Rasch analysis of the Patient Participation in Rehabilitation Questionnaire (PPRQ)

Objective: To evaluate the Patient Participation in Rehabilitation Questionnaire (PPRQ) according to Rasch measurement theory. Method: Five hundred twenty-two post-discharge patients from a neurological rehabilitation unit were included. The PPRQ questionnaire comprises 20 items rated by a cohort of 522 patients about their experiences of participating in rehabilitation. The measurement properties of the PPRQ were evaluated by Rasch analysis of the responses. Results: The Rasch analysis of 20 items showed some major misfits, particularly three items addressing the involvement of family members. After removing those items, the model fit improved and no significant DIF remained. Despite improvements, person values (−2.96 to 4.86 logits) were not fully matched by the item values (−0.61 to 0.77 logits). Neither did the t test for unidimensionality meet the criterion of 5%, and local dependency was present. The unidimensionality and local dependency could, however, be accommodated for by four testlets. Conclusion: The PPRQ-17 showed that a ruler with a reasonable and clinical hierarchy can be constructed, although the expectations of dimensionality and local dependency need to be evaluated further. Despite room for further development, PPRQ-17 nevertheless shows improved measurement precision in terms of patient leniency compared with previous evaluations with classical test theory. In turn, this can play a crucial role when comparing different rehabilitation programs and planning tailored care development activities