Use of Actigraphy for the Evaluation of Sleep Disorders and Circadian Rhythm Sleep-Wake Disorders: An American Academy of Sleep Medicine Systematic Review, Meta-Analysis, and GRADE Assessment

Free AccessCircadian RhythmsUse of Actigraphy for the Evaluation of Sleep Disorders and Circadian Rhythm Sleep-Wake Disorders: An American Academy of Sleep Medicine Systematic Review, Meta-Analysis, and GRADE Assessment Michael T. Smith, MA, PhD, Christina S. McCrae, PhD, Joseph Cheung, MD, MS, Jennifer L. Martin, PhD, Christopher G. Harrod, MS, Jonathan L. Heald, MA, Kelly A. Carden, MD Michael T. Smith, MA, PhD Address correspondence to: Michael T Smith, MA, PhD, Johns Hopkins School of Medicine, 733 N Broadway, Baltimore, MD 21205 E-mail Address: [email protected] Johns Hopkins School of Medicine, Baltimore, Maryland Search for more papers by this author , Christina S. McCrae, PhD University of Missouri, Columbia, Missouri Search for more papers by this author , Joseph Cheung, MD, MS Stanford Center for Sleep Sciences and Medicine, Stanford University, Palo Alto, California Search for more papers by this author , Jennifer L. Martin, PhD David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, California VA Greater Los Angeles Healthcare System, Geriatric Research, Education and Clinical Center, Los Angeles, California Search for more papers by this author , Christopher G. Harrod, MS American Academy of Sleep Medicine, Darien, Illinois Search for more papers by this author , Jonathan L. Heald, MA American Academy of Sleep Medicine, Darien, Illinois Search for more papers by this author , Kelly A. Carden, MD Saint Thomas Medical Partners-Sleep Specialists, Nashville, Tennessee Search for more papers by this author Published Online:July 15, 2018https://doi.org/10.5664/jcsm.7228Cited by:204SectionsAbstractPDFSupplemental Material ShareShare onFacebookTwitterLinkedInRedditEmail ToolsAdd to favoritesDownload CitationsTrack Citations AboutABSTRACTIntroduction:The purpose of this systematic review is to provide supporting evidence for a clinical practice guideline on the use of actigraphy.Methods:The American Academy of Sleep Medicine commissioned a task force of experts in sleep medicine. A systematic review was conducted to identify studies that compared the use of actigraphy, sleep logs, and/or polysomnography. Statistical analyses were performed to determine the clinical significance of using actigraphy as an objective measure of sleep and circadian parameters. Finally, the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process was used to assess the evidence for making recommendations.Results:The literature search resulted in 81 studies that met inclusion criteria; all 81 studies provided data suitable for statistical analyses. These data demonstrate that actigraphy provides consistent objective data that is often unique from patient-reported sleep logs for some sleep parameters in adult and pediatric patients with suspected or diagnosed insomnia, circadian rhythm sleep-wake disorders, sleep-disordered breathing, central disorders of hypersomnolence, and adults with insufficient sleep syndrome. These data also demonstrate that actigraphy is not a reliable measure of periodic limb movements in adult and pediatric patients. The task force provided a detailed summary of the evidence along with the quality of evidence, the balance of benefits and harms, patient values and preferences, and resource use considerations.Citation:Smith MT, McCrae CS, Cheung J, Martin JL, Harrod CG, Heald JL, Carden KA. Use of actigraphy for the evaluation of sleep disorders and circadian rhythm sleep-wake disorders: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment. J Clin Sleep Med. 2018;14(7):1209–1230.INTRODUCTIONThis systematic review is intended to provide supporting evidence for a clinical practice guideline on the use of actigraphy in patients with suspected or diagnosed sleep disorders or circadian rhythm sleep-wake disorders,1 and update the evidence review conducted for the previously published American Academy of Sleep Medicine (AASM) practice parameters on the use of actigraphy in these populations.2 The scientific literature summarized in prior practice parameters established the validity of actigraphy to assess sleep in healthy individuals and select groups of patients. The objective of this systematic review is to examine the clinical value of actigraphy in the assessment and treatment of patients with suspected or diagnosed sleep disorders and circadian rhythm sleep-wake disorders (CRSWDs). The review focuses exclusively on clinical grade devices approved by the FDA as an actigraph or equivalent device that uses an accelerometer to measure limb activity associated with movement during sleep for physiologic applications. The review does not cover consumer wearable devices,3 or other non-prescription devices directly marketed to consumers.BACKGROUNDActigraphy is a procedure that records and integrates the occurrence and