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Keywords:

  • anxiety;
  • breast cancer;
  • depression;
  • fatigue;
  • insomnia;
  • nursing;
  • quality of life;
  • randomized controlled trial

Abstract

  1. Top of page
  2. Abstract
  3. What is already known about this topic
  4. Introduction
  5. Background
  6. The study
  7. Results
  8. Discussion
  9. Conclusion
  10. Acknowledgements
  11. Author contributions
  12. References

Title. Efficacy of an insomnia intervention on fatigue, mood and quality of life in breast cancer survivors

Aim.  This paper is a report of a study to describe the efficacy of cognitive behavioural therapy for insomnia on fatigue, mood and quality of life in breast cancer survivors.

Background.  Women who receive primary treatment for breast cancer often complain of insomnia. Rarely evaluated in insomnia intervention studies is the effect of cognitive behavioural treatment on the psychosocial outcomes of fatigue, mood and quality of life.

Method.  Data were collected between December 2002 and March 2004 with 72 women who were at least 3 months post-completion of primary treatment without current evidence of disease. Women were randomly assigned to either the cognitive behavioural therapy for insomnia group, which received stimulus control instructions, sleep restriction therapy and sleep education and hygiene, or the component control group which received sleep education and hygiene only. The 10-week study consisted of 2 weeks of pre-treatment, 6 weeks of treatment and 2 weeks of post-treatment. Fatigue, mood and quality of life were measured at pre- and post-treatment.

Findings.  Women receiving cognitive behavioural therapy for insomnia had significant improvements in fatigue, trait anxiety, depression and quality of life. The component control group also had statistically significant increases in quality of life, with a trend suggestive of lower depression at post-treatment.

Conclusion.  Globally, as the number of survivors in this population continues to grow, it is imperative that nurses continue testing interventions that may positively affect quality of life and the commonly experienced symptoms of fatigue, anxiety and depression.


What is already known about this topic

  1. Top of page
  2. Abstract
  3. What is already known about this topic
  4. Introduction
  5. Background
  6. The study
  7. Results
  8. Discussion
  9. Conclusion
  10. Acknowledgements
  11. Author contributions
  12. References
  • The prevalence of women worldwide who are surviving breast cancer is increasing.
  • In addition to insomnia, breast cancer survivors widely report elevated levels of fatigue, anxiety, depression and lowered quality of life.
  • Limited information is available on the efficacy of cognitive behavioural therapy for insomnia in improving psychosocial outcomes in breast cancer survivors.

What this paper adds

  • The cognitive behavioural intervention for insomnia was effective in improving fatigue, anxiety, depression and quality of life during a 2-week post-treatment period.
  • Women who received only one component of the intervention, the sleep education and hygiene content, experienced positive short-term changes in quality of slife.
  • Nurses should continue testing interventions that may positively affect quality of life and the commonly experienced symptoms of fatigue, anxiety and depression.

Introduction

  1. Top of page
  2. Abstract
  3. What is already known about this topic
  4. Introduction
  5. Background
  6. The study
  7. Results
  8. Discussion
  9. Conclusion
  10. Acknowledgements
  11. Author contributions
  12. References

Insomnia is a common and significant problem in people with cancer. Prevalence estimates of this problem show 30–73% of all cancer patients report sleep difficulties, including people recently diagnosed with cancer and those having completed treatment (Malone et al. 1994, Anderson et al. 2003). Breast cancer survivors appear particularly susceptible to disturbances in sleep. Recent studies have revealed that an overwhelming majority of breast cancer survivors experience significant sleep difficulties at diagnosis, during treatment and following treatment (Davidson et al. 2002, Carpenter et al. 2004). Another study (Savard et al. 2001) found 51% of women treated for breast cancer reported symptoms of insomnia with 19% meeting diagnostic criteria for clinical insomnia. Reasons for this high insomnia rate in breast cancer survivors may be explained by the fact that women in the general population are twice as likely to have insomnia, and hot flashes because hormonal ablation cancer treatment are one known cause of insomnia (Savard et al. 2001, O’Donnell 2004). The importance of insomnia interventional research for breast cancer survivors is supported by the growing population of women who are surviving breast cancer world-wide. Currently over 1 million women worldwide are diagnosed annually with breast cancer, with a 75% survival rate in most developed countries (World Health Organization 2007).

Insomnia in breast cancer patients is frequently accompanied by symptoms of fatigue, anxiety, depression and a lowered quality of life (Fortner et al. 2002, Carpenter et al. 2004). These commonly-reported symptoms are not often measured in clinical trial outcomes which offer treatment for insomnia. It is imperative that we now broaden the narrowed outcomes of success in treating insomnia to include additional indicators such as positive changes in fatigue, mood and quality of life (Morin 2003, Morin et al. 2006).

