Determinants of and Interventions in Chronic Fatigue.
What are the most important perpetuating factors of chronic fatigue and chronic fatigue syndrome and which interventions are effective in influencing these factors?
- Veronique de Gucht
About 6% of the general population reports chronic fatigue, while about 1% of the adult general population suffers from Chronic Fatigue Syndrome (CFS). CFS is not only a burden for the patients, who suffer from it, but it is also associated with a high use of health care resources and a loss of productivity. Unfortunately, the prognosis of CFS is very poor: less than 10% returns to premorbid levels of functioning. In order to optimize interventions, a better understanding of perpetuating factors is necessary. Research has identified several perpetuating factors of chronic fatigue (syndrome) including physical, cognitive, affective, behavioral and social factors.
We have conducted several studies that explore the relative importance of these factors.
A cross-cultural study that included Dutch (N=196) and Portuguese (N=89) CF patients showed that cognitive and behavioral factors predicted fatigue in both populations, but that psychological consequences such as anxiety, depression and psychological quality of life were significantly worse in Portuguese patients (Marques, De Gucht, Leal, & Maes, 2013).
In another study, we compared a group of Dutch patients who suffered from fatigue for at least one month (N=192) to a group of CFS patients (N=192). Both groups were matched for age and gender. The objective of this study was to identify factors that could contribute to a chronic course of fatigue and other somatic complaints. The results indicated that patients who believe that their fatigue is associated with more severe consequences, that it will last longer and is responsible for more additional somatic symptoms are more likely to be classified as CFS patients, while patients who are more physically active and have higher levels of all-or-nothing behaviour (characterized by an imbalance in activity level) are less likely to be classified as having CFS (De Gucht, Garcia, den Engelsman, & Maes, 2016).
A one-year follow-up study (N=144) in Dutch patients suffering from CFS showed that both illness perceptions and dysfunctional behaviors (all-or-nothing behaviour as well as activity avoidance) predicted perpetuation of fatigue severity and functional disability (physical quality of life). Number and severity of somatic complaints and psychological well-being at follow-up were, however, only determined by negative illness perceptions (manuscript submitted for publication).
In addition, a brief pilot intervention study ‘Four Steps to Control Your Fatigue’, based on motivational counseling and self-regulation theory and aiming at a good balance between physical activity and rest was developed and evaluated in a group of 80 Portuguese CFS patients. The program proved to be effective in reducing fatigue and somatic complaints (Marques, De Gucht, Leal, & Maes, 2015). At 12-month follow-up, there were significant effects on fatigue, physical activity, and Health-Related Quality of Life, indicating that the intervention produced sustained benefits. A process analysis revealed that fatigue severity at follow-up was partially mediated by goal progress on a personal physical activity goal (Marques et al., 2017).