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Sample size: how many participants do I need in my research?
Jeovany Martínez-Mesa1, David Alejandro González-Chica2, João Luiz Bastos2
1Latin American Cooperative Oncology Group, Porto Alegre, RS, Brazil.
Abstract:
The importance of estimating sample sizes is rarely understood by researchers, when planning a study. This paper aims to highlight the centrality of sample size estimations in health research. Examples that help in understanding the basic concepts involved in their calculation are presented. The scenarios covered are based more on the epidemiological reasoning and less on mathematical formulae. Proper calculation of the number of participants in a study diminishes the likelihood of errors, which are often associated with adverse consequences in terms of economic, ethical and health aspects.
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