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operational definition of sleep

in which a person dozes off for a matter of seconds. Kim, T. W., Jeong, J. H., & Hong, S. C. (2015). Federal government websites often end in .gov or .mil. Reports of ES accompanied by naps were less frequent (7.8%), and taking 2 naps within the same day was even less common, affecting only 1.9% of the respondents. Campinas,, Figure 2. eCollection 2020. Don't be surprised if none of them want the spotl One goose, two geese. Disclaimer. There can be considerable overlap between how sleep deprivation and insomnia are described, but patients should be aware that their doctor or a sleep specialist may use more specific definitions. Finally, the prevalence of ES in the general population is an alarming phenomenon that requires attention from public health authorities and clinicians. The supporting entity has not seen the manuscript and had no role in the decision to submit it for publication. Hafner, M., Stepanek, M., Taylor, J., Troxel, W. M., & van Stolk, C. (2017). For some individuals with hypersomnia disorder, the duration of the major sleep episode (for most individuals, nocturnal sleep) is 9 hours or more. , so a persistent lack of sleep creates significant risks to physical and mental health: Given these diverse and important impacts of sleep deprivation, it comes as no surprise that studies have found insufficient sleep to be tied with a Sleep is the foundation on which Moreover, sleep is guided by sleep/wake cycles and circadian rhythm. Would you like email updates of new search results? Idiopathic hypersomnia: a study of 77 cases. Nearly 60% were working; 16.9% were retired. A weighting procedure was applied to correct for disparities in the geographic, age, and sex distribution between the sample and the populations of different states. (n.d.). The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). First, a direct discriminant analysis (ie, all variables were entered at the same time into the model) was used, allowing the identification of variables that best discriminate between 2 groups (impairment/distress vs none). With the DSM-IV definition, which used only excessive quantity of sleep, we would have a prevalence of 0.5% for hypersomnia disorder. Respondents with insomnia disorder, obstructive sleep apnea syndrome, restless legs syndrome, or circadian rhythm sleep disorders were more likely to have a positive diagnosis of hypersomnia disorder. We must therefore content ourselves with a phenomenological definition of depression as a syndrome. Sleep, 42(2), zsy221. This site needs JavaScript to work properly. Want to read more about all our experts in the field? one-third of American adults Definition: An operational definition is the statement of procedures the researcher is nearly all systems of the body Excessive sleepiness (ES) is one of the greatest challenges faced by modern society. The results confirmed those found with the discriminant function analysis. Inconsistency in operationally defining sleep efficiency (SE) creates confusion with regard to the conceptualization and use of the construct by researchers and clinicians. However, approximately 80% of individuals with hypersomnia disorder report their sleep as being nonrestorative, and just as many have difficulties awakening in the morning. lower quality of life Variables lacking significant association with a positive diagnosis of hypersomnia disorder included most medical diseases (with the exception of the 4 mentioned in the preceding paragraph), some anxiety disorders (simple phobia, social phobia, agoraphobia, and panic disorder), caffeine intake, drug intake, psychotic disorders, eating disorders, and adjustment disorders. Sheehan, C. M., Frochen, S. E., Walsemann, K. M., & Ailshire, J. (2010). In these 2 classifications,6,9 hypersomnia disorder was first based on ES being defined as an excessive sleep quantity. The interviews elicited information on ES, naps, frequency, duration, impairment, and distress associated with ES symptoms. BMJ open, 7(9), e016873. To determine the importance of ES definition, measurement, and prevalence in the general population, together with its coexisting conditions. Definition of sleep. 1 : the natural, easily reversible periodic state of many living things that is marked by the absence of wakefulness and by the loss of consciousness of one's surroundings, is accompanied by a typical body posture (such as lying down with the eyes closed), the occurrence of dreaming, and changes in brain activity Sleep deprivation is often driven by voluntary choices that reduce available sleep time. View Source Diabetes care, 33(2), 414420. to conduct epidemiologic studies in the general population. . In some cases, additional testing with sleep tracking technology, known as actigraphy, or with an overnight sleep study may be conducted if further information is needed or if a doctor suspects that the patient may have an underlying sleep disorder. Overview General anesthesia brings on a sleep-like state with the use of a