Wrist Actigraphy
2011; Elsevier BV; Volume: 139; Issue: 6 Linguagem: Inglês
10.1378/chest.10-1872
ISSN1931-3543
AutoresJennifer L. Martin, Alex D. Hakim,
Tópico(s)Obstructive Sleep Apnea Research
ResumoTo record sleep, actigraph devices are worn on the wrist and record movements that can be used to estimate sleep parameters with specialized algorithms in computer software programs. With the recent establishment of a Current Procedural Terminology code for wrist actigraphy, this technology is being used increasingly in clinical settings as actigraphy has the advantage of providing objective information on sleep habits in the patient's natural sleep environment. Actigraphy has been well validated for the estimation of nighttime sleep parameters across age groups, but the validity of the estimation of sleep-onset latency and daytime sleeping is limited. Clinical guidelines and research suggest that wrist actigraphy is particularly useful in the documentation of sleep patterns prior to a multiple sleep latency test, in the evaluation of circadian rhythm sleep disorders, to evaluate treatment outcomes, and as an adjunct to home monitoring of sleep-disordered breathing. Actigraphy has also been well studied in the evaluation of sleep in the context of depression and dementia. Although actigraphy should not be viewed as a substitute for clinical interviews, sleep diaries, or overnight polysomnography when indicated, it can provide useful information about sleep in the natural sleep environment and/or when extended monitoring is clinically indicated. To record sleep, actigraph devices are worn on the wrist and record movements that can be used to estimate sleep parameters with specialized algorithms in computer software programs. With the recent establishment of a Current Procedural Terminology code for wrist actigraphy, this technology is being used increasingly in clinical settings as actigraphy has the advantage of providing objective information on sleep habits in the patient's natural sleep environment. Actigraphy has been well validated for the estimation of nighttime sleep parameters across age groups, but the validity of the estimation of sleep-onset latency and daytime sleeping is limited. Clinical guidelines and research suggest that wrist actigraphy is particularly useful in the documentation of sleep patterns prior to a multiple sleep latency test, in the evaluation of circadian rhythm sleep disorders, to evaluate treatment outcomes, and as an adjunct to home monitoring of sleep-disordered breathing. Actigraphy has also been well studied in the evaluation of sleep in the context of depression and dementia. Although actigraphy should not be viewed as a substitute for clinical interviews, sleep diaries, or overnight polysomnography when indicated, it can provide useful information about sleep in the natural sleep environment and/or when extended monitoring is clinically indicated. American Academy of Sleep Medicine multiple sleep latency test obstructive sleep apnea polysomnography sleep latency sleep-onset latency total sleep time wake after sleep onset The first major medical use of actigraphy was for attempting to evaluate psychologic disorders in the pediatric population using purely mechanical sensors first conceived in the 1950s.1Tryon W Bellak A Hersen M Activity Measurement in Psychology and Medicine. Plenum Press, New York, NY1991Crossref Google Scholar Over subsequent decades, the development of piezoelectric sensors, lithium batteries, and digital data storage has enhanced accuracy, reliability, and storage capacity, and devices can now record objective, long-term data regarding a patient's daily activity level. This is rapidly developing into a significant asset for sleep medicine clinicians. The field of actigraphy owes much of its increasing usefulness to the advancement of devices (actigraphs) used for measuring body movement with increasing frequency and precision, with current devices able to record and store information for weeks or months, and to the development of automatic scoring algorithms in available software packages for the identification of sleep vs wakefulness. Current devices also have the advantage of small size and light weight, making the devices unobtrusive and convenient for patients. Through the collection of data representing body movement over time, the actigraph paints a picture of daily sleep-wake cycles, which can be useful in the diagnosis and evaluation of several clinical sleep disorders and treatment outcomes. In 1995, the American Academy of Sleep Medicine (AASM) concluded that actigraphy was useful as a research tool for the study of sleep, but that its clinical usefulness remained uncertain.2Thorpy M Chesson A Derderian S American Sleep Disorders Association et al.Practice parameters for the use of actigraphy in the clinical assessment of sleep disorders.Sleep. 