Measuring clinical pain in chronic widespread pain: selected methodological issues.

Assessing clinical pain is an important task in clinical practice and research. A large empirical literature has documented that patients' pain reports can be systematically biased by a number of methodological factors. This chapter reviews a selection of methodological issues that can affect pain ratings, including: the impact of recall bias, the use of paper and electronic diaries to assess pain experiences, ecological momentary assessment methods as a way of capturing real-time pain data in the real world, and pain scaling and data analysis considerations. Data from a recent study that implemented an electronic diary for capturing real-time pain data are presented and reviewed in the context of the methodological factors reviewed above. It is concluded that methodological factors can greatly affect our understanding of patients' pain experiences.