degree of limb movement activity over time. Actigraphic devices can be worn on the wrist, ankle or waist, relatively unobtrusively over a period of days to weeks. For sleep applications, the devices are typically worn on the wrist or ankle. Mathematical algorithms are then applied to these data to estimate wakefulness and sleep. In addition to providing a graphical summary of wakefulness and sleep patterns over time (ie, temporal raster plots), actigraphy generates estimates of certain sleep parameters that are also commonly estimated by using sleep logs, or measured directly by polysomnography (PSG), the gold standard measure of sleep. The sleep parameters estimated by actigraphy, in common with standard sleep logs, include: sleep latency (SL); total sleep time (TST); wake after sleep onset (WASO); and sleep efficiency (SE; SE = TST / time in bed). Unlike PSG, actigraphy does not provide estimates of sleep architecture, as information related to the staging of non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep is generally not available, and requires electroencephalogram (EEG), electrooculography (EOG), and electromyography (EMG). Similarly, actigraphy does not provide information related to respiratory function.Actigraphy devices available for clinical use generally include a piezoelectric or a microelectromechanical systems accelerometer. The devices have storage to enable transfer of the resulting values into an interface (usually via USB or serial port) and to program the timing mechanism. Many devices also have at least one event button that can be used by the wearer to document select events (eg, drowsiness, bed time). Some actigraphy devices also have light sensors for detecting white light or specific wavelengths of light.Several factors have been identified as important for the reliable and valid use of actigraphy to measure certain sleep parameters.4 These include: (1) technical features of the device (eg, tri-axial versus dual or single axis accelerometers); (2) software driven data acquisition settings (eg, sampling rates and sensitivity settings); (3) location of device placement5; (4) the mathematical algorithms used to estimate sleep/wake6; (5) clinical features of the population being studied, (6) utilization of a standardized scoring approach to setting rest activity intervals; and (7) training of patients in data collection procedures.7 Standardized information on the technical aspects of actigraphy as well as analysis and interpretation procedures for clinical and research use have recently been published.8 It is important to note that the basic technology in products sold “direct to consumers” may differ significantly from what is available for clinical application. At the present time, data are not adequate to suggest that consumer products can be used as a replacement for clinical devices using validated sleep scoring algorithms, technologies, and procedures.In clinical practice, patients or caregivers are sometimes asked to estimate and record certain sleep parameters and related information manually through daily sleep logs. Sleep logs provide critically important clinical information about the patient's subjective experience. However, when used as a sole assessment tool, sleep logs have some inherent and significant limitations, including: (1) they are subject to bias; (2) sometimes they cannot be completed accurately by patients with cognitive limitations or by infants and children; and (3) they may not be completed because they are cumbersome for many patients and caregivers. In contrast, actigraphy is a relatively passive, objective procedure that involves the use of a nonobtrusive monitor with a low device failure rate. Actigraphy is relatively inexpensive, patient adherence is typically good, and it can provide useful diagnostic information and data regarding treatment response. Actigraphy scoring software typically provides graphical detail about certain sleep parameters and patterns that can be communicated to patients and referring providers in simple, understandable terms.The role of actigraphy may vary based on the specific sleep disorder and sleep assessment procedure. With respect to insomnia disorder, for example, actigraphy may be more useful as an adjunct to sleep logs (the reference standard for insomnia) or as a standalone procedure in special instances where reliable self-report is not feasible, such as young children ranging to identify sleep disruption in psychiatric, neurodevelopmental, medical, and sleep disorders. The sleep patterns of patients with insomnia are characterized by high night-to-night variability.9 Concurrent actigraphy and sleep log collection provides information about that variability as well as the degree and pattern of discrepancy between the 2 types of assessment (ie, objective versus subjective).10,11 Such information is useful for both diagnosis and treatment planning, for example, with respect to identifying and treating paradoxical