Subjective–objective sleep discrepancy in patients with insomnia during and after cognitive behavioural therapy: An actigraphy study

Although patients with insomnia often show a discrepancy between self‐reported and objective sleep parameters, the role of and change in this phenomenon during treatment remain unclear. The present study aimed to assess the effect of cognitive behavioural therapy for insomnia on subjective and objective sleep discrepancy of total sleep time, sleep‐onset latency and wake after sleep onset. The total sleep time discrepancy was also assessed across the entire therapy. The second aim was to examine the treatment outcome of two insomnia groups differing in sleep perception. Thirty‐six adults with insomnia (mean age = 46.7 years, SD = 13.9; 22 females) were enrolled in the final analyses. Patients underwent a 6‐week group cognitive behavioural therapy for insomnia programme. Sleep diary and actigraphy measurements were obtained during the therapy. Patients who underestimated total sleep time (n = 16; underestimating group) were compared with patients who accurately perceived or overestimated total sleep time (n = 20; accurate/overestimating group). After cognitive behavioural therapy for insomnia, a significant decrease of total sleep time and sleep‐onset latency discrepancy was observed without a change in wake after sleep onset discrepancy in the total sample. Only the underestimating group reported decreased sleep‐onset latency discrepancy after the treatment, whereas total sleep time discrepancy significantly changed in both groups. The underestimating group showed a significant decrease of total sleep time discrepancy from Week 1 to Week 2 when the sleep restriction was implemented, whereas the accurate/overestimating group showed the first significant change at Week 4. In conclusion, both groups differing in sleep perception responded similarly to cognitive behavioural therapy for insomnia, although different In conclusion, both groups differing in sleep perception responded similarly to cognitive behavioural therapy for insomnia, although different therapeutic components could play important roles in each group. components could play important roles in each group.     

Comparison of actigraphy with polysomnography and sleep logs in depressed insomniacs

Actigraphy is increasingly used in the assessment and treatment of various clinical conditions, being a convenient and cost‐effective method of capturing bodily movements over long periods of time. This study examined the use of actigraphy in the measurement of sleep of patients with depression and insomnia. Fifty‐four patients diagnosed with a current major depressive episode and chronic insomnia underwent a baseline overnight study with concurrent actigraphic and polysomnography (PSG) monitoring, as well as subjective sleep diaries. Agreement between PSG, actigraphy and sleep diary measurements was evaluated using two‐tailed t‐tests, Pearson’s correlations and the Bland–Altman concordance technique. The only significant difference found between actigraphy and PSG was in latency to persistent sleep, in which actigraphy underestimated sleep latency relative to PSG (P < 0.05). There were moderate positive correlations between actigraphy and PSG for all variables. In contrast, significant differences were observed between sleep diaries and PSG for all sleep variables. Bland–Altman concordance diagrams also demonstrated that, while bias was limited between PSG and the other two measurement types, there were somewhat broad 95% limits of agreement for all sleep variables with both sleep diaries and actigraphy. In summary, actigraphic measurements of sleep more closely approximated those of PSG than did sleep diaries in this sample of depressed insomniacs.     

Validation of actigraphy for determining sleep and wake in children with sleep disordered breathing

There have been limited studies of the validation of actigraphy for the determination of sleep and wake in children and in this study we aimed to compare wrist actigraphy with polysomnography (PSG). We studied 45 children (29 M/16 F), aged between 1 and 12 years (5.8 +/- 2.7 years, mean +/- SD). Actigraphic data were collected during standard overnight PSG. Data from the actiwatch were analysed over four separate activity threshold settings (low, medium, high, auto). Actigraphic data were compared epoch-by-epoch with the matching PSG. Sleep time was not different from PSG values for the low or auto activity thresholds, but was significantly less on the medium and high activity thresholds (P < 0.05). In contrast, the low and auto activity thresholds significantly underestimated wake time (P < 0.05), whilst that recorded on the medium and high activity thresholds were not different to PSG values. Agreement rates across the thresholds were all high ranging from 85.1% to 88.6%. Predictive value for sleep and sensitivity were also high with values ranging from 91.6% to 94.9% and 90.1% to 97.7%, respectively. In contrast, predictive value for wake and specificity were low ranging between 46.7-65.6% and 39.4-68.9%, respectively. There was no effect of subject age, OAHI or PSG arousal index on AR for any of the activity thresholds. We conclude that actigraphy is a reliable method for determining sleep in children when compared against PSG. Actigraphy may be a useful tool in paediatric sleep clinics and research.     

