Nature and Science of Sleep最新文献

{"title":"Night-to-Night Sleep Variability Modulates Subjective Sleep Perception in Chronic Insomnia: A Multilevel Analysis.","authors":"Xiaoyu Xiao, Shuo Liu, Wenjing Jiang, Zhuqing Xu, Fanzun Meng, Fangchun Huang, Xiaochan Bi, Zixiang Guo, Yuqi Li","doi":"10.2147/NSS.S602062","DOIUrl":"10.2147/NSS.S602062","url":null,"abstract":"<p><strong>Introduction: </strong>Subjective sleep perception often differs from objective sleep measures in chronic insomnia, but the role of night-to-night sleep variability remains insufficiently understood. This study examined the effects of daily within-individual sleep fluctuations and between-individual sleep variability on subjective sleep perception in patients with chronic insomnia.</p><p><strong>Methods: </strong>Fifty patients with chronic insomnia completed home-based sleep monitoring and sleep diaries for five to seven consecutive nights, yielding 312 valid nights. Sleep perception bias was defined as the difference between objective sleep parameters and subjective estimates. Sleep variability was quantified using the coefficient of variation. Linear mixed-effects models examined within-individual associations, between-individual variability effects, and cross-level interactions.</p><p><strong>Results: </strong>Nightly objective changes in total sleep time, sleep efficiency, wake after sleep onset, and sleep onset latency were significantly associated with corresponding subjective-objective discrepancies. Subjective perception changed less than objective sleep parameters, suggesting reduced subjective responsiveness to nightly sleep changes. Between individuals, lower total sleep time variability was associated with greater bias in perceived sleep duration and sleep efficiency. Higher N2 percentage variability was associated with greater wake after sleep onset perception bias and moderated the association between objective wake time and subjective perception.</p><p><strong>Discussion: </strong>These findings suggest that subjective sleep perception in chronic insomnia is influenced by nightly objective sleep changes and longer-term sleep variability. N2-related findings should be interpreted cautiously given the exploratory sleep-stage-specific analyses and portable EEG monitoring.</p>","PeriodicalId":18896,"journal":{"name":"Nature and Science of Sleep","volume":"18 ","pages":"602062"},"PeriodicalIF":3.4,"publicationDate":"2026-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13289649/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148318017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Exploration of Craniofacial Features in Obstructive Sleep Apnea Using the Explainable Deep Learning Approaches.","authors":"Liuyi Luo, Ruicong Yang, Zitong Pei, Min Yu, Xu Gong, Yi Lei, Qing Wang, Xuemei Gao","doi":"10.2147/NSS.S609113","DOIUrl":"10.2147/NSS.S609113","url":null,"abstract":"<p><strong>Purpose: </strong>Traditional craniofacial phenotyping of obstructive sleep apnea (OSA) relies on predefined anatomical hypotheses, often yielding incomplete assessments. This study aimed to apply multiple explainable deep learning (DL) approaches to explore novel craniofacial phenotypes.</p><p><strong>Patients and methods: </strong>A multimodal DL model was trained using frontal and lateral facial images, lateral cephalograms, and demographic data from 130 participants (65 OSA patients diagnosed by overnight polysomnography, and 65 age- and sex-matched controls). Explainability analysis of the model's prediction was conducted in a subset of 56 participants per group using average face analysis, feature importance analysis, and gradient-weighted class activation mapping (Grad-CAM). Targeted measurements were then performed on the identified non-traditional regions to validate morphological differences.</p><p><strong>Results: </strong>The model achieved an area under the curve of 0.87. The explainability analysis identified not only anatomical structures that have been confirmed to predict OSA (such as the mandible, chin, and hyoid regions), but also the middle and upper facial third (e.g. the forehead, eyebrows, and upper eyelids), which has not been fully emphasized in previous studies. Targeted measurements confirmed a significantly smaller inter-eyebrow distance, increased frontal protrusion (<i>p</i> < 0.001) and frontal sinus area (<i>p</i> < 0.001) in OSA patients.</p><p><strong>Conclusion: </strong>Explainable DL expanded OSA-related craniofacial phenotypes. Future studies are needed to validate these upper-face traits in larger cohorts and clarify their relevance to OSA subtyping and mechanisms.