Behavioral Self-help Treatment for Insomnia
Behavioral Self-help Treatment for Insomnia
Attrition and drop-out at post- and follow-up assessments were low (see Figure 1).
(Enlarge Image)
Figure 1.
CONSORT flow chart. Participant flow throughout the study.
To measure adherence, participants in the treatment groups estimated how many hours per week they had spent on treatment and how much of the book they had read during treatment. Participants in the treatment group with support reported having read on average 84% (SD = 14%) of the book, and those in the group without support 77% (SD = 27%). Corresponding figures for time spent on treatment were 6.8 (SD = 5.9) and 7.3 (SD = 12.1) hours per week. There were no significant differences between the groups on these adherence measures.
In the waiting list group, six participants sought other treatments during the first period (from pre- to post-assessments), and two during the second period (from post-assessment to follow-up). In the group receiving bibliotherapy with therapist support, only one participant sought another treatment during the first period, and two during the second. In the bibliotherapy group the corresponding figures were two and six participants respectively. A trend for an association between number of participants seeking other treatments, and group, is seen for the first period (χ = 5.174, df = 2, p = .075, N = 131), but not for the second. Data from these individuals is also included in the analyses.
Table 1 presents baseline data of the 133 participants from all over Sweden. Only 7.5% of included participants were diagnosed with primary insomnia with no concurrent active disorder or problem affecting sleep. Participants reported on average 3.4 (SD = 2.3) co-morbid problems, the most common diagnoses being allergic diseases (57.9%), acute (31.6%) and chronic (15%) pain, stress (29.3%), restless legs (25.6%), nightmares (24.8%), snoring (23.3%), bruxism (21.8%), high blood pressure (15%), nocturia (11.3%), tinnitus (11.3%), depression (11.3%), and anxiety (10.5%). Using cut-off scores on MADRS-S, 30.3% of participants suffered from mild depression (MADRS-S 13 -19), and 23.3% would have been diagnosed with major depressive disorder (MADRS-S 20–30). Neither the number of co-morbid problems or presence of any specific problem, nor any of the background variables, differed between the three groups (see below). However, sleep medication use was significantly higher in the waiting list control group compared to the group receiving bibliotherapy without support.
Participants were enrolled and screened between February 26 and March 30 2008. Pre-treatment assessments were conducted between March 27 and April 28, post-treatment assessments between May 22 and June 13, and follow-up between September 11 and October 27, all in 2008.
Except correlations and ANOVAS analyzing effects of co-morbidity, all outcome analyses are computed for intent-to-treat data with last observation carried forward, based on 133 pre-assessment questionnaires and 132 pre-assessment sleep diaries (one in the control group lost due to poor data quality).
Treatment Response and Remission Rates As seen in Figure 2, there were very few responders and remitters in the waiting list control group (1 (2.27%) for both variables), more in the bibliotherapy group (15 (34.9%) and 11 (24.4%)), but by far the most responders and remitters were seen in the group receiving bibliotherapy with therapist support (30 (68.2%) and 27 (61.4%)) at post-assessment. The differences between groups remained at three-month follow-up, and were significant both for post- and three-month follow-up assessments (χ = 17.047–42.289, df = 2, all p's < .001, N = 133).
(Enlarge Image)
Figure 2.
Proportion of treatment responders and remitters according to treatment group. (a) Treatment response defined as a change score on the Insomnia Severity Index of 8 points or more from pre-treatment. (b) Treatment remission defined as an Insomnia Severity Index score of less than 8 points.
Sleep Timing Two MANOVAs were conducted with sleep diary data concerning aspects of sleep timing (i.e. sleep onset latency, wake after sleep onset, total sleep time, and sleep efficiency) as dependent variables, the first comparing all three groups between pre- and post-treatment, and the second between pre-treatment and three-month follow-up. Both MANOVAs showed significant interactions (pre-post: F(8, 252) = 9.351, p = .000, ηp = 0.229; pre-follow up: F(8, 252) = 3.785, p = .000, ηp = 0.107).