Relation between ambulatory actigraphy and laboratory polysomnography in insomnia practice and research

Actigraphy is increasingly used in practice and research studies because of its relative low cost and decreased subject burden. How multiple nights of at‐home actigraphy compare to one independent night of in‐laboratory polysomnography (PSG) has not been examined in people with insomnia. Using event markers (MARK) to set time in bed (TIB) compared to automatic program analysis (AUTO) has not been systematically evaluated. Subjects (n = 30) meeting DSM‐5 criteria for insomnia and in‐laboratory PSG sleep efficiency (SE) of <85% were studied. Subjects were free of psychiatric, sleep or circadian disorders, other chronic conditions and medications that effect sleep. Subjects had an in‐laboratory PSG, then were sent home for 7 nights with Philips Actiwatch Spectrum Plus. Data were analysed using Philips Actiware version 6. Using the mean of seven nights, TIB, total sleep time (TST), SE, sleep‐onset latency (SOL) and wake after sleep onset (WASO) were examined. Compared to PSG, AUTO showed longer TIB and TST and less WASO. MARK only differed from PSG with decreased WASO. Differences between the PSG night and the following night at home were found, with better sleep on the first night home. Actigraphy in people with insomnia over seven nights is a valid indicator of sleep compared to an independent in‐laboratory PSG. Event markers increased the validity of actigraphy, showing no difference in TIB, TST, SE and SOL. AUTO was representative of SE and SOL. Increased SE and TST without increased TIB suggests possible compensatory sleep the first at night home after in‐laboratory PSG.     

Wake detection capacity of actigraphy during sleep

STUDY OBJECTIVES: To evaluate the ability of actigraphy compared to polysomnography (PSG) to detect wakefulness in subjects submitted to 3 sleep conditions with different amounts of wakefulness: a nocturnal sleep episode and 2 daytime recovery sleep episodes, one with placebo and one with caffeine. A second objective was to compare the ability of 4 different scoring algorithms (2 threshold algorithms and 2 regression analysis algorithms) to detect wake in the 3 sleep conditions. DESIGN: Three nights of simultaneous actigraphy (Actiwatch-L, Mini-Mitter/Respironics) and PSG recordings in a within-subject design. SETTING: Chronobiology laboratory. PARTICIPANTS: Fifteen healthy subjects aged between 20 and 60 years (7M, 8F). INTERVENTIONS: 200 mg of caffeine and daytime recovery sleep. RESULTS: An epoch-by-epoch comparison between actigraphy and PSG showed a significant decrease in actigraphy accuracy with increased wakefulness in sleep conditions due to the low sleep specificity of actigraphy (generally <50%). Actigraphy overestimated total sleep time and sleep efficiency more strongly in conditions involving more wakefulness. Compared to the 2 regression algorithms, the 2 threshold algorithms were less able to detect wake when the sleep episode involved more wakefulness, and they tended to alternate more between wake and sleep in the scoring of long periods of wakefulness resulting in an overestimation of the number of awakenings. CONCLUSION: The very low ability of actigraphy to detect wakefulness casts doubt on its validity to measure sleep quality in clinical populations with fragmented sleep or in situations where the sleep-wake cycle is challenged, such as jet lag and shift work.     