Background

  1. Top of page
  2. Abstract
  3. What is already known about this topic
  4. Introduction
  5. Background
  6. The study
  7. Results
  8. Discussion
  9. Conclusion
  10. Acknowledgements
  11. Author contributions
  12. References

Fatigue is widely documented as a prevalent and disturbing problem in studies of cancer patients throughout the world (Smets et al. 1993, Donovan et al. 2004, Patrick et al. 2004). Fatigue can be experienced even before cancer treatment has begun, and has been noted to persist for weeks to months after treatment has ended (Bower et al. 2000, Byar et al. 2006). Women with breast cancer have reported some of the highest rates of fatigue as compared to other types of cancer, with estimates ranging from an incidence of 99% during adjuvant therapy to a rate of 38% after treatment completion (Jacobsen et al. 1999, Servaes et al. 2001). Fatigue has been linked in a number of studies to sleep disturbances. Davidson et al. (2002) report people with cancer have excessive fatigue with a twofold increase in insomnia, particularly susceptible were patients with breast cancer. The role insomnia contributes to cancer-related fatigue has yet to be clearly identified (Ancoli-Israel 2001).

Disturbances in mood were reported in 90% of women awaiting breast cancer surgery, which was moderately to highly distressing for more than 50% of them (Cimprich 1999). Many women with breast cancer have elevated levels of distress, anxiety and depression, and these problems may continue for years after diagnosis (Speigel 1997). Anxiety and depression are common complaints among cancer patients and, like fatigue, they persist over time (Andrykowski & Curran 1998, Longman et al. 1999). When women with breast cancer develop mood disturbances, insomnia may play a role. In the National Institute of Mental Health Epidemiologic Catchment Area study, a statistically significant finding was the increased rate of new incidents of major depression and anxiety disorder for people with continued complaints of insomnia, when compared to individuals who no longer had insomnia (Ford & Kamerow 1989).

Women who survive breast cancer report lowered quality of life following treatment compared to women without cancer (Broeckel et al. 1998). Broeckel’s study emphasized the need for interventions that will improve quality of life in breast cancer survivors. After cancer treatment has ended, breast cancer survivors continue to experience long-term changes in sleep which can negatively affect overall quality of life (Dow et al. 1996). Sleep disturbances are linked to lower quality of life in cancer patients. Insomnia is negatively associated with quality of life in both prostate and breast cancer patients (Redeker et al. 2000, Lintz et al. 2003). Cognitive behaviour therapy for insomnia (CBT-I) is proposed as one method for reducing insomnia symptoms in cancer patients, with a secondary benefit being improved quality of life (O’Donnell 2004). Following CBT-I, improvements in sleep have been associated with higher quality of life scores which were sustained over time for breast cancer survivors (Quesnel et al. 2003).

Limited information is available on the efficacy of a non-pharmacological insomnia intervention on fatigue, mood and quality of life in breast cancer survivors. One randomized controlled study has examined the efficacy of behavioural therapy, cognitive therapy and fatigue and stress management on psychosocial outcomes in breast cancer survivors (Savard et al. 2005). In Savard’s study of 57 Canadian women, the multi-component intervention improved depression, anxiety, fatigue and quality of life with maintenance of the effects for up to 12 months.

Cognitive behavioural therapy for insomnia

Cognitive behavioural therapy for insomnia has been used as a non-pharmacological sleep intervention worldwide. It generally consists of stimulus control instructions (SCI), sleep restriction therapy (SRT), and sleep education and hygiene (SEH) content including cognitive strategies. SCI are a behavioural treatment developed by Bootzin (1972) who conceptualized insomnia within an operant or learning paradigm. For people with insomnia, the bed and bedroom are no longer discriminative stimuli for sleep but rather cues for cognitive arousal. People are taught through their cognitions to re-associate the bed and bedroom with rapidly falling asleep or back to sleep. The aims of SCI are to acquire a consistent sleep pattern, strengthen the bed and bedroom as cues for sleep, and weaken them as cues for activities that interfere with sleep (Bootzin et al. 1983).

Sleep restriction therapy is based on the observation that people with insomnia spend too much time in bed attempting to sleep (Spielman et al. 1987). The treatment focuses on developing a sleep-wake schedule based on the participant’s baseline sleep data. The aims of SRT are to improve sleep efficiency through consolidation of sleep and limiting sleep to a specific time by restricting the amount of time spent in bed. For example, if a participant is spending 9 hours in bed but reports sleeping for 6 hours, a sleep-wake schedule is developed allowing approximately 6 hours of time in bed nightly. Each week schedule adjustments are made based on the previous week’s diary data.

Sleep education and hygiene is a third component of CBT-I and consists of giving basic information about sleep processes and functions, developmental sleep changes, circadian rhythms, individual sleep needs, sleep deprivation and supportive information (Bootzin et al. 1996, Lacks & Morin 1997). Dysfunctional cognitions that may contribute to sleep difficulty are also challenged.

