Psychometric evaluation of the Patient Health Engagement Scale (PHE-s®) in adolescents with chronic diseases: evidence from Türkiye

Aim – Patient engagement is increasingly recognized as a key determinant of adolescents’ adaptation to chronic illness; however, developmentally sensitive measures capturing engagement trajectories in youth remain scarce. Although the Patient Health Engagement Scale (PHE-s®) has demonstrated robust psychometric properties in Turkish adult populations, its applicability to adolescents has not yet been examined. The objective of this study was to examine its psychometric properties among adolescents with chronic diseases in a Turkish inpatient sample. Methods – A cross-sectional psychometric validation study was conducted with 200 adolescents aged 12–19 years hospitalized for chronic conditions in a tertiary pediatric hospital in Türkiye. The PHE-s® was evaluated using a multi-method approach integrating Rasch Partial Credit Modeling, categorical principal component analysis, and confirmatory factor analysis. Internal consistency, test–retest reliability, and differential item functioning across demographic and clinical subgroups were examined. Concurrent validity was assessed through associations with the Child Attitude Toward Illness Scale (CATIS). Results – Analyses supported a unidimensional structure of the adolescent PHE-s®, with strong item loadings and acceptable model fit across analytic approaches. The scale demonstrated high internal consistency (ordinal α = 0.90) and excellent one-week test–retest reliability (ICC = 0.98). Measurement invariance was largely supported across sex, education level, and follow-up attendance, with limited differential item functioning observed by age and medical-device dependence. Patient engagement was moderately and negatively associated with illness attitudes (ρ = −0.53, p < 0.001), indicating that higher engagement corresponds to more positive illness appraisals while reflecting a related but distinct construct. Conclusion – The Turkish PHE-s® is a reliable and valid instrument for assessing psychological engagement trajectories among adolescents with chronic diseases in inpatient settings.