Human macrophage differentiation inducing factor (DIF) can induce differentiation of human myeloid leukemic cells into macrophage-like cells in vitro. A procedure is described for purification of DIF from serum-free human monocytic leukemia THP-1 cell-conditioned medium. The procedure included concentration of a conditioned medium by ultrafiltration, lentil lectin-Sepharose affinity chromatogra...

OBJECTIVES Estimates of group differences in functional disability may be biased if items exhibit differential item functioning (DIF). For a given item, DIF exists if persons in different groups do not have the same probability of responding, given their level of disability. This study examines the extent to which DIF affects estimates of age and gender group differences in disability severity ...

The Dataflow Interchange Format (DIF) is a standard language to specify mixed-grain dataflow models for digital signal, image, and video processing (DSP) systems and other streaming-related application domains. Major objectives of the DIF project are to design this standard language; to provide an extensible repository for representing, experimenting, and developing dataflow models and techniqu...

BACKGROUND Differential item functioning (DIF) methods can be used to determine whether different subgroups respond differently to particular items within a health-related quality of life (HRQoL) subscale, after allowing for overall subgroup differences in that scale. This article reviews issues that arise when testing for DIF in HRQoL instruments. We focus on logistic regression methods, which...

This study was to use differential item functioning (DIF) analysis to examine if there were items in the Mental, Emotional, and Bodily Toughness Inventory (MeBTough) functioning differently across gender and athletic membership. A total of 444 male (56.3%) and female (43.7%) participants (30.9% athletes and 69.1% non-athletes) responded to the MeBTough items. Using Mantel-Haenszel and SIBTEST m...

Background: Immunobullous diseases are morphologically heterogeneous and the differentiation between various subtypes is essential for proper treatment and prognosis. The aim of our study was to analyze and correlate clinical, histopathological, and immunofluorescence findings in autoimmune bullous diseases.Method: A c...

The aims of this paper are to present findings related to differential item functioning (DIF) in the Patient Reported Outcome Measurement Information System (PROMIS) depression item bank, and to discuss potential threats to the validity of results from studies of DIF. The 32 depression items studied were modified from several widely used instruments. DIF analyses of gender, age and education we...

BACKGROUND The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) is a widely used patient reported outcome in osteoarthritis. An important, but frequently overlooked, aspect of validating health outcome measures is to establish if items exhibit differential item functioning (DIF). That is, if respondents have the same underlying level of an attribute, does the item give the...