Development of an Abbreviated Social Phobia and Anxiety Inventory (SPAI) Using Item Response Theory The SPAI-23

• Published in: Psychological assessment Vol. 19; no. 1; pp. 133 - 145
• Main Authors: Roberson-Nay, Roxann, Strong, David R, Nay, William T, Beidel, Deborah C, Turner, Samuel M
• Format: Journal Article
• Language: English
• Published: Washington, DC American Psychological Association 01-03-2007
• Subjects: Adult; Adult and adolescent clinical studies; Anxiety; Anxiety Disorders - diagnosis; Anxiety Disorders - epidemiology; Anxiety Disorders - psychology; Anxiety disorders. Neuroses; Biological and medical sciences; Clinical psychology; Correlation; Correlation analysis; Cross-Sectional Studies; Error of Measurement; Fear & phobias; Female; Gender Differences; Human; Humans; Interpersonal Competence; Inventories; Item Response Theory; Male; Mass Screening - statistics & numerical data; Measures (Individuals); Medical sciences; Medical screening; Middle Aged; Personality Inventory - statistics & numerical data; Phobia; Phobic Disorders - diagnosis; Phobic Disorders - epidemiology; Psychology. Psychoanalysis. Psychiatry; Psychometrics - statistics & numerical data; Psychometrics. Diagnostic aid systems; Psychopathology. Psychiatry; Reference Values; Reproducibility of Results; Screening Tests; Sex Factors; Social Anxiety; Social Phobia; Statistics, Nonparametric; Techniques and methods; Test Construction; Undergraduate Students; SPAI; item response theory; gender; social anxiety; screening measure; Abbreviated form; Human; Questionnaire; Social phobia; Item response theory; Anxiety disorder; Psychometrics; Social Phobia and Anxiety Inventory Turner et al
• ISSN: 1040-3590; 1939-134X
• DOI: 10.1037/1040-3590.19.1.133

An abbreviated version of the Social Phobia and Anxiety Inventory (SPAI) was developed using methods based in nonparametric item response theory. Participants included a nonclinical sample of 1,482 undergraduates (52% female, mean age = 19.4 years) as well as a clinical sample of 105 individuals (56% female, mean age = 36.4 years) diagnosed with either generalized (73%) or specific social phobia (27%). Twenty-three of the 45 SPAI items demonstrated good discrimination along the social anxiety continuum. In addition, option characteristic curves (OCCs) indicated that the SPAI's 7-point scale may generate errors in ranking individuals. Thus, options were collapsed to improve item performance. No gender differences emerged between any of the items' OCCs, suggesting that items function similarly among men and women. The abbreviated version also correlated highly with the original 45-item SPAI and exhibited similar patterns of correlations with measures of social anxiety. The SPAI-23 has considerable practical benefits, including a screening of both social and agoraphobic anxiety as well as decreased assessment and scoring time.