Behavior change is an integral part of improved self-management of many chronic health disorders. For people with chronic widespread pain (CWP) or fibromyalgia syndrome (FMS) this is no easy task. The chronic condition of pain without a clear physiological explanation often entails a downward spiral of pain, fear of pain and avoidance behavior, fatigue and depressive symptoms, which makes behavior change extremely challenging . The development of CWP and FMS involves a complex dynamic biopsychosocial process, and multidimensional rehabilitation seems to be the most effective treatment approach . An essential part of the treatment should be an intervention based on cognitive behavioral therapy (CBT) to increase self-management skills [3, 4]. CBT with focus on mindfulness and acceptance processes has been found to be effective for people with different chronic health disorders , including pain . The goal is for the patient to accept, rather than struggle with unwanted thoughts, emotions and symptoms, and to commit to valued behavior [6, 7]. Because of differences in philosophical background and applied techniques between the mindfulness approach and more traditional CBT, some define the mindfulness approach as a new generation of behavioral therapy  whereas others view it as consistent with CBT .
Internet-administrated cognitive behavioral interventions are increasingly used to support people with health problems [10, 11]. Effective operationalization of important elements seems possible because, for some conditions, the effectiveness of Internet-based CBT has been shown to be similar to that of face-to-face CBT [10–12]. A recent meta-analysis of 11 studies shows that Internet-delivered cognitive behavioral interventions for people with chronic pain have a significantly greater effect on pain level than waiting list conditions . The pooled effect size was small, but all the reviewed interventions also improved significantly other health-related and behavioral outcomes (e.g., distress and work capability) compared with the waiting list group.
Results of a recent review of Internet interventions aiming to support behavior changes indicate that interventions including mobile phone text messages and/or some personal online contact can be more helpful in supporting behavior change than Internet interventions without those features . Today's mobile phones commonly include an integrated Internet facility, (e.g., personal digital assistants (PDAs) and smartphones), which opens new possibilities for Internet-based CBT. By using a Web-enabled mobile phone instead of a desktop or laptop computer, the patient can register and send information to the therapist when in different situations. An important goal of CBT is to improve functioning by detecting how automatic thoughts influence feelings and behavior . For this purpose, patients are encouraged to keep some form of record of their thoughts, emotions and behavior (e.g., "What did I feel in the situation?"). The Experience Sampling Method is a way to obtain information on thoughts, feelings and behavior in real time with minimal retrospective bias (e.g., "Right now I am feeling...") . Questions in this format can be answered using the mobile phone and may support self-monitoring [16, 17]. The Internet connection makes it possible to submit this information online and make it immediately available to a therapist. The therapist is thereby provided with situational information with a reduced risk of memory bias. Importantly, this also enables the therapist to give the patient prompt feedback on the registered information via a text message [16, 18]. In a randomized controlled trial of 76 patients with irritable bowel syndrome, a cluster of symptoms without clear organic abnormalities, the intervention group kept daily online symptom diaries for four weeks and received daily CBT based feedback on a mobile phone. Compared with the control group, the intervention group showed improvements in key symptoms such as catastrophizing thoughts and in quality of life. The effect on catastrophizing was sustained at a three-month follow-up . Using mobile phones and text messaging to support behavior change seems effective for people with different health conditions [14, 19]. To our knowledge, no studies exist on the effect of mobile phone interventions to support people with chronic widespread pain .
The purpose of this pretrial study was to describe the development and usability of a cognitive behavioral intervention for people with chronic pain using Web-enabled mobile phones. The mobile phones were used to keep online diaries on thoughts, feelings and behavior and to receive situational feedback from a therapist. Acceptability, response rate and user friendliness of the technological system were investigated.