title: Rasch-family models are more valuable than score-based approaches for analysing longitudinal patient-reported outcomes with missing data.
abstract: The objective was to compare classical test theory and Rasch-family models derived from item response theory for the analysis of longitudinal patient-reported outcomes data with possibly informative intermittent missing items. A simulation study was performed in order to assess and compare the performance of classical test theory and Rasch model in terms of bias, control of the type I error and power of the test of time effect. The type I error was controlled for classical test theory and Rasch model whether data were complete or some items were missing. Both methods were unbiased and displayed similar power with complete data. When items were missing, Rasch model remained unbiased and displayed higher power than classical test theory. Rasch model performed better than the classical test theory approach regarding the analysis of longitudinal patient-reported outcomes with possibly informative intermittent missing items mainly for power. This study highlights the interest of Rasch-based models in clinical research and epidemiology for the analysis of incomplete patient-reported outcomes data.
authors.affiliation: EA4275 'Biostatistique, Phamacoépidémiologie et Mesures Subjectives en Santé', University of Nantes, France elodie.debock@gmail.com.
authors.forename: Élodie
authors.initials: É
authors.lastname: de Bock
authors.affiliation: EA4275 'Biostatistique, Phamacoépidémiologie et Mesures Subjectives en Santé', University of Nantes, France.
authors.forename: Jean-Benoit
authors.initials: JB
authors.lastname: Hardouin
authors.affiliation: EA4275 'Biostatistique, Phamacoépidémiologie et Mesures Subjectives en Santé', University of Nantes, France.
authors.forename: Myriam
authors.initials: M
authors.lastname: Blanchin
authors.affiliation: EA4275 'Biostatistique, Phamacoépidémiologie et Mesures Subjectives en Santé', University of Nantes, France.
authors.forename: Tanguy
authors.initials: T
authors.lastname: Le Neel
authors.affiliation: EA4275 'Biostatistique, Phamacoépidémiologie et Mesures Subjectives en Santé', University of Nantes, France.
authors.forename: Gildas
authors.initials: G
authors.lastname: Kubis
authors.affiliation: EA4275 'Biostatistique, Phamacoépidémiologie et Mesures Subjectives en Santé', University of Nantes, France.
authors.forename: Angélique
authors.initials: A
authors.lastname: Bonnaud-Antignac
authors.affiliation: EA4275 'Biostatistique, Phamacoépidémiologie et Mesures Subjectives en Santé', University of Nantes, France.
authors.forename: Étienne
authors.initials: É
authors.lastname: Dantan
authors.affiliation: EA4275 'Biostatistique, Phamacoépidémiologie et Mesures Subjectives en Santé', University of Nantes, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Sébille
mesh_terms: D015982:Bias; D006801:Humans; D000071066:Patient Reported Outcome Measures; D012107:Research Design
keywords: Item response theory; Rasch model; classical test theory; longitudinal; missing data; patient-reported outcomes/PROMs