This was a secondary analysis of a previous randomized clinical trial, in which individuals with fibromyalgia were randomized to EAET, CBT, or Education as a control intervention. Only females who completed baseline and post treatment assessments were analyzed (n=196). The primary outcome was change in overall clinical pain severity from pre-treatment to post-treatment, and the primary predictor of interest was pressure pain tolerance at baseline.
Among patients with low pain tolerance at baseline (n=154), both EAET and CBT led to small but significant improvements in clinical pain severity (CBT mean [95% CI]=0.66 [0.24, 1.07]; EAET=0.76 [0.34, 1.17]). Conversely, in patients with normal pain tolerance (n=42), there was no significant improvement in clinical pain after CBT (0.13 [-0.88, 1.14]), a small improvement after FM Education (0.81 [0.14, 1.48]), but a much larger and statistically significant improvement after EAET (2.14 [1.23, 3.04]).
Normal levels of pressure pain tolerance at baseline predicted greater improvement in clinical pain severity following EAET than CBT. QST may provide insights about individual responses to psychologically-based therapies for individuals with chronic pain.