Reliability and validity of the Brief Illness Perception Questionnaire (B-IPQ) in individuals with a recently acquired spinal cord injury

Abstract

Objective To assess the reliability and validity of the Brief Illness Perception Questionnaire (B-IPQ) and possible subscales, and to interpret Brief Illness Perception Questionnaire (B-IPQ) total scores, in individuals with a spinal cord injury. Design Cross-sectional Setting Seven Dutch rehabilitation centres Subjects Individuals with a recently acquired traumatic or non-traumatic spinal cord injury at the start of inpatient spinal cord injury rehabilitation (N = 270). Main measure The Brief Illness Perception Questionnaire (B-IPQ) consists of eight items on an individual's cognitive and emotional representation of one's health conditions. Principal component analysis was performed to identify possible Brief Illness Perception Questionnaire (B-IPQ) subscales. Validity was assessed by testing hypotheses on correlations between the Brief Illness Perception Questionnaire (B-IPQ) and other measures. Cut-off points of the Brief Illness Perception Questionnaire (B-IPQ) total score were determined. Results Mean (SD) age of participants was 60.1 (16.5) years, 188 (71%) were male, and 119 (44%) had tetraplegia. Three potential subscales were revealed. Cronbach's alpha was acceptable for only one subscale. This subscale was named ‘consequences’ and included the items ‘consequences’, ‘symptom burden’, ‘concern’, and ‘emotions’. The Brief Illness Perception Questionnaire (B-IPQ) total and the consequence subscale showed the expected strong correlations (>.50) with symptoms of anxiety and depression. Mean (SD) scores were 40.9 (12.3) on the 8-item Brief Illness Perception Questionnaire (B-IPQ) (range 0–80) and 25.1 (8.1) on the consequences subscale (range 0–40). Cut-off points for the Brief Illness Perception Questionnaire (B-IPQ) total score were determined as follows: <42 indicating low experienced threat, 42–49 indicating moderate experienced threat, and ≥50 indicating high experienced threat. Conclusion The Brief Illness Perception Questionnaire (B-IPQ) total and consequences subscale seem applicable in individuals with a spinal cord injury in the rehabilitation practice and research.