• Sleep Medicine and Psychophysiology
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• v.28 no.2
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• pp.70-77
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• 2021

Objectives: Our study aims to investigate the clinical and polysomnographic variables associated with subjective sleep perception. Methods: Among the patients who underwent nocturnal polysomnography (PSG) at the Center for Sleep and Chronobiology of Seoul National University Hospital from May 2018 to July 2019, 109 diagnosed with insomnia disorder based on DSM-5 were recruited for the study, and their medical records were retrospectively analyzed. Self-report questionnaires about clinical characteristics including Pittsburgh sleep quality index (PSQI), Beck depression inventory (BDI), and Epworth sleepiness scale (ESS) were completed. Subjective sleep quality was measured using variables of subjective total sleep time (subjective TST), subjective sleep onset latency (subjective SOL), subjective number of awakenings, morning feeling after awakening, and sleep discrepancy (subjective TST-objective TST) the morning after PSG. Pearson and Spearman correlation analyses were used to determine the factors associated with subjective sleep perception. Results: In patients with insomnia, subjective TST was negatively correlated with Wake After Sleep Onset (WASO) (p = 0.001) and N1 sleep (p = 0.039) parameters on polysomnography. Also, it was negatively correlated with PSQI (p < 0.001) and BDI (p = 0.014) scores. Sleep discrepancy was negatively correlated with PSQI score (p = 0.018). Morning feeling was negatively correlated with PSQI (p = 0.019) and BDI (p < 0.001) scores. Conclusion: Our results demonstrated that subjective sleep perception is associated with PSG variables (WASO and N1 sleep) and with PSQI and BDI scores. In clinical practice, it is helpful to assess and manage insomnia patients in consideration of objective sleep variables, subjective sleep quality, and depressed mood, which can influence subjective sleep perception.

• Korean Journal of Psychosomatic Medicine
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• v.18 no.1
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• pp.30-39
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• 2010

Objectives：Assessment of sleep disturbance is an essential part of the diagnostic criteria used for several psychiatric disorders. Change in sleep patterns over time may indicate response to treatment. In clinical practice, sleep is usually evaluated subjectively by patient self-report. This study was aimed to compare subjective sleep assessment with objective sleep measurement by actigraphy in psychiatric inpatients. Methods：A total of 32 psychiatric inpatients were studied. Patients were asked to wear a wrist actigraphy for three consecutive days and nights and to fill out a sleep log each morning. The severity of depression and anxiety was evaluated according to Beck Depression Inventory and State-Trait Anxiety Inventory on the first day of the study. The subjective level of satisfaction with quality of sleep was also evaluated according to visual analog scale. Nurses assessed sleep at one hour interval between 10:00 PM and 6:00 AM for three consecutive nights. Results：There was statistically significant difference of sleep latency between patient's sleep log and acti-graphic measurement. Nursing reports were more consistent with actigraphic measurement than sleep log. Interestingly, subjectively poor sleepers show no significant difference in sleep parameters compared with those of good sleepers. Subjectively poor sleepers report longer sleep latency than that of actigraphic assessment. The discrepancy between subjective and objective assessment of sleep latency was significantly correlated with scores of Beck Depression Inventory and State-Trait Anxiety Inventory. Conclusion：These results show that there are discrepancies between subjective and objective assessment of sleep. The discrepancy of sleep assessment could be influenced by severe depression and anxiety. Especially objective sleep measurement is needed to assess sleep in psychiatric inpatients with severe depression or anxiety and the subjectively poor sleepers for more reliable measurements.

• Sleep Medicine and Psychophysiology
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• v.27 no.1
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• pp.24-31
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• 2020

Objectives: Subjective-objective discrepancy of sleep (SODS) is a common symptom and one of the major phenotypes of insomnia. A distorted perception of sleep deficit might be related to abnormal brain reactivity to insomnia-related stimuli. We aimed to investigate differences in brain activation to insomnia-related stimuli vs. general anxiety-inducing stimuli among insomnia patients with SODS, insomnia patients without SODS, and healthy controls (HCs). Methods: All participants were evaluated for subjective sleep status using a sleep diary and questionnaires; occult sleep disorders and objective sleep status were assessed using polysomnography and actigraphy. Task functional magnetic resonance imaging was performed during insomnia-related stimuli (Ins) and general anxiety-inducing stimuli (Gen). Brain reactivity to Ins versus Gen was compared among insomnia with SODS, insomnia without SODS, and HC groups, and a combined insomnia disorder group (ID, insomnia with and without SODS) was also compared with HCs. Results: In the insomnia with SODS group compared to the insomnia without SODS group, the right precuneus and right supplementary motor areas showed significantly increased BOLD signals in response to Ins versus Gen. In the ID group compared to the HC group, the left anterior cingulate cortex showed significantly increased BOLD signals in response to Ins versus Gen. Conclusion: The insomnia with SODS and ID groups showed higher brain activity in response to Ins versus Gen, while this was not observed in the insomnia without SODS and HC groups, respectively. These results suggest that insomnia patients with sleep misperception are more sensitive to sleep-related threats than general anxiety-inducing threats.