The focus of this paper is the effect of CBT-I on psychosocial outcomes that have been associated with insomnia in breast cancer survivors and not the effect of CBT-I on sleep outcomes, which have been reported elsewhere (Epstein & Dirksen 2007).

The study

  1. Top of page
  2. Abstract
  3. What is already known about this topic
  4. Introduction
  5. Background
  6. The study
  7. Results
  8. Discussion
  9. Conclusion
  10. Acknowledgements
  11. Author contributions
  12. References

Aim

The aim of this exploratory study was to describe the efficacy of CBT-I on fatigue, mood and quality of life in breast cancer survivors. The specific research questions were:

  • Does CBT-I improve fatigue, mood and quality of life in breast cancer survivors?
  • What is the direct and indirect effect of the intervention on the psychosocial outcomes as mediated by insomnia severity?
  • What is the relationship between insomnia severity and the psychosocial variables of fatigue, mood and quality of life?

Design

A randomized experimental design was used, with two groups (CBT-I and component control) and two measurement times (pre- and post-treatment). Participants were randomly assigned to treatment groups by the research assistant through the use of a random numbers table. The research assistant was not blinded to the group assignment.

Participants

The convenience sample of breast cancer survivors recruited in the southwestern United States of America (USA) included women, 18 years of age or older, with a diagnosis of stages I, II or III breast cancer who were at least 3 months post-completion of primary cancer treatment and without current evidence of disease. Women were considered for inclusion if they were concerned about their sleep, reported impaired daytime functioning and disturbed sleep including: (a) sleep onset latency and/or wake after sleep onset of 30 minutes or more on three nights per week for two weeks (corroborated through the daily sleep diaries) and (b) a disturbed sleep complaint of at least 3 months. Exclusion criteria included cognitive impairment as determined by the Mini-Mental State Examination (Folstein et al. 1975) and/or suspicion of sleep apnea, restless leg syndrome or periodic limb movement disorder based on a screening interview. The insomnia inclusion criteria were developed from the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association 2000), the International Classification of Sleep Disorders (American Sleep Disorders Association 1997) and the insomnia intervention research literature. Women who were taking a stable dose of antidepressants and sleep medications were not excluded. After meeting study criteria, participants were entered into the baseline study phase. Previous meta-analysis results on the non-pharmacological treatment of insomnia (Morin et al. 1994) provided the effect sizes for a power calculation. From this calculation, it was determined 32 women in each treatment group or a total of 64 women, were the minimum number needed to address study aims.

Women were recruited primarily from newspaper advertising, physician referral and breast cancer support groups. Figure 1 describes the flow of participants through the study phases. Three hundred and forty-eight potential participants were identified over the data collection period of December 2002–March 2004. As shown, 219 participants were excluded in the initial phone screen; 195 were not interested and 24 did not meet eligibility criteria. The remaining 129 participants were next assessed for study inclusion by a sleep and health status interview. From this number, 48 participants were excluded. We recruited 86 women into the study. Five participants dropped during the baseline phase prior to treatment with the remaining 81 women randomized to treatment. Six individuals from the CBT-I group withdrew from treatment for various reasons including treatment was not helping, did not like treatment, no longer interested (n = 2), scheduling problems and a family death. Three individuals from the component control (CC) group withdrew from treatment for various reasons including not interested, scheduling problems, and not able to contact. A total of 72 women completed the post-treatment phase, 34 in the CBT-I group and 38 in the CC group.

image

Figure 1.  Flow of participants through the study.

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Intervention

Sleep education and hygiene is a credible treatment with minimal efficacy in reducing insomnia (Morin et al. 1994) and thus it was the non-active intervention component as opposed to the active treatment components (SRT and SCI) which the CBT-I group received. The usual care for breast cancer survivors with chronic insomnia was most often nothing for their problem or sleep medication (over-the counter or prescription), which was ineffective for most women, thus their desire to be study participants. If one group receives usual care only, then the group receiving the experimental intervention could show significant improvement compared to the usual care control group, which many times may amount to no care or attention (Brink 2003). The CC group received the same attention and number of contact hours as the CBT-I group to control for the possible effect of interpersonal contact impacting outcomes (Shadish et al. 2002).

The 10-week intervention study consisted of a 2-week pre-treatment (baseline) period, a 6-week treatment period and a 2-week post-treatment period. At a baseline meeting, participants in both treatment groups completed questionnaires on fatigue, mood and quality of life. During the 2-week pre-treatment period, the participants completed daily sleep diaries to further determine eligibility and wore a wrist actigraph each night to record the sleep assessment.

