• Users Online: 274
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 
REVIEW ARTICLE
Year : 2020  |  Volume : 6  |  Issue : 2  |  Page : 123-131

Basic principles of sample size calculation


Department of Biostatistics, All India Institute of Medical Sciences, New Delhi, India

Correspondence Address:
Dr. Shivam Pandey
Department of Biostatistics, All India Institute of Medical Sciences, New Delhi
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jpcs.jpcs_34_20

Rights and Permissions

The calculation of sample size helps a medical researcher to assess cost, time, and feasibility of his project besides scientific justification and validity. Although frequently reported in journals, the details or the elements of sample size calculation are not consistently provided by the authors. Sample size calculations reported do not match with replication of sample size in many studies. Most trials with negative results do not have a large enough sample size. Hence, reporting of sample size and power needs to be improved. The sample size calculation can be guided by previous literature, pilot studies, and past clinical experiences. The collaborative effort of the researcher and the statistician is required at this stage. Estimated sample size is our best guess. Issues such as anticipated loss to follow-up, large subgroup analysis, and complicated study designs, demand a large sample size to ensure power throughout the trial. The present article will help the reader understand the importance of pilot study in sample size estimation, second understand the relationship between primary objective and sample size of a study, third understand the essential components required in a sample size estimation, and fourth calculate sample sizes using real-life examples using an online software.


[FULL TEXT] [PDF]*
Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)
 

 Article Access Statistics
    Viewed124    
    Printed2    
    Emailed0    
    PDF Downloaded46    
    Comments [Add]    

Recommend this journal