Measurement properties of the Health Anxiety by Proxy Scale (HAPYS): A new questionnaire to assess parents' worries about their child's health.

Objective: Health anxiety by proxy refers to parents' excessive worries about their child's health. The Health Anxiety by Proxy scale (HAPYS) is a new self-report questionnaire to assess parents' worries and behaviors regarding their child's health. This study aimed to investigate the measurement properties of the HAPYS.

Methods: Questionnaires were completed by 204 parents, and a HAPYS score was obtained for 200 parents: 39 parents diagnosed with health anxiety, 33 parents with different anxiety disorders, 33 parents with a Functional Somatic Disorder, and 95 healthy parents. We evaluated the following measurement properties: structural validity, reliability, convergent validity ((pain catastrophizing, parents' reports of child's emotional and physical symptoms), discriminant validity (parental reports of child's well-being), and known-groups validity (see compared groups above).

Results: HAPYS demonstrated a one factor dimensionality, and excellent internal reliability (α = 0.95; CI: 0.93-0.97) and test-retest reliability after two weeks (ICC = 0.91; CI: 0.87-0.94). Convergent validity with the construct of parental catastrophizing about child pain was good (r = 0.72; CI: 0.64-0.78)). Good known-groups validity was demonstrated by the largest total HAPYS score observed in parents with health anxiety (median = 35; IQR: 9-53) and the lowest score in healthy parents (median = 9; IQR: 5-15) (p < 0.001).

Conclusion: The findings support that HAPYS is a useful measure of health anxiety by proxy. Future research should examine the measurement properties in larger samples and different languages with further statistical analyses of structural validity.