Korean J Psychosom Med.  2019 Dec;27(2):77-84. 10.22722/KJPM.2019.27.2.77.

Factorial Validity of the Korean Version of the Illness Intrusive Rating Scale among Psychiatric Outpatients Mainly Diagnosed with Anxiety or Depressive Disorders

• Cho Y
• Kim D
• Kim E
• Jo HY
• Yun M
• Lee H

• KMID: 2470695
• DOI: http://doi.org/10.22722/KJPM.2019.27.2.77

Abstract

OBJECTIVES
The Illness Intrusiveness Rating Scale (IIRS) is a well-validated self-report instrument for assessing negative impact of chronic illness and/or adverse effects of its treatment on everyday life domains. Although extensive literature probed its psychometric properties in medical illness, little attention was paid for its validity for psychiatric population. This study aimed to test factorial structure of the Korean Version of the IIRS (IIRS-K) in a consecutive sample of psychiatric outpatients.
METHODS
Data set of 307 first-visit patients of psychiatric clinic at Guri Hanyang univ. Hospital were used. Exploratory and confirmatory factor analysis, internal consistency were tested in IIRS-K. We also checked Spearman's correlation analysis between IIRS-K, Zung's self-report anxiety scale and Zung's self-report depression scale.
RESULTS
76.9% of the patients were with anxiety disorder and depressive disorder. The principal component factor analysis of the IIRS-K extracted three-factor structure accounted for 63.2% of total variance that was contextually similar to the original English version. This three-factor solution showed the best fit when tested confirmatory factor analysis compared to the original IIRS, two-factor model of IIRS-K suggested from medical outpatients, and one-factor solution. The IIRS-K also showed good internal consistency (Cronbach's α=0.90) and good convergent validity with anxiety and depression scales.
CONCLUSIONS
The IIRS-K showed the three-factor structure that was similar but not identical to original version. Overall, this study proved factorial validity of the IIRS-K and it can be used for Korean clinical population.

Keyword

Anxiety and depressive disorder; Psychiatric patients; Illness Intrusiveness Rating scale; Factor analysis; Quality of life

MeSH Terms

Anxiety Disorders
Anxiety*
Chronic Disease
Dataset
Depression
Depressive Disorder*
Factor Analysis, Statistical
Humans
Outpatients*
Psychometrics
Quality of Life
Weights and Measures