• Research in Community and Public Health Nursing
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• v.33 no.4
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• pp.396-407
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• 2022

Purpose: The purpose of this study was to assess insomnia and the quality of sleep, investigate the concordance between objective and self-report sleep patterns, and identify physiological, psychological, and situational factors influencing insomnia and sleep quality among firefighters. Methods: A descriptive, cross-sectional study was conducted with 103 firefighters in Korea. The collected data were analyzed using SPSS 23.0. Descriptive statistics, the independent t-test, and hierarchical logistic regression analysis were performed. Results: Insomnia was found in 66 (64.1 %) of the total subjects, and the average quality of sleep (PSQI) was 5.65 (SD=2.57). Total sleep time (401.00 minutes) and sleep latency (21.60 minutes) measured using self-reported scales were longer than the ones measured using objective measurements by approximately 48.70 and 17.10 minutes, respectively. Factors related to insomnia included the role as a paramedic (OR=4.28, 95% CI: 1.02~17.92), anxiety (OR=1.12, 95% CI: 1.01~1.24), and sedentary lifestyle (OR=0.85, 95% CI: 0.78~0.94), and factors related to sleep quality were physical illness status (OR=5.17, 95% CI: 1.53~17.51) and social support (OR=0.86, 95% CI: 0.78~0.95). Conclusion: The results show a high prevalence of insomnia, poor quality of sleep and the discrepancy between objective and subjective sleep patterns among firefighters. To promote sleep quality and health, early screening and treatment of anxiety and physical illness are required. It is necessary to conduct further studies examining the relationship between physical activity level and sleep.

• The korean journal of orthodontics
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• v.35 no.1 s.108
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• pp.60-68
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• 2005

The evaluation of malocclusion has to be done quantitatively and qualitatively. This will be lead toward an analysis of malocclusion severity as well as treatment difficulty. The method of proper evaluation of malocclusion severity and treatment difficulty is necessary to assess treatment effect and efficiency for the orthodontists and to establish fundamentals for planning and executing the health-related policies in private and public institutions. The purposes of this study as the first part of the objective and quantitative analysis of malocclusion were 1) to measure treatment difficulty based on the opinions of several orthodontists. and 2) to investigate the relationships between objective malocclusion severity and subjective treatment difficulty 100 pairs of dental casts that had various types and severity of malocclusion were selected from the orthodontic departments of Kyurghee University and Samsung Medical Center The objective malocclusion severity was measured with the PAR (Peer Assessment Rating) index and the subjective treatment difficulty was evaluated by 8 experienced orthodontists. The relationships between objective malocclusion severity and subjective treatment difficulty were statistically evaluated. There were significant relationships between objective malocclusion severity and subjective treatment difficulty especially in the measurements of the upper anterior alignment, the buccal occlusion. the overjet, the overbite and the midline discrepancy en the malocclusion components. The results of this study can provide the background knowledge to develop a new occlusal index. which contains both the malocclusion severity and treatment difficulty for Korean orthodontists.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.367-394
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• 1994

The purpose of this study was to evaluate self perception of occlusal status and recognition for orthodontic treatment as well as the prevalence of orthodontic treatment need objectively and subjectively. 3979 (male 2107, female 1872) school students of age 7~18 were analyzed by questionnaire and clinical examination and the results were as follows, 1. Perception of occlusal status on one's own was more generous than that of orthodontist's and it was affected by the factors such as age, patterns of malocclusion. 2. Recogniuon of subjective need for orthodontic treatment was more generous than that of objective need for the treatment, and factors such as age and sex of patient, parents' age and rate of education, income, occupation, classification of malocclusion and regional discrepancy were influenced. 3. Negative aspect of orthodontic treatment was influenced by the environmental factors. 4. A survey of want for orthodontic treatment showed one's alteration in recognition of the occlusal status with age and esthetic component was much more emphasized than functional component. 5. The multivariate discriminanat analysis for orthodontic treatment group showed that mother's rate of education, classification of malocclusion, demographic characteristics were critical in the determination of treatment group. 6. Test of inter-examiner reliability showed moderate coincidence.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.2
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• pp.208-218
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• 2014

