Multiple Imputation of missing values in exploratory factor analysis of multidimensional scales: estimating latent trait scores

ABSTRACT Researchers frequently have to analyze scales in which some participants have failed to respond to some items. In this paper we focus on the exploratory factor analysis of multidimensional scales (i.e., scales that consist of a number of subscales) where each subscale is made up of a number of Likert-type items, and the aim of the analysis is to estimate participants' scores on the corresponding latent traits. We propose a new approach to deal with missing responses in such a situation that is based on (1) multiple imputation of non-responses and (2) simultaneous rotation of the imputed datasets. We applied the approach in a real dataset where missing responses were artificially introduced following a real pattern of non-responses, and a simulation study based on artificial datasets. The results show that our approach (specifically, Hot-Deck multiple imputation followed of Consensus Promin rotation) was able to successfully compute factor score estimates even for participants that have missing data.

Trèlat's beads as oral manifestations in patients with HIV/TB

Tuberculosis (TB) is a contagious infectious disease caused by Mycobacterium tuberculosis (Koch's bacillus). Co-infection with human immunodeficiency virus (HIV) and TB has reached a significant importance as a public health problem and this association has been recognized as the most significant event that changed "the balance between man and Koch's bacillus" in the last century, and has a large contribution to the risk for disease spreading. Tuberculosis has two main standard categories of clinical manifestations: primary and secondary. Primary TB is responsible for the initial infection with lungs being the involved organ. Oral lesions are observed as a secondary TB clinical manifestation with most frequent sites being hard and soft palate, tongue, lips, gums, tonsils, and salivary glands. A case of classical TB lesions in the oral cavity is reported, and the importance of a correct diagnosis through careful history taking is emphasized. Treatment selection needs to be done assertively, with great determination and building a link between patient and treatment protocol, in order to promote patient's adherence.