Following the 2-week pre-treatment data collection period, randomization occurred and all participants then met in their respective treatment groups for 4-weekly classes, which were conducted by a Master’s level Registered Nurse therapist. The last 2 weeks of treatment were conducted through individual weekly telephone sessions. Each class followed a standard format using a treatment manual. The first class was approximately 2 hours in length, the remaining three classes were an hour or less, and the telephone sessions lasted approximately 15 minutes. The first CBT-I class included a SEH information video and discussion, SRT and SCI. The first CC class consisted of a detailed review and discussion of SEH, and identification of specific sleep hygiene components applicable to each participant. For both groups, sessions 2–6 focused on reviewing daily sleep diaries, discussing progress to date and encouraging adherence to treatment recommendations. Bar graphs of baseline and weekly treatment sleep variables obtained for each participant were used as teaching tools. The participants completed daily sleep diaries during treatment to aid in the determination of specific treatment recommendations and to help cognitively shape the participants’ awareness of behaviour change.

During the 2-week post-treatment phase participants continued to complete the sleep diaries and wore the wrist actigraph. At the end of the post-treatment period, they completed the same study questionnaires as at pre-treatment. Participants in the CC group were offered CBT-I after the post-treatment measurement phase. Four waves of the treatment design were implemented.

Data collection

Demographics

Participants completed a demographic and clinical characteristics form at the baseline meeting. This form gathered information on age, marital status, ethnicity, education and income level, and clinical information including date of diagnosis and completion of treatment, number of other chronic illnesses, cancer stage, hormone therapy and insomnia history.

Questionnaires

All study questionnaires have been used in studies of breast cancer survivors outside of the USA. Fatigue was measured using the Profile of Mood States Fatigue/Inertia Subscale (POMSF/I). This subscale is from the 65-point adjective rating scale of the POMS. Items on the Fatigue/Vigor subscale measure fatigue (McNair et al. 1992). The subscale contains seven adjectives suggesting weariness, inertia and low energy level. Item responses are answered on a 5-point scale from 0 (not at all) to 4 (extremely), for a total score ranging from 0 to 28. Higher scores mean greater fatigue. The subscale demonstrates test–retest reliability, internal consistency, concurrent, and construct validity (McNair et al. 1992). In this study, Cronbach’s alphas across time ranged from 0·92 to 0·95 for both groups.

Mood was assessed by indices of anxiety and depression: the State-Trait Anxiety Inventory (STAI) and the Center for Epidemiologic Studies-Depression Scale (CES-D). The STAI consists of a state (STAI-S) and a trait anxiety scale (STAI-T) (Spielberger 1983). Each scale has 20 items in a Likert format. The STAI-S ranges from 1 (not at all) to 4 (very much so), with STAI-T responses of 1 (almost never) to 4 (almost always). Totalled subscale scores range from 20 to 80. On both scales the higher the score the greater anxiety. Test–retest correlations indicate adequate stability with correlations relatively high for STAI-T and low for STAI-S. The scales have evidence of concurrent, convergent, divergent and construct validity (Spielberger 1983). In this study, Cronbach’s alphas across time ranged from 0·91 to 0·97 (state) and 0·88 to 0·94 (trait) for both groups.

The CES-D is a 20-item self-report scale that identifies the presence and severity of depressive symptoms (Radloff 1977). Item scores range from 0 (rarely or none of the time) to 3 (most or all of the time). Higher scores indicate greater depression. Total scale scores range from 0 to 60. A score of ≥16 indicates depression. The CES-D is used in both clinical and general populations with reliability coefficients above 0·90 and 0·85, respectively (Craig & Van Natta 1976, Weissman et al. 1977). In this study, Cronbach’s alphas across time ranged from 0·86 and 0·92 for both groups.

Quality of life was measured by the Functional Assessment of Cancer Therapy-Breast (FACT-B) (version 4). The FACT-B is a 39-item self-report scale that measures the multiple dimensions of quality of life in women with breast cancer (Cella et al. 1993). The Fact-B is derived from the Fact-G which measures general quality of life in cancer patients. The FACT-G assesses physical well-being (seven items) (FACT-PWB), emotional well-being (6-items) (FACT-EWB), social well-being (seven items) (FACT-SWB), functional well-being (7-items) (FACT-FWB) and relationship with doctor (three items). Nine items specific to quality of life in breast cancer are included in the FACT-B. Scale responses range from 0 (not at all) to 4 (very much). Higher scores indicate better quality of life. Scores may be totalled for each of the subscales and for total scale scores. Total FACT-B scores range from 0 to 156. The FACT-B has demonstrated an alpha coefficient of 0·90 with convergent, divergent and known groups validity (Brady et al. 1997). Subscale alpha coefficients have ranged from 0·63 to 0·86. In this study for both groups across time, Cronbach’s alphas ranged from 0·88 to 0·90 for the total scale, with subscale coefficients ranging from 0·66 to 0·87.

Insomnia severity was measured by the Insomnia Severity Index (ISI) (Morin 1993). The 7-item ISI evaluates perceived insomnia severity in a Likert-type format with responses ranging from 1 (not at all) to 5 (very much). A totalled scale cut-off score of 15 indicates clinically significant insomnia (Morin et al. 1999). The ISI has established psychometric properties and is sensitive to change (Bastien et al. 2001). In this study, Cronbach’s alpha across time ranged from 0·64–0·85.