insomnia.In patients with suspected or diagnosed CRSWD, characterizing sleep across multiple 24-hour periods is essential for both adult and pediatric populations. Actigraphy-generated temporal raster plots can be extremely useful in visually depicting changing periodicities associated with circadian dysrhythmia, which can facilitate accurate diagnosis. This is true for multiple, specific CRSWDs, and also for differential diagnosis when the type of CRSWD is not clear based on clinical history alone. This is particularly critical as the treatment itself must be tailored to the precise CRSWD. For example, the timing of light exposure or melatonin administration is dependent upon precise estimates of intrinsic circadian phase. Actigraphy may also be a viable method for documenting disturbed sleep/ wake patterns in individuals with shift work sleep disorder. The ability of actigraphy software to show time-based relations and easily identify shifting trends in bedtimes and wake times make it an especially useful tool for the assessment of multiple CRSWDs.Actigraphy may also play a role when administration of a home sleep apnea test (HSAT) is appropriate in adult populations.12 For gold standard sleep apnea assessment, PSG is used to measure the apnea-hypopnea index (AHI) as determined by the number of respiratory events × 60 divided by the TST in minutes. HSAT refers to a study performed to diagnose sleep-related breathing disorders such as obstructive sleep apnea (OSA), generally without direct determination of sleep versus wake or of sleep stages. The use of the respiratory event index (REI) was introduced to be used for HSATs that do not record sleep by EEG, EOG and EMG. The REI describes the total number of respiratory events scored × 60 divided by monitoring time. HSAT devices that do not have any mechanism for removing the wake time from the denominator in the calculation use total recording time (TRT) in determining the REI. Devices that use TRT in the index calculation are likely to underestimate the severity of the sleep-disordered breathing (SDB) and may result in increased false negatives. HSAT devices that use built-in actigraphy with the ability to eliminate wake and artifact time in estimating sleep time, therefore, may improve the diagnostic accuracy of the REI.Actigraphy may be especially useful in documenting insufficient sleep both for the purpose of improving the interpretation of the Multiple Sleep Latency Test (MSLT) in adult and pediatric patients with suspected central disorders of hypersomnolence and for assessing insufficient sleep syndrome (ISS). Objective measurement may be especially important in facilitating treatment of the sometimes complex medical and occupational risks associated with ISS.Some studies have sought to evaluate whether actigraphy worn on the ankles might provide a reasonable estimate of periodic limb movements in adult and pediatric patients, although it is increasingly clear that additional measures of arousal may be important in evaluating the clinical significance of periodic limb movement during sleep.METHODSExpert Task ForceThe AASM commissioned a task force (TF) of sleep medicine clinicians with expertise in the use of actigraphy in patients with suspected sleep disorders to develop this systematic review. The TF was required to disclose all potential conflicts of interest (COI) according to the AASM's COI policy prior to being appointed to the TF, and throughout the development of this document. In accordance with the AASM's conflicts of interest policy, TF members with a Level 1 conflict were not allowed to participate. TF members with a Level 2 conflict were required to recuse themselves from any related discussion or writing responsibilities. All relevant conflicts of interest are listed in the Disclosures section.PICO QuestionsPICO (Patient, Intervention, Comparison, and Outcomes) questions were developed by the TF after a review of the existing AASM practice parameters on the use of actigraphy,2 and a review of relevant systematic reviews, meta-analyses, and guidelines published since June 2005. To develop the PICO questions, the TF identified sleep disorders for which actigraphy may provide clinically useful information (summarized in Table 1), and the clinically relevant outcomes that actigraphy provides for each sleep disorder (summarized in Table 2). The AASM Board of Directors approved the final list of questions before the literature searches were performed.Table 1 PICO questions.Table 1 PICO questions.Table 2 “Critical” outcomes by patient population.Table 2 “Critical” outcomes by patient population.The TF compared actigraphy to both sleep logs and PSG to determine whether actigraphy provides information that is consistent with PSG and also distinct from patient-reported data. The TF set two different sets of clinical significance thresholds (CST) for each outcome and PICO to determine if the data provided by actigraphy was clinically significant. The