Indian journal of Medical Biochemistry

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VOLUME 24 , ISSUE 1 ( January-April, 2020 ) > List of Articles


Utilization of Hospital Laboratory Data for Establishing Normal Reference Interval of Quantitative Medical Parameters: Double Filtration Method

Abhaya Indrayan, Mohini Bhargava, Shubham Shukla

Keywords : Laboratory data, Normal values, Reference interval,Double filtration method

Citation Information : Indrayan A, Bhargava M, Shukla S. Utilization of Hospital Laboratory Data for Establishing Normal Reference Interval of Quantitative Medical Parameters: Double Filtration Method. Indian J Med Biochem 2020; 24 (1):9-11.

DOI: 10.5005/jp-journals-10054-0130

License: CC BY-NC 4.0

Published Online: 22-08-2020

Copyright Statement:  Copyright © 2020; Jaypee Brothers Medical Publishers (P) Ltd.


Background: India and other developing countries need their own reference intervals for various medical parameters because these populations differ from Western population for the genetic profile, anatomical structure, dietary habits, and lifestyle. Such reference intervals have not been worked out so far for most parameters because it is difficult to have a large database on healthy people in these countries. Aims and objectives: Large hospitals generally have a huge database of laboratory values but a substantial proportion of them belong to sick subjects whose values cannot be included for establishing normal reference intervals. Thus, the database remains unutilized. We propose a simple method to utilize these data for establishing reference intervals. Materials and methods: A simple double filtration method is used to exclude all outliers and abnormal values that could finally provide uncontaminated data on healthy values. This method is based on quartiles and interquartile range. The method is illustrated on a dataset from the laboratory of a large tertiary care hospital. Results: The filtered values have been seen to follow a smooth distribution pattern and can be used to establish our reference intervals using the usual 2.5th and 97.5th percentiles. The method is illustrated for A/G ratio in the data from our hospital, and the reference interval obtained. Conclusion: Double filtration method can be used on hospital laboratory data to establish reference intervals of medical parameters.

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  1. Sairam S, Domalapalli S, Muthu S. Hematological and biochemical parameters in apparently healthy Indian population: defining reference intervals. Indian J Clin Biochem 2014;29(3):290–297. DOI: 10.1007/s12291-013-0365-5.
  2. Lang RM, Bierig M, Devereux RB, et al. Recommendations for chamber quantification. Eur J Echocardiogr 2006;7(2):79–108. DOI: 10.1016/j.euje.2005.12.014.
  3. Indrayan A, Malhotra RK. Medical Biostatistics. 4th ed., Chapman & Hall/CRC Press; 2018. pp. 239–244.
  4. Everitt BS, Palmer CR. Encyclopedic Companion to Medical Statistics. Wiley; 2011. p. 276.
  5. Manikandan S. Measures of dispersion. J Pharmacol Pharmacother 2011;2(4):315–316. DOI: 10.4103/0976-500X.85931.
  6. Indrayan A, Holt MP. Concise Encyclopedia of Biostatistics for Medical Professionals. Chapman & Hall/CRC Press; 2017. p. 427.
  7. CLSI Clinical and Laboratory Standards Institute. EP 28-A3c: Defining, Establishing, and Verifying Reference Intervals as in the Clinical Laboratory – Approved Guidelines, Third Edition. CLSI 2010: p. 2.
  8. Walker BR, Colledge NR, Ralston SH, et al. Davidson's principles & practice of medicine. 22nd ed., Churchill Livingstone–Elsevier; 2014. p. 5.
  9. Furruqh S, Anitha D, Venkatesh T. Estimation of reference values in liver function test in health plan individuals of an urban south Indian population. Ind J Clin Biochem 2004;19(2):72–79. DOI: 10.1007/BF02894260.
  10. Myeloma, Understanding your lab results.
  11. Partlett C, Riley RD. Random effects meta-analysis: coverage performance of 95% confidence and prediction intervals following REML estimation. Stat Med 2017;36(2):301–317. DOI: 10.1002/sim.7140.
  12. Tate JR, Myers GL. Harmonization of clinical laboratory test results. E J Int Fed Clin Chem 2016;27:5–14.
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