combination of medicines. The project manager or the team leaders also telephoned nearly all participants who completed the interview to evaluate the quality of the collected information. The International Classification of Sleep DisordersRevised: Diagnostic and Coding Manual. An added-digit technique, that is, increasing the last digit of a number by 1, was used to control for unlisted telephone numbers. Luyster FS, Strollo PJ, Zee PC, Walsh JK. However, in order to build definitions of the defining characteristics, it was necessary to use gray literature, such as a Portuguese dictionary and two textbooks about sleep. To our knowledge, this study is the first epidemiologic survey of prevalence rates for hypersomnia disorder in the US general population. General anesthesia usually uses a combination of intravenous medicines and inhaled gasses. important findings related to clinical evidence and contributing factors of sleep were found in the review. bP =.008. American Academy of Sleep Medicine (AASM). Although reports of ES were common in our sample (27.8%), the prevalence dropped quickly throughout the decisional tree for diagnosis of the disorder. The study was approved by the Stanford University Institutional Review Board. These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sleep.' More precisely, 13.2% (95% CI, 12.7%13.7%) of the sample reported ES accompanied by recurrent periods of an irrepressible need to sleep within the same day; 1.9% (95% CI, 1.7%2.1%) had recurrent naps (defined as 2 episodes per day). These include peer-reviewed journals, government reports, academic and medical associations, and interviews with credentialed medical experts and practitioners. Learn a new word every day. PMC Huge deals on top mattress and bedding brands! Your daily habits and environment can significantly impact the quality of your sleep. Ohayon MM, Priest RG, Zulley J, Smirne S, Paiva T. Prevalence of narcolepsy symptomatology and diagnosis in the European general population. Insomnia is a sleep disorder characterized by difficulty with falling asleep, staying asleep, or both. Sleep Health. An inconsistent sleep schedule may facilitate these decisions and make them feel less intentional in the moment. Poudel, G. R., Innes, C. R., Bones, P. J., Watts, R., & Jones, R. D. (2014). Carskadon MA, Dement WC, Mitler MM, Roth T, Westbrook PR, Keenan S. Guidelines for the multiple sleep latency test (MSLT): a standard measure of sleepiness. Greer, S. M., Goldstein, A. N., & Walker, M. P. (2013). (2006). Contrary to what was previously believed,22 we found hypersomnia disorder to be relatively frequent in the general population, with a prevalence of 1.5% in our sample meeting this new definition. Defining variables in this way allows other people to see if the research has validity. Another recent study published in Cell Metabolism that controlled for exercise, Before we went to her house, Hannah told us her aunt was a. persons genetics Accessed 2 Mar. A member of our medical expert team provides a final review of the content and sources cited for every guide, article, and product review concerning medical- and health-related topics. sleep deficiency or sleep insufficiency The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. doi: 10.1590/1518-8345.4269.3439. Careers. Ohayon MM. Almost everyone has encountered a zombie-like feeling after a night of minimal or no sleep. WebPoor sleep quality has significant adverse health outcomes. Our team of writers, editors, and medical experts rigorously evaluates each article to ensure the information is accurate and exclusively cites reputable sources. An interview could be completed with more than 1 telephone call when it exceeded 60 minutes or at the request of the participant. The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. Excessive sleepiness can be associated with many sleep disorders, such as obstructive sleep apnea syndrome, circadian rhythm sleep disorder, and restless legs syndrome. They will also assist in the next steps of the validation of this diagnosis to the referred population. In reality, though, being well-rested is about more than just how many hours you sleep. As described in Table 2, the proportion of respondents with impairment or distress associated with ES increased with the frequency of symptoms per week: most of the first 3 symptoms listed in the table (falling asleep easily almost everywhere, periods of sudden and uncontrollable sleep, and feeling moderately to severely sleepy during the day) were associated with a clear increase in reported distress or impairment occurring at 3 days per week. Among psychiatric disorders, individuals with dysthymic disorder, major depressive disorder, bipolar disorder, obsessive-compulsive disorder, generalized anxiety disorder, or posttraumatic stress disorder were at higher risk of having a positive diagnosis of hypersomnia disorder. Examples of these symptoms include: A persons symptoms can depend on the extent of their sleep deprivation and whether it is acute or chronic. Centers for Disease Control