Atormac
Neurology India
menu-bar5 Open access journal indexed with Index Medicus
  Users online: 51  
 Home | Login 
About Editorial board Articlesmenu-bullet NSI Publicationsmenu-bullet Search Instructions Online Submission Subscribe Videos Etcetera Contact
  Navigate Here 
 Search
 
  
 Resource Links
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
    Article in PDF (384 KB)
    Citation Manager
    Access Statistics
    Reader Comments
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this Article
   References

 Article Access Statistics
    Viewed1158    
    Printed22    
    Emailed0    
    PDF Downloaded33    
    Comments [Add]    

Recommend this journal

 


 
Table of Contents    
CORRESPONDENCE
Year : 2015  |  Volume : 63  |  Issue : 6  |  Page : 1005-1006

Age and sex matching in case control studies


Department of Community Medicine, Dr. Rajendra Prasad Government Medical College, Tanda, Himachal Pradesh, India

Date of Web Publication20-Nov-2015

Correspondence Address:
Sunil Kumar Raina
Department of Community Medicine, Dr. Rajendra Prasad Government Medical College, Tanda, Himachal Pradesh
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0028-3886.170110

Rights and Permissions



How to cite this article:
Raina SK. Age and sex matching in case control studies. Neurol India 2015;63:1005-6

How to cite this URL:
Raina SK. Age and sex matching in case control studies. Neurol India [serial online] 2015 [cited 2019 Dec 9];63:1005-6. Available from: http://www.neurologyindia.com/text.asp?2015/63/6/1005/170110


Sir,

I went through with interest the article entitled "A study on cognitive decline with respect to metabolic syndrome and inflammation in elderly Indians" published in Neurology India 2015;63:537-41.[1] It is being estimated that around 10-37% of the elderly population with dementia in developing countries are having potentially vulnerable living circumstances requiring long-term and specialized care.[2] Keeping in view the public health importance of this finding, the study on cognitive decline with respect to metabolic syndrome is a valuable addition to literature on dementia. The authors deserve credit for this. However, I have a small concern with the description used by the authors in the methodology part of this study. The authors have divided the study participants into two groups. The authors then state that the mean age in group 1 was 69.52 ± 6.69 years (maximum = 86 years, minimum = 61 years). The mean age in group 2 was 69.04 ± 6.76 years (maximum = 82 years, minimum = 60 years). Thus, both the groups had a similar age profile, and they were age matched. In the group 1, 40% (n = 20) were female and 60% (n = 30) were male subjects. In group 2, 48% (n = 24) were female and 52% (n = 26) were male subjects. Thus, the two groups were sex-matched. The statement on age and sex matching does not seem to be accurate as the figures for both the variables (age and sex) differ in the two groups. Matching is an important way of accounting for confounding in case-control studies. In matched studies, the most efficient allocation of a fixed number of controls is usually the one that sets the ratio of controls-to-cases to be approximately equal. [3] Therefore, for 20 females and 30 males in group 1, we should have 20 females and 30 males in group 2 also. If this is done, then we are matching for sex. Similarly in the age matching between two groups, authors need to reflect as to how a maximum age of 86 years (in group 1) was matched with the maximum age of 82 years (in group 2). This also assumes significance in view of the fact that age in itself is an important predictor of cognitive decline.[2]

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
  References Top

1.
Ghosh A, Biswas AK, Banerjee A. A study on cognitive decline with respect to metabolic syndrome and inflammation in elderly Indians. Neurol India 2015; 63:537-41.  Back to cited text no. 1
[PUBMED]  Medknow Journal  
2.
Raina SK, Raina S, Chander V, Grover A, Singh S, Bhardwaj A. Is dementia differentially distributed- A study on the prevalence of dementia in Migrant, Urban, Rural and Tribal elderly population of Himalayan region in northern India. North Am J Med Sci. 2014;6:172-7.  Back to cited text no. 2
    
3.
Miettine OS. Theoretical Epidemiology: Principles of Occurrence Research in Medicine. New York: John Wiley and Sons Inc; 1985. p. 66.  Back to cited text no. 3
    




 

Top
Print this article  Email this article
   
Online since 20th March '04
Published by Wolters Kluwer - Medknow