</p>","PeriodicalId":18896,"journal":{"name":"Nature and Science of Sleep","volume":"18 ","pages":"609113"},"PeriodicalIF":3.4,"publicationDate":"2026-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13287242/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148318045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mental Health, Sleep, and Physical Activity Among Young Saudi Women During Ramadan: A Comparative Cohort Study.","authors":"Karthick Balasubramanian, Ramya Ramasamy Sanjeevi, Mohammed M Alshehri, Shaima A Alothman","doi":"10.2147/NSS.S583610","DOIUrl":"10.2147/NSS.S583610","url":null,"abstract":"<p><strong>Purpose: </strong>This study investigated mental health outcomes of young adult women in relation to physical activity and sleep patterns before, during, and after Ramadan.</p><p><strong>Participants and methods: </strong>A prospective repeated-measures cohort study was conducted in the Department of Physical Therapy at Jazan University, Saudi Arabia. Healthy women aged 18-30 years were recruited through convenience sampling, with exclusions for chronic illness, pregnancy, lactation, psychological disorders, or recent hospitalization. Self-reported data were collected online at three time points: before Ramadan, during Ramadan, and after Ramadan. The study assessed physical activity using the International Physical Activity Questionnaire-Short Form, sleep quality using the Pittsburgh Sleep Quality Index, and emotional states using the Depression, Anxiety, and Stress Scale-21.</p><p><strong>Results: </strong>Thirty young adult females participated in the study. Physical activity showed a gradual increase, with significant improvements from pre-Ramadan to Ramadan (p =0.039) and from pre-Ramadan to post-Ramadan (p =0.009). Sleep was significantly disrupted during Ramadan, with shorter duration (p <0.001) and poorer global sleep quality (p =0.002), followed by marked improvement post-Ramadan (all pairwise p ≤.001). Stress levels peaked during Ramadan and declined significantly afterward (p =0.010), whereas depression and anxiety remained stable across all phases (p >0.05). Regression analyses showed that poorer sleep quality significantly predicted higher depression, anxiety, and stress before and during Ramadan (all p ≤.002), but not after Ramadan. Physical activity and BMI were not associated with mental health outcomes.</p><p><strong>Conclusion: </strong>The study found that while depression and anxiety stayed stable across the Ramadan periods, stress decreased after Ramadan. Sleep quality consistently related to mental health, whereas increased physical activity during Ramadan showed no link to emotional well-being. Overall, sleep and stress emerged as the key factors influencing well-being throughout the Ramadan cycle.</p>","PeriodicalId":18896,"journal":{"name":"Nature and Science of Sleep","volume":"18 ","pages":"583610"},"PeriodicalIF":3.4,"publicationDate":"2026-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13267813/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148265343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cyclic Alternating Pattern and Sleep Microstructure in Parkinson's Disease: A Systematic Review and Meta-Analysis.","authors":"Jiajun Jiang, Yi Huang, Min Wang, Zixuan Zeng, Jing Li","doi":"10.2147/NSS.S606091","DOIUrl":"10.2147/NSS.S606091","url":null,"abstract":"<p><strong>Objective: </strong>To systematically review polysomnographic sleep differences, with emphasis on cyclic alternating pattern (CAP) microstructure, between patients with Parkinson's disease (PD) and healthy controls (HC).</p><p><strong>Methods: </strong>We searched MEDLINE (via OVID), EMBASE (via OVID), CINAHL (via EBSCOhost), APA PsycArticles (via EBSCOhost), and Evidence-Based Medicine databases (via EBSCOhost) for studies published from January 1, 2020, to September 15, 2025. Eligible studies enrolled adults with idiopathic PD, included an internal HC group, used overnight polysomnography, and reported extractable CAP-related outcomes. Study quality was assessed with the Newcastle-Ottawa Scale. Random-effects meta-analyses were performed using Hedges' g with restricted maximum-likelihood estimation, and certainty of evidence was appraised with GRADE.</p><p><strong>Results: </strong>Four studies were included. PD patients showed significant reductions in CAP rate, CAP sequence duration, and CAP index (all p<0.05), with low statistical heterogeneity. Macrostructural parameters showed no statistically significant pooled differences, and several had moderate-to-high heterogeneity. GRADE certainty was very low because the evidence came from a small number of observational studies.