Investigating the active ingredients of cognitive behaviour therapy and counselling for patients with chronic fatigue in primary care: developing a new process measure to assess treatment fidelity and predict outcome.

OBJECTIVES

To develop a brief measure of the therapy process and use it to examine which therapeutic ingredients were associated with outcome in a sample of patients from a randomized controlled trial (RCT) of cognitive behaviour therapy (CBT) versus counselling for patients with chronic fatigue in primary care. It was hypothesized that the two therapies would be clearly distinguishable and that in terms of process variables, the therapeutic alliance would be important in predicting outcome.

DESIGN

The data for this study were collected alongside a RCT in primary care and included audiotaped therapy sessions. These tapes were assessed by two independent raters using a newly devised measure in order to evaluate therapy process and its relationship with outcome.

METHODS

Tapes from 71 patients participating in the RCT were assessed to form the basis of the process analysis. Outcome was self-reported fatigue symptoms at 6 months follow-up. Data reduction was achieved via a principal component analysis (PCA). Factors were entered into a multiple regression analysis to produce a final model of predictors of outcome.

RESULTS

The process measure showed that although the treatments could be distinguished, there was some overlap between them. The key predictor of a good fatigue outcome was emotional processing, including the expression, acknowledgement and acceptance of emotional distress.

CONCLUSION

A new process measure was developed successfully which now warrants further testing. It was able to assess treatment adherence and unpack, and distinguish the common factor which predicted outcome across therapy modalities. The findings lend preliminary support to the view that the specific techniques associated with particular 'brand names' of therapy are not necessarily the 'active ingredients' that help patient's change within the primary care setting. Emotional processing predicted outcome for patients with chronic fatigue and therefore future research might explore this in more depth, in order to understand better how it can be facilitated.