1.Testing the reliability and validity of the Korean version of the Pittsburgh Sleep Quality Index using Fitbit devices: a cross-sectional analysis
Si-Yeon LEE ; Ja-Eun CHOI ; Ji-Won LEE ; Yaeji LEE ; Jae-Min PARK ; Kyung-Won HONG
Korean Journal of Family Medicine 2025;46(1):42-47
Background:
Sleep disorders and insomnia are prevalent worldwide, with negative health outcomes. The Pittsburgh Sleep Quality Index (PSQI) is a widely used self-report assessment tool for evaluating sleep quality, comprising seven subdomains. The Korean version of the PSQI (PSQI-K) has been tested for reliability and validity in small sample sizes but lacks large-scale validation using objective measures.
Methods:
This study was conducted with 268 Korean adults attending health check programs. Participants completed the PSQI-K questionnaire and wore Fitbit devices (Fitbit Inc., USA) to ascertain sleep parameters. Reliability was analyzed using the Cronbach’s α coefficient, and construct validity was determined through factor analysis. Criteria validity was assessed by correlating their index scores with Fitbit sleep parameters. We identified the optimal cutoff for detecting sleep disorders.
Results:
The Cronbach’s α coefficient was 0.61, indicating adequate internal consistency. Factor analysis revealed three factors, explaining 48.2% of sleep quality variance. The index scores were negatively correlated with Fitbit sleep efficiency, total sleep time, and number of awakenings (P<0.05). The optimal cutoff point for identifying sleep disorder groups was ≥6.
Conclusion
The PSQI-K demonstrated good reliability and validity when correlated with Fitbit sleep parameters, offering a practical screening tool for identifying sleep disorders among Korean adults. Cutoff scores can help identify patients for sleep interventions. However, further large-scale studies are required to validate these findings.
2.Testing the reliability and validity of the Korean version of the Pittsburgh Sleep Quality Index using Fitbit devices: a cross-sectional analysis
Si-Yeon LEE ; Ja-Eun CHOI ; Ji-Won LEE ; Yaeji LEE ; Jae-Min PARK ; Kyung-Won HONG
Korean Journal of Family Medicine 2025;46(1):42-47
Background:
Sleep disorders and insomnia are prevalent worldwide, with negative health outcomes. The Pittsburgh Sleep Quality Index (PSQI) is a widely used self-report assessment tool for evaluating sleep quality, comprising seven subdomains. The Korean version of the PSQI (PSQI-K) has been tested for reliability and validity in small sample sizes but lacks large-scale validation using objective measures.
Methods:
This study was conducted with 268 Korean adults attending health check programs. Participants completed the PSQI-K questionnaire and wore Fitbit devices (Fitbit Inc., USA) to ascertain sleep parameters. Reliability was analyzed using the Cronbach’s α coefficient, and construct validity was determined through factor analysis. Criteria validity was assessed by correlating their index scores with Fitbit sleep parameters. We identified the optimal cutoff for detecting sleep disorders.
Results:
The Cronbach’s α coefficient was 0.61, indicating adequate internal consistency. Factor analysis revealed three factors, explaining 48.2% of sleep quality variance. The index scores were negatively correlated with Fitbit sleep efficiency, total sleep time, and number of awakenings (P<0.05). The optimal cutoff point for identifying sleep disorder groups was ≥6.
Conclusion
The PSQI-K demonstrated good reliability and validity when correlated with Fitbit sleep parameters, offering a practical screening tool for identifying sleep disorders among Korean adults. Cutoff scores can help identify patients for sleep interventions. However, further large-scale studies are required to validate these findings.
3.Predicting Mortality and Cirrhosis-Related Complications with MELD3.0: A Multicenter Cohort Analysis
Jihye LIM ; Ji Hoon KIM ; Ahlim LEE ; Ji Won HAN ; Soon Kyu LEE ; Hyun YANG ; Heechul NAM ; Hae Lim LEE ; Do Seon SONG ; Sung Won LEE ; Hee Yeon KIM ; Jung Hyun KWON ; Chang Wook KIM ; U Im CHANG ; Soon Woo NAM ; Seok-Hwan KIM ; Pil Soo SUNG ; Jeong Won JANG ; Si Hyun BAE ; Jong Young CHOI ; Seung Kew YOON ; Myeong Jun SONG
Gut and Liver 2025;19(3):427-437
Background/Aims:
This study aimed to evaluate the performance of the Model for End-Stage Liver Disease (MELD) 3.0 for predicting mortality and liver-related complications compared with the Child-Pugh classification, albumin-bilirubin (ALBI) grade, the MELD, and the MELD sodium (MELDNa) score.