1995; 18: 285-287Crossref PubMed Scopus (154) Google Scholar This statement was expanded in 2002 to indicate the potential use of actigraphy to measure sleep in clinical settings; however, the strength of the evidence remained relatively weak.3Littner M Kushida CA Anderson WM Standards of Practice Committee of the American Academy of Sleep Medicine et al.Practice parameters for the role of actigraphy in the study of sleep and circadian rhythms: an update for 2002.Sleep. 2003; 26: 337-341Crossref PubMed Scopus (525) Google Scholar In an updated report in 2007, growing research literature supported the use of actigraphy for clinical application, particularly in the evaluation of circadian rhythm disorders, insomnia, hypersomnia, and obstructive sleep apnea (OSA).4Morgenthaler T Alessi C Friedman L Standards of Practice Committee; American Academy of Sleep Medicine et al.Practice parameters for the use of actigraphy in the assessment of sleep and sleep disorders: an update for 2007.Sleep. 2007; 30: 519-529Crossref PubMed Scopus (870) Google Scholar This report contributed to the establishment of a category 3 Current Procedural Terminology code (ie, emerging technology) for actigraphy, which was advanced to a category 1 Current Procedural Terminology code in 2009. There are multiple methods for evaluating patients' sleep complaints, including clinical interviews, sleep diaries, polysomnography (PSG) (laboratory or home based), and actigraphy. The usefulness of actigraphy depends on the specific presenting complaint, and each of the aforementioned assessment methods has both advantages and disadvantages. This article reviews recent studies on the validity of wrist actigraphy in the assessment of sleep patterns, discusses the use of actigraphy relative to other tools available to the sleep medicine clinician, and outlines key considerations in the use of actigraphy in specific sleep disorders patients. In recent years, multiple studies have been published on the validity of wrist actigraphy. Tables 15Wang SY Chang HJ Lin CC Sleep disturbances among patients with non-small cell lung cancer in taiwan: congruence between sleep log and actigraphy.Cancer Nurs. 2010; 33: E11-E17Crossref PubMed Scopus (16) Google Scholar, 6Sánchez-Ortuño MM Edinger JD Means MK Almirall D Home is where sleep is: an ecological approach to test the validity of actigraphy for the assessment of insomnia.J Clin Sleep Med. 2010; 6: 21-29Crossref PubMed Scopus (68) Google Scholar, 7Natale V Plazzi G Martoni M Actigraphy in the assessment of insomnia: a quantitative approach.Sleep. 2009; 32: 767-771Crossref PubMed Scopus (130) Google Scholar, 8Chae KY Kripke DF Poceta JS et al.Evaluation of immobility time for sleep latency in actigraphy.Sleep Med. 2009; 10: 621-625Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar, 9Blackwell T Redline S Ancoli-Israel S Study of Osteoporotic Fractures Research Group et al.Comparison of sleep parameters from actigraphy and polysomnography in older women: the SOF study.Sleep. 2008; 31: 283-291Crossref PubMed Scopus (199) Google Scholar, 10Paquet J Kawinska A Carrier J Wake detection capacity of actigraphy during sleep.Sleep. 2007; 30: 1362-1369Crossref PubMed Scopus (263) Google Scholar, 11Bradshaw DA Yanagi MA Pak ES Peery TS Ruff GA Nightly sleep duration in the 2-week period preceding multiple sleep latency testing.J Clin Sleep Med. 2007; 3: 613-619Crossref PubMed Scopus (37) Google Scholar, 12García-Díaz E Quintana-Gallego E Ruiz A et al.Respiratory polygraphy with actigraphy in the diagnosis of sleep apnea-hypopnea syndrome.Chest. 