The concepts of patient empowerment, patient participation and patient-centeredness have been introduced as part of the trend towards a more participatory health care and have largely been used interchangeably. Although these concepts have been discussed for a number of years, their exact meaning in hospital care remains somewhat unclear. This absence of theoretical and conceptual clarity has led to (1) poor understanding and communication among researchers, health practitioners and policy makers and (2) problems in measurement and comparison between studies across different hospitals.