Validation of the Scale for the Assessment of Illness Behavior (SAIB) in a community sample of elderly people P.M. Engelberg a, *, S. Singer b , K. Bhaskaran c , E. Bra ¨ hler b , H. Glaesmer b a Department of Methods and Psychodiagnostics, University of Wuppertal, Germany b Department of Medical Psychology and Medical Sociology, University of Leipzig, Germany c Department of Non-communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom 1. Introduction Intensive use of health care systems among individuals without a matching need for treatment may strain resources and lead to compromised care for those in the most need. Such inappropriate use of health services has been conceptualized as abnormal illness behavior by Issy Pilowsky in his seminal book (Pilowsky, 1997). This concept was primarily developed for patients with chronic pain and somatoform disorders and most of the research activities so far have focused on similar groups, that is on patients with mental disorders (Bleichhardt, Timmer, & Rief, 2005; Duddu, Isaac, & Chaturvedi, 2006; Pilowsky & Katsikitis, 1994; Rief, Martin, Klaiberg, & Bra ¨ hler, 2005; Scicchitano, Rounsefell, & Pilowsky, 1996). However, (inappropriate) health care use is not necessarily restricted to such groups and some studies have investigated illness behavior in patients with different diseases and in community samples (Black, Pilowsky, & Gill, 1995; Clark & Smith, 1998; Jae, Jang, & Lee, 2008; Mewes, Rief, Bra ¨ hler, Martin, & Glaesmer, 2008; Roberts et al., 1997; Scicchitano, Lovell, Pearce, Marley, & Pilowsky, 1996). Illness behavior is an important characteristic for all individuals in a population, but it is especially relevant in the elderly (Glaesmer, Gunzelmann, Martin, Bra ¨ hler, & Rief, 2008). For example, in men, retirement is associated with an increase in health care seeking behavior (Roberts et al., 1997). Therefore, it is of interest to investigate illness behavior in community samples, especially among elderly people. However, problems may occur if questionnaires developed for clinical samples are used in the general population without further exploration of their appropriateness, e.g. the scale structure may be different in community samples. The SAIB has been suggested as an instrument for capturing illness behavior (Rief, Ihle, & Pilger, 2003), and may have advantages over the more commonly used Illness Behavior Questionnaire (IBQ) (Pilowsky, 1983) which predominantly covers cognitive and affective aspects of health, rather than illness behavior itself (Prior & Bond, 2008). The seven scales of the IBQ are (1) general hypochondriasis, (2) disease conviction, (3) psycholog- ical vs. somatic focusing, (4) affective inhibition, (5) affective disturbance, (6) denial and (7) irritability. The five SAIB scales are (1) verification of diagnosis, (2) expression of symptoms, Archives of Gerontology and Geriatrics 56 (2013) 175–180 A R T I C L E I N F O Article history: Received 1 March 2012 Received in revised form 8 July 2012 Accepted 14 July 2012 Available online 9 August 2012 Keywords: Confirmatory factor analysis (CFA) Construct validity Illness behavior Instruments Old age Validation A B S T R A C T The aim of this study was to evaluate the construct validity of the SAIB in a community sample of elderly people. The SAIB was administered to a large community sample representative of the German population aged 60–85 years (n = 1593). The original model was assessed and then refined through confirmatory and exploratory factor analyses. Criterion validity was evaluated by comparing SAIB scores with external criteria in 3 categories: subjective health, chronic illness and health care utilization. The originally suggested five factor structure of the SAIB yielded a comparative fit index (CFI) of 0.70 and the weighted root mean square residual (WRMR) was 3.68. A shortened questionnaire with 13 items and four factors resulted in better model fit (CFI 0.97 and WRMR 1.3). Correlations between subjective health and the new scales ranged from 0.06 to 0.33. Effect sizes (Cohens d) of mean differences in factor scores between those with and without healthcare system contact varied by healthcare type, ranging from 0.05 to 0.94; effect sizes were largest in relation to contact with psychotherapy and alternative medicine practitioners. We propose a shortened version of the SAIB with a different scale structure, which resulted in better model fit with our data. Neither the original nor revised SAIB appeared to discriminate well in terms of health care use, suggesting that the illness behavior as currently conceptualized may not fully explain the increased use of healthcare in the elderly. ß 2012 Elsevier Ireland Ltd. All rights reserved. * Corresponding author at: Department of Methods and Psychodiagnostics, University of Wuppertal, Gaußstr. 20, 42119 Wuppertal, Germany. Tel.: +49 202 439 3324; fax: +49 202 439 2994. E-mail address: engelberg@uni-wuppertal.de (P.M. Engelberg). Contents lists available at SciVerse ScienceDirect Archives of Gerontology and Geriatrics jo ur n al ho mep ag e: www .elsevier .c om /lo cate/ar c hg er 0167-4943/$ – see front matter ß 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.archger.2012.07.004