first CSTs were set for comparisons of actigraphy to sleep logs and was defined as the minimum allowable mean difference between the measurements. When comparing actigraphy to sleep logs, a mean difference greater than these thresholds indicates a clinically meaningful difference and a need for objective reporting of sleep parameters. A summary of these CSTs is presented in Table 3; a graphical representation of these thresholds is presented in Figure 1. The second CSTs were set for comparisons of actigraphy to PSG and were defined as the maximum allowable 95% confidence interval (CI) for the mean difference (unless otherwise noted in Table 4). When comparing actigraphy to PSG, a 95% CI within these thresholds indicates that actigraphy provides a sufficiently narrow range of possible mean differences relative to PSG, and therefore provides consistent objective measurements for reporting of sleep parameters. A summary of these CSTs is presented in Table 4; a graphical representation of these thresholds is presented in Figure 2. The CSTs were established prior to analysis based on the clinical judgement and experience of the TF and informed by the literature. Larger CSTs were established for pediatric populations due to increased measurement error associated with caregiver report, and both PSG and self-report sleep diary alternatives pose additional challenges for some pediatric populations, such as those with developmental disabilities, which likely increase measurement error. In addition, there is more variability across pediatric patients based on age and other factors. The TF endeavored to balance the need for accuracy, care giver burden, and the differential sleep needs of pediatric groups relative to adults.Table 3 Clinical significance thresholds for the minimum allowable mean difference between actigraphy versus sleep log or caregiver report.Table 3 Clinical significance thresholds for the minimum allowable mean difference between actigraphy versus sleep log or caregiver report.Figure 1: Hypothetical mean difference of actigraphy versus sleep log measurements (clinically significant).Download FigureTable 4 Clinical Significance Thresholds for the maximum allowable 95% CI of the mean difference between actigraphy versus PSG.Table 4 Clinical Significance Thresholds for the maximum allowable 95% CI of the mean difference between actigraphy versus PSG.Figure 2: Hypothetical range of mean differences of actigraphy versus PSG measurements (clinically significant).CI = confidence interval, PSG = polysomnography.Download FigureLiterature Searches, Evidence Review and Data ExtractionLiterature searches were performed using the PubMed and Embase databases for individual questions. A combination of MeSH terms and keywords listed in the supplemental material were used. The databases were searched from June 1, 2005 through January 10, 2018 for any relevant literature published since the 2007 guideline literature search was performed. The articles that were cited in the 2007 AASM practice parameters were included if they met the study inclusion criteria. In addition, the task force reviewed all AASM guidelines published since 2006, to identify additional references that may be relevant to actigraphy. The limits of the searches (requiring all listed criteria to be met) were: humans, English, all adults (with the exception of questions 4, 5, and 7), and randomized controlled trial (RCT) or observational studies. A total of 3,073 citations were identified from both databases, and 37 studies were identified in the other AASM practice parameters.Articles were included for review and possible data extraction if they focused on patient assessment or monitoring of treatment response for a sleep disorder with actigraphy, sleep logs and/or PSG; addressed at least one of the PICO questions; and included one of the outcomes of interest. Articles were excluded if they focused on actigraphy not related to sleep; were not RCTs or observational studies; were duplicates; involved non-human subjects; involved subjects without a suspected or diagnosed sleep or circadian rhythm sleep-wake disorder; used actigraphy to monitor treatment response of a comorbid condition; or used actigraphy as a measurement tool, but did not provide evidence for any PICO questions. Studies were also excluded if they did not present data for any of the critical outcomes and/or did not present data in a format suitable for statistical analysis. A total of 81 articles from the literature searches were accepted and considered for meta-analysis and evidence grading. Specific data elements of all accepted studies were extracted into evidence tables (not published) to address each clinical question. Upon review of these articles, 81 studies were determined to be suitable for meta-analysis and/or the Grading of Recommendations Assessment, Development and Evaluation (GRADE) process. An evidence base flow diagram is presented in Figure 3.Figure 3: Evidence base flow