Is 30 The Magic Number? Issues In Sample Size Estimation

Authors

  • Sitanshu Sekhar Kar JIPMER, Pondicherry
  • Archana Ramalingam JIPMER, Pondicherry

Keywords:

sample size, estimation, epidemiological studies, Open Epi

Abstract

Research has become mandatory for career advancement of medical graduates. Researchers are often confounded by issues related to calculation of the required sample size. Various factors like level of significance, power of the study, effect size, precision and variability affect sample size. Also design issues like sampling technique and loss to follow up need to be considered before calculating sample size. Once these are understood, the researcher can estimate the required sample size using softwares like Open Epi. Correct estimation of sample size is important for the internal validity of the study and also prevents unnecessary wastage of resources.

References

Medical council of India Postgraduate medical education regulations, 2000 (amended up to December, 2010) [Internet]. [Cited on 16/2/2012]. Available from: http://www.mciindia.org/rules-and-regulation/Postgraduate-Medical-Education-Regulations-2000.pdf

Minimum Qualifications for Teachers in Medical Institutions Regulations, 1998 (amended up to November, 2010). MCI. [Internet]. [Cited on 16/2/2012]. Available from: http://www.mciindia.org/rules-and-regulation/Teachers-Eligibility-Qualifications-Rgulations-1998.pdf

Marlies Noordzij, Giovanni Tripepi, Friedo W. Dekker, Carmine Zoccali, Michael W. Tanck,Kitty J. Jager. Sample size calculations: basic principles and common pitfalls. Nephrol Dial Transplant (2010) 25: 1388–1393

Frederick J Gravetter, Larry B Wallnau. Statistics for the behavioral sciences 8th edition. Wadsworth, Cengage learning. 2009.

Betty R Kirkwood, Jonathan A C Sterne 2nd edition. Massachusetts. Blackwell Science Ltd. 2003. P 420

OpenEpi [Internet]. Wikipedia, the free encyclopedia. 2012 [cited 2012 Oct 7]. Available from: http://en.wikipedia.org/w/index.php?title=OpenEpi&oldid=486949640

Dean AG, Sullivan KM, Soe MM. OpenEpi: Open Source Epidemiologic Statistics for Public Health, Version 2.3. [Home page from Intenet] [updated 2011/23/06 ; cited on 2012/02/16]. Available from: http://www.openepi.com/OE2.3/Menu/OpenEpiMenu.htm

Betty R Kirkwood, Jonathan A C Sterne 2nd edition. Massachusetts. Blackwell Science Ltd. 2003. p423.

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Published

2013-03-31

How to Cite

1.
Kar SS, Ramalingam A. Is 30 The Magic Number? Issues In Sample Size Estimation. Natl J Community Med [Internet]. 2013 Mar. 31 [cited 2024 Mar. 28];4(01):175-9. Available from: https://njcmindia.com/index.php/file/article/view/1489

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Section

Short Communication