Indian Journal of Dermatology
  Publication of IADVL, WB
  Official organ of AADV
Indexed with Science Citation Index (E) , Web of Science and PubMed
 
Users online: 3713  
Home About  Editorial Board  Current Issue Archives Online Early Coming Soon Guidelines Subscriptions  e-Alerts    Login  
    Small font sizeDefault font sizeIncrease font size Print this page Email this page


 
Table of Contents 
CORRESPONDENCE
Year : 2018  |  Volume : 63  |  Issue : 1  |  Page : 82
Critical comment on “Vitamin D level in alopecia areata”


1 Centre for Nursing Research and Community Empowerment, Mother Mary's Institute of Nursing, Hoshiarpur, Punjab, India
2 Department of Community Medicine, School of Public Health, PGIMER, Chandigarh, India

Date of Web Publication13-Feb-2018

Correspondence Address:
Radha Saini
Centre for Nursing Research and Community Empowerment, Mother Mary's Institute of Nursing, Hoshiarpur, Punjab
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/ijd.IJD_552_17

Rights and Permissions



How to cite this article:
Saini R, Kaushal K. Critical comment on “Vitamin D level in alopecia areata”. Indian J Dermatol 2018;63:82

How to cite this URL:
Saini R, Kaushal K. Critical comment on “Vitamin D level in alopecia areata”. Indian J Dermatol [serial online] 2018 [cited 2019 Nov 21];63:82. Available from: http://www.e-ijd.org/text.asp?2018/63/1/82/225316




Sir,

We appreciate the article “Vitamin D level in alopecia areata” published in Indian J Dermatol 2017;62:407-10 and for raising an important issue of highlighting the importance of Vitamin D in the treatment of patients with alopecia areata (AA).[1]

In the Material and Methods, the authors have mentioned that “This was a hospital-based cross-sectional study involving 50 patients of AA. The control group consisted of 35 age- and sex-matched individuals selected randomly from our OPD with no history of AA.”

However, we have a few concerns related to the methodology being adopted by the authors. First, the authors have clearly written that it is a cross-sectional study, but they have chosen cases and controls. The outline of methodology sounds confusing. The authors might be saying comparison group rather than age and sex-matched controls. How were the alopecia areata (AA) patients recruited in the study? Were all these patients, that is, cases recruited consecutively by the authors or were they taken randomly among many patients of AA visiting the outpatient department?

It is not clear in the study as to how the authors have calculated the sample size of 50 patients in case group and 35 in control group. In cross-sectional studies, the aim is to estimate the prevalence of unknown parameter(s) from the target population using a random sample. Hence, an adequate sample size is needed to estimate the population prevalence with good precision.[2] If the sample size is too small, the investigator may not be able to answer the study question. In this study, the sample size is 85. It is difficult to derive causal relationships from a cross-sectional analysis.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
   References Top

1.
Bhat YJ, Latif I, Malik R, Hassan I, Sheikh G, Lone KS, et al. Vitamin D level in alopecia areata. Indian J Dermatol 2017;62:407-10.  Back to cited text no. 1
[PUBMED]  [Full text]  
2.
Pourhoseingholi MA, Vahedi M, Rahimzadeh M. Sample size calculation in medical studies. Gastroenterol Hepatol Bed Bench 2013;6:14-7.  Back to cited text no. 2
[PUBMED]    




 

Top
Print this article  Email this article
 
 
  Search
 
  
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
    Article in PDF (254 KB)
    Citation Manager
    Access Statistics
    Reader Comments
    Email Alert *
    Add to My List *
* Registration required (free)  


    References

 Article Access Statistics
    Viewed987    
    Printed10    
    Emailed0    
    PDF Downloaded49    
    Comments [Add]    

Recommend this journal