diagram.AASM = American Academy of Sleep Medicine, CRSWD = circadian rhythm sleep-wake disorder, PICO = Patient, Intervention, Comparison, and Outcomes.Download FigureMeta-Analysis and Interpretation of Clinical SignificanceMeta-analyses were performed on outcomes of interest for each PICO question. Review Manager 5.3 software (The Cochrane Collaboration, London, United Kingdom) was used to compare the use of actigraphy versus sleep logs and actigraphy versus PSG for the assessment of sleep parameters and of treatment response in patients with various sleep disorders. All analyses were performed using the random effects model with results displayed as a forest plot. Meta-analyses were performed when at least 5 studies were available by pooling data across studies for each relevant outcome of interest for each PICO (studies for PICO 7 were grouped by patient population). When 3–4 studies were available, meta-analyses were performed at the discretion of the task force. For several questions, there was insufficient evidence to perform meta-analyses for certain comparisons and outcome measures. In these cases, studies are described individually.For the assessment of sleep parameter estimates, the mean differences in baseline sleep parameter measurements from actigraphy, sleep logs and PSG were determined by pooling both intervention and non-intervention studies. (For simplicity, the term “baseline” is used in the text to describe all data extracted for the pre-intervention phase of interventional studies and the initial assessment time point for cross sectional studies.) For the assessment of treatment response, given the limited number of treatment outcome studies identified, the heterogeneity of intervention types and assessment time points, the task force was not able to evaluate whether actigraphy was sensitive to change relative to sleep logs or PSG. Instead, the TF analyzed the mean difference of posttreatment measurements from actigraphy, sleep logs and PSG. The pooled results for each continuous outcome measure are expressed as the mean difference between the intervention and comparator. The results of the meta-analyses are presented in the supplemental material.Interpretation of clinical significance for the outcomes of interest was conducted in two different ways. First, by comparing the mean difference in measurements of actigraphy and sleep logs against their CSTs (Table 3). Next, by comparing the 95% CI of the mean difference of actigraphy versus PSG measurements to their CSTs (Table 4). For comparisons of actigraphy to sleep logs, the CST was defined as the minimum allowable mean difference between the measurements; a mean difference greater than the threshold demonstrates that actigraphy provides unique information from sleep logs, and objective measurements are warranted (see Figure 1, which shows an example of a clinically significant mean difference). For comparisons of actigraphy to PSG, the CST was defined as the maximum allowable 95% CI for the mean difference between actigraphy and PSG (unless otherwise noted in Table 4); a 95% CI within the threshold demonstrates that actigraphy provides a sufficiently narrow range of possible mean differences relative to PSG (regardless of the mean difference, unless otherwise noted in Table 4). A sufficiently narrow range of mean differences indicates that actigraphy provides consistent objective measurements relative to PSG, and may be useful as an objective measurement of sleep parameters (see Figure 2, which shows an example of a sufficiently narrow range of mean differences).Detailed reviews of the evidence and clinical significance of the findings for all critical outcomes are provided for each PICO question.GRADE Assessment for Developing RecommendationsThe evidence was assessed according to the GRADE process for the purposes of making clinical practice recommendations.13,14 The TF considered the following four GRADE domains: quality of evidence, balance of beneficial and harmful effects, patient values and preferences, and resource use, as described below: Quality of evidence: based on an assessment of the overall risk of bias (randomization, blinding, allocation concealment, selective reporting), imprecision (95% CI relative to the CST, sample size < 200), inconsistency and indirectness (study population), and risk of publication bias (funding sources), the TF determined their overall confidence that the estimated differences in measurements found in the body of evidence were representative of the true differences in measurements that patients would experience. The overall quality of the evidence was based on all outcomes that the TF deemed critical for decision making.Benefits versus harms: based on any harms/side effects reported within the accepted literature, and the clinical expertise of the TF, the TF determined if the beneficial outcomes of using actigraphy outweighed any harms. Benefits versus harms compared to alternative measurement tools was