Derivation and internal validation of an equation for albumin-adjusted calcium at a tertiary hospital in Selangor, Malaysia
Introduction: Total calcium concentration is widely used to assess body calcium status although limited by many confounding factors. Thus, this study aimed to derive and internally validate an albumin-adjusted calcium equation for a selected Malaysian population. Method: This cross-sectional study i...
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| Format: | Article |
| Language: | English |
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Fakulti Perubatan dan Sains Kesihatan Universiti Putra Malaysia
2020
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| Online Access: | http://psasir.upm.edu.my/id/eprint/88364/ http://psasir.upm.edu.my/id/eprint/88364/1/Derivation%20and%20Internal%20Validation%20of%20an%20Equation%20for.pdf |
| _version_ | 1848860604140355584 |
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| author | Azmi, Jannaltul Adni Thambiah, Subashini C. Abdul Hamid, Hanisah Zahari Sham, Siti Yazmin Samsudin, Intan Nureslyna Osman, Malina |
| author_facet | Azmi, Jannaltul Adni Thambiah, Subashini C. Abdul Hamid, Hanisah Zahari Sham, Siti Yazmin Samsudin, Intan Nureslyna Osman, Malina |
| author_sort | Azmi, Jannaltul Adni |
| building | UPM Institutional Repository |
| collection | Online Access |
| description | Introduction: Total calcium concentration is widely used to assess body calcium status although limited by many confounding factors. Thus, this study aimed to derive and internally validate an albumin-adjusted calcium equation for a selected Malaysian population. Method: This cross-sectional study involved 1011 adults at an emergency department of a tertiary hospital. Patients who had total calcium, ionised calcium and albumin measurements taken simultaneously were included. Derivation of the albumin-adjusted calcium equation was based on the adjustment equation obtained from the Association for Clinical Biochemistry and Laboratory Medicine 2015 position paper. Additionally, the equation was internally validated and compared with ionised calcium (gold standard) and the conventional Payne’s equation. Results: The newly derived equation = total calcium + 0.017 (41.35 – albumin). Internal validation exhibited the amount of shrinkage of 0.049. It tends to overestimate the adjusted calcium by a mean difference of 0.029 mmol/L compared to Payne’s equation. The comparison between Payne’s equation and the new equation with ionised calcium reclassified 402 and 486 patients, respectively into different calcium status. When both equations were compared, calcium status classification significantly differed in all and hypoalbuminaemic subjects by 90 and 16 patients, respectively. Conclusion: Locally derived albumin-adjusted calcium equation differed statistically in calcium status classification when compared to the Payne’s equation. However, to confirm this significance, the result must be compared to ionised calcium under strict, controlled preanalytical conditions. In terms of clinical significance, there was no difference in classification of calcium status between Payne’s and the new equation at medical decision limits. |
| first_indexed | 2025-11-15T12:47:52Z |
| format | Article |
| id | upm-88364 |
| institution | Universiti Putra Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T12:47:52Z |
| publishDate | 2020 |
| publisher | Fakulti Perubatan dan Sains Kesihatan Universiti Putra Malaysia |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | upm-883642021-12-28T07:29:55Z http://psasir.upm.edu.my/id/eprint/88364/ Derivation and internal validation of an equation for albumin-adjusted calcium at a tertiary hospital in Selangor, Malaysia Azmi, Jannaltul Adni Thambiah, Subashini C. Abdul Hamid, Hanisah Zahari Sham, Siti Yazmin Samsudin, Intan Nureslyna Osman, Malina Introduction: Total calcium concentration is widely used to assess body calcium status although limited by many confounding factors. Thus, this study aimed to derive and internally validate an albumin-adjusted calcium equation for a selected Malaysian population. Method: This cross-sectional study involved 1011 adults at an emergency department of a tertiary hospital. Patients who had total calcium, ionised calcium and albumin measurements taken simultaneously were included. Derivation of the albumin-adjusted calcium equation was based on the adjustment equation obtained from the Association for Clinical Biochemistry and Laboratory Medicine 2015 position paper. Additionally, the equation was internally validated and compared with ionised calcium (gold standard) and the conventional Payne’s equation. Results: The newly derived equation = total calcium + 0.017 (41.35 – albumin). Internal validation exhibited the amount of shrinkage of 0.049. It tends to overestimate the adjusted calcium by a mean difference of 0.029 mmol/L compared to Payne’s equation. The comparison between Payne’s equation and the new equation with ionised calcium reclassified 402 and 486 patients, respectively into different calcium status. When both equations were compared, calcium status classification significantly differed in all and hypoalbuminaemic subjects by 90 and 16 patients, respectively. Conclusion: Locally derived albumin-adjusted calcium equation differed statistically in calcium status classification when compared to the Payne’s equation. However, to confirm this significance, the result must be compared to ionised calcium under strict, controlled preanalytical conditions. In terms of clinical significance, there was no difference in classification of calcium status between Payne’s and the new equation at medical decision limits. Fakulti Perubatan dan Sains Kesihatan Universiti Putra Malaysia 2020 Article PeerReviewed text en http://psasir.upm.edu.my/id/eprint/88364/1/Derivation%20and%20Internal%20Validation%20of%20an%20Equation%20for.pdf Azmi, Jannaltul Adni and Thambiah, Subashini C. and Abdul Hamid, Hanisah and Zahari Sham, Siti Yazmin and Samsudin, Intan Nureslyna and Osman, Malina (2020) Derivation and internal validation of an equation for albumin-adjusted calcium at a tertiary hospital in Selangor, Malaysia. Malaysian Journal of Medicine and Health Sciences, 16 (suppl. 9). 16 - 25. ISSN 1675-8544; ESSN: 2636-9346 https://medic.upm.edu.my/jurnal_kami/malaysian_journal_of_medicine_and_health_sciences_mjmhs/mjmhs_vol_16_supp_9_november_2020-59151 |
| spellingShingle | Azmi, Jannaltul Adni Thambiah, Subashini C. Abdul Hamid, Hanisah Zahari Sham, Siti Yazmin Samsudin, Intan Nureslyna Osman, Malina Derivation and internal validation of an equation for albumin-adjusted calcium at a tertiary hospital in Selangor, Malaysia |
| title | Derivation and internal validation of an equation for albumin-adjusted calcium at a tertiary hospital in Selangor, Malaysia |
| title_full | Derivation and internal validation of an equation for albumin-adjusted calcium at a tertiary hospital in Selangor, Malaysia |
| title_fullStr | Derivation and internal validation of an equation for albumin-adjusted calcium at a tertiary hospital in Selangor, Malaysia |
| title_full_unstemmed | Derivation and internal validation of an equation for albumin-adjusted calcium at a tertiary hospital in Selangor, Malaysia |
| title_short | Derivation and internal validation of an equation for albumin-adjusted calcium at a tertiary hospital in Selangor, Malaysia |
| title_sort | derivation and internal validation of an equation for albumin-adjusted calcium at a tertiary hospital in selangor, malaysia |
| url | http://psasir.upm.edu.my/id/eprint/88364/ http://psasir.upm.edu.my/id/eprint/88364/ http://psasir.upm.edu.my/id/eprint/88364/1/Derivation%20and%20Internal%20Validation%20of%20an%20Equation%20for.pdf |