backgroundseveral studies have examined the relationship between human development index (hdi) and various health outcomes. the aim of this study was to investigate the relationship between hdi, and infant mortality rate, mortality rate of children under one year and under 5 years, maternal mortality rate, and total fertility rate.materials and methodsin this ecologic study, data on hdi, total ...

background: maternal mortality (mm) is an avoidable death andthere is national, international and political commitment to reduceit. the objective of this study is to examine the relation of mm tosocioeconomic factors and its inequality in iran’s provinces at anecologic level.methods: the overall mm from each province was considered for3 years from 2004 to 2006. the five independent variables wh...

background and aims: air pollution is one of the health problems worldwide. previous epidemiological studies have investigated the impacts of air pollution on respiratory and cardiovascular diseases. the aim of this study was to determine the associations between air pollution levels and different health indicators among world countries. methods: this ecological study was performed in 2013 by u...

This paper summarizes the salient features of the ecologic method, with emphasis on its application in the study of environmental health. Various types of ecologic design are described, with examples. Finally, the main advantages and disadvantages are indicated. A companion paper discusses the methodology of ecologic designs in more detail and describes a census of data sets with potential suit...

Ecologic studies use data aggregated over groups rather than data on individuals. Such studies are popular because they use existing databases and can offer large exposure variation if the data arise from broad geographical areas. Unfortunately, the aggregation of data that define ecologic studies results in an information loss that can lead to ecologic bias. Specifically, ecologic bias arises ...

Atmospheric leakage between a CELSS and its surround is driven by the differential pressure between the two. In an earth-based CELSS, both negative and positive differential pressures of atmosphere are created as the resultant of three influences: thermal expansion/contraction, transition of water between liquid and vapor phases, and external barometric pressure variations. The resultant may ty...

BACKGROUND As ecologic studies are often inexpensive to conduct, consideration of the magnitude and direction of ecologic biases may be useful in both study design and sensitivity analysis of results. This paper examines three types of ecologic bias: confounding by group, effect measure modification by group, and non-differential exposure misclassification. METHODS Bias of the risk difference...

A number of authors have attempted to defend ecologic (aggregate) studies by claiming that the goal of those studies is estimation of ecologic (contextual or group-level) effects rather than individual-level effects. Critics of these attempts point out that ecologic effect estimates are inevitably used as estimates of individual effects, despite disclaimers. A more subtle problem is that ecolog...

The ecologic study design is routinely used by epidemiologists in spite of its limitations. It is presently unknown how well the challenges of the design are dealt with in epidemiologic research. The purpose of this bibliometric review was to critically evaluate the characteristics, statistical methods, and reporting of results of modern cross-sectional ecologic papers. A search through 6 major...

Ecologic niche modeling has allowed numerous advances in understanding the geographic ecology of species, including distributional predictions, distributional change and invasion, and assessment of ecologic differences. We used this tool to characterize ecologic differentiation of Triatoma brasiliensis populations, the most important Chagas' disease vector in northeastern Brazil. The species' e...