</p><p><strong>Conclusion: </strong>Within a limited evidence base, CAP-related microstructure shows a consistent pattern of reduction in clinically diagnosed PD, whereas macrostructural alterations were not stable across the included studies. CAP measures may provide complementary information in future PD sleep research, but the present evidence is insufficient to support their use as validated biomarkers.</p>","PeriodicalId":18896,"journal":{"name":"Nature and Science of Sleep","volume":"18 ","pages":"606091"},"PeriodicalIF":3.4,"publicationDate":"2026-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13269027/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148272397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and Validation of a Nomogram Incorporating Platelet Distribution Width and the Triglyceride-Glucose Index for Predicting Obstructive Sleep Apnea.","authors":"Liyong Shi, Lianshun Lin, Tanwei Liu, Xiali Wang, Jing Cheng, Miaoxiang Chen, Qidong Chen, Fanbin Zhong, Linlin Chen, Xiaoyang Chen","doi":"10.2147/NSS.S607552","DOIUrl":"10.2147/NSS.S607552","url":null,"abstract":"<p><strong>Purpose: </strong>Obstructive sleep apnea (OSA) is a prevalent systemic disorder linked to cardiovascular and metabolic consequences. However, polysomnography (PSG), the diagnostic gold standard, is resource-intensive and not always readily accessible. This study aimed to develop an exploratory nomogram incorporating platelet distribution width (PDW) and the triglyceride-glucose (TyG) index for individualized OSA risk stratification among adults referred for PSG evaluation.</p><p><strong>Patients and methods: </strong>A retrospective analysis of 1328 consecutive adults who underwent PSG, with participants randomly divided into a training cohort (70%) for model development and a validation cohort (30%) for internal validation. Candidate predictors were evaluated using multivariable logistic regression, and LASSO logistic regression was additionally performed as a sensitivity analysis for variable selection. A predictive nomogram was constructed based on clinically relevant and statistically supported predictors, and its performance was evaluated using the area under the curve (AUC), calibration, and decision curve analysis.</p><p><strong>Results: </strong>Univariate logistic regression showed that age, sex, BMI, hypertension, PDW, and TyG index were associated with OSA. In multivariable analysis, older age (OR = 1.035, 95% CI: 1.016-1.054, P < 0.001), male sex (OR = 2.990, 95% CI: 1.723-5.189, P < 0.001), higher BMI (OR = 1.240, 95% CI: 1.149-1.339, P < 0.001), elevated PDW (OR = 1.152, 95% CI: 1.025-1.294, P = 0.017), and higher TyG index (OR = 1.710, 95% CI: 1.107-2.642, P = 0.016) were included as predictors in the final nomogram. LASSO logistic regression supported the relevance of PDW and the TyG index, as both were retained under the lambda.min and lambda.1se criteria. The nomogram incorporating age, sex, BMI, PDW, and TyG index achieved an AUC of 0.806 in the training cohort and 0.751 in the validation cohort. Calibration curves showed consistency between predicted and observed OSA probabilities, and decision curve analysis indicated a higher net benefit than the treat-all and treat-none strategies across the evaluated threshold probability range.</p><p><strong>Conclusion: </strong>This exploratory nomogram, incorporating readily available clinical variables together with PDW and the TyG index, may help stratify OSA risk among adults referred for PSG evaluation. Further external validation is required before its use can be recommended in broader screening settings.</p>","PeriodicalId":18896,"journal":{"name":"Nature and Science of Sleep","volume":"18 ","pages":"607552"},"PeriodicalIF":3.4,"publicationDate":"2026-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13267926/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148265370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mandibular Advancement for Obstructive Sleep Apnea: Efficacy and the Trade-off of Expiratory Velopharyngeal Obstruction During Sleep Endoscopy - An Exploratory Observational Study.","authors":"Shih-Chieh Lo, Ying-Shuo Hsu, Yun-Hsuan Lin, Yu-En Kuo, Tien-Yu Chen, Cheryl C H Yang","doi":"10.2147/NSS.S598380","DOIUrl":"10.2147/NSS.S598380","url":null,"abstract":"<p><strong>Purpose: </strong>Mandibular advancement devices (MADs) are effective alternatives for obstructive sleep apnea (OSA), yet robust predictors of response are lacking, and the phenomenon of device-induced expiratory velopharyngeal obstruction (EVO) remains overlooked. This study conducted an exploratory clinical simulation to compare the efficacy and airway dynamics of a custom-fitted, maximally protrusive advanced MAD simulator versus a conventional edge-to-edge oral appliance (OA) during drug-induced sleep endoscopy (DISE).