Methods:
We evaluated a multicenter retrospective cohort of incorporated patients with cirrhosis between 2013 and 2019. We conducted comparisons of the area under the receiver operating characteristic curve (AUROC) of the MELD3.0 and other models for predicting 3-month mortality. Additionally, we assessed the risk of cirrhosis-related complications according to the MELD3.0 score.
Results:
A total of 3,314 patients were included. The mean age was 55.9±11.3 years, and 70.2% of the patients were male. Within the initial 3 months, 220 patients (6.6%) died, and the MELD3.0had the best predictive performance among the tested models, with an AUROC of 0.851, outperforming the Child-Pugh classification, ALBI grade, MELD, and MELDNa. A high MELD3.0score was associated with an increased risk of mortality. Compared with that of the group with a MELD3.0 score <10 points, the adjusted hazard ratio of the group with a score of 10–20 pointswas 2.176, and that for the group with a score of ≥20 points was 4.892. Each 1-point increase inthe MELD3.0 score increased the risk of cirrhosis-related complications by 1.033-fold. The risk of hepatorenal syndrome showed the highest increase, with an adjusted hazard ratio of 1.149, followed by hepatic encephalopathy and ascites.
Conclusions
The MELD3.0 demonstrated robust prognostic performance in predicting mortality in patients with cirrhosis. Moreover, the MELD3.0 score was linked to cirrhosis-related complications, particularly those involving kidney function, such as hepatorenal syndrome and ascites.
4.Predicting Mortality and Cirrhosis-Related Complications with MELD3.0: A Multicenter Cohort Analysis
Jihye LIM ; Ji Hoon KIM ; Ahlim LEE ; Ji Won HAN ; Soon Kyu LEE ; Hyun YANG ; Heechul NAM ; Hae Lim LEE ; Do Seon SONG ; Sung Won LEE ; Hee Yeon KIM ; Jung Hyun KWON ; Chang Wook KIM ; U Im CHANG ; Soon Woo NAM ; Seok-Hwan KIM ; Pil Soo SUNG ; Jeong Won JANG ; Si Hyun BAE ; Jong Young CHOI ; Seung Kew YOON ; Myeong Jun SONG
Gut and Liver 2025;19(3):427-437
Background/Aims:
This study aimed to evaluate the performance of the Model for End-Stage Liver Disease (MELD) 3.0 for predicting mortality and liver-related complications compared with the Child-Pugh classification, albumin-bilirubin (ALBI) grade, the MELD, and the MELD sodium (MELDNa) score.
Methods:
We evaluated a multicenter retrospective cohort of incorporated patients with cirrhosis between 2013 and 2019. We conducted comparisons of the area under the receiver operating characteristic curve (AUROC) of the MELD3.0 and other models for predicting 3-month mortality. Additionally, we assessed the risk of cirrhosis-related complications according to the MELD3.0 score.
Results:
A total of 3,314 patients were included. The mean age was 55.9±11.3 years, and 70.2% of the patients were male. Within the initial 3 months, 220 patients (6.6%) died, and the MELD3.0had the best predictive performance among the tested models, with an AUROC of 0.851, outperforming the Child-Pugh classification, ALBI grade, MELD, and MELDNa. A high MELD3.0score was associated with an increased risk of mortality. Compared with that of the group with a MELD3.0 score <10 points, the adjusted hazard ratio of the group with a score of 10–20 pointswas 2.176, and that for the group with a score of ≥20 points was 4.892. Each 1-point increase inthe MELD3.0 score increased the risk of cirrhosis-related complications by 1.033-fold. The risk of hepatorenal syndrome showed the highest increase, with an adjusted hazard ratio of 1.149, followed by hepatic encephalopathy and ascites.
