Methodik diagnostischer Validierungsstudien

Abstract

The evaluation of diagnostic tests play an important role in clinical research. Though detailed standards have been developed for treatment evaluation, widely accepted methodological standards in diagnostic test research are still lacking. Following recent methodological research German biostatisticians usually distinguish between 4 types of diagnostic validation studies (Phase I to IV). The diagnostic value of a test can be described by indexes like sensitivity, specificity and predictive values. Sensitivity and specificity are so-called nosological probabilities whereas predictive values describe the probabilities of the disease given a positive or negative test result, respectively. These posterior probabilities depend on the prevalence of the disease in question. The methodological problems that arise in the planning of diagnostic studies differ from those encountered in treatment evaluation. This contribution presents an annotated checklist of the most important faults and shortcomings in the planning and the analysis of diagnostic validation studies. Avoiding these deficiencies may help that the study results are accepted by biostatisticians, clinicians and cost units.

The Inventory of Interpersonal Problems (IIP-64) as a Screening Measure for Avoidant Personality Disorder

“…In no study were estimators of predictive values adjusted for base rate, which is mandatory when a representative result is aimed at (Mercaldo, Zhou, & Lau, 2005). Many studies provided neither confidence intervals for diagnostic indices (like sensitivity), nor the information needed to compute such confidence intervals, although this should routinely be reported (Jensen & Abel, 1999). Finally, in most of the studies the number of persons with any of the 10 specific DSM-IV personality disorders was very low, so all PDs were simply aggregated into one general category ("PD"), which was then predicted.…”

Interdisziplinärer Konsensus zur Diagnostik und Therapie von Hodentumoren Ergebnisse einer Update-Konferenz auf Grundlage evidenzbasierter Medizin (EBM)

“…Die nachfolgenden Angaben zur Wertigkeit der jeweiligen bildgebenden Diagnostikverfahren beruhen in der Regel nicht auf prospektiven Phase-III-Studien, sodass eine EBM-Graduierung im Einzelnen nicht vorgenommen werden kann; allerdings ist die Validität der Angaben dem EBM-Grad IIA (analog der Genauigkeit von Phase-III-Studien) gleichzusetzen, da das Ergebnis der Bildgebung in der Regel mit der histopathologischen Diagnose korreliert wird [48,49]. [113,114]).…”