also considered.Patient values and preferences: based on the clinical expertise of the TF members and any data published on the topic relevant to patient preferences for actigraphy, the TF determined if patient values and preferences would be consistent across the majority of patients, and if patients would use actigraphy based on the body of evidence.Resource use: based on the clinical expertise of the TF members, the TF determined if accessibility and costs associated with actigraphy compared favorably to alternative measurement tools. Information on both costs to patients and to the health care system were considered. A summary of each GRADE domain is provided after the detailed evidence review for each PICO question.Public Comment and Final ApprovalDrafts of the systematic review and accompanying guideline were made available for public comment for a two-week period on the AASM website. AASM members, the general public and other relevant stakeholders were invited to provide feedback on the drafts. The TF took into consideration all the comments received and made decisions about whether to revise the draft based on the scope and feasibility of comments. The public comments and revised documents were submitted to the AASM Board of Directors who subsequently approved the final documents for publication.The AASM expects this systematic review to have an impact on professional behavior, patient outcomes, and, possibly, health care costs. This review reflects the state of knowledge at the time of publication and will be reviewed and updated as new information becomes available.THE USE OF ACTIGR APHYThe aims of the current systematic reviews and data analyses were to address 7 PICO questions pertaining to the use of actigraphy relative to sleep logs and/or PSG across a wide range of clinical populations, and in conjunction with HSAT and MSLT. While sufficient data were available for meta-analyses for most PICO questions, there are caveats that should be considered with respect to interpreting the results. With regard to sleep parameters, the TF noted variability across studies with respect to definitions and technical details such as algorithms and sensitivity threshold settings used or reported. As is common practice, many studies utilized information noted by the patient in a sleep log for the analysis and interpretation of actigraphy-estimated sleep parameters. This is important particularly with respect to determining bedtime (“lights off”) to calculate SL. Other studies relied completely on actigraphy algorithms to estimate SL, while some studies failed to report these details. The TF decided not to analyze the number of nightly awakenings as a sleep parameter of interest, since actigraphy typically identifies numerous isolated brief awakenings lasting less than a minute (eg, 30 seconds), which are common even in normal sleep and often not perceived, remembered or retrospectively reported by patients. Diary measures of awakenings likely reflect a distinct construct related to consolidated frank awakenings, which are not consistently defined or reported in standard software to date, making comparison across devices and sleep log estimates of questionable utility. The TF also cautions that generalizability of some of the meta-analytic findings may be limited due to a small number of studies meeting the inclusion/ exclusion criteria and/or patients across studies. Generalizability to the broad spectrum of sleep disorder patients seen in clinical settings may also be limited by heterogeneity across sleep disorder severity and subpopulations with clinical comorbidities, both of which may influence validity.Below are detailed summaries of the evidence identified in the literature searches and the statistical analyses performed by the task force. Each evidence summary is accompanied by a discussion of the quality of evidence, balance of benefits and harms, patient values and preferences, and resource use considerations that contributed to the development of the recommendations, which are provided in the accompanying clinical practice guideline.1Use of Actigraphy in the Evaluation of Insomnia in AdultsOur review of the literature identified 46 studies11,15–59 that used actigraphy concurrent with sleep logs and/or PSG in adults with suspected or diagnosed insomnia. Both non-intervention and intervention studies met the eligibility criteria and were included. The number of studies included in the analyses varied by sleep parameter and whether the comparison was to sleep logs or PSG. Overall, more studies were identified that provided comparisons of actigraphy to sleep logs than to PSG.The data for examining the use of actigraphy for assessment were either based on a single night or drawn from the baseline periods of intervention trials with insomnia and represent sleep parameter values averaged over 1 to 2 weeks. Similarly, data for analyses examining the use of actigraphy to assess treatment response were either based