Correction of biochemical reference intervals taking into account age characteristics in a multidisciplinary hospital

Introduction. The use of universal reference intervals for biochemical parameters without considering age may lead to systematic errors in the interpretation of laboratory results in elderly and senile patients, especially in the setting of a multidisciplinary hospital.

The objective of this study was to develop age-specific reference intervals for key biochemical parameters – creatinine, urea, and total protein – in patients of a multidisciplinary hospital.

Methods and materials. The research was conducted at the Clinical Diagnostic Laboratory of the City Multidisciplinary Hospital № 2 in St. Petersburg using retrospective data from 2024. More than 5,500 patients were included and divided into three age groups: 35–59, 60–74, and 75 years and older. Analytical measurements were performed on the Abbott Architect c8000 analyzer using standard methods. Reference intervals were calculated using the improved Hoffmann method, and the Kosmic model with covariate adjustment.

Results. The obtained intervals demonstrated a significant shift of boundaries compared with the manufacturer’s reference ranges, especially in elderly and senile patients. With increasing age, creatinine and urea levels increased, while total protein values decreased (p < 0.01 for all parameters). These results confirm the necessity of revising and implementing age-specific reference intervals in clinical laboratory practice.

Conclusion: The use of locally adapted reference values will improve the accuracy of biochemical data interpretation, reduce diagnostic errors, and ensure compliance with ISO 15189 requirements.

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