Conclusions
The MELD3.0 demonstrated robust prognostic performance in predicting mortality in patients with cirrhosis. Moreover, the MELD3.0 score was linked to cirrhosis-related complications, particularly those involving kidney function, such as hepatorenal syndrome and ascites.
5.Predicting Mortality and Cirrhosis-Related Complications with MELD3.0: A Multicenter Cohort Analysis
Jihye LIM ; Ji Hoon KIM ; Ahlim LEE ; Ji Won HAN ; Soon Kyu LEE ; Hyun YANG ; Heechul NAM ; Hae Lim LEE ; Do Seon SONG ; Sung Won LEE ; Hee Yeon KIM ; Jung Hyun KWON ; Chang Wook KIM ; U Im CHANG ; Soon Woo NAM ; Seok-Hwan KIM ; Pil Soo SUNG ; Jeong Won JANG ; Si Hyun BAE ; Jong Young CHOI ; Seung Kew YOON ; Myeong Jun SONG
Gut and Liver 2025;19(3):427-437
Background/Aims:
This study aimed to evaluate the performance of the Model for End-Stage Liver Disease (MELD) 3.0 for predicting mortality and liver-related complications compared with the Child-Pugh classification, albumin-bilirubin (ALBI) grade, the MELD, and the MELD sodium (MELDNa) score.
Methods:
We evaluated a multicenter retrospective cohort of incorporated patients with cirrhosis between 2013 and 2019. We conducted comparisons of the area under the receiver operating characteristic curve (AUROC) of the MELD3.0 and other models for predicting 3-month mortality. Additionally, we assessed the risk of cirrhosis-related complications according to the MELD3.0 score.
Results:
A total of 3,314 patients were included. The mean age was 55.9±11.3 years, and 70.2% of the patients were male. Within the initial 3 months, 220 patients (6.6%) died, and the MELD3.0had the best predictive performance among the tested models, with an AUROC of 0.851, outperforming the Child-Pugh classification, ALBI grade, MELD, and MELDNa. A high MELD3.0score was associated with an increased risk of mortality. Compared with that of the group with a MELD3.0 score <10 points, the adjusted hazard ratio of the group with a score of 10–20 pointswas 2.176, and that for the group with a score of ≥20 points was 4.892. Each 1-point increase inthe MELD3.0 score increased the risk of cirrhosis-related complications by 1.033-fold. The risk of hepatorenal syndrome showed the highest increase, with an adjusted hazard ratio of 1.149, followed by hepatic encephalopathy and ascites.
Conclusions
The MELD3.0 demonstrated robust prognostic performance in predicting mortality in patients with cirrhosis. Moreover, the MELD3.0 score was linked to cirrhosis-related complications, particularly those involving kidney function, such as hepatorenal syndrome and ascites.
6.Testing the reliability and validity of the Korean version of the Pittsburgh Sleep Quality Index using Fitbit devices: a cross-sectional analysis
Si-Yeon LEE ; Ja-Eun CHOI ; Ji-Won LEE ; Yaeji LEE ; Jae-Min PARK ; Kyung-Won HONG
Korean Journal of Family Medicine 2025;46(1):42-47
Background:
Sleep disorders and insomnia are prevalent worldwide, with negative health outcomes. The Pittsburgh Sleep Quality Index (PSQI) is a widely used self-report assessment tool for evaluating sleep quality, comprising seven subdomains. The Korean version of the PSQI (PSQI-K) has been tested for reliability and validity in small sample sizes but lacks large-scale validation using objective measures.
Methods:
This study was conducted with 268 Korean adults attending health check programs. Participants completed the PSQI-K questionnaire and wore Fitbit devices (Fitbit Inc., USA) to ascertain sleep parameters. Reliability was analyzed using the Cronbach’s α coefficient, and construct validity was determined through factor analysis. Criteria validity was assessed by correlating their index scores with Fitbit sleep parameters. We identified the optimal cutoff for detecting sleep disorders.
Results:
The Cronbach’s α coefficient was 0.61, indicating adequate internal consistency. Factor analysis revealed three factors, explaining 48.2% of sleep quality variance. The index scores were negatively correlated with Fitbit sleep efficiency, total sleep time, and number of awakenings (P<0.05). The optimal cutoff point for identifying sleep disorder groups was ≥6.