Ethical considerations

The study was approved by the appropriate ethics committees. All participants received an explanation of the study before participating, gave written informed consent before voluntary participation and were assured of their freedom to withdraw from the study at any time. Confidentiality was strictly maintained at all times.

Data analysis

Descriptive statistics were used to examine demographic and clinical characteristics and total scale scores for the two treatment groups. To determine whether differences in characteristics existed between the two groups at pre-treatment, t-tests were used for interval or ratio data and chi-squared tests for nominal data. A one-way analysis of variance was used to determine whether between group differences existed at baseline for the total scale scores for fatigue, mood and quality of life. The impact of treatment group on fatigue, mood and quality of life was tested using repeated measures analysis of variance (rmanova). Significant interaction effects were examined using paired and independent t-tests. To test the direct and indirect effects of the intervention on psychosocial outcomes, mediational analysis was used (Baron & Kenney 1986, MacKinnon et al. 2002). Pearson’s correlation coefficients were computed to examine the relationship between insomnia severity and fatigue, mood and quality of life in each group following treatment. During the study, data safety and monitoring were performed at regular intervals with a designated institutional research monitor to examine study conduct and progress.

Results

  1. Top of page
  2. Abstract
  3. What is already known about this topic
  4. Introduction
  5. Background
  6. The study
  7. Results
  8. Discussion
  9. Conclusion
  10. Acknowledgements
  11. Author contributions
  12. References

The 72 breast cancer survivors who completed the study had a mean age of 58 years (sd = 10·2) and were predominantly white (96%) and married (68%). The mean income range was US$50,000–60,000, with a mean education level of 15·5 years (Table 1). Sixty-eight per cent of the women were either retired or employed full-time. Most had stages I (50%) or II (29%) disease at diagnosis. Time since diagnosis was a mean of 6·1 years (range = 5 months–31 years) with a mean time since primary treatment had ended of 4·8 years (range = 3 months–30 years). Mean duration of insomnia was 5 years (range = 4 months–30 years). At baseline, no statistically significant differences were found between women in the two groups on any demographic or clinical characteristics.

Table 1.   Demographic and clinical characteristics
 CBT-I groupCC group
  1. OTC, over the counter; CBT-I, cognitive behavioural therapy for insomnia; CC, component control.

  2. *Disease had not spread for 6 women (8·3%), stage unknown.

Age (years)Mean (sd) 57·2 (9·9)Mean (sd) 59·2 (10·7)
Range 29–74 (n = 34)Range 30–86 (n = 38)
Marital status (%)
 Married24 (70·6)25 (65·8)
 Other7 (29·4)13 (34·2)
Education completed (years)  (High school = 12 years)Mean (sd) 15·8 (3·1) Range 9–24 (n = 33)Mean (sd) 15·2 (2·6) Range 12–20 (n = 35)
Employment status (%)
 Full time7 (20·6)10 (26·3)
 Part time7 (20·6)6 (15·8)
 None3 (8·8)5 (13·2)
 Retired17 (50·0)16 (42·1)
Number of other chronic illnessesMean (sd) 1·2 (1·0) Range 0–4 (n = 34)Mean (sd) 1·8 (1·4) Range 0–6 (n = 38)
Stage at diagnosis (%)*
 I19 (55·9)17 (46·3)
 II9 (26·5)12 (31·7)
 III4 (11·8)5 (12·2)
Type of treatment
 Lumpectomy only (%)0 (0)1 (2·6)
 Mastectomy only (%)8 (23·5)9 (23·7)
 Lumpectomy/adjuvant therapy (%)18 (53)19 (50)
 Mastectomy/adjuvant therapy (%)8 (23·6)8 (21·1)
 Hormone therapy (current) (%)19 (55·9)20 (52·6)
Number of months since diagnosedMean (sd) 85·3 (84·8) Range 9–374 (n = 34)Mean (sd) 63·8 (52·1) Range 5–220 (n = 38)
Number of months since end of treatmentMean (sd) 65·0 (85·9) Range 4–369 (n = 34)Mean (sd) 51·3 (58·4) Range 3–213 (n = 38)
Duration of insomnia (years)Mean (sd) 5·9 (7·4) Range 6 mo–30 yr (n = 32)Mean (sd) 4·9 (6·1) Range 4 mo–30 yr (n = 38)
Past sleep medication use (%)
 Prescription
  No17 (50·0)21 (55·3)
  Yes17 (50·0)17 (44·7)
 OTC
  No26 (76·5)30 (78·9)
  Yes8 (23·5)8 (21·1)

Pre- and post-treatment means of the two groups for fatigue, anxiety, depression, quality of life and insomnia severity are presented in Tables 2 and 3. Effect sizes shown in Table 2 are represented by Cohen’s d as low (0·2), medium (0·5), and large (0·8) (Cohen 1988). One-way anovas at baseline revealed no significant differences between the two groups for fatigue, anxiety, depression and quality of life.

