title: Innovative application of a multidimensional item response model in assessing the influence of social desirability on the pseudo-relationship between self-efficacy and behavior.
abstract: This study examined multidimensional item response theory (MIRT) modeling to assess social desirability (SocD) influences on self-reported physical activity self-efficacy (PASE) and fruit and vegetable self-efficacy (FVSE). The observed sample included 473 Houston-area adolescent males (10-14 years). SocD (nine items), PASE (19 items) and FVSE (21 items) were measured with previously validated self-report instruments containing Likert-type responses. Physical activity was objectively measured using the Computer Science Application Incorporated/Manufacturing Technology Incorporated (CSA/MTI) accelerometer. Total fruit, juice and vegetable consumption was measured with a food frequency questionnaire. Correlations between self-efficacy and behaviors were minimal, regardless of controlling for SocD. However, in a simulated sample derived to demonstrate the utility of MIRT when relationships exist, the pseudo-relationships between self-efficacy and behaviors were substantially weaker after controlling for SocD. MIRT provided disattenuated correlations between SocD and self-efficacy, thereby providing more precise estimates of the real influence of SocD on the relationship between self-efficacy and behavior. However, as shown in the observed sample, more research is needed to understand the influence of SocD on the relationship between self-efficacy and behaviors for different populations and for different degrees of SocD response bias.
authors.affiliation: Department of Pediatrics, Children's Nutrition Research Center, Baylor College of Medicine, 1100 Bates Street, Houston, TX 77030, USA. kwatson@bcm.tmc.edu
authors.forename: Kathy
authors.initials: K
authors.lastname: Watson
authors.forename: Tom
authors.initials: T
authors.lastname: Baranowski
authors.forename: Debbe
authors.initials: D
authors.lastname: Thompson
authors.forename: Russell
authors.initials: R
authors.lastname: Jago
authors.forename: Janice
authors.initials: J
authors.lastname: Baranowski
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Klesges
mesh_terms: D002648:Child; D003627:Data Interpretation, Statistical; D005638:Fruit; D015438:Health Behavior; D006801:Humans; D008297:Male; D017145:Models, Educational; D011594:Psychometrics / Q000379:methods*; D020377:Self Efficacy; D012928:Social Desirability; D011795:Surveys and Questionnaires; D014675:Vegetables