Background Chronic pain (i.e. pain lasting longer than three months) is common. Psychological therapies (e. g. cognitive behavioural therapy) can help people to cope with pain, depression and disability that can occur with such pain. Treatments currently are delivered via hospital out-patient consultation (face-to-face) or more recently through the Internet. This review looks at the evidence for psychological therapies delivered via the Internet for adults with chronic pain. Objectives Our objective was to evaluate whether Internet-delivered psychological therapies improve pain symptoms, reduce disability, and improve depression and anxiety for adults with chronic pain. Secondary outcomes included satisfaction with treatment/treatment acceptability and quality of life. Search methods We searched CENTRAL (Cochrane Library), MEDLINE, EMBASE and PsycINFO from inception to November 2013 for randomised controlled trials (RCTs) investigating psychological therapies delivered via the Internet to adults with a chronic pain condition. Potential RCTs were also identified from reference lists of included studies and relevant review articles. In addition, RCTs were also searched for in trial registries. Selection criteria Peer-reviewed RCTs were identified and read in full for inclusion. We included studies if they used the Internet to deliver the primary therapy, contained sufficient psychotherapeutic content, and promoted self-management of chronic pain. Studies were excluded if the number of participants in any arm of the trial was less than 20 at the point of extraction. Data collection and analysis Fifteen studies met the inclusion criteria and data were extracted. Risk of bias assessments were conducted for all included studies. We categorised studies by condition (headache or non-headache conditions). Four primary outcomes; pain symptoms, disability, depression, and anxiety, and two secondary outcomes; satisfaction/acceptability and quality of life were extracted for each study immediately post-treatment and at follow-up (defined as 3 to 12 months post-treatment). Main results Fifteen studies (N=2012) were included in analyses. We assessed the risk of bias for included studies as low overall. We identified nine high 'risk of bias' assessments, 22 unclear, and 59 low 'risk of bias' assessments. Most judgements of a high risk of bias were due to inadequate reporting. Analyses revealed seven effects. Participants with headache conditions receiving psychological therapies delivered via the Internet had reduced pain (number needed to treat to benefit = 2.72, risk ratio 7.28, 95% confidence interval (CI) 2.67 to 19.84, p < 0.01) and a moderate effect was found for disability post-treatment (standardised mean difference (SMD) -0.65, 95% CI -0.91 to -0.39, p < 0.01). However, only two studies could be entered into each analysis; hence, findings should be interpreted with caution. There was no clear evidence that psychological therapies improved depression or anxiety post-treatment (SMD -0.26, 95% CI -0.87 to 0.36, p > 0.05; SMD -0.48, 95% CI -1.22 to 0.27, p > 0.05), respectively. In participants with non-headache conditions, psychological therapies improved pain post-treatment (p < 0.01) with a small effect size (SMD -0.37, 95% CI -0.59 to -0.15), disability post-treatment (p < 0.01) with a moderate effect size (SMD -0.50, 95% CI -0.79 to -0.20), and disability at follow-up (p < 0.05) with a small effect size (SMD -0.15, 95% CI -0.28 to -0.01). However, the follow-up analysis included only two studies and should be interpreted with caution. A small effect was found for depression and anxiety post-treatment (SMD -0.19, 95% CI -0.35 to -0.04, p < 0.05; SMD -0.28, 95% CI -0.49 to -0.06, p < 0.01), respectively. No clear evidence of benefit was found for other follow-up analyses. Analyses of adverse effects were not possible. No data were presented on satisfaction/acceptability. Only one study could be included in an analysis of the effect of psychological therapies on quality of life in participants with headache conditions; hence, no analysis could be undertaken. Three studies presented quality of life data for participants with non-headache conditions; however, no clear evidence of benefit was found (SMD -0.27, 95% CI -0.54 to 0.01, p > 0.05). Authors' conclusions There is insufficient evidence to make conclusions regarding the efficacy of psychological therapies delivered via the Internet in participants with headache conditions. Psychological therapies reduced pain and disability post-treatment; however, no clear evidence of benefit was found for depression and anxiety. For participants with non-headache conditions, psychological therapies delivered via the Internet reduced pain, disability, depression, and anxiety post-treatment. The positive effects on disability were maintained at follow-up. These effects are promising, but considerable uncertainty remains around the estimates of effect. These results come from a small number of trials, with mostly wait-list controls, no reports of adverse events, and non-clinical recruitment methods. Due to the novel method of delivery, the satisfaction and acceptability of these therapies should be explored in this population. These results are similar to those of reviews of traditional face-to-face therapies for chronic pain.
