A mixed methods study has the potential to produce knowledge that is unavailable to a qualitative study and a quantitative study undertaken independently. Any unique insight or "yield" from a mixed methods study may be difficult to assess in practice. However, given that integration of data or findings from different components of a study is a core characteristic of mixed methods research, two possible indicators of yield can be used: first, the extent to which researchers exploit the potential for integration in mixed methods studies; and second, the way in which this integration is communicated in peer-reviewed journal articles. Here, the authors apply these indicators to mixed methods studies in health services research in the United Kingdom. (Contains 6 tables and 1 note.)