Table 2.   Fatigue, mood and quality of life Mean, sd and effect sizes for CBT-I (n = 34) and CC (n = 38) groups
 Pre-treatmentPost-treatmentEffect size
MeansdMeansd
  1. CBT-I, cognitive behavioural therapy for insomnia; CC, component control; POMS-F, Profile of Mood States-Fatigue Scale; STAI-S and T, State-Trait Anxiety Inventory; CES-D, Center for Epidemiologic Studies-Depression Scale; FACT-G, Functional Assessment of Cancer Therapy-General; FACT-B, Functional Assessment of Cancer Therapy- Breast; PWB, physical well-being; SWB, social well-being; EWB, emotional well-being; FWB, functional well-being.

  2. *Statistically significant pre- to post-treatment change (P ≤ 0·05).

POMSF/I
 CBT-I11·16·75·7*5·30·43
 CC9·88·38·57·6
STAI-S
 CBT-I30·28·729·08·80·42
 CC31·89·333·713·3
STAI-T
 CBT-I36·510·232·9*7·80·24
 CC36·19·335·09·4
CES-D
 CBT-I11·67·37·8*7·30·15
 CC10·97·89·19·7
FACT-G
 CBT-I83·311·991·615·00·26
 CC84·8 9·287·714·7
FACT-B
 CBT-I108·514·8118·8*11·90·37
 CC 109·020·0113·1*18·2
FACT-B PWB
 CBT-I22·05·624·8*3·30·14
 CC23·14·124·3*3·8
FACT-B SWB
 CBT-I22·14·923·33·90·38
 CC22·26·121·45·9
FACT-B EWB
 CBT-I20·12·820·82·30·06
 CC20·43·120·64·0
FACT-B FWB
 CBT-I19·14·022·7*4·20·27
 CC19·14·721·5*4·7
Table 3.   Insomnia severity mean and sd for CBT-I (n = 34) and CC (n = 38) groups
 Pre-treatmentPost-treatment
MeansdMeansd
  1. CBT-I, cognitive behavioural therapy for insomnia; CC, component control; ISI, Insomnia Severity Index.

ISI
CBT-I23·914·2714·385·31
CC22·714·0216·315·03

Main effects for time and the interaction effects are presented in Table 4. There were statistically significant time effects for fatigue, trait anxiety, depression and quality of life. From pre- to post-treatment, the CBT-I group improved on fatigue, trait anxiety and depression (with a trend toward significance for the CC group). Both groups improved on quality of life. Statistically significant interaction effects were found for fatigue and quality of life. At post-treatment, a trend was noted towards lower fatigue [t(70) = 1·87, P = 0·07] and higher quality of life-social [t(70) = 1·66, P = 0·10] in the CBT-I group.

Table 4. F values for fatigue, mood and quality of life outcomes
Time effect and paired t-testGroup × time interaction effect and independent t-test
  1. CBT-I, cognitive behavioural therapy for insomnia; CC, component control; POMS-F, Profile of Mood States-Fatigue Scale; STAI-S and T, State-Trait Anxiety Inventory; CES-D, Center for Epidemiologic Studies-Depression Scale; FACT-B, Functional Assessment of Cancer Therapy-Breast; PWB, physical well-being; SWB, social well-being; EWB, emotional well-being; FWB, functional well-being.

POMS-F/I
F (1,70) = 17·37, P = 0·001 CBT-I t(33) = 5·08, = 0·001F (1,70) = 6·54, P = 0·01 CBT-I t(70) = 1·87, P = 0·07
STAI-S
= 0·80P = 0·22
STAI-T
F (1,70) = 7·81, P = 0·01 CBT-I t(33) = 2·40, P = 0·02P = 0·14
CES-D
F (1,70) = 8·90, P = 0·004 CBT-I t(33) = 2·36, P = 0·02 CC t(37) = 1·73, P = 0·09P = 0·29
FACT-B
F (1,70) = 31·57, P = 0·001 CBT-I t(33) = −5·32, P = 0·001 CC t(37) = −2·46, P = 0·02F (1,70) = 5·42, P = 0·02
FACT-B PWB
F (1,70) = 14·73, P = 0·001 CBT-I t(33) = −2·89, P = 0·007 CC t(37) = −2·60, P = 0·013P = 0·11
FACT-B SWB
P = 0·58F (1,70) = 4·73, = 0·03 CBT-I t(70) = 1·66, P = 0·10
FACT-B EWB
P = 0·23= 0·49
FACT-B FWB
F (1,70) = 64·28, P = 0·001 CBT-I t(33) = −6·30, P = 0·001 CC t(33) = −4·90, P = 0·001P = 0·11

Mediational analysis determined that the intervention did not have a direct effect on psychosocial outcomes (Table 5); therefore, based on MacKinnon et al. (2002), the indirect effect of the intervention was not tested.

