The effect of homework compliance on treatment outcomes for participants with myalgic encephalomyelitis/chronic fatigue syndrome.

Patients with Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS) have varying degrees of symptom severity and duration (Fukuda et al., 1994). The high levels of fatigue and impaired physical functioning experienced by individuals with ME/CFS can often result in drastic life changes affecting physical, social, and mental well being as well as overall quality of life (Anderson & Ferrans, 1997; Prins et al., 2001; Van Houdenhove & Luyten, 2008). While further research is exploring the multiple factors that contribute to the severity and duration of the illness, individuals with ME/CFS continue to have difficulty managing its debilitating effects. In order to address both physical disability and coping skills, non-pharmacological interventions have been developed as palliative treatment approaches for a number of chronic illnesses. For example, behavioral interventions have demonstrated positive outcomes in coping with pain among individuals with cancer (Redinbaugh, Creola, Arnold, & Baum, 2004), and cognitive-behavioral stress management has been shown to reduce distress, improved quality of life, and increase cellular functioning in participants with HIV and different forms of cancer (Antoni et al., 2006a; Antoni et al., 2006b; Penedo et al., 2006). However, the use of these treatment approaches for ME/CFS has been extremely controversial. Non-pharmacological interventions that involve increasing levels of physical activity can pose challenges for participants with ME/CFS who struggle to complete minimal activity due to their level of disability (Bazelmans, Prins, & Bleijenberg, 2006; Twisk & Maes, 2009). Further, participants with ME/CFS often experience post-exertional malaise, and exercise can actually worsen participants’ symptoms. For example, Black, O’Connor, and McCully (2005) found that after a four week period, participants with ME/CFS who increased their daily activity by an average of 28% experienced a worsening in overall mood, muscle pain intensity, and time spent each day with fatigue. Later reports by Black and McCully (2005) concluded that participants with ME/CFS developed exercise intolerance as demonstrated by a reduction in total daily activity after 4 to 10 days of increased activity. Survey reports from individuals with ME/CFS have found that graded exercise protocols can influence symptom flare-ups (Cooper, 2001; Preliminary Report, 2001). Arecent review reported that different non-pharmacological interventions produce varying results for participants with ME/CFS and may not be well suited for many individuals with ME/CFS (Twisk & Maes, 2009). Similarly, some studies of behavioral interventions for ME/CFS have reported high dropout rates, which may indicate a lack of acceptability of the treatment among participants (Whiting et al., 2001). Price, Mitchell, Tidy, and Hunot (2008) reviewed 15 studies of cognitive behavioral therapy (CBT) with a total of 1,043 participants with ME/CFS. At treatment end, 40% of the CBT group showed clinical improvement in contrast to only 26% in usual care, but changes were not maintained at a 1 to 7 month follow-up when including people who had dropped out. Further research is needed to identify aspects of these interventions that might be related to outcomes. One method for understanding outcomes of non-pharmacological interventions for ME/CFS is to evaluate treatment engagement. In particular, examining compliance with protocol that is assigned for completion outside of treatment (i.e., homework) can provide context for understanding intervention effects. Completion of homework assignments, such as at-home practice between sessions, is an important element to any psychotherapeutic intervention (Burns & Spangler, 2000). The implementation of at-home practice and homework assignments has been used for many illnesses in order to help individuals manage symptoms and regain control of their daily activities (Addis & Jacobson, 2000; Kazantzis, Whittington, & Dattilio, 2010; Neimeyer & Feixas, 1990). In a recent meta-analysis of non-pharmacological interventions, Kazantzis et al. (2010) reported that 68% of participants experience improvement in treatments that require homework while only 32% of participants improve in treatments that do not require any homework; suggesting that between-session assignments are an active component of treatment. Although several studies have examined the efficacy of non-pharmacological interventions for ME/CFS, no studies have determined the role of homework compliance in study outcomes. The goal of this study was to explore the effect of homework compliance on treatment outcomes following participant involvement in non-pharmacological interventions for ME/CFS. This study examined homework compliance within a longitudinal study of participants with ME/CFS in order to determine whether regular completion of homework assignments contributed to positive outcomes. It was hypothesized that participants with ME/CFS who were more engaged in treatment through compliance with between-session homework and at-home practice would show significantly greater improvements in areas of functioning compared to those who were less engaged.