Validity and reliability of the INICO-FEAPS Scale: An assessment of quality of life for people with intellectual and developmental disabilities

https://doi.org/10.1016/j.ridd.2014.10.049Get rights and content

Highlights

  • A quality of life instrument for persons with intellectual and developmental disabilities is described.

  • The instrument comprises two parallel forms: a self-report and a report of others.

  • Confirmatory factor analysis is used to provide evidences of validity.

  • Internal consistency coefficients showed a good reliability of the scale.

  • Participants represented a cross sample of individuals for whom the scale's use is appropriate.

Abstract

This paper documents the validation of a comprehensive scale designed to assess quality-of-life related personal outcomes for people with intellectual and developmental disabilities who receive support in social organizations. The INICO-FEAPS Scale was administered to 1627 people whose ages ranged between 16 and 72 years old. The instrument comprises 72 parallel items organized around eight quality-of-life domains in each of the two forms: a self-report and a report by others. Several internal consistence indexes showed a good reliability of the scale. CFA was used to compare the goodness-of-fit to the data of alternative models. The eight-correlated first-order factors showed the best fit to the data in comparison to the unidimensional solution and hierarchical models. The instrument serves as a helpful tool for organizations to operate as bridges to the community, develop person-centered planning and individualized support, and implement evidence-based practices for quality improvement.

Section snippets

Participants

The 1624 participants in this study were chosen by accidental sampling among those receiving support in 66 social organizations throughout Spain. Most of the Spanish counties included participants, with the exception of Asturias, Aragon, and Islas Baleares (even though it is true that the data was missing for 450 cases whose origins might be in these areas). Most of the participants were from Madrid (13.5%), Castilla La Mancha (12.2%), Extremadura (11.1%), and Castilla y Leon (10.4%), while the

Reliability: internal consistence

An analysis of internal consistency through Cronbach's alpha together with the calculation of the discrimination parameters for the items through the Graded Response Model (Samejima, 1969) were carried out for the items. As aforementioned, those 16 items that in any of the two subscales showed Cronbach's alpha coefficients lower than .200 in discrimination parameters below .400 were eliminated (Verdugo et al., 2013a, Verdugo et al., 2013b) and the final scale was reduced to 72 items (i.e., 9

Discussion

This study pursued a double aim. On the one hand, it aimed to test the psychometric properties of the INICO-FEAPS Scale through the provision of adequate evidence about its reliability and validity in its administration to people with an intellectual disability. In this regard, both the internal consistency indexes obtained for the total scale and each quality-of-life domain are adequate. As has been found in other similar instruments, self-determination appeared as the most reliable domain and

Conflicts of interest

The authors report no conflicts of interest and are solely responsible for the content and writing of this paper.

Acknowledgments

This study was supported in part with funding from the Spanish Ministry of Economy and Competitiveness (R&D Projects, 2012) (PSI2012-33139 and PSI2012-36278) and Grupo AMAS. The project received approval from the University of Salamanca IRB. The authors would like to thank the organizations, people with intellectual disability, professionals, and families for completing the questionnaires and FEAPS for its support on this project.

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