### Resumé

Serum ferritin (S-ferritin) and the saturation of transferrin iron-binding capacity (TIBC-sat) were evaluated as screening procedures for idiopathic haemochromatosis in a non-diseased population. Special attention was paid to the influence of the analytical quality, but the effects of prevalence and discrimination limits were also considered. Changes in the analytical quality for S-ferritin and TIBC-sat used as single tests highly influenced the number of false test-positives. Increasing the coefficient of variation from 0.0 to 0.2 resulted in nearly a doubling of the number of false test-positives to be further investigated. Using even a high, yet achievable analytic quality with a low coefficient of variation of 0.056 and 0.059 for S-ferritin and TIBC-sat respectively, screening procedures had unacceptably high fractions of false test-positives and false test-negatives associated with any discrimination limit. If the prevalence of haemochromatosis is 0.003, the predictive value of a positive test result did not exceed 0.05, accepting a fraction of false test-negatives of 0.025. This was found to be too low for a screening test to be used in the general population. The combined use of S-ferritin and TIBC-sat resulted in higher performance with a sensitivity of 0.90, a specificity of 0.99 and a predictive value of a positive test result of 0.29 if a fraction of misclassification of 0.01 is accepted for each.

Originalsprog | Engelsk |
---|---|

Bogserie | Scandinavian Journal of Clinical and Laboratory Investigation |

Vol/bind | 51 |

Udgave nummer | 2 |

Sider (fra-til) | 143-148 |

Antal sider | 6 |

ISSN | 0036-5513 |

DOI | |

Status | Udgivet - 1. jan. 1991 |

### Fingeraftryk

### Citer dette

*Scandinavian Journal of Clinical and Laboratory Investigation*,

*51*(2), 143-148. https://doi.org/10.1080/00365519109091100

}

*Scandinavian Journal of Clinical and Laboratory Investigation*, bind 51, nr. 2, s. 143-148. https://doi.org/10.1080/00365519109091100

**Screening for haemochromatosis : Influence of analytical imprecision, diagnostic limit and prevalence on test validity.** / Wiggers, P.; Dalhøj, J.; Petersen, P. Hyltoft; Blaabjerg, O.; Hørder, M.

Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

TY - JOUR

T1 - Screening for haemochromatosis

T2 - Influence of analytical imprecision, diagnostic limit and prevalence on test validity

AU - Wiggers, P.

AU - Dalhøj, J.

AU - Petersen, P. Hyltoft

AU - Blaabjerg, O.

AU - Hørder, M.

PY - 1991/1/1

Y1 - 1991/1/1

N2 - Serum ferritin (S-ferritin) and the saturation of transferrin iron-binding capacity (TIBC-sat) were evaluated as screening procedures for idiopathic haemochromatosis in a non-diseased population. Special attention was paid to the influence of the analytical quality, but the effects of prevalence and discrimination limits were also considered. Changes in the analytical quality for S-ferritin and TIBC-sat used as single tests highly influenced the number of false test-positives. Increasing the coefficient of variation from 0.0 to 0.2 resulted in nearly a doubling of the number of false test-positives to be further investigated. Using even a high, yet achievable analytic quality with a low coefficient of variation of 0.056 and 0.059 for S-ferritin and TIBC-sat respectively, screening procedures had unacceptably high fractions of false test-positives and false test-negatives associated with any discrimination limit. If the prevalence of haemochromatosis is 0.003, the predictive value of a positive test result did not exceed 0.05, accepting a fraction of false test-negatives of 0.025. This was found to be too low for a screening test to be used in the general population. The combined use of S-ferritin and TIBC-sat resulted in higher performance with a sensitivity of 0.90, a specificity of 0.99 and a predictive value of a positive test result of 0.29 if a fraction of misclassification of 0.01 is accepted for each.

AB - Serum ferritin (S-ferritin) and the saturation of transferrin iron-binding capacity (TIBC-sat) were evaluated as screening procedures for idiopathic haemochromatosis in a non-diseased population. Special attention was paid to the influence of the analytical quality, but the effects of prevalence and discrimination limits were also considered. Changes in the analytical quality for S-ferritin and TIBC-sat used as single tests highly influenced the number of false test-positives. Increasing the coefficient of variation from 0.0 to 0.2 resulted in nearly a doubling of the number of false test-positives to be further investigated. Using even a high, yet achievable analytic quality with a low coefficient of variation of 0.056 and 0.059 for S-ferritin and TIBC-sat respectively, screening procedures had unacceptably high fractions of false test-positives and false test-negatives associated with any discrimination limit. If the prevalence of haemochromatosis is 0.003, the predictive value of a positive test result did not exceed 0.05, accepting a fraction of false test-negatives of 0.025. This was found to be too low for a screening test to be used in the general population. The combined use of S-ferritin and TIBC-sat resulted in higher performance with a sensitivity of 0.90, a specificity of 0.99 and a predictive value of a positive test result of 0.29 if a fraction of misclassification of 0.01 is accepted for each.

KW - Diagnostic test

KW - Serum ferritin

KW - TIBC-sat

KW - Transferrin saturation

UR - http://www.scopus.com/inward/record.url?scp=0025891274&partnerID=8YFLogxK

U2 - 10.1080/00365519109091100

DO - 10.1080/00365519109091100

M3 - Journal article

C2 - 2042019

AN - SCOPUS:0025891274

VL - 51

SP - 143

EP - 148

JO - Scandinavian Journal of Clinical and Laboratory Investigation. Supplement

JF - Scandinavian Journal of Clinical and Laboratory Investigation. Supplement

SN - 0085-591X

IS - 2

ER -