What are age matched controls?
Age and sex matching of controls means a similar proportion to the cases fall into the various categories defined by the matching variable (sex and age in this study). For instance, if 25% of the cases are males aged 65-75 years, 25% of the controls would be taken to have similar characteristics.
What is an age matched control Why is it important to include in this type of study?
Age- and sex- matched controls are essential because biologic characteristics can be modified by age and sex, in ways both known and unknown. For example, young children have higher absolute lymphocyte counts on peripheral blood than adults.
What is the purpose of matching?
The goal of matching is to reduce bias for the estimated treatment effect in an observational-data study, by finding, for every treated unit, one (or more) non-treated unit(s) with similar observable characteristics against who the covariates are balanced out.
What is a matched control study?
The Matched Pair Case-Control Study calculates the statistical relationship between exposures and the likelihood of becoming ill in a given patient population. This study is used to investigate a cause of an illness by selecting a non-ill person as the control and matching the control to a case.
What is a matched control?
2.1. In an individually matched case-control study, the population of interest is identified, and cases are randomly sampled or selected based on particular inclusion criteria. Each of these cases is then matched to one or more controls based on a variable (or variables) believed to be a confounder.
What are the benefits of matching in a case-control study?
Firstly, matching in case-control studies ensures that the matching factors, such as age or sex, are equally distributed between cases and controls. Although matching thus removes the original confounding effect of these factors, it may introduce a new bias.
What are matched cases?
What does matched control group mean?
noun. Statistics. (More fully “matched control group”) a control group of individuals selected to resemble an experimental group in all properties except the one under investigation.
How many controls are in a case?
Investigators planning case-control studies are usual- ly advised to include no more than four or five controls per case because little statistical power is gained by fur- ther increasing this ratio (1,2).
What is matched control?
In an individually matched case-control study, the population of interest is identified, and cases are randomly sampled or selected based on particular inclusion criteria. Each of these cases is then matched to one or more controls based on a variable (or variables) believed to be a confounder.
Why are matched controls important?
Why do you need to control for age in a matched study?
Thus, matching has not removed age confounding and it is still necessary to control for age (this occurs because the matching process in a case-control study changes the association between the matching factor and the outcome and can create an association even if there were none before the matching was conducted).
When to use age as an age factor?
age-matched control. in a comparison of performance between groups it is desirable to create the groups by pairing a series of treatment animals and control animals for all significant variables, of which age would be one of the most important.
Do you need to control for Matching factors in a matched design?
Thus, a matched design may require controlling for the matching factors in the analysis. However, it is not the case that a matched design requires a matched analysis.
How does the matching process affect exposure analysis?
In essence, the matching process makes the controls more similar to the cases not only for the matching factor but also for the exposure itself. This introduces a bias that needs to be controlled in the analysis.