Conclusion
The PSQI-K demonstrated good reliability and validity when correlated with Fitbit sleep parameters, offering a practical screening tool for identifying sleep disorders among Korean adults. Cutoff scores can help identify patients for sleep interventions. However, further large-scale studies are required to validate these findings.
7.Predicting Mortality and Cirrhosis-Related Complications with MELD3.0: A Multicenter Cohort Analysis
Jihye LIM ; Ji Hoon KIM ; Ahlim LEE ; Ji Won HAN ; Soon Kyu LEE ; Hyun YANG ; Heechul NAM ; Hae Lim LEE ; Do Seon SONG ; Sung Won LEE ; Hee Yeon KIM ; Jung Hyun KWON ; Chang Wook KIM ; U Im CHANG ; Soon Woo NAM ; Seok-Hwan KIM ; Pil Soo SUNG ; Jeong Won JANG ; Si Hyun BAE ; Jong Young CHOI ; Seung Kew YOON ; Myeong Jun SONG
Gut and Liver 2025;19(3):427-437
Background/Aims:
This study aimed to evaluate the performance of the Model for End-Stage Liver Disease (MELD) 3.0 for predicting mortality and liver-related complications compared with the Child-Pugh classification, albumin-bilirubin (ALBI) grade, the MELD, and the MELD sodium (MELDNa) score.
Methods:
We evaluated a multicenter retrospective cohort of incorporated patients with cirrhosis between 2013 and 2019. We conducted comparisons of the area under the receiver operating characteristic curve (AUROC) of the MELD3.0 and other models for predicting 3-month mortality. Additionally, we assessed the risk of cirrhosis-related complications according to the MELD3.0 score.
Results:
A total of 3,314 patients were included. The mean age was 55.9±11.3 years, and 70.2% of the patients were male. Within the initial 3 months, 220 patients (6.6%) died, and the MELD3.0had the best predictive performance among the tested models, with an AUROC of 0.851, outperforming the Child-Pugh classification, ALBI grade, MELD, and MELDNa. A high MELD3.0score was associated with an increased risk of mortality. Compared with that of the group with a MELD3.0 score <10 points, the adjusted hazard ratio of the group with a score of 10–20 pointswas 2.176, and that for the group with a score of ≥20 points was 4.892. Each 1-point increase inthe MELD3.0 score increased the risk of cirrhosis-related complications by 1.033-fold. The risk of hepatorenal syndrome showed the highest increase, with an adjusted hazard ratio of 1.149, followed by hepatic encephalopathy and ascites.
Conclusions
The MELD3.0 demonstrated robust prognostic performance in predicting mortality in patients with cirrhosis. Moreover, the MELD3.0 score was linked to cirrhosis-related complications, particularly those involving kidney function, such as hepatorenal syndrome and ascites.
8.Testing the reliability and validity of the Korean version of the Pittsburgh Sleep Quality Index using Fitbit devices: a cross-sectional analysis
Si-Yeon LEE ; Ja-Eun CHOI ; Ji-Won LEE ; Yaeji LEE ; Jae-Min PARK ; Kyung-Won HONG
Korean Journal of Family Medicine 2025;46(1):42-47
Background:
Sleep disorders and insomnia are prevalent worldwide, with negative health outcomes. The Pittsburgh Sleep Quality Index (PSQI) is a widely used self-report assessment tool for evaluating sleep quality, comprising seven subdomains. The Korean version of the PSQI (PSQI-K) has been tested for reliability and validity in small sample sizes but lacks large-scale validation using objective measures.
Methods:
This study was conducted with 268 Korean adults attending health check programs. Participants completed the PSQI-K questionnaire and wore Fitbit devices (Fitbit Inc., USA) to ascertain sleep parameters. Reliability was analyzed using the Cronbach’s α coefficient, and construct validity was determined through factor analysis. Criteria validity was assessed by correlating their index scores with Fitbit sleep parameters. We identified the optimal cutoff for detecting sleep disorders.
Results:
The Cronbach’s α coefficient was 0.61, indicating adequate internal consistency. Factor analysis revealed three factors, explaining 48.2% of sleep quality variance. The index scores were negatively correlated with Fitbit sleep efficiency, total sleep time, and number of awakenings (P<0.05). The optimal cutoff point for identifying sleep disorder groups was ≥6.
