Validity, reliability and responsiveness of the Body Image Quality of Life Inventory in patients treated for infective endocarditis.

RATIONALE AND OBJECTIVES

Suffering through infective endocarditis (IE) can drastically alter a person's physical appearance, and body image-related concerns have been reported by patients. The extent and severity of the phenomenon has not previously been explored, as no quantitative measure has been validated in this patient population. The purpose of this study was thus to assess the validity, reliability and responsiveness of the Danish Body Image Quality of Life Inventory (BIQLI-DA) on patients treated for IE.

METHODS

We evaluated the psychometric properties of the BIQLI-DA on data obtained in the CopenHeart IE trial, which is a randomised clinical trial evaluating the effects of comprehensive cardiac rehabilitation for patients treated for IE. We administered the BIQLI-DA as part of data collection at baseline and 6 months. We examined the psychometric properties through correlations to other measures, including body mass index, Medical Outcome Short Form 36 and Hospital Anxiety and Depression Scale. In addition, we examined internal consistency on item and scale level and performed anova group-by-time interaction to test for responsiveness.

RESULTS AND STUDY LIMITATION

Participants were seventy patients with a mean age of 58 years and of which 83% were men. Results indicated convergent construct validity by confirming hypothesised associations to potentially related constructs. The BIQLI-DA was found to be highly internally consistent with a Cronbach's alpha of 0.96. Instrument responsiveness was indicated by a significant group-by-time interaction. Support for the validity of the BIQLI-DA might have been strengthened by a larger sample with more women. A more optimal design for testing responsiveness would possibly have allowed for clearer conclusions.

CONCLUSIONS

The BIQLI-DA may be applicable in healthcare research as it seems to be valid, reliable and responsive; however, evidence should be strengthened through further exploration of instrument performance, particularly regarding responsiveness.