2007; 131: 725-732Abstract Full Text Full Text PDF PubMed Scopus (56) Google Scholar, 13Sivertsen B Omvik S Havik OE et al.A comparison of actigraphy and polysomnography in older adults treated for chronic primary insomnia.Sleep. 2006; 29: 1353-1358Crossref PubMed Scopus (150) Google Scholar, 14Lichstein KL Stone KC Donaldson J et al.Actigraphy validation with insomnia.Sleep. 2006; 29: 232-239PubMed Google Scholar, 15Hedner J Pillar G Pittman SD Zou D Grote L White DP A novel adaptive wrist actigraphy algorithm for sleep-wake assessment in sleep apnea patients.Sleep. 2004; 27: 1560-1566Crossref PubMed Scopus (158) Google Scholar and 216Sung M Adamson TM Horne RS Validation of actigraphy for determining sleep and wake in preterm infants.Acta Paediatr. 2009; 98: 52-57Crossref PubMed Scopus (42) Google Scholar, 17Werner H Molinari L Guyer C Jenni OG Agreement rates between actigraphy, diary, and questionnaire for children's sleep patterns.Arch Pediatr Adolesc Med. 2008; 162: 350-358Crossref PubMed Scopus (287) Google Scholar, 18Sitnick SL Goodlin-Jones BL Anders TF The use of actigraphy to study sleep disorders in preschoolers: some concerns about detection of nighttime awakenings.Sleep. 2008; 31: 395-401Crossref PubMed Scopus (138) Google Scholar, 19Hyde M O'Driscoll DM Binette S et al.Validation of actigraphy for determining sleep and wake in children with sleep disordered breathing.J Sleep Res. 2007; 16: 213-216Crossref PubMed Scopus (126) Google Scholar summarize 15 studies published since 2004 that compared wrist actigraphy to other established methods of assessing sleep. In total, 10 studies compared actigraphy to PSG in adults of various ages, and two compared actigraphy to videosomnography in infants. Three studies compared wrist actigraphy to daily sleep diaries. Taken together, these studies suggest that wrist actigraphy is useful in the estimation of total sleep time (TST), sleep percentage, and wake after sleep onset (WASO). Findings are less consistent, however, in terms of estimating sleep-onset latency (SOL), particularly among patients with sleep disorders. Studies of adults are shown in Table 1; studies of infants and children are shown in Table 2. Three additional studies with publication dates prior to 2004 are listed in the AASM practice parameters as providing level 1 evidence for the use of actigraphy.4Morgenthaler T Alessi C Friedman L Standards of Practice Committee; American Academy of Sleep Medicine et al.Practice parameters for the use of actigraphy in the assessment of sleep and sleep disorders: an update for 2007.Sleep. 2007; 30: 519-529Crossref PubMed Scopus (870) Google Scholar We have focused our discussion on the most recent studies, given the changes in devices and software that may decrease the relevance of older studies.Table 1Summary of Actigraphy Validation Studies in Adults (Published 2004–2010)Study/YearTotal Sample Size, No. (Mean Age, y)Study SubjectsComparison MethodologyDevice (Manufacturer)Software/ProtocolMain Findings/ConclusionsWang et al5Wang SY Chang HJ Lin CC Sleep disturbances among patients with non-small cell lung cancer in taiwan: congruence between sleep log and actigraphy.Cancer Nurs. 2010; 33: E11-E17Crossref PubMed Scopus (16) Google Scholar/201039 (61.5)Non-small cell lung cancer patientsActigraphy vs sleep diaryMicroMini (Ambulatory Monitoring, Inc)Action 3.8 (Ambulatory Monitoring, Inc)87% congruency between actigraphy and sleep diaries. Actigraphy showed significantly more nighttime awakenings.Sánchez-Ortuño et al6Sánchez-Ortuño MM Edinger JD Means MK Almirall D Home is where sleep is: an ecological approach to test the validity of actigraphy for the assessment of insomnia.J Clin Sleep Med. 2010; 6: 21-29Crossref PubMed Scopus (68) Google Scholar/201062 (28.4)Insomnia sufferers (n = 31); control subjects (n = 31)Actigraphy vs PSG vs sleep diaryMini-Mitter (Mini-Mitter Co)Not specifiedNo significant difference in WASO, TST, or SE for control subjects or insomnia patients. Stronger correlation between actigraphy and sleep diaries than PSG and sleep diaries for SOL.Natale et al7Natale V Plazzi G Martoni M Actigraphy in the assessment of insomnia: a quantitative approach.Sleep. 