Separate analyses were performed to establish which interactions were significant (see Table 2 and Table 3). From pre- to post-assessments, bibliotherapy with therapist support gave larger gains than did waiting in all sleep timing measures except total sleep time, and also larger gains in wake after sleep onset, and sleep efficiency, compared to bibliotherapy. Bibliotherapy improved sleep onset latency and sleep efficiency more than did waiting. Regarding changes from pre- to three-month follow-up assessments, bibliotherapy with therapist support now produced larger gains in all sleep timing measures, compared to waiting. However, only the difference in sleep efficiency remained between bibliotherapy with and without support. Finally, differences between bibliotherapy and waiting now included total sleep time, as well as the earlier differences seen in sleep onset latency and sleep efficiency.
Subjective Sleep Measures, Insomnia Severity and Sleep Quality Two MANOVAs were conducted with questionnaire ratings of subjective sleep as dependent variables (i.e. insomnia severity (ISI), sleep related behaviors (SRBQ), and dysfunctional beliefs (DBAS), and sleep diary data concerning subjective measures of sleep; bed time stress level and sleep quality). Both MANOVAs showed statistically significant effects of interaction (pre-post: F(10, 250) = 11.358, p < .001, ηp = .312; pre-follow up: F(8, 252) = 7.174, p < .001, ηp = .185).
Separate 2 × 2 ANOVAs were performed to establish which interactions were significant (see Table 4 and Table 5). From pre- to post-assessments, bibliotherapy with therapist support produced larger improvements in all subjective sleep ratings than did waiting, and also larger improvements than bibliotherapy alone. Bibliotherapy (without therapist support) resulted in larger improvements than did waiting, in all aspects but bed time stress levels. At three-month follow-up, all changes were maintained in the two treatment groups, and the differences between groups remained stable.
Day-time Functioning and Psychological Distress Two MANOVAs were conducted with diary ratings of day-time functioning (i.e. Positive Day Time Ratings and Day Time Fatigue), and questionnaire ratings of perceived stress (PSS) and psychological distress (CORE-OM) as dependent variables. Both MANOVAs showed statistically significant effects of interaction (pre-post: F(8, 252) = 3.724, p < .001, ηp = .106; pre-follow up: F(8, 252) = 2.193, p = .029, ηp = .065).
Again, separate 2 × 2 analyses were performed to establish which interactions were significant (see Table 6 and Table 7). From pre- to post-assessments, bibliotherapy with therapist support produced larger improvements on all measures of day-time functioning and psychological distress than did waiting, and also larger improvements than bibliotherapy alone in all aspects but perceived stress. Bibliotherapy alone did not result in larger improvements in these measures compared to waiting. At three-month follow-up the differences between bibliotherapy with support and waiting remained stable, with the exception of psychological distress. The bibliotherapy groups, with or without support, now had similar improvements in all measures. At this assessment point, participants who had received bibliotherapy without support had improved more on day-time ratings and fatigue than participants in the waiting list control condition.
Co-morbidity and Outcome At post-treatment, the correlation between total number of co-morbid problems and ISI change scores was small but significant and negative (ρ(87) = -0.22, p = .040). In other words, larger number of co-morbid problems was associated with slightly lower improvements in insomnia severity. This association was not significant at three-month follow-up (ρ(79) = -0.19, p = .095).
To find out if specific co-morbid conditions affected treatment outcome, ANOVAs were performed for the more prevalent co-morbid conditions (i.e. allergy, acute pain, stress, restless legs, nightmares, snoring, bruxism, high blood pressure, chronic pain, nocturia, tinnitus, depression, and anxiety) with ISI as the dependent variable. To increase stability of measurement for each diagnosis, individuals whose problem could not be clearly verified or ruled out at the assessment interview were not included in these analyses. ANOVAs showed significant main effects of group only for chronic pain (F(1, 131) = 6.937, p = .009) and stress (F(1, 105) = 6.633, p = .011), i.e. individuals with chronic pain or stress problems suffered more severe insomnia at all occasions. Only individuals with nightmares responded to the treatment with less marked improvements on the ISI, as seen by an interaction effect for nightmares (F(1.83, 221.27) = 3.566, p = .034).
