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Updated: Aug 15, 2025

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Published on: March 22, 2022
Application of the Hoffmann, Bhattacharya, nonparametric test, and Q-Q plot methods for establishing reference
Chaomei Yang1, Lei Lang1, Si Wang1
1Clinical Laboratory, Chongqing Emergency Medical Center, Chongqing University Central Hospital, School of Medicine, Chongqing University, Chongqing 400014, China.
This study compared four methods for estimating reference intervals (RIs) for urea, creatinine, and uric acid (UA). Hoffmann and Bhattacharya methods showed reliable results for indirect RI estimation from laboratory data.
Area of Science:
- Clinical Chemistry
- Laboratory Medicine
- Biostatistics
Background:
- Reference intervals (RIs) are crucial for interpreting laboratory test results and guiding clinical decisions.
- Accurate RI estimation is essential for reliable biomarker interpretation.
- Various statistical methods exist for RI determination, each with potential advantages and limitations.
Purpose of the Study:
- To evaluate and compare the application value of four different methods (Hoffmann, Bhattacharya, nonparametric test, and Q-Q plot) for estimating reference intervals.
- To assess the reliability of these methods for common laboratory biomarkers including urea, creatinine, and uric acid (UA).
- To verify the differences in RI estimations across methods using biological variability data.
Main Methods:
- A cross-sectional study utilizing patient data from January 2020 to April 2022.
- RI estimation for urea, creatinine, and UA using Hoffmann, Bhattacharya, nonparametric, and Q-Q plot methods.
- Verification of RI differences using reference change value (RCV%) based on biological variability.
Main Results:
- In the clinical group, most method differences for RI upper limits were within the permissible RCV% range.
- The nonparametric test yielded an RI for urea with a lower limit within the permissible RCV% range.
- In the physical examination group, relative RI differences among methods were generally within acceptable RCV% ranges, with specific exceptions for lower limits and UA RI.
Conclusions:
- The Hoffmann and Bhattacharya methods demonstrate potential for providing reliable reference intervals.
- These methods are suitable for indirect estimation of urea, creatinine, and UA from existing laboratory datasets.
- The findings support the use of Hoffmann and Bhattacharya methods in routine laboratory practice for RI determination.
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