Combining cardiac monitoring with actigraphy aids nocturnal arousal detection during ambulatory sleep assessment in insomnia

Study ObjectivesThe objective assessment of insomnia has remained difficult. Multisensory devices collecting heart rate (HR) and motion are regarded as the future of ambulatory sleep monitoring. Unfortunately, reports on altered average HR or heart rate variability (HRV) during sleep in insomnia are equivocal. Here, we evaluated whether the objective quantification of insomnia improves by assessing state-related changes in cardiac measures.MethodsWe recorded electrocardiography, posture, and actigraphy in 33 people without sleep complaints and 158 patients with mild to severe insomnia over 4 d in their home environment. At the microscale, we investigated whether HR changed with proximity to gross (body) and small (wrist) movements at nighttime. At the macroscale, we calculated day-night differences in HR and HRV measures. For both timescales, we tested whether outcome measures were related to insomnia diagnosis and severity.ResultsAt the microscale, an increase in HR was often detectable already 60 s prior to as well as following a nocturnal chest, but not wrist, movement. This increase was slightly steeper in insomnia and was associated with insomnia severity, but future EEG recordings are necessary to elucidate whether these changes occur prior to or simultaneously with PSG-indicators of wakefulness. At the macroscale, we found an attenuated cardiac response to sleep in insomnia: patients consistently showed smaller day-night differences in HR and HRV.ConclusionsIncorporating state-related changes in cardiac features in the ambulatory monitoring of sleep might provide a more sensitive biomarker of insomnia than the use of cardiac activity averages or actigraphy alone.     

The effect of arousals during sleep onset on estimates of sleep onset latency

It is well established that insomniacs overestimate sleep-onset latency. Furthermore, there is evidence that brief arousals from sleep may occur more frequently in insomnia. This study examined the hypothesis that brief arousals from sleep influence the perception of sleep-onset latency. An average of four sleep onsets was obtained from each of 20 normal subjects on each of two nonconsecutive, counterbalanced, experimental nights. The experimental nights consisted of a control night (control condition) and a condition in which a moderate respiratory load was applied to increase the frequency of microarousals during sleep onset (mask condition). Subjective estimation of sleep-onset latency and indices of sleep quality were assessed by self-report inventory. Objective measures of sleep-onset latency and microarousals were assessed using polysomnography. Results showed that sleep-onset latency estimates were longer in the mask condition than in the control condition, an effect not reflected in objective sleep-stage scoring of sleep-onset latency. Furthermore, an increase in the frequency of brief arousals from sleep was detected in the mask condition, and this is a possible source for the sleep-onset latency increase perceived by the subjects. Findings are consistent with the concept of a physiological basis for sleep misperception in insomnia.     

A review of sleep disturbance in children and adolescents with anxiety

The present review examines the relations between sleep disturbance and anxiety in children and adolescents. The review begins with a detailed discussion of normative developmental trends in sleep, and the relation between sleep quality and emotion dysregulation in children. The extant literature on sleep disturbance in clinically anxious children with a focus on subjective versus objective measures of sleep is then summarized in detail. Finally, a review of the reciprocal relationship between sleep and emotion regulation is provided. The available research suggests that sleep disturbance is quite prevalent in children with anxiety disorders, although the directionality of the association between sleep disturbance and anxiety in children remains unclear. Despite this limitation, a reciprocal relationship between sleep quality and anxiety appears to be well established. Research using objective measures of sleep quality (e.g. polysomnography, sleep actigraphy, sleep bruxism) is warranted to better understand this relation. Further, complicating factors such as the environment in which sleep quality is measured, the developmental stage of participants, varying severity of anxiety and the timeframe during which assessment takes place should all be considered when examining sleep disturbance in this population.     

Comparison of sleep parameters from actigraphy and polysomnography in older women: the SOF study