Sleep Medication Use Out of 59 individuals using sleep medication at pre-assessment (see Table 1), 21 had ceased sleep medication at the post-assessment interviews. Relatively few of these, 4 out of 25 (16.7%) and 3 out of 14 (21.4%), were found in the waiting list and bibliotherapy groups respectively, compared to 14 out of 20 (70%) in the group receiving bibliotherapy with therapist support. This advantage for the group receiving bibliotherapy with therapist support was significant (χ = 15.179, df = 2, p > .001, N = 58).
To control for the possibility that non-users started to use sleep medication during treatment, the total number of participants using sleep medication post-treatment was also compared. In this analysis, 7 were found in the group receiving therapist support, 11 in the bibliotherapy only group, and 21 in the waiting list control group, and this difference was significant (χ = 12.181, df = 2, p = .002, N = 132). At three-month follow-up assessment, 7 participants in the group receiving therapist support used sleep medication, which was significantly lower than 15 in the bibliotherapy group, and 19 in the waiting list control group (χ = 8.355, df = 2, p = .015, N = 130).
The most important adverse event was one individual in the treatment group with support who dropped out of treatment due to increased pain as an effect of sleep restriction. In all, 23 individuals in the treatment groups reported one adverse event and 2 individuals reported two adverse events. More specifically, 9 felt that sleep restriction made them more tired or was too demanding, 2 individuals in the treatment group without support dropped out of treatment because some part of the treatment was too demanding, 3 felt the sleep diary increased their sleep related concerns, or was too demanding to fill out, 4 did not agree with the suggested life-style changes or sleep-wake rhythm, another 2 had trouble sleeping when ceasing sleep medication, and 1 experienced increases in other problems when sleep was no longer a problem. The remaining 5 experienced slight adverse experiences, such as having a hard time not watching TV in bed, or not drinking coffee in the evenings, and one reported having problems in that their sleep was so sound after treatment that they did not hear the alarm in the morning.
Results
Attrition, Drop-out, Adherence and Use of Other Treatments
Attrition and drop-out at post- and follow-up assessments were low (see Figure 1).
(Enlarge Image)
Figure 1.
CONSORT flow chart. Participant flow throughout the study.
To measure adherence, participants in the treatment groups estimated how many hours per week they had spent on treatment and how much of the book they had read during treatment. Participants in the treatment group with support reported having read on average 84% (SD = 14%) of the book, and those in the group without support 77% (SD = 27%). Corresponding figures for time spent on treatment were 6.8 (SD = 5.9) and 7.3 (SD = 12.1) hours per week. There were no significant differences between the groups on these adherence measures.
In the waiting list group, six participants sought other treatments during the first period (from pre- to post-assessments), and two during the second period (from post-assessment to follow-up). In the group receiving bibliotherapy with therapist support, only one participant sought another treatment during the first period, and two during the second. In the bibliotherapy group the corresponding figures were two and six participants respectively. A trend for an association between number of participants seeking other treatments, and group, is seen for the first period (χ = 5.174, df = 2, p = .075, N = 131), but not for the second. Data from these individuals is also included in the analyses.
Recruitment and Baseline Data
Table 1 presents baseline data of the 133 participants from all over Sweden. Only 7.5% of included participants were diagnosed with primary insomnia with no concurrent active disorder or problem affecting sleep. Participants reported on average 3.4 (SD = 2.3) co-morbid problems, the most common diagnoses being allergic diseases (57.9%), acute (31.6%) and chronic (15%) pain, stress (29.3%), restless legs (25.6%), nightmares (24.8%), snoring (23.3%), bruxism (21.8%), high blood pressure (15%), nocturia (11.3%), tinnitus (11.3%), depression (11.3%), and anxiety (10.5%). Using cut-off scores on MADRS-S, 30.3% of participants suffered from mild depression (MADRS-S 13 -19), and 23.3% would have been diagnosed with major depressive disorder (MADRS-S 20–30). Neither the number of co-morbid problems or presence of any specific problem, nor any of the background variables, differed between the three groups (see below). However, sleep medication use was significantly higher in the waiting list control group compared to the group receiving bibliotherapy without support.
