An ecological study is one where you take values of a variable for an entire population, the outcome from that population, and use that to draw inference. A cross-sectional study is where you look at individuals within a population at a single point in time.
What type of study is an ecologic study?
Ecologic studies are studies in which the unit of observation is a group, not separate individuals, for one or more study variables. For example, exposure and risk factors are known only at the group level, such as the average air pollution concentration in different cities.
What is the difference between cross-sectional and ecological studies?
Cross-sectional studies collect the data of the exposure variable and the outcome at the same time, to describe characteristics of the sample or to study associations. Ecological studies describe and analyze correlations among different variables, and the unit of analysis is aggregated data from multiple individuals.
What is an example of an ecological study?
Examples of the use of ecological studies include: Correlating population disease rates with factors of interest, such as healthcare use. Demonstrating changes in mortality over time (time series) Comparing the prevalence of a disease between different regions at a single point in time (geographical studies)
What is the 2 types of cross-sectional study?
Longitudinal studies and cross-sectional studies are two different types of research design. In a cross-sectional study you collect data from a population at a specific point in time; in a longitudinal study you repeatedly collect data from the same sample over an extended period of time.
What is an ecologic study design?
An ecological study is an observational study defined by the level at which data are analysed, namely at the population or group level, rather than individual level. … They are inexpensive and easy to carry out, using routinely collected data, but they are prone to bias and confounding.
Are ecologic studies expensive?
Ecologic Studies: A- are expensive and require a great deal of time to conduct. D- Exposure and disease histories are collected simultaneously. In case-control studies, the odds ratio is used as an estimate of the relative risk.
What is an ecological study in epidemiology?
Ecological studies are epidemiological evaluations in which the unit of analysis is populations, or groups of people, rather than individuals. … Individual-level variables are properties of each person whereas ecological variables are properties of groups, organizations, or places.
Are ecologic studies retrospective or prospective?
However, because these studies collect data after disease has already occurred, they are considered retrospective, which is a limitation.
In what situations might a researcher choose an ecologic level study over an individual level study?
Ecological studies are used when data at an individual level is unavailable, or large-scale comparisons are needed to study the population-level effect of exposures on a disease condition. Therefore, ecological study results are applicable only at the population level.
What is cross-sectional study in epidemiology?
Cross-sectional studies measure the cause (exposure) and the effect (disease) at the same point in time. They compare the rates of diseases or symptoms of an exposed group with an unexposed group. Strictly speaking, the exposure information is ascertained simultaneously with the disease information.
What are epidemiological studies?
By definition, epidemiology is the study (scientific, systematic, and data-driven) of the distribution (frequency, pattern) and determinants (causes, risk factors) of health-related states and events (not just diseases) in specified populations (neighborhood, school, city, state, country, global).
What are the 3 basic methods of ecological research?
ecological research methods include observation, experimentation, and modeling. Ecological research involves many different methods and tools. Three main components of ecological research are observation, experimenta- tion, and modeling.