REQUIRED SAMPLE SIZE FOR COMPARING PROPORTIONS IN TWO INDEPENDENT SAMPLES
https://doi.org/10.22328/2413-5747-2020-6-3-76-83
Abstract
This paper continues our series of articles on required sample size for the most common basic statistical tests used in biomedical research. Sample size calculations are rarely performed in research planning in Russia often resulting in Type II errors, i.e. on acceptance on false null hypothesis due to insufficient sample size. The most common statistical test for analyzing proportions in independent samples is Pearson’s chi-squared test. In this paper we present a simple algorithm for calculating required sample size for comparing two independent proportions. In addition to manual calculations we present a step-by-step guide on how to use WinPepi and Stata software for calculating sample size for independent proportions. In addition, we present a table for junior researchers with already calculated sample sizes for comparing proportions from 0,1 to 0,9 by 0,1 with 95% confidence level and 80% statistical power.
About the Authors
A. M. Grjibovski
Northern State Medical University; North-Eastern Federal University
Russian Federation
Russian Federation
M. A. Gorbatova
Northern State Medical University
Russian Federation
Russian Federation
A. N. Narkevich
Рrofessor V. F. Voyno-Yasenetsky Krasnoyarsk State Medical University
Russian Federation
Russian Federation
K. A. Vinogradov
Рrofessor V. F. Voyno-Yasenetsky Krasnoyarsk State Medical University
Russian Federation
Russian Federation
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Review
For citations:
Grjibovski A.M., Gorbatova M.A., Narkevich A.N., Vinogradov K.A. REQUIRED SAMPLE SIZE FOR COMPARING PROPORTIONS IN TWO INDEPENDENT SAMPLES. Marine Medicine. 2020;6(3):76-83. (In Russ.) https://doi.org/10.22328/2413-5747-2020-6-3-76-83
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