Indian Journal of Pathology and Microbiology
Home About us Instructions Submission Subscribe Advertise Contact e-Alerts Ahead Of Print Login 
Users Online: 1515
Print this page  Email this page Bookmark this page Small font sizeDefault font sizeIncrease font size
Year : 2023  |  Volume : 66  |  Issue : 1  |  Page : 85-90

Z score analysis: A novel approach to interpretation of an erythrogram

1 Department of Pathology, Polo Labs, Mohali, Punjab, India
2 Department of Pathology, Polo Labs, Ivy Hospital, Mohali, Punjab, India
3 Department of Pathology, Dr. Ahujas' Pathology and Radiology Collection Centre, Dehradun, Uttarakhand, India

Correspondence Address:
Kriti Chauhan
F-317, Industrial Area, Sector 74, Sahibzada Ajit Singh Nagar, Punjab – 160 071
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijpm.ijpm_1188_21

Rights and Permissions

Context: Z score defines the shift of an observed value from the mean. Aims: By determining the direction of this shift and its absolute value for mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC), one can quickly screen the hemogram for any spurious results in RBC parameters and also predict the type of anemia. This is because MCH and MCHC are derived parameters (from Hb, RBC, MCV) and thereby reflect the true as well as false changes in an erythrogram. Materials and Methods: A total of 975 hemograms were studied retrospectively. Basic statistical formulae using mean and standard deviation were applied to calculate z scores for MCH and MCHC. Results obtained were compared with the standard method and validated by an independent cohort of 100 random samples run on a different machine. Results and Statistical Analysis: Z score was found to be statistically significant (p <.001) in diagnosing iron deficiency anemias, megaloblastic anemias, hemolytic anemias, regenerative anemias, anemia of chronic disease and spurious findings. Z score was not significant (p = 0.9) in predicting beta thalassemia trait. The sensitivity was low for the differentials of microcytic hypochromic anemias. Conclusions: Despite this, Z score can be of immense help to the clinicians and pathologists in making quick interpretation of the underlying red cell abnormalities. Also, it can be used as a quality assessment tool in hematology laboratories taking pre analytical and analytical factors into account.

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
    PDF Downloaded25    
    Comments [Add]    

Recommend this journal