nsomnia is a common sleep problem which affects 10–15% of the adult population worldwide (Chung et al., 2015 and Ohayon, 2002). It is associated with negative health consequences (Taylor et al., 2007), work absenteeism (Kessler et al., 2011 and Kleinman et al., 2009), motor car accidents (Daley et al., 2009), and increased healthcare utilization (Walsh, 2004). Cognitive behavioral therapy for insomnia (CBT-I) is a multi-component intervention including sleep hygiene education, sleep restriction, stimulus control, cognitive restructuring and relaxation training (Morin et al., 2006). With benefits of low cost and easy accessibility, self-help CBT-I has been used as an efficacious and acceptable entry-level treatment in a stepped-care delivery model of CBT-I (Espie, 2009 and Ho et al., 2015). However, dropout from treatment potentially diminishes its therapeutic effect and poses clinical concern. A sense of dissatisfaction or failure can be developed and result in the worsening of symptoms. In addition, a reduced motivation to receive further therapist-administered CBT-I can occur, hence reducing the likelihood of receiving effective treatment. Therefore, strategies for preventing or minimizing dropout from self-help CBT-I are important.
The term “dropout” can be defined as withdrawal prior to completing adequate treatment. Dropout from psychological treatment typically, but not always, occurs early and before significant improvement is achieved (Ogrodniczuk, Joyce, & Piper, 2005); in such circumstances, and when there appears to be no justifiable reason, dropout is considered to be inappropriate. Due to differences in study design, sample characteristics and “dropout” definition, previous studies reported a wide range of dropout from self-help CBT-I, ranging from 0% to 44.4%, with an average of 15.6% (Ho et al., 2015). Some factors may contribute to the decision to terminate prematurely (Ogrodniczuk et al., 2005). For example, subjects may feel that the self-help program is impersonal, inconvenient, hard to follow, or that it is not meeting their expectations. Subjects may have insufficient motivation, low psychological mindedness, or may dropout when improvement is not quick enough. Specific to CBT-I, participants may dropout because they find the treatment recommendations counterintuitive, experience significant daytime sleepiness early in treatment, complain of boredom and lack of activities upon the advice to reduce time in bed, or are ambivalent about changing their sleep-wake habit (Riedel & Lichstein, 2001).
Although dropout from self-help CBT-I is clinically relevant, research on factors related to dropout is scarce, especially for self-help CBT-I. Ong et al. found no significant predictor of dropout from group CBT-I that lasted 7 sessions, but shorter total sleep time (TST) and greater severity of depression at baseline were associated with dropout prior to the fourth session (Ong, Kuo, & Manber, 2008). Age, sex, chronotype, dysfunctional attitudes about sleep, and use of sleep medications were not associated with treatment non-completion or early dropout. Perlis et al. examined 85 patients with primary insomnia and found that those who did not accept individual CBT-I or dropped out prior to the fourth session had shorter baseline TST and greater number of awakenings than those who received at least 4 sessions (Perlis et al., 2000). Age, sex, marital status, race, prevalence of medical or psychiatric disorders, anxiety and depression severity, and self-reported sleep onset latency (SOL) and wake after sleep onset (WASO) were not associated with treatment non-acceptance or early dropout. Another study showed that longer TST at baseline, not shorter, and psychiatric comorbidity were predictive of dropout from a 5-week internet-based sleep hygiene educational program (Hebert, Vincent, Lewycky, & Walsh, 2010). The authors found that the Theory of Planned Behavior (Ajzen, 1991) and the Transtheoretical Model of Behavior Change (Prochaska & DiClemente, 1983) were not able to predict dropout from the self-help program. Essentially, it means that the level of intention and stage of preparation at baseline were unrelated to dropout.
In view of the mixed results in previous studies and limited data on dropout from self-help CBT-I, we aimed to identify the characteristics of subjects who could not complete a 6-week internet-based CBT-I program. Based on findings in previous studies, we hypothesized that baseline severity of insomnia and depression can predict non-completion and early dropout from self-help CBT-I.
