Long-term follow-up after cognitive behaviour therapy for chronic fatigue syndrome

Highlights

• Positive effects of CBT for CFS are partly maintained at long term follow-up, up to 10 years post treatment.

• One out of two of all participants does not perceive themselves as a CFS patient.

• A subgroup of patients shows evidence of relapse and once again report severe fatigue and/or compromised physical functioning

Abstract

Objective

Cognitive behaviour therapy (CBT) is an effective treatment for chronic fatigue syndrome (CFS). Main aim was to determine whether treatment effects were maintained up to 10 years after treatment.

Methods

Participants (n = 583) of previously published studies on the effects of CBT for CFS were contacted for a long-term follow-up assessment. They completed questionnaires on main outcomes fatigue severity (CIS) and physical functioning (SF-36). The course of these outcomes since post-treatment assessment was examined using mixed model analyses.

Results

Between 21 and 125 months after finishing CBT, 511 persons (response rate 88%) completed a follow-up assessment. At follow-up, mean fatigue severity was significantly increased to 37.60 (SD = 12.76) and mean physical functioning significantly decreased to 73.16 (SD = 23.56) compared to post-treatment assessment. At follow-up still 37% of the participants had fatigue scores in the normal range and 70% were not impaired in physical functioning.

Conclusion

Positive effects of CBT for CFS on fatigue and physical functioning were partly sustained at long-term follow-up. However, a subgroup of patients once again reported severe fatigue, and compromised physical functioning. Further research should elucidate the reasons for this deterioration to facilitate the development of treatment strategies for relapse prevention.

Introduction

Patients with chronic fatigue syndrome (CFS) suffer from medically unexplained, severe fatigue leading to substantial disability [5]. According to the US Centers for Disease Control and Prevention (CDC), persons with CFS have experienced fatigue for at least six months, and their fatigue must be accompanied by other symptoms [5], [6]. Cognitive behaviour therapy (CBT) is an effective treatment for CFS and has been developed based on a model of perpetuating factors [7]. This model assumes that behaviour- and fatigue-related beliefs maintain fatigue and disability. CBT aimed at these cognitive-behavioural factors significantly reduces fatigue and disability [8], [9] and a minority of patients are fully recovered post-treatment [3], [10]. However, little is known about the long-term effects of CBT for CFS [8]. Research into the long-term efficacy of CBT for other disorders has shown that sustainment of treatment effects is not self-evident [11], [12].

For CFS, several studies that investigated short-term treatment effects found sustained effects up to eight months after the end of treatment [13], [14], [15]. Two studies had a longer follow-up period [16], [17]. In the smaller study of Deale et al. [16], most patients reported sustained improvement at five-year follow-up. However, significantly more patients were severely fatigued and fewer patients reported good physical functioning at long-term follow-up compared to short-term follow-up. More recently, Sharpe et al. [17] found sustained positive effects of CBT on fatigue and physical functioning at a median follow-up period of 19 months.

Previous research showed that CFS patients with somatic co-morbidity [3] and more pain [18] have less favourable outcomes following CBT. Mental health problems are more prevalent in CFS patients and are known to be associated with fatigue [19]. All of these factors might not only influence treatment outcome but especially when they occur after end of treatment also influence long-term effects of CBT.

In this study, we examined whether the positive effects of CBT on fatigue severity and physical functioning were maintained up to 10 years after the end of treatment. We also included participants' short-term follow-up data in the analyses. In order to determine what factors might be influencing treatment outcomes, we also examined whether somatic co-morbidity that occurred since the end of treatment and was still present, participants' pain and mental health at the time of the long-term follow-up, and several other patient and treatment characteristics were associated with the course of fatigue and physical functioning over time.