STUDY OBJECTIVES: Total sleep time (TST), sleep efficiency (SE), and wake after sleep onset (WASO) as assessed by actigraphy gathered in 3 different modes were compared to polysomnography (PSG) measurements. Each mode was compared to PSG to determine which was more accurate. Associations of the difference in TST measurement with demographics and sleep characteristics were examined. DESIGN: Observational study. SETTING: Community-based. PARTICIPANTS: Sixty-eight women (mean age 81.9 years) from the latest visit of the Study of Osteoporotic Fractures who were concurrently measured with PSG and actigraphy. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: In-home 12-channel PSG was gathered along with actigraphy data in 3 modes: proportional integration mode (PIM), time above threshold (TAT) and zero crossings mode (ZCM). The PIM mode corresponded better to PSG, with a mean overestimation of TST of 17.9 min. For the PIM mode, the estimation of TST and SE by PSG and actigraphy significantly differed (P < 0.01), while the estimation of WASO was similar (P = 0.27). The intraclass correlation between the 2 procedures was moderate to high (PIM mode: TST 0.76; SE 0.61; WASO 0.58). On average, the PIM mode underestimated TST by 68 min for those who slept < or = 5 hr, overestimated TST by 31 min for those with SE < 70%, and underestimated TST by 24 min for self-reported poor sleepers (P < 0.05). CONCLUSIONS: Sleep parameters from actigraphy corresponded reasonably well to PSG in this population, with the PIM mode of actigraphy correlating highest. Those with poor sleep quality had the largest measurement error between the 2 procedures.     

Discrepancy between wrist‐actigraph and polysomnographic measures of sleep in patients with stable heart failure and a novel approach to evaluating discrepancy

Wrist‐actigraphy is often used to measure sleep characteristics in a variety of populations, but discrepancies between actigraphic and polysomnographic measures have been noted in populations experiencing poor sleep quality. The purpose of this study is to examine the discrepancy between these measures and risk factors for discrepancy in people with heart failure using a novel index. We used sleep measures simultaneously recorded by actigraphy and polysomnography, and clinical data from a cross‐sectional study of 155 patients with heart failure (age = 60.5 [16.1] years; 65.2% male) recruited from evidence‐based heart failure disease management programmes. The discrepancy and consistency between the two measures were evaluated using Bland–Altman plots, intra‐class correlations and a newly developed index that represents activity counts in wake episodes. Overall, participants had short total sleep time (327.7 [95.9] min) and poor sleep efficiency (71.3 [16.0]%) on polysomnography. The discrepancies between sleep measures were small in patients less than 60 years old, and there was excellent consistency (intra‐class correlation = 0.81) compared with older patients who had poorer consistency (intra‐class correlation = 0.53) on total sleep time. Higher daytime motor activity, poor sleep quality and more severe insomnia were associated with smaller discrepancies in older, but not younger, patients, and associations were more sensitively detected by the new index. These findings suggest the importance of aging, disability and co‐morbidity that may influence motor activity from which sleep estimates are scored with actigraphy. The new index may be useful in identifying factors associated with the correspondence between actigraphy and polysomnography.     

Case-control study of subjective and objective differences in sleep patterns in older adults with insomnia symptoms

Older adults have high prevalence rates of insomnia symptoms, yet it is unclear if these insomnia symptoms are associated with objective impairments in sleep. We hypothesized that insomnia complaints in older adults would be associated with objective differences in sleep compared with those without insomnia complaints. To test this hypothesis, we conducted a cross‐sectional study in which older adults with insomnia complaints (cases, n = 100) were compared with older adults without insomnia complaints (controls, n = 100) using dual‐night in‐lab nocturnal polysomnography, study questionnaires and 7 days of at‐home actigraphy and sleep diaries. Cases were noted to have reduced objective total sleep time compared with controls (25.8 ± 8.56 min, P = 0.003). This was largely due to increased wakefulness after sleep onset, and not increased sleep latency. When participants with sleep‐related breathing disorder or periodic limb movement disorder were excluded, the polysomnography total sleep time difference became even larger. Cases also had reduced slow‐wave sleep (5.10 ± 1.38 min versus 10.57 ± 2.29 min, effect size −0.29, P = 0.04). When comparing self‐reported sleep latency and sleep efficiency with objective polysomnographic findings, cases demonstrated low, but statistically significant correlations, while no such correlations were observed in controls. Cases tended to underestimate their sleep efficiency by 1.6% (±18.4%), while controls overestimated their sleep efficiency by 12.4% (±14.5%). In conclusion, we noted that older adults with insomnia complaints have significant differences in several objective sleep findings relative to controls, suggesting that insomnia complaints in older adults are associated with objective impairments in sleep.     