Participants were enrolled and screened between February 26 and March 30 2008. Pre-treatment assessments were conducted between March 27 and April 28, post-treatment assessments between May 22 and June 13, and follow-up between September 11 and October 27, all in 2008.
Numbers Analyzed
Except correlations and ANOVAS analyzing effects of co-morbidity, all outcome analyses are computed for intent-to-treat data with last observation carried forward, based on 133 pre-assessment questionnaires and 132 pre-assessment sleep diaries (one in the control group lost due to poor data quality).
Primary Outcomes
Treatment Response and Remission Rates As seen in Figure 2, there were very few responders and remitters in the waiting list control group (1 (2.27%) for both variables), more in the bibliotherapy group (15 (34.9%) and 11 (24.4%)), but by far the most responders and remitters were seen in the group receiving bibliotherapy with therapist support (30 (68.2%) and 27 (61.4%)) at post-assessment. The differences between groups remained at three-month follow-up, and were significant both for post- and three-month follow-up assessments (χ = 17.047–42.289, df = 2, all p's < .001, N = 133).
(Enlarge Image)
Figure 2.
Proportion of treatment responders and remitters according to treatment group. (a) Treatment response defined as a change score on the Insomnia Severity Index of 8 points or more from pre-treatment. (b) Treatment remission defined as an Insomnia Severity Index score of less than 8 points.
Sleep Timing Two MANOVAs were conducted with sleep diary data concerning aspects of sleep timing (i.e. sleep onset latency, wake after sleep onset, total sleep time, and sleep efficiency) as dependent variables, the first comparing all three groups between pre- and post-treatment, and the second between pre-treatment and three-month follow-up. Both MANOVAs showed significant interactions (pre-post: F(8, 252) = 9.351, p = .000, ηp = 0.229; pre-follow up: F(8, 252) = 3.785, p = .000, ηp = 0.107).
Separate analyses were performed to establish which interactions were significant (see Table 2 and Table 3). From pre- to post-assessments, bibliotherapy with therapist support gave larger gains than did waiting in all sleep timing measures except total sleep time, and also larger gains in wake after sleep onset, and sleep efficiency, compared to bibliotherapy. Bibliotherapy improved sleep onset latency and sleep efficiency more than did waiting. Regarding changes from pre- to three-month follow-up assessments, bibliotherapy with therapist support now produced larger gains in all sleep timing measures, compared to waiting. However, only the difference in sleep efficiency remained between bibliotherapy with and without support. Finally, differences between bibliotherapy and waiting now included total sleep time, as well as the earlier differences seen in sleep onset latency and sleep efficiency.
Ancillary Analyses
Subjective Sleep Measures, Insomnia Severity and Sleep Quality Two MANOVAs were conducted with questionnaire ratings of subjective sleep as dependent variables (i.e. insomnia severity (ISI), sleep related behaviors (SRBQ), and dysfunctional beliefs (DBAS), and sleep diary data concerning subjective measures of sleep; bed time stress level and sleep quality). Both MANOVAs showed statistically significant effects of interaction (pre-post: F(10, 250) = 11.358, p < .001, ηp = .312; pre-follow up: F(8, 252) = 7.174, p < .001, ηp = .185).
Separate 2 × 2 ANOVAs were performed to establish which interactions were significant (see Table 4 and Table 5). From pre- to post-assessments, bibliotherapy with therapist support produced larger improvements in all subjective sleep ratings than did waiting, and also larger improvements than bibliotherapy alone. Bibliotherapy (without therapist support) resulted in larger improvements than did waiting, in all aspects but bed time stress levels. At three-month follow-up, all changes were maintained in the two treatment groups, and the differences between groups remained stable.
Day-time Functioning and Psychological Distress Two MANOVAs were conducted with diary ratings of day-time functioning (i.e. Positive Day Time Ratings and Day Time Fatigue), and questionnaire ratings of perceived stress (PSS) and psychological distress (CORE-OM) as dependent variables. Both MANOVAs showed statistically significant effects of interaction (pre-post: F(8, 252) = 3.724, p < .001, ηp = .106; pre-follow up: F(8, 252) = 2.193, p = .029, ηp = .065).