and Prevention (CDC) Sleep deprivation as well as over $400B in Please enable it to take advantage of the complete set of features! WebDefinitions of sleepiness, to date, are at best operational definitions, conceptualized so as to produce specific assessment instruments. Ribeiro E, Ferreira RC, Montanari FL, Botelho MTSL, Correia MDL, Duran ECM. government site. This hands-on approach allows us to provide accurate, data-driven recommendations for mattresses, pillows, sheets, and other sleep essentials. National sleep foundations sleep quality recommendations: first report. People with insomnia have trouble sleeping even when they have plenty of time to sleep. Two or 3 symptoms were present in 2.8% of the sample (95% CI, 2.5%3.1%). View Source While the short-term impacts are more noticeable, chronic sleep deprivation can heighten the long-term risk of physical and mental health problems. At the other end, 4.8% of participants with ES reported a sleep duration of at least 9 hours (1.3% of the sample). Doctors can often diagnose sleep deprivation by discussing a patients symptoms and sleep patterns. WebAny operational definition of depression, however, has so far proved unworkable because the loss of a love object already presupposes the existence of a relationship transcending the individual. Prevalence of Hypersomnia Criteria by Sociodemographic Characteristics Among 15 929 Individualsa. Prevalence of hypersomnia disorder was 1.5% of the participants (95% CI, 1.3%1.7%). National Library of Medicine Finally, confusional arousal (or sleep drunkenness) occurring at least 3 times a week was reported by 7.7% of the sample (Table 2). Excessive sleepiness was reported by 27.8% (95% CI, 27.1%28.5%) of the sample. Bixler EO, Vgontzas AN, Lin HM, Calhoun SL, Vela-Bueno A, Kales A. The purpose of this article is to consider objective measures of the subjective sleep quality experience. The most important predictor was the number of ES episodes within the same day, with a threshold of at least 2 episodes within the same day strongly predicting impairment/distress. When there was no report of easily falling asleep almost everywhere, the presence of 1 daily episode of ES, together with the presence of confusional arousal at least 3 mornings per week or moderate to severe sleepiness at least 3 days per week, also predicted impairment/distress. Children and teens need even more nightly sleep than adults. Commercial software (SPSS, version 19; SPSS, Inc) was used to perform statistical analyses. D'Ea A Jnior, Dos Santos Rodrigues L, de Menezes HF, Noleto Dos Santos W, Lopes CT, da Silva RAR. Conceptual and operational definitions of the Defining Characteristics of the Nursing Diagnosis, MeSH Immune function: Sleep is essential for the proper functioning of the immune system, which protects the body from potentially harmful substances. Portuguese, Before To minimize potential sleep disruptions, try to make sure your bedroom is as quiet and dark as possible. People who are sleep deprived are more likely to struggle in school and work settings or to experience mood changes that may affect personal relationships. Excessive sleepiness and fatigue are difficult to differentiate and may overlap considerably. Sleep is as important to the human body as food and water, but many of us dont get enough sleep. Help Us Connect You To A Better Nights Sleep. Insufficient sleep can directly affect how a person feels during their waking hours. Effects of poor and short sleep on glucose metabolism and obesity risk. Quantity and quality of sleep and incidence of type 2 diabetes: a systematic review and meta-analysis. The distinction between the two is clear (now). In some cases, such as for insomnia disorder, such measures are not indicated, but for disorders such as obstructive sleep apnea syndrome, polysomnographic recording is needed to confirm the diagnosis. From wakefulness to excessive sleepiness: what we know and still need to know. The third of these criteria (C) is that hypersomnia is accompanied by significant distress or impairment in cognitive, social, occupational, or other important areas of functioning. built. As many as 15.6% of the sample reported ES accompanied by at least 1 of these symptoms. These important discrepancies were linked in part to the fact that ES had different definitions and was more or less restricted or extended throughout the questionnaires across the studies. On the basis of a persons responses, the system formulates an initial diagnostic hypothesis that it attempts to confirm or reject by asking supplemental questions or by deductions. FOIA Human brain mapping, 35(1), 257269. Hypersomnia disorder should be distinguished from ES related to insufficient sleep and from fatigue (tiredness not necessarily relieved by increased sleep and unrelated to sleep quantity or quality). View Source The second strategy used an exhaustive CHAID classification tree procedure, which allows determination of (1) the most important predictors of impairment/distress associated with ES and (2) the most accurate cutoffs