBP). Interpretation: Substantial progress has been made in reducing the global disease burden attributable to a range of risk factors, particularly those related to maternal and child health, WaSH, and household air pollution. Maintaining efforts to minimise the impact of these risk factors, especially in low SDI locations, is necessary to sustain progress. Successes in moderating the smoking-related burden by reducing risk exposure highlight the need to advance policies that reduce exposure to other leading risk factors such as ambient particulate matter air pollution and high SBP. Troubling increases in high FPG, high BMI, and other risk factors related to obesity and metabolic syndrome indicate an urgent need to identify and implement interventions

Tuberculosis and HIV/AIDS coinfection in patients attending Directly Observed Treatment Short‐course (DOTS) centers in Anambra State, Nigeria: A retrospective study

Background and Aim(S)This study retrospectively assessed the prevalence of TB and human immunodeficiency virus (HIV)/AIDS coinfection among patients that attended the Directly Observed Treatment Short-course (DOTS) centers in Anambra State, Southeast, Nigeria, between 2013 and 2017.MethodsThe study adopted a descriptive and retrospective epidemiological survey design. A total of 1443 case files of patients aged 15−60 who were treated in DOTS centers selected from Anambra State's 21 Local Government Areas between 2013 and 2017 were investigated. The uniform data form, a standardized instrument used in Anambra State's health facilities for data collection, was used to collect data from case files of all those identified as coinfected with TB and HIV/AIDS.ResultsThe mean prevalence rate of TB and HIV/AIDS coinfection in the state during the 5-year period (2013–2017) was 20.00%. The highest annual prevalence of TB and HIV/AIDS coinfection was recorded in 2014 (23.84%). The state's prevalence of TB and HIV/AIDS coinfection increased dramatically from 13.17% in 2013 to 23.84% in 2014, followed by a slight downward trend to 22.80% in 2015, 20.17% in 2016, and 20.03% in 2017. In terms of gender, age, marital status, and occupation, females (59.5%), those aged 15 to 25 years (30.7%), married people (43.90%), and traders/business owners (50.7%), respectively, had the highest rates of tuberculosis and HIV/AIDS coinfection during the study period.ConclusionThe findings of this study show that young people, females, married people, and traders/business owners appear to be the most vulnerable groups affected by TB and HIV/AIDS coinfection, accounting for the majority of the disease burden in the state. To address the high prevalence of TB and HIV/AIDS coinfection in the Anambra State, novel intervention and control programs should be developed and implemented, and existing intervention frameworks should be strengthened