Biofeedback and chronic headache : correlates of success in a long-term follow-up study
Despite the growing acceptance of biofeedback as an effective modality of treatment for chronic headache, there remains considerable lack of clarity as to which factors are responsible for treatment success. Thirty-three adults who had completed biofeedback training for chronic headache no earlier than six months prior to this study completed a retrospective questionnaire. Their responses were combined with data from their histories and treatment files and grouped into four categories for investigation: subject characteristics, treatment variables, physiological parameters, and non-specific factors and effects. These variables were analyzed and compared to the criterion variables: change in headache frequency, change in depression, and change in medication potency. The major finding of this study is that each of the criterion variables was found to be significantly decreased from pre-treatment levels at a minimum of six months post-training. However, correlations among the criterion variable were at best moderate. Change indepression scores, change in medication potency and change in perceived coping ability were found to be significantly related. Several physiological measures of task acquisition were found to be predictive of success and finger temperature was found to be a more reliable predictor of success than EMG. Placebo response was ruled out as a major factor in success and subjects responses indicate that the subject perceive success in biofeedback as being a) multi-determined and b) involving both physical and cognitive components. Limitations of the study and suggestions for future research are discussed.