Again, separate 2 × 2 analyses were performed to establish which interactions were significant (see Table 6 and Table 7). From pre- to post-assessments, bibliotherapy with therapist support produced larger improvements on all measures of day-time functioning and psychological distress than did waiting, and also larger improvements than bibliotherapy alone in all aspects but perceived stress. Bibliotherapy alone did not result in larger improvements in these measures compared to waiting. At three-month follow-up the differences between bibliotherapy with support and waiting remained stable, with the exception of psychological distress. The bibliotherapy groups, with or without support, now had similar improvements in all measures. At this assessment point, participants who had received bibliotherapy without support had improved more on day-time ratings and fatigue than participants in the waiting list control condition.
Co-morbidity and Outcome At post-treatment, the correlation between total number of co-morbid problems and ISI change scores was small but significant and negative (ρ(87) = -0.22, p = .040). In other words, larger number of co-morbid problems was associated with slightly lower improvements in insomnia severity. This association was not significant at three-month follow-up (ρ(79) = -0.19, p = .095).
To find out if specific co-morbid conditions affected treatment outcome, ANOVAs were performed for the more prevalent co-morbid conditions (i.e. allergy, acute pain, stress, restless legs, nightmares, snoring, bruxism, high blood pressure, chronic pain, nocturia, tinnitus, depression, and anxiety) with ISI as the dependent variable. To increase stability of measurement for each diagnosis, individuals whose problem could not be clearly verified or ruled out at the assessment interview were not included in these analyses. ANOVAs showed significant main effects of group only for chronic pain (F(1, 131) = 6.937, p = .009) and stress (F(1, 105) = 6.633, p = .011), i.e. individuals with chronic pain or stress problems suffered more severe insomnia at all occasions. Only individuals with nightmares responded to the treatment with less marked improvements on the ISI, as seen by an interaction effect for nightmares (F(1.83, 221.27) = 3.566, p = .034).
Sleep Medication Use Out of 59 individuals using sleep medication at pre-assessment (see Table 1), 21 had ceased sleep medication at the post-assessment interviews. Relatively few of these, 4 out of 25 (16.7%) and 3 out of 14 (21.4%), were found in the waiting list and bibliotherapy groups respectively, compared to 14 out of 20 (70%) in the group receiving bibliotherapy with therapist support. This advantage for the group receiving bibliotherapy with therapist support was significant (χ = 15.179, df = 2, p > .001, N = 58).
To control for the possibility that non-users started to use sleep medication during treatment, the total number of participants using sleep medication post-treatment was also compared. In this analysis, 7 were found in the group receiving therapist support, 11 in the bibliotherapy only group, and 21 in the waiting list control group, and this difference was significant (χ = 12.181, df = 2, p = .002, N = 132). At three-month follow-up assessment, 7 participants in the group receiving therapist support used sleep medication, which was significantly lower than 15 in the bibliotherapy group, and 19 in the waiting list control group (χ = 8.355, df = 2, p = .015, N = 130).
Adverse Events
The most important adverse event was one individual in the treatment group with support who dropped out of treatment due to increased pain as an effect of sleep restriction. In all, 23 individuals in the treatment groups reported one adverse event and 2 individuals reported two adverse events. More specifically, 9 felt that sleep restriction made them more tired or was too demanding, 2 individuals in the treatment group without support dropped out of treatment because some part of the treatment was too demanding, 3 felt the sleep diary increased their sleep related concerns, or was too demanding to fill out, 4 did not agree with the suggested life-style changes or sleep-wake rhythm, another 2 had trouble sleeping when ceasing sleep medication, and 1 experienced increases in other problems when sleep was no longer a problem. The remaining 5 experienced slight adverse experiences, such as having a hard time not watching TV in bed, or not drinking coffee in the evenings, and one reported having problems in that their sleep was so sound after treatment that they did not hear the alarm in the morning.
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