Adverse childhood experiences associated with sleep in primary insomnia

The objectives were to explore the association between self-reported adverse childhood experiences (ACE) and sleep in adults suffering from primary insomnia and to examine the impact of presleep stress on this relationship. Fifty-nine patients with primary insomnia, aged 21-55 years, were administered the Childhood Trauma Questionnaire (CTQ) and then divided into two groups according to the achieved scores: with moderate/severe or low/no reports of ACE. The participants spent three consecutive nights in the sleep laboratory in order to record polysomnographic and actigraphic sleep parameters. A stress induction technique was administered by activating negative autobiographical memories immediately before sleep in the second or third night. Results show that 46% of the insomniac patients reported moderate to severe ACE. This group exhibited a significantly greater number of awakenings and more movement arousals compared to patients with low or no reports of ACE. Actigraphic data also indicated more disturbed sleep and increased nocturnal activity for the high-ACE group. On the other hand, no specific group differences were found with regard to stress condition. The results support the assumption that it is possible to identify a subgroup among patients with primary insomnia who has experienced severe maltreatment in childhood and adolescence. This subgroup appears to differ in several sleep parameters, indicating a more disturbed sleep compared to primary insomniacs with low or no reports of ACE. With regard to sleep-disturbing nightly patterns of arousal, parallels between individuals with high ACE and trauma victims as well as post-traumatic stress disorder-patients suggest themselves.     

The use of actigraphy for assessment of the development of sleep/wake patterns in infants during the first 12 months of life

Maturation of sleep/wake patterns is one of the most important physiological developments during the first year of life. In this study, we aimed to compare the use of actigraphy and parental sleep diaries (SD) for recording the development of sleep/wake patterns longitudinally in term infants in their own home environments over the first 12 months of life. Twenty healthy term infants (7F/13M) were studied for 3 days each month in their own homes over the first 12 months of life. Sleep/wake patterns were recorded using both SD and actigraphy (AW) (AW64, Mini Mitter Co. Inc., Sunriver, OR, USA). The development of sleep and wake was analysed over 24 h, during the day (08:00-20:00 hours) and during the night (20:00-08:00 hours). A total of 186 studies had complete data sets for both analysis methods. Overall, there was no difference between methods of measurement for determination of the total percentage of sleep or wake over 24 h, or for the total percentage of sleep or wake during the day. However, at night, AW scored less time asleep (73.3 +/- 0.9%) and more time awake (26.7 +/- 0.9%) compared with the SD (80.7 +/- 1.04% and 19 +/- 1.0%, respectively, P < 0.001). Mean percentage sleep during the day decreased from 51% at 1 month to 28% at 12 months with the 1-month values being significantly higher than all other ages, while mean percentage sleep at night was only different between 1 month and 11 and 12 months. In conclusion actigraphy provides a useful tool for assessing the development infant sleep.     

Internight sleep variability: its clinical significance and responsiveness to treatment in primary and comorbid insomnia

Although sleep diary and actigraphy data are usually collected daily for 1 or 2 weeks, traditional analytical approaches aggregate these data into mean values. Internight variability of sleep often accompanies insomnia. However, few studies have explored the relevance of this ‘construct’ in the context of diagnosis, clinical impact, treatment effects and/or whether having ‘variable sleep’ carries any prognostic significance. We explored these questions by conducting secondary analyses of data from a randomized clinical trial. The sample included primary (PI: n = 40) and comorbid insomnia (CMI: n = 41) sufferers receiving four biweekly sessions of cognitive–behavioural therapy (CBT) or sleep hygiene education. Using the within‐subject standard deviations of diary‐ and actigraphy‐derived measures collected for 2‐week periods [sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST) and sleep efficiency (SE)], we found that CMI sufferers displayed more variable self‐reported SOLs and SEs than PI sufferers. However, higher variability in diary and actigraphy‐derived measures was related to poorer sleep quality only within the PI group, as measured by the Pittsburgh Sleep Quality Index (PSQI). Within both groups, the variability of diary‐derived measures was reduced after CBT, but the variability of actigraphy‐derived measures remained unchanged. Interestingly, the variability of actigraphy measures at baseline was correlated with PSQI scores at 6‐month follow‐up. Higher SOL variability was associated with worse treatment outcomes within the PI group, whereas higher WASO variability was correlated with better treatment outcomes within the CMI group. Sleep variability differences across insomnia diagnoses, along with their distinctive correlates, suggest that mechanisms underlying the sleep disruption/complaint and treatment response in both patient groups are distinct. Further studies are warranted to support variability as a useful metric in insomnia studies.     

