Whether chronic pain is medically explained or not does not moderate the response to cognitive-behavioural therapy

Objectives: To determine whether pain-related treatment outcomes, following an online Cognitive Behavioural Therapy (CBT) intervention for chronic pain, were moderated by the pain etiology of a medically explained or unexplained origin.

Methods: Data were available from 471 participants who completed the online pain management program between March 2013 and August 2014. Participants' pain symptoms were classified as being medically explained symptoms (MES: n = 292) or medically unexplained symptoms (MUS: n = 222) via analysis of clinical data. Outcome variables were pain-related disability, average pain intensity, depression and anxiety.

Results: Moderation analyses were non-significant for all dependent variables. Between group differences (CBT and control) were larger for depression in those classified with MES, compared with MUS (MUS: mean change = -3.50 [95% CI = -4.98 to -2.22]; MES: mean change = -5.72 [95% CI = -7.49 to -4.09]). However, between group differences were small for pain intensity (MUS: mean change = -0.03 [95% CI = -0.83 to -0.81]; MES: mean difference = -1.12 [95% CI = -1.84 to 0.40]).

Conclusion: The therapeutic outcomes examined in this study associated with an online CBT program do not appear to be altered by whether the participants' pain symptoms are medically explained or unexplained.