How to calculate sample size for different study designs in medical research?

Jaykaran Charan, Tamoghna Biswas, Jaykaran Charan, Tamoghna Biswas

Abstract

Calculation of exact sample size is an important part of research design. It is very important to understand that different study design need different method of sample size calculation and one formula cannot be used in all designs. In this short review we tried to educate researcher regarding various method of sample size calculation available for different study designs. In this review sample size calculation for most frequently used study designs are mentioned. For genetic and microbiological studies readers are requested to read other sources.

Keywords: Medical research; sample size; study designs.

Conflict of interest statement

Conflict of Interest: None.

References

    1. Jaykaran, Saxena D, Yadav P, Kantharia ND. Negative studies published in medical journals of India do not give sufficient information regarding power/sample size calculation and confidence interval. J Postgrad Med. 2011;57:176–7.
    1. Jaykaran, Yadav P, Kantharia ND. Reporting of sample size and power in negative clinical trials published in Indian medical journals. J Pharm Negative Results. 2011;2:87–90.
    1. Jaykaran, Saxena D, Yadav P. Negative studies published in Indian Medical journals are underpowered. Indian Pediatr. 2011;48:490–1.
    1. Naduvilath TJ, John RK, Dandona L. Sample size for ophthalmology studies. [Last cited in 2012 Sep 2];Indian J Ophthalmol [serial online] 2000 48:245. Available from: .
    1. Patra P. Sample size in clinical research, the number we need. Int J Med Sci Public Health. 2012;1:5–9.
    1. Shah H. How to calculate sample size in animal studies? Natl J Physiol Pharm Pharmacol. 2011;1:35–9.
    1. Kasiulevicius V, Sapoka V, Filipaviciute R. Sample size calculation in epidemiological studies. Gerontology. 2006;7:225–31.
    1. Cai J, Zeng D. Sample size/power calculation for case-cohort studies. Biometrics. 2004;60:1015–24.
    1. Festing MF, Altman DG. Guidelines for the design and statistical analysis of experiments using laboratory animals. Institute for Laboratory Animal Research. ILAR J. 2002;43:244–58.

Source: PubMed

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