# Verification of reference intervals for routine biochemical tests using the reflimR in Turkish adults

## TL;DR

This study verifies reference intervals for 19 biochemical tests in Turkish adults using the reflimR method and compares them with manufacturer-provided values.

## Contribution

The study introduces reflimR as a potential rapid method for reference interval verification in a Turkish population.

## Key findings

- 40 of 76 reference interval limits were accepted using reflimR, while 21 required checking and 15 were rejected.
- Discrepancies were observed in ALT, GGT, and total bilirubin tests when comparing reflimR with other methods.
- Verification failures may be due to differences in ethnicity, sex, age, and geographic factors between populations.

## Abstract

This study aimed to verify the reference interval(s) (RIs) for routine biochemistry tests in adult Turkish population using the reflimR method and compare them with the manufacturer-provided RIs. The RIs of 19 routine biochemical parameters, analyzed using Beckman Coulter analyzers between February and October 2024, were evaluated using the reflimR algorithm. The RIs were estimated separately for females and males using five indirect approaches (reflimR, refineR, KOSMIC, Hoffmann, and Bhattacharya). A traffic light algorithm based on permissible uncertainty was used to interpret whether the RIs limits calculated with reflimR were within the tolerance limits. Using reflimR, 40 of 76 RI limits were accepted, 21 required checking, and 15 were rejected for RI verification compared with the manufacturer-provided values. The comparison of reflimR with other indirect methods generally produced concordant results, except for the alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), and total bilirubin tests. The reflimR algorithm may offer a swift and accessible method for calculating and verifying RIs. Verification failures may arise from fundamental variations, including ethnicity, sex, age demographics, and geographic factors, between the manufacturer’s study results and our analyzed population.