Becoming a secondary actor of one's own life: A qualitative study of the experiences of informal caregivers in the care of people with chronic pain.

Participants were purposively chosen from the Unit of Pain at the University Hospital 'Puerta del Mar' who attended the consultation accompanying their relatives. All the eligible participants were approached by the clinician. After this initial approach by the clinician, one of the researchers met the potential participant and they went to a quieter place in a clinical setting for the interview, before which the participant was shown a letter with more comprehensive information about the study and its aim. The participants were left alone to read and think carefully before giving their written informed consent. Participation was voluntary and the subjects received no financial contribution for their time.