Uso dos métodos Mantel-Haenszel para a detecção do funcionamento diferencial dos itens e software relacionado / Using Mantel-Haenszel methods for detecting differential item functioning

As estatísticas englobadas sob a denominação métodos Mantel-Haenszel (MH), por suas simplicidades, baixo custo computacional e bons resultados, são os métodos mais empregadas para detectar o funcionamento diferencial dos itens (DIF). Os métodos MH podem ser usados para detectar o DIF tanto em itens dicotômicos como em itens politômicos, permitindo comparar dois ou mais grupos simultaneamente, e aplicam-se tanto no âmbito da Teoria Clássica dos Testes (TCT) como da Teoria da Resposta ao Item (TRI). Este artigo fornece uma visão completa e integrada dos métodos MH e apresenta um programa que permite aplicar essas estatísticas no estudo do DIF. O programa é gratuito e está disponível em Espanhol, Inglês e Português.

Statistics comprised under Mantel-Haenszel (MH) methods designation constitute one of the most popular and low cost differential item functioning (DIF) detection methods. Mantel-Haenszel methods permit DIF assessment of dichotomous and polytomous items in multiple groups simultaneously, and they can be applied both under Classical Test Theory and Item Response Theory. This paper provides a framework for integrating the different MH statistics used in DIF research, and describes the software that has been developed to provide an easy-to-use program for conducting DIF analyses using the statistics. The program is free of charge and it is available in the following languages: Spanish, English and Portuguese.

Interobserver agreement of gleason score and modified gleason score in needle biopsy and in surgical specimen of prostate cancer

INTRODUCTION: Gleason score, which has a high interobserver variability, is used to classify prostate cancer. The most recent consensus valued the tertiary Gleason pattern and recommended its use in the final score of needle biopsies (modified Gleason score). This pattern is considered to be of high prognostic value in surgical specimens. This study emphasized the evaluation of the modified score agreement in needle biopsies and in surgical specimen, as well as the interobserver variability of this score MATERIALS AND METHODS: Three pathologists evaluated the slides of needle biopsies and surgical specimens of 110 patients, reporting primary, secondary and tertiary Gleason patterns and after that, traditional and modified Gleason scores were calculated. Kappa test (K) assessed the interobserver agreement and the agreement between the traditional and modified scores of the biopsy and of the surgical specimen RESULTS: Interobserver agreement in the biopsy was K = 0.36 and K = 0.35, and in the surgical specimen it was K = 0.46 and K = 0.36, for the traditional and modified scores, respectively. The tertiary Gleason grade was found in 8 percent, 0 percent and 2 percent of the biopsies and in 8 percent, 0 percent and 13 percent of the surgical specimens, according to observers 1, 2 and 3, respectively. When evaluating the agreement of the traditional and modified Gleason scores in needle biopsy with both scores of the surgical specimen, a similar agreement was found through Kappa CONCLUSION: Contrary to what was expected, the modified Gleason score was not superior in the agreement between the biopsy score and the specimen, or in interobserver reproducibility, in this study.