The Perceived Illness Experience Scale (PIE): reliability and validity revisited

Area of Science:

• Orthopedics
• Psychometrics
• Pediatric Oncology

Background:

• Limb salvage surgery is a common treatment for primary bone tumors in pediatric patients.
• Assessing the full impact of chronic illness requires patient-reported outcomes beyond functional measures.
• The Perceived Illness Experience Scale (PIE) was developed to capture the patient's perspective on chronic illness.

Purpose of the Study:

• To psychometrically evaluate the Perceived Illness Experience Scale (PIE) in young patients treated with limb salvage surgery.
• To assess the construct validity of the PIE by correlating it with well-being and function measures.
• To determine the utility of mothers as proxy raters for the PIE.

Main Methods:

• Psychometric evaluation of the PIE using a sample of 34 pediatric patients (mean age 17) post-limb salvage surgery.
• Patients completed the PIE, SF-36 (well-being), and function measures.
• Mothers completed the PIE to assess proxy-rater reliability.

Main Results:

• The PIE demonstrated construct validity through significant correlations with SF-36 scores.
• Significant correlations were found between patient function and three PIE sub-scales.
• High agreement between patient and mother PIE ratings indicated mothers can serve as effective proxy raters.

Conclusions:

• The PIE is a valid instrument for assessing the perceived impact of chronic illness in pediatric patients undergoing limb salvage surgery.
• Comprehensive patient assessment should include subjective experiences (PIE) alongside objective functional outcomes.
• Mothers can provide reliable proxy data using the PIE when patient self-report is not feasible.