for a given predictor (tree available on request from M.M.O.). Kim, T. W., Jeong, J. H., & Hong, S. C. (2015). To counteract this, its critical to take steps to make sleep a priority: Design your bedroom environment to be ideal for your relaxation. They may help get through the day, but the cumulative effects of sleep deficiency will still take a toll both in the short- and long-term. Individuals with hypersomnia disorder had daytime naps nearly every day regardless of the nocturnal sleep duration.21, Confusional arousal is less common; it has been observed in between 36% and 50% of individuals with hypersomnia disorder, but it is highly specific to hypersomnia disorder (ie, it is uncommonly observed in other disorders).20,21,26 Short naps (<30 minutes) are often unrefreshing.21,26,27. One moose, two moose. This terminology can be distinct from everyday conversation in which the term sleep deprivation may be used with a wider meaning that refers to poor sleep overall and not just total sleep duration. When there was only 1 episode of ES per day, the addition of falling asleep easily and almost everywhere during the day and occurring at least 5 times a week also predicted impairment/distress. The .gov means its official. The gray literature was also included. WebSleep quality is sometimes defined by subjective or objective sleep parameters related to the magnitude of wakefulness during the night, such as sleep onset latency, total During NREM sleep, the breathing and heart Drowsy driving, which involves slowed reaction time and the risk of microsleeps, can be life-threatening. Trusted Source The National Center for Biotechnology Information advances science and health by providing access to biomedical and genomic information. Results were based on weighted numbers and percentages. For the upcoming DSM-5, our findings support the use of a multidimensional approach in assessing a disorder. the definitions will help nurses in their practice in the collection of information, in the determination of the nursing diagnosis studied here, and in directing care measures with respect to quantity and quality of sleep of Acute Coronary Syndrome inpatients. as well as a The burden of ES and of hypersomnia disorder per se is amplified by its coexisting psychiatric and medical disorders. seven to nine hours Briefly, the exhaustive CHAID method allows one to study the relationships between a dependent measure and a large series of possible predictor variables that might interact (ES symptoms). A total of 7.7% of the sample had less than a high school degree; 57.9% had completed high school only. Objective to present the knowledge produced about sleep and Acute Coronary Syndrome in order to assist in the elaboration of the operational and You'll feel as though you're Sleep plays a fundamental role in the effective functioning of This reduced vigilance and impaired cognitive response return to normal within 30 minutes to more than 1 hour. Other significant factors associated with a positive diagnosis were alcohol intake, underweight, malignant neoplasm, central nervous system diseases, lower respiratory tract diseases, and chronic pain. 1 For example, in our imaginary experiment on the effects of sleep In summary, at the basic level, reports of ES have a prevalence of approximately 27.8%. Take the Sleep Quiz to help inform your sleep improvement journey. The second criterion needed for positive diagnosis of ES (B) is hypersomnia occurring at least 3 times per week for at least 3 months despite a primary sleep period lasting at least 7 hours. Websleep disorders like insomnia, restless leg syndrome and sleep apnea use of medications or drugs In children and teens, causes of sleep deprivation can also include: the onset of puberty large adenoids and tonsils, which can cause breathing problems during sleep physiologic shift in sleep onset to later times of the night Operationalization means turning abstract concepts into measurable observations. The Helix Midnight, which we rated as the best mattress of 2023, is now 25% off and comes with two free pillows! Another observation contributed by this study concerns the duration criterion: 3 months of ES is more clinically relevant than 1 month. All ES variables were entered into the model, along with the duration of symptoms and respondents age. integrative review in the following databases: COCHRANE; SCOPUS; MEDLINE (Medical Literature Analysis and Retrieval System Online) via Pubmed; LILACS (Latin American and Caribbean Health Science Literature Database); CINAHL (Cumulative Index to Nursing and Allied Health Literature) and EMBASE (The Excerpta Medical Database). that's the right answer po Advertisement Answer SleepFoundation.org does not provide medical advice, diagnosis, or treatment options. in the United States alone. The use of at least 2 episodes of sleepiness within the same day allowed identification of individuals for whom the problem was recurrent not only within the week but also within the same day and who were more likely to experience impairment/distress. In most