Relationship Assessment Scale (RAS-5): Análisis factorial confirmatorio multigrupo y teoría de respuesta al ítem

Relationship satisfaction (RS) is a protective factor for emotional well-being in romantic relationships. To facilitate research and professional practice related to RS, there is a need for brief instruments that demonstrate optimal psychometric properties. The objective was to analyze the psychometric properties of the Relationship Assessment Scale (RAS-5), a unidimensional 5-item instrument, in a Peruvian population. The sample consisted of 351 adults in various types of romantic relationships, from urban and rural areas of Peru, covering cities in the country’s three natural regions (coast, highlands, and jungle). The most represented district was San Juan de Lurigancho (N = 71). In terms of gender, women accounted for 55.8% of the sample. Two age groups were identified: 18 to 25 years (56.7%) and 26 to 56 years (43.3%). The sampling method was non-probabilistic and purposive. A multigroup factor analysis found that the unidimensional structure of the 5-item scale is invariant across gender and age. Furthermore, optimal reliability was found for both test scores (α = 0.922) and construct reliability (ω = 0.956). From an item response theory perspective, the item and test information curves demonstrated greater metric precision at low and medium levels of the latent trait. Finally, an empirical distinction was found, along with a direct correlation with emotional well-being. It is concluded that the RAS-5 is an optimal brief measure for assessing SRP.