2009; 32: 767-771Crossref PubMed Scopus (130) Google Scholar/2009408 (40.4)Insomnia sufferers (n =126); control subjects (n = 282)Actigraphy in insomniacs vs control subjectsBasic Mini-Motionlogger (Ambulatory Monitoring, Inc)ACT Millennium (Ambulatory Monitoring, Inc)Actigraphy showed significant differences in SOL, TST, WASO, SE, and NA > 5 between insomnia sufferers and control subjects. TIB showed no significant difference.Chae et al8Chae KY Kripke DF Poceta JS et al.Evaluation of immobility time for sleep latency in actigraphy.Sleep Med. 2009; 10: 621-625Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar/200933 (54)20 subjects with OSA, 13 with ≥ 5 periodic limb movements/hActigraphy (with different sensitivity thresholds and protocols for defining SO) vs PSGActiwatch-L (Mini-Mitter-Respironics, Inc)Actiware 5.0 (Mini-Mitter-Respironics, Inc)5-min immobility protocol most accurate for identifying SO using actigraphy. SL was underestimated when PSG latencies were short and overestimated when PSG latencies were long.Blackwell et al9Blackwell T Redline S Ancoli-Israel S Study of Osteoporotic Fractures Research Group et al.Comparison of sleep parameters from actigraphy and polysomnography in older women: the SOF study.Sleep. 2008; 31: 283-291Crossref PubMed Scopus (199) Google Scholar/200868 women (81.9)Women age ≥ 65 y at risk for osteoporotic fractures (SOF study)Actigraphy (TAT, ZCM, and PIM modalities) vs PSGSleepwatch-O (Ambulatory Monitoring, Inc)Action W-2 using the Cole-Kripke algorithmActigraphy underestimated TST by 68 min for those sleeping ≤ 5 h and overestimated TST by 31 min for subjects with SE < 70%, as compared with PSG. Using the best modality (PIM), sleep parameters TST, WASO, and SE did not differ from PSG by more than 17.9, 6.8 min, and 3.8%, respectively. Lower agreement was found for TAT and ZCM.Paquet et al10Paquet J Kawinska A Carrier J Wake detection capacity of actigraphy during sleep.Sleep. 2007; 30: 1362-1369Crossref PubMed Scopus (263) Google Scholar/200715 (Not mentioned- adults)Healthy subjects (caffeine vs placebo) undergoing nighttime PSG or recovery sleep PSG after SDActigraphy (2 sensitivity modes) vs PSGActiwatch-L (Mini-Mitter-Respironics, Inc)Actiware 5 (Cambridge Neurotechnology)Significant overestimations of TST and SE in the setting of non-nighttime PSG, which had low SE. Specificity for sleep was 50% overall despite > 90% sensitivity.Bradshaw et al11Bradshaw DA Yanagi MA Pak ES Peery TS Ruff GA Nightly sleep duration in the 2-week period preceding multiple sleep latency testing.J Clin Sleep Med. 2007; 3: 613-619Crossref PubMed Scopus (37) Google Scholar/200754 (30.7)EDS patients referred for MSLT with PSGActigraphy vs PSG vs sleep diaryUnspecified model actigraphic watch (Precision Control Design)Action W, version 2.4.20 (Ambulatory Monitoring, Inc)The mean SL found in nights prior to MSLT using actigraphy was significantly correlated with PSG SL during MSLT. SL from sleep diaries significantly over-estimated SL and underestimated TST.García-Díaz et al12García-Díaz E Quintana-Gallego E Ruiz A et al.Respiratory polygraphy with actigraphy in the diagnosis of sleep apnea-hypopnea syndrome.Chest. 2007; 131: 725-732Abstract Full Text Full Text PDF PubMed Scopus (56) Google Scholar/200762 (Not mentioned- adult)Suspected OSARespiratory polygraphy device with actigraphy vs PSGApnoescreen II (Eric Jaeger GmbH & Co)Not specifiedAddition of actigraphy to home-based OSA diagnostic device modestly improved sensitivity for patients with RDI ≥30, but there was no change in patients with RDI of 15–30. Actigraphy overestimated TST and SE.Sivertsen et al13Sivertsen B Omvik S Havik OE et al.A comparison of actigraphy and polysomnography in older adults treated for chronic primary insomnia.Sleep. 2006; 29: 1353-1358Crossref PubMed Scopus (150) Google Scholar/200634 (60.5)Chronic primary insomniaActigraphy vs PSGActiwatch Plus (Cambridge Neurotechnology)Actiwatch Sleep Analysis 2001, version 1.19 (Cambridge Neurotechnology)Actigraphy had a sensitivity for detecting sleep of 95.2% but a specificity of only 36.3% for detecting wakefulness, for an accuracy of 83.1%. Actigraphy underestimated total wake time and SOL and overestimated TST and SE.Lichstein et al14Lichstein KL Stone KC Donaldson J et al.Actigraphy validation with insomnia.Sleep. 