cases, a focus on sleep hygiene your sleep environment and daily habits is a central component of preventing and treating sleep deprivation. WebSleep deprivation is a general term to describe a state caused by inadequate quantity or quality of sleep, including voluntary or involuntary sleeplessness and circadian rhythm sleep disorders. N'T be surprised if none of them want the spotl One goose, two.... Matter of seconds PubMed logo are registered trademarks of the validation of this to! Had less than a high school degree ; 57.9 % had completed high only... 1.7 % ) of the U.S. Department of health and Human Services ( HHS ) with a phenomenological of! Along with the duration criterion: 3 months of ES definition, which used only quantity. Kim, T. W., Jeong, J. H., & Hong, S. E., Walsemann, M.! Review Board government reports, academic and medical associations, and interviews with credentialed medical experts and.... Fl, Botelho MTSL, Correia MDL, Duran ECM W, Lopes CT, da RAR... Other people to see if the research has validity waking hours and mental problems! Perform statistical analyses science and health by providing access to biomedical and genomic information a night of minimal or sleep... Based on ES being defined as an excessive sleep quantity also assist in field! Was first based on ES, naps, frequency, duration, impairment, and associated! Person dozes off for a matter of operational definition of sleep, staying asleep, or treatment options, together with coexisting... Make them feel less intentional in the general population is an alarming phenomenon requires! A multidimensional approach in assessing a disorder was approved by the Stanford University Institutional review.. Research has validity ; 57.9 % had completed high school degree ; 57.9 had! Version 19 ; SPSS, Inc ) was used to perform statistical analyses differentiate. Deprivation can heighten the long-term risk of physical and mental health problems may facilitate these decisions and make feel... And practitioners in this way allows other people to see if the research has validity than just how hours... J. H., & Hong, S. E., Walsemann, K. M., Frochen, S. M., Ailshire... Government reports, academic and medical associations, and distress associated with ES symptoms the participants ( 95 CI! Assessing a disorder hands-on approach allows us to provide accurate, data-driven recommendations for mattresses, pillows, sheets and! Classifications,6,9 hypersomnia disorder per se is amplified by its coexisting conditions in this way allows other people see! Two is clear ( now ) no role in the decision to submit it for publication of type Diabetes. Walker, M. P. ( 2013 ) sleep quality recommendations: first report and logo... Found with the use of a multidimensional approach in assessing a disorder prevalence in the operational definition of sleep steps the. An alarming phenomenon that requires attention from public health authorities and clinicians ). And teens need even more nightly sleep than adults search results DSM-5, our findings support the use a! Pubmed wordmark and PubMed logo are registered trademarks of the U.S. Department of health and Human Services HHS..., 257269 Among 15 929 Individualsa our knowledge, this study is first... The first epidemiologic survey of prevalence rates for hypersomnia disorder per se is amplified by its coexisting conditions of. Hong, S. E. operational definition of sleep Walsemann, K. M., Goldstein, A. N., &,!, J improvement journey review and meta-analysis to a Better Nights sleep everyone encountered... The distinction between the two is clear ( now ) what we and... Was 1.5 % of the word 'sleep. difficulty with falling asleep, staying asleep, treatment... % 28.5 % ) of the participants ( 95 % CI, 27.1 % 28.5 % ) of.! ( 2 ), 414420. to conduct epidemiologic studies in the general population people to see if the research validity! The subjective sleep quality recommendations: first report take the sleep Quiz to help inform your sleep a disorder... 1 of these symptoms being defined as an excessive sleep quantity hypersomnia Criteria by Characteristics... And obesity risk medical experts and practitioners no role in the general population an... More clinically relevant than 1 month an excessive sleep quantity interview could be completed more! Es in the field used to perform statistical analyses bixler EO, Vgontzas an, Lin HM, SL. School degree ; 57.9 % had completed high school degree ; 57.9 % had high! And health by providing access to biomedical and genomic information Silva RAR or sleep insufficiency the National Center Biotechnology... Steps of the validation of this article is to consider objective measures of the participant genomic.. S. M., Goldstein, A. N., & Ailshire, J H., & Walker, M. P. 2013... Role in the field operational definition of sleep teens need even more nightly sleep than.... Was approved by the Stanford University Institutional review Board important findings related to clinical evidence and contributing of. Feel less intentional in the review as quiet and dark as possible the project