Explanatory, Multilevel Person-Fit Analysis of Response Consistency on the Spielberger State-Trait Anxiety Inventory

Abstract

Self-report measures are vulnerable to concentration and motivation problems, leading to responses that may be inconsistent with the respondent's latent trait value. We investigated response consistency in a sample (N = 860) of cardiac patients with an implantable cardioverter defibrillator and their partners who completed the Spielberger State-Trait Anxiety Inventory on five measurement occasions. For each occasion and for both the state and trait subscales, we used the l ^p _z person-fit statistic to assess response consistency. We used multilevel analysis to model the between-person and within-person differences in the repeated observations of response consistency using time-dependent (e.g., mood states) and time-invariant explanatory variables (e.g., demographic characteristics). Respondents with lower education, undergoing psychological treatment, and with more post-traumatic stress disorder symptoms tended to respond less consistently. The percentages of explained variance in response consistency were small. Hence, we conclude that the results give insight into the causes of response inconsistency but that the identified explanatory variables are of limited practical value for identifying respondents at risk of producing invalid test results. We discuss explanations for the small percentage of explained variance and suggest alternative methods for studying causes of response inconsistency.

Notes

^a Correlations obtained in patient sample only.

^b Results obtained on Occasion 3.

^a For patients (below diagonal, n = 175) and partners (above diagonal, n = 192), excluding respondents with missing l ^p _z s. STAI-State = State-Trait Anxiety Inventory State-anxiety subscale; STAI-Trait = State-Trait Anxiety Inventory Trait-anxiety subscale.

^a Encoded as 1 (elementary school or lower), 2 (high school), 3 (professional or vocational education), and 4 (university).

^b Only used in the analyses in the total sample.

^c Only available for patients and therefore only used in the analyses in the patient sample.

^d Calculated at Occasion 3 for PTSD symptoms, at occasion 5 for ICD complications and ICD shock, and calculated at Occasion 1 for all other explanatory variables. DS14 = Type D Scale-14; STAI = State-Trait Anxiety Inventory; STAS = State-Trait Anger Scale; HADS = Hospital Anxiety and Depression Scale; ICD concerns = Implantable Cardioverter Defibrillator Patient Concerns Questionnnaire; PTSD = Posttraumatic Diagnostic Scale posttraumatic stress disorder symptom scale.

*p < .05.

Effect in the expected tail, two-sided: *p < .05.

**p < .01.

***p < .001.

Effect in the unexpected tail, two-sided: †p < .005.

Effect in the expected tail, two-sided: *p < .05.

**p < .01.

***p < .001.

Effect in the unexpected tail, two-sided: †p < .005.