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Equine veterinary journal2025; doi: 10.1111/evj.14454

Review of biological variation and its applications in interpretation of equine clinical pathology results.

Abstract: Biological variation in laboratory results refers to physiological fluctuations that occur around a homeostatic setpoint (HSP) for various laboratory measurands. Assessment of biological variation includes determining individual variation (CV), group variation (CV), and analytical variation (CV). Reference change value (RCV) is an objective tool for an evidence-based approach to interpret data by assessing the significance of consecutive results in an individual for the diagnosis, prognosis, and monitoring of disease. The individualised reference intervals (iRI) are derived from the determination of the HSP for an individual and the RCV. Evaluation of dispersion (DI) of results around any numerical result, reference interval limit, or recommended cut-off value can help define grey zones in clinical data interpretation. The Index of Individuality (II), which compares the amount of biological variation in a group (CV) relative to the amount of biological variation in an individual (CV), is useful to determine if 95% population-based or iRI would be more valuable to detect a significant change in a measurand. The critical number of specimens provides confidence in a defined probability needed for the estimation of the HSP for laboratory measurands. Biological variation data may help support or disprove empirically derived or consensus-derived interpretation recommendations. Biological variation data has the potential to improve the diagnostic accuracy of clinical laboratory testing. Examples of these applications are included.
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Publication Date: 2025-01-02 PubMed ID: 39748488DOI: 10.1111/evj.14454Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The researchers analyzed how biological variation in lab results, caused by natural fluctuations in the body, influences the interpretation of results in equine veterinary medicine.

Understanding Biological Variation

  • The study focuses on the concept of biological variation, which refers to the physiological fluctuations in lab results that happen around a homeostatic setpoint (HSP) for various laboratory measurements.
  • Biological variation is assessed by looking at individual variation, group variation, and analytical variation. All these variations are represented as coefficients of variation (CV).

Reference Change Value and Individualised Reference Intervals

  • Reference Change Value (RCV) is a tool used to make sense of data by checking the relevance of results over time in a specific individual. This helps in diagnosing, forecasting, and monitoring diseases.
  • The researchers also discussed individualised reference intervals (iRI), which are derived from establishing an individual’s HSP and their RCV.

Evaluation of Dispersion and Index of Individuality

  • The dispersion of results around a numerical result, limit of a reference interval, or a recommended cut-off value helps to define uncertain areas in interpreting clinical data.
  • The Index of Individuality (II) is a tool used to determine if a 95% population-based measurement or an individualised reference interval (iRI) is more valuable in detecting a significant change in a measurement.

Critical Number of Specimens

  • A ‘critical number of specimens’ concept provides confidence in a defined probability necessary for determining the HSP for laboratory measurements.

Applications and Implications of Biological Variation

  • Data on biological variation can help either support or disprove recommendations on interpretation that have been derived either from empirical data or consensus.
  • Understanding biological variation has the potential to enhance the diagnostic accuracy of clinical lab testing.
  • The article also provides examples of how understanding and applying these concepts can be beneficial in equine veterinary medicine.

Cite This Article

APA
Fernandes T, Robin M, Freeman KP. (2025). Review of biological variation and its applications in interpretation of equine clinical pathology results. Equine Vet J. https://doi.org/10.1111/evj.14454

Publication

Equine veterinary journal
ISSN: 2042-3306
NlmUniqueID: 0173320
Country: United States
Language: English

Researcher Affiliations

Fernandes, T
  • Equine Veterinary Medical Center, Doha, Qatar.
Robin, Matthew
  • Equine Veterinary Medical Center, Doha, Qatar.
Freeman, Kathleen P
  • Veterinary Information Network, Davis, California, USA.

References

This article includes 15 references
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