Advances in measuring pediatric overall health: the PROMIS® Pediatric Global Health scale (PGH-7)

In this cross-sectional study, we aimed to assess the reliability, validity, and efficiency of the Patient-Reported Outcomes Measurement Information System (PROMIS) Pediatric Global Health scale (PGH-7) to reduce patient burden when assessing overall health in clinical practice. In total, 1082 children (8–18), representative of the Dutch population, completed the PGH-7 and the Pediatric Quality of Life Inventory (PedsQL™ 4.0), a common legacy instrument used in clinical practice to assess overall health. The assumptions for fitting an item response theory model were assessed: unidimensionality, local independence, and monotonicity. Subsequently, a model was fitted to the data to assess item fit and cultural differential item functioning (DIF) between Dutch and US children. A strong correlation (> .70) was expected between the PGH-7 and PedsQL, as both instruments measure physical, mental, and social domains of health. Percentages of participants reliably measured (> 0.90) were assessed using the standard error of measurement (SE(θ) < 0.32). Efficiency was calculated ((1 − SE(θ)²)/n_items) to compare how well both measures performed relative to number of items administered. The PGH-7 met all assumptions and displayed good structural and convergent (r = .69) validity. One item displayed cultural DIF. Both questionnaires measured reliably (%n_PGH-7 = 73.8%, %n_PedsQL = 76.6%) at the mean and 2SD in clinically relevant direction. PGH-7 items were 2.6 times more efficient in measuring overall health than the PedsQL.

   Conclusion: The PGH-7 displays sufficient validity and reliability in the general Dutch pediatric population and measures more efficiently than the PedsQL, the most commonly used legacy instrument. The PGH-7 can be used in research and clinical practice to reduce patient burden when assessing overall health.