Using individual patient data to adjust for indirectness did not successfully remove the bias in this case of comparative test accuracy

Junfeng Wang, Patrick Bossuyt, Ronald Geskus, Aeilko Zwinderman, Madeleine Dolleman, Simone Broer, Frank Broekmans, Ben Willem Mol, Mariska Leeflang, on behalf of the IMPORT Study Group

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3 Citations (Scopus)


Objectives In comparative systematic reviews of diagnostic accuracy, inconsistencies between direct and indirect comparisons may lead to bias. We investigated whether using individual patient data (IPD) can adjust for this form of bias. Study Design and Setting We included IPD of 3 ovarian reserve tests from 32 studies. Inconsistency was defined as a statistically significant difference in relative accuracy or different comparative results between the direct and indirect evidence. We adjusted for the effect of threshold and reference standard, as well as for patient-specific variables. Results Anti-Müllerian hormone (AMH) and follicle stimulation hormone (FSH) differed significantly in sensitivity (-0.1563, P = 0.04). AMH and antral follicle count (AFC) differed significantly in sensitivity (0.1465, P < 0.01). AMH and AFC differed significantly in specificity (-0.0607, P = 0.02). The area under the curve (AUC) differed significantly between AFC and FSH (0.0948, P < 0.01) in the direct comparison but not (0.0678, P = 0.09) in the indirect comparison. The AUCs of AFC and AMH differed significantly (-0.0830, P < 0.01) in the indirect comparison but not (-0.0176, P = 0.29) in the direct comparison. These differences remained after adjusting for indirectness. Conclusion Estimates of comparative accuracy obtained through indirect comparisons are not always consistent with those obtained through direct comparisons. Using IPD to adjust for indirectness did not successfully remove the bias in this case study.

Original languageEnglish
Pages (from-to)290-298
Number of pages9
JournalJournal of Clinical Epidemiology
Issue number3
Publication statusPublished - 1 Jan 2015
Externally publishedYes


  • Comparative meta-analysis
  • Diagnostic test accuracy
  • Generalized estimating equation
  • Individual patient data
  • Receiver operating characteristic
  • Sensitivity and specificity

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