Objectives: The major objective of this study was to develop and validate a tier 1 exposure model utilizing worker exposure monitoring data and characteristics of worker activities routinely performed at construction sites, in order to estimate worker exposures without sampling. Methods: The Registration, Evaluation, Authorization and Restriction of Chemicals(REACH) system of the European Union(EU) allows the usage of exposure models for anticipating chemical exposure of manufacturing workers and consumers. Several exposure models have been developed such as Advanced REACH Tools(ART). The ART model is based on structured subjective assessment model. Using the same framework, a tier 1 exposure model has been developed. Worker activities at construction sites have been analyzed and modifying factors have been assigned for each activity. Korean Occupational Safety and Health Agency(KOSHA) accrued work exposure monitoring data for the last 10 years, which were retrieved and converted into exposure scores. A separate set of sampling data were collected to validate the developed exposure model. These algorithm have been realized on Excel spreadsheet for convenience and easy access. Results: The correlation coefficient of the developed model between exposure scores and monitoring data was 0.36, which is smaller than those of EU models(0.6~0.7). One of the main reasons explaining the discrepancy is poor description on worker activities in KOSHA database. Conclusions: The developed tier 1 exposure model can help industrial hygienists judge whether or not air sampling is required or not.

• Investigative Magnetic Resonance Imaging
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• v.24 no.2
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• pp.76-84
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• 2020

Background: Determination of inter-method differences between clinically available volumetry methods are essential for the clinical application of brain volumetry in a wider context. Purpose: The purpose of this study was to examine the inter-method reliability and differences between the Siemens morphometry (SM) software and the NeuroQuant (NQ) software. Materials and Methods: MR images of 86 subjects with subjective or objective cognitive impairment were included in this retrospective study. For this study, 3D T1 volume images were obtained in all subjects using a 3T MR scanner (Skyra 3T, Siemens). Volumetric analysis of the 3D T1 volume images was performed using SM and NQ. To analyze the inter-method difference, correlation, and reliability, we used the paired t-test, Bland-Altman plot, Pearson's correlation coefficient, intraclass correlation coefficient (ICC), and effect size (ES) using the MedCalc and SPSS software. Results: SM and NQ showed excellent reliability for cortical gray matter, cerebral white matter, and cerebrospinal fluid; and good reliability for intracranial volume, whole brain volume, both thalami, and both hippocampi. In contrast, poor reliability was observed for both basal ganglia including the caudate nucleus, putamen, and pallidum. Paired comparison revealed that while the mean volume of the right hippocampus was not different between the two software, the mean difference in the left hippocampus volume between the two methods was 0.17 ml (P < 0.001). The other brain regions showed significant differences in terms of measured volumes between the two software. Conclusion: SM and NQ provided good-to-excellent reliability in evaluating most brain structures, except for the basal ganglia in patients with cognitive impairment. Researchers and clinicians should be aware of the potential differences in the measured volumes when using these two different software interchangeably.

• Korean Journal of Psychosomatic Medicine
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• v.13 no.1
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• pp.32-40
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• 2005

Objectives : This study looked at the symptoms of alexithymia in schizophrenia and their association with clinical variables and schizophrenic symptomatology. Methods Consecutive fifty eight inpatients with DSM-IV diagnoses of schizophrenia completed 26item version of Toronto Alexithymia Scale (TAS), Symptom Checklist-90-Revised(SCL-90-R), and Positive and Negative Syndrome Scale(PANSS). Results : Authors did not find any correlation between scores of PANSS and TAS. However, all the subscale scores of SCL-90-R were significantly correlated with total score of TAS. Also, 'difficulty identifying and deistinguishing between feelings and bodily sensations' and 'difficulty describing feelings' significantly correlated with SCL-90-R subscale scores. 'Reduced daydreaming' had mixed findings and 'externally oriented thinking' did not correlate. Multiple regression model included Global Severity Index of SCL-90-R accounting 28.2% of variance for TAS scores. Conclusion : These findings together with discrepancy in results between objective and subjective tests suggest that alexithymia in schizophrenia may have two constructs, 'difficulty to describe and communicate feelings(state)' and 'externally oriented thinking(trait)' Authors suggest further study needs to confirm construct validity of TAS in this population.