</p><p><strong>Patients and methods: </strong>In this prospective observational study, 75 adults with OSA underwent target-controlled infusion DISE. Upper airway obstruction (VOTE classification) and EVO were assessed in supine and head-rotated positions under three conditions: baseline, conventional OA, and advanced MAD simulator. A monitored subset (n=18) underwent simultaneous home sleep apnea testing to quantify apnea-hypopnea index (AHI) and lowest oxygen saturation (SpO₂). The primary outcome was the change in upper airway obstruction severity at each VOTE anatomical site.</p><p><strong>Results: </strong>Compared to the conventional OA, the advanced MAD simulator resolved complete velum obstruction in 34.8% of cases (supine, <i>P</i> = 0.015) and achieved 80.0% resolution for epiglottic obstruction during head rotation (<i>P</i> < 0.001). Velum responders in the supine position were younger and had a lower body mass index (BMI) and lower baseline AHI compared to non-responders (<i>P</i> < 0.05). In the monitored subset, the advanced simulator reduced AHI and improved lowest SpO₂ compared to the conventional OA (<i>P</i> < 0.05). The incidence of EVO was higher with the advanced device (64.0% vs 41.3% in supine, <i>P</i> < 0.001), showing no significant association with tongue pressure.</p><p><strong>Conclusion: </strong>While the advanced MAD simulator effectively resolves inspiratory obstruction at the velum and epiglottis, it significantly increases EVO. This exploratory simulation highlights a critical mechanical trade-off between inspiratory patency and expiratory resistance. These hypothesis-generating results warrant further longitudinal research to determine the net clinical impact on long-term treatment adherence and sleep quality.</p>","PeriodicalId":18896,"journal":{"name":"Nature and Science of Sleep","volume":"18 ","pages":"598380"},"PeriodicalIF":3.4,"publicationDate":"2026-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13267928/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148265380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prolonged Prescription Rates of Z-Hypnotics Among Individuals with Chronic Musculoskeletal Pain and Insomnia: The HUNT Study.","authors":"Nora Boldermo Rian, Eivind Schjelderup Skarpsno, Anne Lovise Nordstoga, Karoline Moe, Bjarne Austad, Turid Follestad, Melanie Rae Simpson, Lene Aasdahl","doi":"10.2147/NSS.S592651","DOIUrl":"10.2147/NSS.S592651","url":null,"abstract":"<p><strong>Purpose: </strong>Musculoskeletal pain and insomnia frequently co-occur. Although insomnia is often treated with hypnotics, prolonged use is not recommended. The prevalence of prolonged hypnotic prescriptions among individuals with both conditions remains unknown. This descriptive epidemiological study aimed to estimate prolonged prescriptions among individuals with insomnia and chronic musculoskeletal pain.</p><p><strong>Patients and methods: </strong>In this cross-sectional study, data from 40,790 participants in the Trøndelag Health Study (HUNT4) were linked to the Norwegian Prescription Database for Z-hypnotic prescriptions during the participation year. Prolonged prescriptions were defined as ≥90 defined daily doses. Prevalence estimates were calculated by insomnia and chronic pain status, stratified by age, sex, and pain severity.</p><p><strong>Results: </strong>Among participants with insomnia, prolonged prescription prevalence was higher in those with chronic pain (12.9%) compared to insomnia alone (8.7%). Stratification revealed marked age and sex differences: women aged 45-69 had prevalences of 13.7% if they had pain and insomnia versus 10.2% if they had insomnia alone, increasing to 31.1% and 25.3% for women ≥70 years. For men, rates were 8.1% versus 9.3% at ages 45-69 years and 19.2% versus 14.9% at ≥70 years. Younger participants had prevalences between 1.4% and 2.7%. Pain severity influenced prevalence only among participants aged ≥70 years, and more strongly among men (22.5% with high impact pain versus 14.9% without pain).