Ethnicity-based variations in biological reference interval- A systematic scoping review.

BACKGROUND

Biological reference intervals (RIs) are fundamental tools in clinical diagnostics, traditionally derived from geographically and ethnically homogeneous populations, predominantly of Western origin. Such generalized RIs often fail to account for variations arising from genetic, environmental, and lifestyle factors, which can impact clinical decision-making and contribute to health inequities, particularly in countries across Africa, India, and many other Southeast Asian nations. This scoping review investigates ethnicity-based variations in RIs for a range of biomarkers to highlight the importance of population-specific RIs.

METHODS

Adhering to the Joanna Briggs Institute (JBI) guidelines, this scoping review examined the literature on ethnicity-based RI variations across multiple biomarkers, including Von Willebrand factor, C-reactive protein, thyroid-stimulating hormone, albumin, creatinine, and more. Studies were identified via searches in MEDLINE (via PubMed), Embase, Scopus, and Web of Science up to December 30, 2024. Eligibility was determined using the Population-Concept-Context (PCC) framework, focusing on observational studies analysing ethnicity-specific differences. Data extraction and charting were performed using CADIMA software, with independent review by two authors to ensure consistency.

RESULTS

Out of 4,514 articles, a total of 15 studies met the inclusion criteria, encompassing multi-ethnic populations. Significant variations in biomarker levels were observed across ethnic groups, highlighting the inadequacy of generalized RIs. Notable differences included variations in lipid profiles, vitamin B12, and anti-Mullerian hormone levels. Regional distribution analysis highlighted gaps in research from underrepresented ethnic populations.

CONCLUSION

This review emphasizes the critical need for ethnicity-specific RIs to improve diagnostic accuracy and promote equitable healthcare outcomes. Further research should focus on developing robust methodologies for establishing inclusive and representative RIs.