Psychological inflexibility and clinical impact: Adaptation of the Acceptance and Action Questionnaire-II in a sample of patients on haemodialysis treatment Carlos J. Delgado Domínguez; Javier Varas García; Francisco J. Ruiz; Beatriz Díaz Espejo; Petra Cantón Guerrero; Elena Ruiz Sánchez; Noelia González Jurado; Abraham Rincón Bello; Rosa Ramos Sánchez;