Item Response Theory Applied to the Spiritual Needs Questionnaire (SpNQ) in Portuguese

Abstract

The item response theory (IRT), or latent trace theory, is based on a set of mathematical models to complement the qualitative analysis of the items in a given questionnaire. This study analyzes the items of the Spiritual Needs Questionnaire (SpNQ) in the Portuguese version, applied to HIV+ patients, with R Studio 3.4.1, mirt statistical package, to find out if the items of the SpNQ possess appropriate psychometric qualities to discriminate between respondents as to the probability of marking one answer and not another, in the same item, showing whether or not the questionnaire is biased towards a pattern of response desired by the researcher. The parameters of discrimination, difficulty, information, and the characteristic curve of the items are evaluated. The reliable items to measure the constructs of each of the five dimensions of the SpNQ of this HIV+ sample (Religious Needs; Inner Peace and Family Support Needs; Existential Needs; Social Recognition Needs; and Time Domain Needs) are presented, as well as the most likely response categories, depending on the latent trace level of the individuals. The questionnaire items showed satisfactory discrimination and variability of difficulty, confirming the good psychometric quality of SpNQ.Religions 2020, 11, 139 2 of 13 or not there is a specific need within four dimensions (social, emotional, existential, and religious), and how strong it is, using a 4-step scale. It differentiates four main dimensions, i.e., religious needs, existential needs, inner peace needs, and giving/generativity needs (Büssing et al. 2010. The SpNQ was validated into Portuguese (Valente et al. 2018) in a sample of HIV+ patients, presenting internal consistency ranging from 0.51 to 0.83.SpNQ has already been translated and validated in 12 studies. However, the psychometric analyses performed so far were based only on the classical theory of tests (CTT), based on exploratory factor analysis and internal consistency analysis, all conventional quantitative approaches to test the reliability and validity of a scale based on its items (Cappelleri et al. 2014;Sartes and de Souza-Formigoni 2013). Differently, the present study sought to evaluate the SpNQ items from the perspective of IRT, in order to obtain evidence of complementary validity of the characteristics of the items that make up the instrument-in this case, in Portuguese-to answer this main question: Do the items of the SpNQ questionnaire validated in Portuguese possess appropriate psychometric qualities to discriminate between respondents as to the probability of marking one answer and not another, in the same item, showing whether or not the questionnaire is biased towards a pattern of responses desired by the researcher?The SpNQ was validated in different countries and different socio-cultural contexts of its various applications would benefit from the results of this analysis, through the calculation of the guarantee of accuracy and differentiation of the patients' responses.

Designing and psychometric properties of the hospitalized patients’ spiritual needs questionnaire (HPSNQ) in the medical-surgical hospital setting

“…Although IRT has demonstrated its utility in the field of psychometric research, it has only been applied to evaluate the psychometric characteristics of the Spiritual Needs Questionnaire (SpNQ) in its Portuguese version for HIV + patients in Oliveira da Silva’s (2020) study. The study showed that the SpNQ items were appropriately discriminating and had varying levels of difficulty, indicating that the questionnaire has good psychometric properties [ 53 ]. This suggests that IRT could and should be utilized to enhance the quality of assessment questionnaires related to patients’ spiritual needs [ 103 ].…”

“…Muslims view spirituality and religion (beliefs and practices) as inseparable and do not distinguish between the two concepts [ 52 ]; in fact, the concept of religion is intertwined with spirituality [ 43 ]. It should be noted that only Oliveira da Silva’s (2020) study employed item response theory to validate the Portuguese version of the SpNQ for use among patients with HIV [ 53 ]. IRT can be an effective approach for developing, assessing, and refining questionnaires, producing precise, valid, and relatively brief instruments that minimize response burden [ 54 ].…”