2006; 29: 232-239PubMed Google Scholar/200657 (Not mentioned-adult)Primary and comorbid insomniaActigraphy vs PSG vs sleep diaryActiwatch AW64 (Mini-Mitter Co)Actiware Sleep 3.3 (Mini-Mitter Co)WASO, TST, and SE were not significantly different among PSG, actigraphy, and sleep diaries. Actigraphy and PSG were not significantly different in SOL and NA. Sleep diaries correlated with PSG in these measures but did not correlate significantly.Hedner et al15Hedner J Pillar G Pittman SD Zou D Grote L White DP A novel adaptive wrist actigraphy algorithm for sleep-wake assessment in sleep apnea patients.Sleep. 2004; 27: 1560-1566Crossref PubMed Scopus (158) Google Scholar/2004228 (48.8)Suspected OSAActigraphy vs PSGWatch_PAT100 System (Itamar Medical) with built-in actigraph (Ambulatory Monitoring, Inc)ASWA in the zzzPAT package (Itamar Medical)SE, TST, and SL between PSG and actigraphy were not different among patients with mild, moderate, or severe OSA. Actigraphy overestimated SL, especially among those with mild OSA.EDS = excessive daytime somnolence; MSLT = multiple sleep latency test; NA = number of awakenings; OSA = obstructive sleep apnea; PIM = proportional integration mode; PSG = polysomnography; RDI = espiratory disturbance index; SD = sleep deprivation; SE = sleep efficiency; SL = sleep latency; SO = sleep onset; SOF = study of osteoporotic fractures; SOL = sleep-onset latency; TAT = time above threshold; TIB = time in bed; TST = total sleep time; WASO = wake after sleep onset; ZCM = zero crossing mode. Open table in a new tab Table 2Summary of Actigraphy Validation Studies in Infants and Children (Published 2004–2010)Study/YearTotal Sample Size, No. (Mean Age)Study SubjectsComparison MethodologyDevice (Manufacturer)Software/ProtocolMain Findings/ConclusionsSung et al16Sung M Adamson TM Horne RS Validation of actigraphy for determining sleep and wake in preterm infants.Acta Paediatr. 2009; 98: 52-57Crossref PubMed Scopus (42) Google Scholar/200910 with 38 overnight studies total (31.2 wk)Baseline studies across gestational agesActigraphy (with different sensitivity thresholds) vs video somnographyActiwatch AW64 (Mini-Mitter Co)Actiware Sleep 3.3 (Mini-Mitter Co)The predictive value of sleep using actigraphy ranged from 91.3% to 96.5% across threshold settings with a sensitivity of 88.2% to 96.8% vs video analysis. Device was not reliable for predicting wakefulness.Werner et al17Werner H Molinari L Guyer C Jenni OG Agreement rates between actigraphy, diary, and questionnaire for children's sleep patterns.Arch Pediatr Adolesc Med. 2008; 162: 350-358Crossref PubMed Scopus (287) Google Scholar/200850 (5.9 y)Baseline studyActigraphy vs sleep diaryActiwatch Plus AW4 (Cambridge Neurotechnology)Actiware 5 (Cambridge Neurotechnology)Satisfactory agreement between actigraphy and sleep diary for sleep start, end, and assumed sleep. Insufficient agreement between actual sleep time and nocturnal awake time.Sitnick et al18Sitnick SL Goodlin-Jones BL Anders TF The use of actigraphy to study sleep disorders in preschoolers: some concerns about detection of nighttime awakenings.Sleep. 2008; 31: 395-401Crossref PubMed Scopus (138) Google Scholar/200858 (47 mo)22 subjects with autism, 11 subjects with nonspecific developmental delays, and 25 control subjectsActigraphy vs video somnographyActiwatch AW64 (Mini-Mitter Co)Unspecified Mini-Mitter softwareIn an epoch-by-epoch analysis, there was 94% agreement, 97% sensitivity, and 24% specificity for sleep compared with video somnography. Sleep-onset time, SOL, sleep end time, TST, number of awakenings, and total sleep duration and number of nocturnal awakenings correlated significantly.Hyde et al19Hyde M O'Driscoll DM Binette S et al.Validation of actigraphy for determining sleep and wake in children with sleep disordered breathing.J Sleep Res. 2007; 16: 213-216Crossref PubMed Scopus (126) Google Scholar/200745 (5.8 y)Healthy children (age 1–12 y)Actigraphy vs PSGActiwatch AW64 (Mini-Mitter Co)Actiware Sleep 3.3 (Mini-Mitter Co)With epoch-by-epoch comparison, agreement rates were high (85.1%–88.6%). Predictive value for sleep (91.6%–94.9%) and sensitivity for sleep (90.1%–97.7%) were high. Predictive value for wake (46.7%–65.6%) and specificity (39.4%–68.9%) were low. No effect of age, AHI, or PSG arousal index.AHI = apnea-hypopnea index. See Table 1 legend for expansion of other abbreviations. Open