Associations between sleep duration and cognitive impairment in mild cognitive impairment

The prevalence of mild cognitive impairment (MCI) increases among elderly people and is associated with a high risk of dementia. Identifying factors that may contribute to the progress of MCI to dementia is critical. The objective of this study was to examine the association of objective sleep with cognitive performance in MCI patients. A subsample of 271 participants with a diagnosis of probable Alzheimer's disease (AD; N = 50) or mild cognitive impairment (MCI; N = 121) and 100 persons who were not cognitively impaired (NI) were recruited from a large population‐based cohort in the island of Crete, Greece (3140 older adults aged >60 years). All participants underwent extensive neuropsychiatric/neuropsychological evaluation and a 3‐day 24‐hr actigraphy. Objective sleep variables and their association with neuropsychological performance were examined across the three groups, controlling for demographics, body mass index, depression, sleep apnea symptoms and psychotropic medications. Patients with AD had significantly longer 24‐hr total sleep time (TST) compared to the MCI and NI groups. Long 24‐hr TST was associated with reduced performance on tasks that placed significant demands on attention and processing speed in the MCI group and the AD group. Elderly patients with MCI have similar objective sleep duration to normal controls, whereas AD patients sleep longer. Long sleep duration in patients with multidomain subtypes of MCI is associated with critical non‐memory cognitive domains. It appears that within the MCI group those that sleep longer have more severe cognitive impairment.     

Prevalence and predictors of significant sleep disturbances in children undergoing ambulatory tonsillectomy and adenoidectomy

Objective To evaluate children's sleep patterns before and afterambulatory surgery and to identify predictors of sleep decrementsfollowing surgery. Methods Participants were 55, 6- to 12-year-oldchildren undergoing tonsillectomy and adenoidectomy. Sleep wasassessed using actigraphy for 5 nights prior to and 5 nightsfollowing surgery. Parent state and trait anxiety, and childperioperative anxiety and temperament were assessed. Data onpostoperative pain and use of analgesics were collected. ResultsChildren had significantly less efficient sleep following surgerythan before surgery. Approximately one-third of children demonstratedclinically significant decrements in sleep efficiency. Discriminantfunction analysis indicated less sociable and more anxious childrenwere more likely to experience these sleep decrements, as werechildren who experienced greater pain in the postoperative period.Conclusion Children's sleep is an important consideration inrecovery from surgery and this article takes a first step towardidentifying predictors of the development of clinically significantsleep disruptions following surgery.     

Psychological interventions to improve sleep in college students: A meta‐analysis of randomized controlled trials

Sleep disturbances and insomnia are common in college students, and reduce their quality of life and academic performance. The aim of this meta‐analysis was to evaluate the efficacy of psychological interventions aimed at improving sleep in college students. A meta‐analysis was conducted with 10 randomized controlled trials with passive control conditions (N = 2,408). The overall mean effect size (Hedges’ g) of all sleep‐related outcomes within each trial was moderate to large (g = 0.61; 95% confidence interval: 0.41?0.81; numbers‐needed‐to‐treat = 3). Effect sizes for global measures of sleep disturbances were g = 0.79; 95% confidence interval: 0.52?1.06; and for sleep‐onset latency g = 0.65; 95% confidence interval: 0.36?0.94. The follow‐up analyses revealed an effect size of g = 0.56; 95% confidence interval: 0.45?0.66 for the combined sleep‐related outcomes based on three studies. No significant covariates were identified. These results should be interpreted cautiously due to an overall substantial risk of bias, and in particular with regard to blinding of participants and personnel. Nevertheless, they provide evidence that psychological interventions for improving sleep are efficacious among college students. Further research should explore long‐term effects and potential moderators of treatment efficacy in college students.