Reference intervals for the P-Albumin bromocresol purple method

Abstract

Correct reference intervals are an important part of test results. As establishing own reference intervals is a very expensive task, the NORIP reference intervals are often transferred for use in Nordic laboratories. The NORIP reference interval on P-Albumin was here compared to current results for laboratories using the bromocresol purple (BCP) method for P-Albumin. External quality control reports were used to investigate the change in levels between the BCP and BCG methods on P-Albumin. An algorithm was built for extracting and isolating the laboratory’s healthy subject population. The algorithm was used to extract test results from the laboratory information system. Parametric and non-parametric statistical methods were used to evaluate the P-Albumin test result populations. The indirect method used here clearly shows that the NORIP reference intervals for P-Albumin are not fit for the current bromocresol purple methods. The method was also used to suggest new reference interval limits.

Keywords:

• Albumin
• bromocresol
• BCG
• BCP
• green
• indirect
• purple
• reference interval

Note

Acknowledgements

The author wishes to thank Jonna Pelanti at LABQUALITY for supplying Serum A reports (2001–2014). The data on Serum A were used courtesy of LABQUALITY. Additionally, the author wishes to thank the staff at Department of Clinical Biochemistry, Aalborg University Hospital, for valuable discussions, Simon Lykkeboe for help with SQL design, and Axel Brock for critical reading of the manuscript.

Ethical approval

The study was a technical and quality investigation in accordance with the guidelines of the Northern Denmark Regional Science and Ethics Committee.

Disclosure statement

The author declares no conflict of interest.

Notes

1 For reference intervals not in NORIP the following local intervals were used (analysis: sex, age interval, reference interval): Ftin (μg/L): M,>17,22-355; F,<50,15-120; F,≥50,15-290; TSH (miu/L): M/F,>17,0.3-4.5; Trfe (μmol/L): M/F,>17,24-41.