Table 5.   Test of direct effect of intervention on psychosocial outcomes
Psychosocial outcomeStandardized path coefficient
  1. QOL, quality of life.

Fatigue0·123, = 0·24
State anxiety0·164, = 0·17
Trait anxiety0·065, = 0·58
Depression0·030, = 0·80
QOL-breast cancer−0·011, P = 0·33

A significant correlation was found between insomnia severity and fatigue for both groups at post-treatment. Insomnia severity also correlated significantly with trait and state anxiety and quality of life for the CC group at post-treatment (Table 6).

Table 6.   Correlations of insomnia severity with fatigue, mood and quality of life for CBT-I (n = 34) and CC (n = 38) groups at post-treatment
 POMS F/ISTAI-SSTAI-TCES-DFACT-B
  1. CBT-I, cognitive behavioural therapy for insomnia; CC, component control; ISI, Insomnia Severity Index; POMS-F, Profile of Mood States-Fatigue Scale; STAI-S and T, State-Trait Anxiety Inventory; CES-D, Center for Epidemiologic Studies-Depression Scale; FACT-B, Functional Assessment of Cancer Therapy-Breast.

  2. *Statistically significant r (P < 0·05).

ISI
 CBT-I 0·66*0·080·070·26−0·24
 CC0·40*0·33*0·48*0·28−0·39*

Discussion

  1. Top of page
  2. Abstract
  3. What is already known about this topic
  4. Introduction
  5. Background
  6. The study
  7. Results
  8. Discussion
  9. Conclusion
  10. Acknowledgements
  11. Author contributions
  12. References

Study limitations

Women who participated were primarily white, married, well-educated and had high income levels. Study results are limited in their generalizability until they are replicated in breast cancer survivors of varied ethnic and cultural backgrounds with lower education and income levels. The lack of a no-treatment control group may be a design limitation; however, recruiting women with a clinical problem into a study and then not offering them something to help may pose ethical problems. Participants need an explanation of the reason for not receiving treatment and may be more likely to drop out from the study than people receiving treatment (Kazdin 2003). The problem for this study may have been a comparison group treatment that included non-specific treatment factors such as attention and contact. Future studies will need to include a control group without the non-specific factors. The 2-week post-treatment measurement period evaluated immediate effects of the intervention and thus the long-term sustainability of the intervention is not known.

Strengths of the study included the randomization of participants to treatment group, and the use of reliable and validated measures that had been used in prior breast cancer survivor studies with samples similar in cancer inclusion criteria to ours.

Discussion of results

Mean levels of fatigue, anxiety, depression and quality of life measured at pre-treatment were similar to those in previous breast cancer survivor studies with women who were ≥3 months post-completion of primary treatment without current evidence of disease (Hann et al. 1997, Broeckel et al. 1998, Courneya et al. 2003). These results validated that women experience fatigue, anxiety, depression and lowered quality of life following breast cancer treatment. Insomnia also appears to be a prevalent symptom during this time.

The findings suggest that women from pre- to post-treatment in the CBT-I group reported short-term positive changes in fatigue, trait anxiety, depression and quality of life. Thus, CBT-I appears to be a promising treatment for improving these often-cited problems. Interestingly, the CC group who received only SEH content also indicated statistically significant and positive improvements in quality of life. A medium effect size (d = 0·43) was obtained for fatigue, with a trend towards a greater reduction experienced by women in the CBT-I group. These results support findings demonstrating the positive impact of an insomnia intervention on general and physical fatigue levels in breast cancer survivors (Quesnel et al. 2003). In the current study, when fatigue was mentioned to a healthcare provider, women reported being often told to ‘rest’, which if performed in bed could contribute to the development of a chronic insomnia problem. The value in offering an insomnia intervention that might improve not only sleep but also fatigue is supported in this study.

Trait anxiety levels measured at pre-treatment were similar to those obtained from another study in which breast cancer participants were undergoing active treatment (Schreier & Williams 2004). Thus, anxiety in women who have survived breast cancer may not dissipate after treatment ends. This finding offers support for research conducted in England that found clinically significant anxiety continuing to exist for some women at 12, 24 and 36 months post-completion of breast cancer treatment (Fallowfield et al. 1994). Women in our CBT-I group at post-treatment had a mean anxiety level (32·9) close to the normative level (31·8) noted in women (50- to 69-year old) in the general population (Spielberger 1983). These encouraging results indicate that anxiety continuing past treatment can be positively influenced by a nurse-led intervention targeting chronic insomnia.