table in a new tab EDS = excessive daytime somnolence; MSLT = multiple sleep latency test; NA = number of awakenings; OSA = obstructive sleep apnea; PIM = proportional integration mode; PSG = polysomnography; RDI = espiratory disturbance index; SD = sleep deprivation; SE = sleep efficiency; SL = sleep latency; SO = sleep onset; SOF = study of osteoporotic fractures; SOL = sleep-onset latency; TAT = time above threshold; TIB = time in bed; TST = total sleep time; WASO = wake after sleep onset; ZCM = zero crossing mode. AHI = apnea-hypopnea index. See Table 1 legend for expansion of other abbreviations. When a patient presents with a sleep complaint, clinicians typically begin with a detailed clinical interview. At times, this interview is sufficient to diagnose a sleep disorder, whereas at other times additional assessments are needed. When making the decision regarding which assessments are most appropriate, one must consider the process of differential diagnosis, patient burden, cost, and the importance of understanding sleep in the natural sleep environment vs documenting the characteristics of sleep architecture. Table 3 outlines several considerations one might reflect on in determining the appropriate assessment method(s) to employ.Table 3Main Advantages and Disadvantages of Actigraphy vs Other Sleep Assessment MethodsSleep Assessment MethodMain AdvantagesMain DisadvantagesSleep questionnairesBrief, easily administered in conjunction with clinical interviewLow patient burdenSubject to recall biasesLimited usefulness in patients who are unable to self-report reliably (eg, young children, dementia patients)Limited validity compared with PSGSleep diaryProvides documentation of daily variabilityPatient burden higher than questionnaires; requires patient to complete diary each day for maximum validityDocuments habits in the home sleep environmentInfluenced by patient's expectations about sleepLess recall bias than questionnaires because information is recorded dailyActigraphyProvides objective information about daily variability and sleep qualityLimited usefulness in assessment of SOLRecords information in the home sleep environmentHigher cost than sleep diariesNot influenced by patient expectations, recall bias, or memory impairmentsPatients should complete sleep diaries concurrently to enhance quality of informationLower cost than PSGLaboratory PSG“Gold standard” objective assessment of sleepHigh participant burdenHigh costDoes not provide information on sleep habits at homeCan lead to a “first night effect” phenomenonSee Table 1 legend for expansion of abbreviations. Open table in a new tab See Table 1 legend for expansion of abbreviations. Sleep diaries represent an important clinical tool and are often used in the behavioral treatment of sleep disorders such as insomnia.20Chesson Jr, AL Anderson WM Littner M Standards of Practice Committee of the American Academy of Sleep Medicine et al.Practice parameters for the nonpharmacologic treatment of chronic insomnia. An American Academy of Sleep Medicine report.Sleep. 1999; 22: 1128-1133Crossref PubMed Scopus (228) Google Scholar Despite their wide-spread use, sleep diaries have some limitations. Self-documentation of sleep frequency and duration can be prone to systematic biases that have clinical implications. For example, when documenting adherence to a sleep schedule using a sleep diary, Carney et al21Carney CE Lajos LE Waters WF Wrist actigraph versus self-report in normal sleepers: sleep schedule adherence and self-report validity.Behav Sleep Med. 2004; 2: 134-143Crossref PubMed Scopus (35) Google Scholar reported that bedtime was a full hour earlier than the bedtime reflected in the actigraphy data. Other research has shown significant differences in self-reported documentation of nap frequency, nap duration, nighttime awakenings, and sleep latency (SL) compared with actigraphy.22Lockley SW Skene DJ Arendt J Comparison between subjective and actigraphic measurement of sleep and sleep rhythms.J Sleep Res. 1999; 8: 175-183Crossref PubMed Scopus (501) Google Scholar Parents of pediatric patients have reported TSTs that are significantly greater (by an average of 1-2 h) than those reflected in actigraphy recordings of their child.17Werner H Molinari L