Merete Watt Boolsen, Lise Munk Plum & Jens G. Hillingsø: We question the social science methodology in survey-questionnaire Danish National Survey of Patient Experiences (LUP). The results from the survey are part of the accreditation system in The Danish Healthcare Quality Programme (DDKM). The methodological validity is researched through LUP-publications. We find that LUP has doubtful scientific quality which means that the validity of the survey results as such is questionable. Since this has consequences for the practical, economic, political and health-care decisions, we recommend that the total accreditation programme should be reconsidered.