Psychometric properties of the Spanish version of the Implicit Models of Illness Questionnaire for physical and mental diseases

The goal of this study was to establish the psychometric properties of the Spanish version of the Implicit Models of Illness Questionnaire (Turk et al., 1986), the Cuestionario de Creencias sobre la Enfermedad (CCSE; van der Hofstadt & Rodríguez-Marín, 1997) for five physical and mental diseases: depression, schizophrenia, cancer, hypertension, and influenza. 348 individuals (62.6% women) with different experience with these diseases (having/not having suffered from the disease, having/not having lived with someone with such diagnosis) answered the CCSE for those illnesses. Psychometric properties of the scale were found to be appropriate. The obtained dimensions (factors) are: identity, personal control, symptoms, consequences, and cure/time-line. The scale and subscales reliability is appropriate. The scale shows suitable construct validity, since similar results have been obtained for the diseases included. Our results are consonant with those informed by Turk et al. (1986), differing with those obtained by van der Hofstadt & Rodríguez-Marín (1997). Nevertheless, some items could be revised or eliminated in order to improve the properties of the scale. Since health professionals find it so valuable both the knowledge of personal beliefs of patients and the lay illness representation of healthy people, in order to adequate their promotion and prevention strategies and clinical (treatment/rehabilitation) interventions, the results of this study show that this scale may help them for this purpose, in the case of both physical and mental diseases.