Guyer C Jenni OG Agreement rates between actigraphy, diary, and questionnaire for children's sleep patterns.Arch Pediatr Adolesc Med. 2008; 162: 350-358Crossref PubMed Scopus (287) Google Scholar, 23So K Adamson TM Horne RS The use of actigraphy for assessment of the development of sleep/wake patterns in infants during the first 12 months of life.J Sleep Res. 2007; 16: 181-187Crossref PubMed Scopus (111) Google Scholar Self-reported sleep duration in sleep diaries also seems to overestimate time asleep in both young adults24Lauderdale DS Knutson KL Yan LL Liu K Rathouz PJ Self-reported and measured sleep duration: how similar are they?.Epidemiology. 2008; 19: 838-845Crossref PubMed Scopus (1104) Google Scholar and elderly subjects who lack sleep complaints,25Van Den Berg JF Van Rooij FJ Vos H et al.Disagreement between subjective and actigraphic measures of sleep duration in a population-based study of elderly persons.J Sleep Res. 2008; 17: 295-302Crossref PubMed Scopus (300) Google Scholar compared with actigraphy. Although these studies do not imply that sleep diaries are not clinically useful, they do suggest that actigraphy may be useful when patient documentation of sleep habits does not align with other aspects of the clinical presentation. As with any home-based monitoring, the patient must be provided with detailed instructions about the device and information on technical support should problems arise. Typically, the duration of recording should be 1 week; however, depending on the specific diagnostic question, recordings of longer or shorter duration are sometimes indicated. The patient should be informed that the device records movement (and light, if relevant) and should be provided with instructions for the removal of the device if it is not fully waterproof. The patient must then return the device so the data recorded can be uploaded onto a computer for scoring and analysis. The scoring of actigraphy should follow an established protocol. Although there is no consensus in the field on the precise protocol, in general, specific rules should be in place for the review of recordings for artifacts, for determining the major sleep period (typically from “bedtime” to “rise time”), and for the information to be gleaned from the report. As described previously, clinicians can have confidence in measures of TST, sleep percentage, and amount of time awake at night. Other variables, such as daytime napping and SOL, should be interpreted more cautiously. Often, review of the recording in its entirety can be informative; however, to view night-to-night patterns, a “double plot” can be useful (as in Fig 1). In these plots, each day is repeated adjacent to and below the previous day. This “lines up” the nights of data and can be particularly useful in depicting circadian rhythm sleep disorders. The use of a concurrent sleep diary during actigraphy recording provides multiple additional benefits: The diary can contribute backup sleep/wake data in the event of actigraph malfunction or noncompliance with its use. The diary can help differentiate awake but relatively motionless periods from true sleep when interpreting the actigraph data and, thus, can potentially improve the accuracy of sleep-onset identification. The diary provides a place where a patient can document his/her reasons for napping, arousals, uncharacteristic behavior, and so forth, which would assist the clinician in finding an underlying cause of the disorder. The exact information gathered depends, in part, on the device used and the differential diagnostic considerations. For example, some devices may have an “event marker” that patients can press when getting in and out of bed. A diary may, therefore, be needed only to document unusual activities during the day that might impact the recording (eg, device removal for sports, travel across time zones). At a minimum, the patient is typically asked to document the times he/she got into bed for the night and the time he/she last arose in the morning. A sample sleep diary is shown in Figure 2. Another strategy to enhance the quality of information from actigraphy is the inclusion of a light sensor on the actigraphy device. This can be particularly us
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