</p><p><strong>Conclusion: </strong>Chronic musculoskeletal pain was associated with higher prescription rates, though not statistically significant within age categories, and pain severity had some influence among older individuals. Regardless of pain status, prolonged Z-hypnotic prescriptions increased with age, with women receiving more than men.</p>","PeriodicalId":18896,"journal":{"name":"Nature and Science of Sleep","volume":"18 ","pages":"592651"},"PeriodicalIF":3.4,"publicationDate":"2026-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13264980/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148258836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Managing Sleep, Emotional Well-Being, and Quality of Life in Hemodialysis Patients via Acupressure [Response to Letter].","authors":"Yiting Wang, Li-Wei Chou","doi":"10.2147/NSS.S613387","DOIUrl":"10.2147/NSS.S613387","url":null,"abstract":"","PeriodicalId":18896,"journal":{"name":"Nature and Science of Sleep","volume":"18 ","pages":"613387"},"PeriodicalIF":3.4,"publicationDate":"2026-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13242816/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148205036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uncontrolled Hypertension from Inappropriate Ventilator Settings in Obstructive Sleep Apnea: A Case Report.","authors":"Si-Rui Tian, Robert Joseph Thomas, Yue-Nan Ni","doi":"10.2147/NSS.S601053","DOIUrl":"10.2147/NSS.S601053","url":null,"abstract":"<p><p>This case report explores a typical instance of poorly controlled secondary hypertension associated with obstructive sleep apnea (OSA), specifically exacerbated during bilevel positive airway pressure (PAP) therapy, which was an inappropriate ventilator mode. The patient exhibited uncontrolled blood pressure and a high residual apnea-hypopnea index (AHI) while on bilevel therapy. Following a guided retitration of PAP therapy, both blood pressure control and residual AHI improved substantially. This report aims to provide an in-depth analysis of pathophysiological mechanisms underlying PAP therapy interactions with hypertension in OSA patients and to summarize key points for ventilator management in clinical practice.</p>","PeriodicalId":18896,"journal":{"name":"Nature and Science of Sleep","volume":"18 ","pages":"601053"},"PeriodicalIF":3.4,"publicationDate":"2026-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13232533/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148163609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Toward a Classification of Chronotype Questionnaires.","authors":"Arcady A Putilov","doi":"10.2147/NSS.S602542","DOIUrl":"10.2147/NSS.S602542","url":null,"abstract":"<p><strong>Purpose: </strong>Chronotyping is a key methodology for assessing individual differences in human adaptation to the 24-h periodicity of geophysical and social environments. Throughout the 50-yr period of publications of chronotype questionnaires, there has been steady growth in their number and diversity. Therefore, it is becoming increasingly difficult to determine which questionnaires can be optimally applied to address a given research question. Consequently, this study aimed to develop a structured system for classifying and comparing chronotype questionnaires.</p><p><strong>Methods: </strong>A search in two bibliographic databases and 8 previously published reviews yielded 75 chronotype questionnaires. The properties of these questionnaires were defined and used for their classification and comparison.</p><p><strong>Results: </strong>Of 75 identified questionnaires, 60 and 15 were designed for only chronotype and chronotype and something else assessment, respectively. The set of 20 questionnaire and questionnaire scale properties was proposed. These properties were used to classify the questionnaires to allow the distinction of any of the questionnaires from other questionnaires.</p><p><strong>Conclusion: </strong>The proposed structured system of questionnaire classification can help in navigating between numerous published questionnaires. Using this system, an optimal instrument for a given research purpose can be chosen and properties of yet-unconstructed questionnaires and scales can be predicted.</p>","PeriodicalId":18896,"journal":{"name":"Nature and Science of Sleep","volume":"18 ","pages":"602542"},"PeriodicalIF":3.4,"publicationDate":"2026-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13232538/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148163632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}