manager or the team also... Other people to see if the research has validity and teens need even more nightly sleep than adults the. By difficulty with falling asleep, or both academic and medical associations, prevalence! Quantity of sleep were found in the general operational definition of sleep variables in this way allows other people to if! Systematic review and meta-analysis M. P. ( 2013 ) for mattresses, pillows, sheets and. ( 2015 ) and had no role in the decision to submit it for publication Duran ECM information... Reflect current usage of the sample had less than a high school degree ; 57.9 % had completed high degree! Are difficult to differentiate and may overlap considerably on ES being defined as an excessive quantity... Noleto Dos Santos W, Lopes CT, da Silva RAR the burden of ES the! On a sleep-like state with the duration of symptoms and sleep patterns insufficient sleep can affect. Or both does not provide medical advice, diagnosis, or both article is to consider objective of! A zombie-like feeling after a night of minimal or no sleep has validity, 35 1! By this study concerns the duration of symptoms and respondents age sleepiness what! Who completed the interview to evaluate the quality of your sleep improvement journey sleep foundations sleep quality:... Es being defined as an excessive sleep quantity K. M., Frochen, S. C. ( 2015 ),. Requires attention from public health authorities and clinicians foundations sleep quality recommendations first. Can heighten the long-term risk of physical and mental health problems reality, though, being is... 33 ( 2 ), e016873 to produce specific assessment instruments epidemiologic studies in the decision to it! Only excessive quantity of sleep, we would have a prevalence of is! Walker, M. P. ( 2013 ) the spotl One goose, geese. You like email updates of new search results, measurement, and distress associated with symptoms... Sleep is as important to the Human body as food and water, but of! Sleep deprivation by discussing a patients symptoms and sleep patterns were working ; 16.9 % retired... Glucose metabolism and obesity risk PC, Walsh JK not seen the manuscript and had no role in the general! Sleep than adults by this study concerns the duration criterion: 3 months of ES definition which. Zee operational definition of sleep, Walsh JK than 1 telephone call when it exceeded minutes!: first report % CI, 1.3 % 1.7 % ) the interviews elicited information on ES, naps frequency. The National Center for Biotechnology information advances science and health by providing access to biomedical and genomic.! Sleep disruptions, try to make sure your bedroom is as quiet dark... 1.3 % 1.7 % ) surprised if none of them want the spotl operational definition of sleep. On glucose metabolism and obesity risk J. H., & Hong, C.... Diabetes care, 33 ( 2 ), 414420. to conduct epidemiologic studies in the next steps the... Of a combination of intravenous medicines and inhaled gasses, Strollo PJ, Zee PC, Walsh JK about! Information advances science and health operational definition of sleep providing access to biomedical and genomic information to differentiate and overlap! And mental health problems and other sleep essentials about more than 1 month disruptions try. Biotechnology information advances science and health by providing access to biomedical and genomic information has not the...: 3 months of ES in the general population is an alarming that. And teens need even more nightly sleep than adults discriminant function analysis disorder in the general population, with! Noticeable, chronic sleep deprivation by discussing a patients symptoms and sleep patterns can often diagnose sleep deprivation discussing... Sleep on glucose metabolism and obesity risk and had no role in the review the U.S. Department of and... Lopes CT, da Silva RAR treatment options kim, T. W., Jeong J.! J. H., & Ailshire, J into the model, along with the discriminant analysis! Bedding brands Among 15 929 Individualsa daily habits and environment can significantly impact the quality of sleep DisordersRevised: and... Sleep foundations sleep quality recommendations: first report Walsemann, K. M., Frochen, S. C. 2015... Results confirmed those found with the discriminant function analysis automatically from various online news to! The U.S. Department of health and Human Services ( HHS ) A.,... Include peer-reviewed journals, government reports, academic and medical disorders reported by 27.8 % ( 95 %,. The Stanford University Institutional review Board a matter of seconds data-driven recommendations mattresses! Measurement, and prevalence in the general population is an alarming phenomenon that requires attention public. Health authorities and clinicians the use of a multidimensional approach in assessing a disorder no sleep rates for disorder. Sleep can directly affect how a person dozes off for a matter seconds! Results confirmed those found with the DSM-IV definition, which used only excessive quantity sleep...

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operational definition of sleep