Depression was significantly improved in the CBT-I group, which supports findings in which a multi-component intervention that included CBT-I reduced depression in breast cancer survivors (Savard et al. 2005). This effect was sustained for up to 12 months after treatment had ended. The strength of the intervention in our study in reducing depression is evidenced by the mean CES-D scores, which were lowered by almost 4 points in the CBT-I group at post-treatment. A clinically significant decrease in depression was experienced by 33% (n = 10) of women who received CBT-I.

Quality of life improved for women in both groups. The mean change from pre- to post-treatment in general quality of life (FACT-G) scores was 8 points for the CBT-I group and 3 points for the CC group. A FACT-G score that changes 4 or more points is viewed as a clinically important difference (CID) (Cella et al. 2002). These FACT-G change scores indicate a CID for the CBT-I group. Guidelines do not exist for a CID for changes in quality of life-breast cancer (Fact-B) scores. It is promising that an insomnia intervention may improve both a patient’s sleep and overall quality of life. The increased quality of life scores for the CC group who only received the SEH content strengthens support for nurses to provide education about sleep and dysfunctional cognitions to women who report insomnia By giving this information to women, short-term improvements in quality of life might be experienced.

The many positive psychosocial outcomes noted in the CC group may be caused by a number of factors. First, CC participants met with the understanding that they all had a sleep problem. Talking about insomnia to the therapist and other breast cancer survivors over the 10-week study period may have made them more aware of their insomnia, with the SEH content providing education on the factors that perpetuate insomnia. Thus, the strength of the SEH content, when coupled with weekly sessions devoted to the topic of insomnia, may have been a stronger treatment than previously expected for reducing insomnia. Secondly, positive empathetic rapport among women in many of the groups, starting at baseline and continuing through treatment, was evident to the investigators and nurse therapist. Perhaps this cohesiveness allowed women to feel supported, and it was this group support in addition to SEH content that helped to improve fatigue, mood and quality of life. Future research should explore the value of a sleep education self-help brochure which the nurse could offer to survivors who are experiencing insomnia. This would determine if a lower cost alternative to what was offered to the CC group might also be effective in improving outcomes. Isolating the therapeutic components in the CC group might be accomplished through research that focuses on the role and respective contributions that attention, support from others, and an increase in insomnia self-awareness might have in effecting positive changes in fatigue, mood and quality of life.

The premise that it is the reduction in insomnia in breast cancer survivors and not the direct effect of the intervention that has a positive impact on fatigue, mood and quality of life has preliminary support in the study data. Insomnia as detailed earlier is strongly associated with fatigue, anxiety, depression and quality of life in women who have survived breast cancer. By improving insomnia in both the CBT-I and CC groups it was not unexpected to find that psychosocial outcomes might also be positively impacted.

Conclusion

  1. Top of page
  2. Abstract
  3. What is already known about this topic
  4. Introduction
  5. Background
  6. The study
  7. Results
  8. Discussion
  9. Conclusion
  10. Acknowledgements
  11. Author contributions
  12. References

Breast cancer is a widespread and costly disease. This study suggests that breast cancer survivors with chronic insomnia experience fatigue, anxiety, depression and lowered quality of life. Limited interventions are available that would help nurses manage many of the psychosocial symptoms commonly experienced by woman who are breast cancer survivors. Examining the prevalence of breast cancer survivors symptoms among women in the context of cultures other than the USA is recommended. Further testing of intervention efficacy on psychosocial outcomes would strengthen the findings of this study if replicated in a diversity of nurse practice settings.

In a future study, long-term (≥12 months) follow-up of participants would determine if the positive effects of the intervention on psychosocial outcomes is sustained over time. If replicated in a study with a larger sample, our findings suggest that in addition to improving sleep, the benchmark of treatment success should also include positive changes in variables that are frequently associated with insomnia in breast cancer survivors including fatigue, anxiety, depression and quality of life.

Acknowledgements

  1. Top of page
  2. Abstract
  3. What is already known about this topic
  4. Introduction
  5. Background
  6. The study
  7. Results
  8. Discussion
  9. Conclusion
  10. Acknowledgements
  11. Author contributions
  12. References

This research was funded by a grant from the National Institutes of Health/National Cancer Institute CA91869. This material is the result of work supported with resources and the use of facilities at the Carl T. Hayden Veterans Affairs Medical Center and Clinics Phoenix, AZ.

Author contributions

  1. Top of page
  2. Abstract
  3. What is already known about this topic
  4. Introduction
  5. Background
  6. The study
  7. Results
  8. Discussion
  9. Conclusion
  10. Acknowledgements
  11. Author contributions
  12. References

SRD and DRE were responsible for the study conception and design and the drafting of the manuscript. SRD and DRE performed the data collection and data analysis. SRD and DRE obtained funding and provided administrative support. SRD and DRE made critical revisions to the paper. SRD and DRE provided statistical expertise. SRD and DRE supervised the study.

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  9. Conclusion
  10. Acknowledgements
  11. Author contributions
  12. References
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