Pyschometric properties of the Brief Inventory of Situations and Responses of Anxiety (ISRA-B)

Introduction and objectives
Anxiety is the most studied emotional reaction, which alerts us of the possibility of obtaining a negative result, making it adaptive in the vast majority of cases, although it is also one of the underlying factors of the most prevalent emotional disorders. Therefore, its assessment has generated a lot of research and transfer. The Inventory of Situations and Responses of Anxiety (ISRA) was developed in Spain and it includes 22 situations (S) and 24 responses (R) of anxiety, by which 224 items are formed by crossing them (i.e., «in such Situation, I experience this Reaction»). For more than three decades, it has been widely used in research and practice, and its psychometric properties have been published in different countries. A shorter, 46-item version (ISRA-B), with a 22 S scale plus another of 24 R was developed. The same eight facets of anxiety were assessed, showing good psychometric properties as well. However, there are few publications on the psychometric data using Spanish population. The objective of this study was to analyze the psychometric properties of ISRA-B in Spain.

Methods
Three thousand three hundred and forty six volunteers (36.4% men), aged 15 to 94 years (mean: 30.3; SD: 14.6) were included.

Results
The results confirmed excellent internal consistency for the Total (.94) and the Responses subscale (0.91), good for the Situations (0.89), as well as the Physiological (, 86) and Cognitive (0.84) response systems, and acceptable for the Motor (0.70). Good test-retest stability was also found after two months (0.78) and good external validity when correlated with the original ISRA (0.87). The results confirm the factor structure of the ISRA-B, adjusted to Lang's triple response system model and to Endler's S × R interaction model, on which it is based. Likewise, the normative data are presented, differentiated by sex and group.

Conclusions
It is concluded that the ISRA-B is a valid and reliable instrument, which improves its applicability compared to the original ISRA by simplifying its format and number of items, while preserving its psychometric properties.