Conclusion
The PSQI-K demonstrated good reliability and validity when correlated with Fitbit sleep parameters, offering a practical screening tool for identifying sleep disorders among Korean adults. Cutoff scores can help identify patients for sleep interventions. However, further large-scale studies are required to validate these findings.
9.Skin-directed radiotherapy for primary cutaneous T-cell lymphomas
Ha Un KIM ; Yeon Joo KIM ; Mi Woo LEE ; Woo Jin LEE ; Sang-wook LEE ; Youngju SONG ; Byungchul CHO ; Si Yeol SONG
Radiation Oncology Journal 2024;42(3):228-236
Purpose:
To evaluate the efficacy and toxicities of skin-directed radiotherapy (RT) in primary cutaneous T-cell lymphoma (CTCL).
Materials and Methods:
We retrospectively analyzed 57 CTCL lesions treated with skin-directed RT between January 2000 and December 2022. Lesions were categorized into three distinct groups: early-stage disease treated with local RT, advanced-stage disease treated with local RT, and advanced-stage disease treated with total skin electron beam therapy (TSEBT). Treatment outcomes, including response rates, recurrence patterns, and local progression probability, were assessed for each group.
Results:
Mycosis fungoides (MF) constituted 90.9% of the advanced-stage pathologies, while CD4+ primary cutaneous small/medium T-cell lymphoproliferative disorder was common in the early stage lesions (55%). Median RT doses were 30.6 Gy, 27 Gy, and 32 Gy for the local RT with early stage, the local RT with advanced stage, and TSEBT with advanced stage, respectively. The complete response rates were high across the groups: 95.5%, 70.8%, and 90.9%, respectively. Seven local recurrences (29.2%) occurred in the local RT group with advanced stage, while seven patients (63.6%) in the TSEBT group experienced local failure. All recurrences were observed in lesions and patients with MF. Acute toxicities were mainly grade 1 or 2, with no grade 3 or higher events. No significant association between RT dose and local progression rates in MF lesions was found.
Conclusion
Skin-directed RT in CTCL is effective for local control and well-tolerated with less toxicity.
10.Development of the Diagnostic Matrix of the Seoul Cognitive Status Test, Compared to Traditional Paper-andPencil Neuropsychological Tests
Seunghee NA ; Young Ju KIM ; Si Eun KIM ; Na-Yeon JUNG ; Seung Joo KIM ; Hee Jin KIM ; Joon Soo SHIN ; Duk L. NA ; Sang Won SEO ; Yeshin KIM ; Eek-Sung LEE
Dementia and Neurocognitive Disorders 2024;23(4):224-235
Background:
and Purpose: We aimed to develop the diagnostic matrix of the Seoul Cognitive Status Test (SCST) and compare its performance with traditional paper-and-pencil neuropsychological tests, including the Seoul Neuropsychological Screening Battery-II (SNSB-II) and the Korean version of the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD-K).
Methods:
We recruited 197 participants from the head-to-head SCST-SNSB cohort, and 204 participants from the head-to-head SCST-CERAD cohort. They underwent either SNSB-II or CERAD-K, in addition to SCST. The diagnostic matrix was developed by combining cognitive function, determined by neuropsychological tests, and activities of daily living (ADL), determined by Instrumental-ADL scales.
Results:
The diagnostic agreement between the SCST and the SNSB-II was 83.9% (weighted kappa=0.87). The agreement between the SCST and the CERAD-K was 84.3% (weighted kappa=0.88). In the SCST-SNSB cohort, all differences in SCST scores between the cognitively unimpaired (CU), mild cognitive impairment (MCI), and dementia diagnosed with the SNSB-II were significant in all cognitive domains (all p<0.01), except for the executive domain between CU and MCI (p=0.145). In the SCST-CERAD cohort, all differences in SCST scores between the 3 groups diagnosed with the CERAD-K were significant in all cognitive domains (all p<0.01), except for the language and visuospatial domains between MCI and dementia (p=0.169 and p=0.778, respectively).
Conclusions
Our findings suggest that the tablet-based SCST may be another option to traditional paper-and-pencil neuropsychological tests, especially in situations where time and space are relatively limited, and neuropsychological testing specialists are not available.

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