Purpose: The purpose of this study is to develop the Theory of Uncertainty on COVID-19 using the strategy of theory derivation. Methods: Theory derivation was carried out in the following steps: review the literature to explore the phenomena related to uncertainty on COVID-19; select a parent theory that provides valuable concepts and a useful structure for derivation, and identify the concepts and structure of the parent theory to use in derivation; modify and redefine the concepts and structure of the parent theory to create a derived theory. In the literature review process, relevant findings were synthesized to support the propositions of the derived theory. Results: The Theory of Uncertainty on COVID-19 was derived from the Uncertainty in Illness Theory to make it relevant and applicable to a specific aspect of uncertainty on COVID-19, health-related uncertainty perceived by a person who has not contracted COVID-19. It is a middle-range theory targeting the general population and consists of a linear and unidirectional model centered on three themes: antecedents of uncertainty, appraisal of uncertainty, and coping with uncertainty. Conclusion The Theory of Uncertainty on COVID-19 will be able to contribute to efforts to manage perceived uncertainty on pandemic diseases and improve individual biopsychosocial health in the future.

Purpose: The purpose of this study is to develop the Theory of Uncertainty on COVID-19 using the strategy of theory derivation. Methods: Theory derivation was carried out in the following steps: review the literature to explore the phenomena related to uncertainty on COVID-19; select a parent theory that provides valuable concepts and a useful structure for derivation, and identify the concepts and structure of the parent theory to use in derivation; modify and redefine the concepts and structure of the parent theory to create a derived theory. In the literature review process, relevant findings were synthesized to support the propositions of the derived theory. Results: The Theory of Uncertainty on COVID-19 was derived from the Uncertainty in Illness Theory to make it relevant and applicable to a specific aspect of uncertainty on COVID-19, health-related uncertainty perceived by a person who has not contracted COVID-19. It is a middle-range theory targeting the general population and consists of a linear and unidirectional model centered on three themes: antecedents of uncertainty, appraisal of uncertainty, and coping with uncertainty. Conclusion The Theory of Uncertainty on COVID-19 will be able to contribute to efforts to manage perceived uncertainty on pandemic diseases and improve individual biopsychosocial health in the future.

Purpose: The purpose of this study is to develop the Theory of Uncertainty on COVID-19 using the strategy of theory derivation. Methods: Theory derivation was carried out in the following steps: review the literature to explore the phenomena related to uncertainty on COVID-19; select a parent theory that provides valuable concepts and a useful structure for derivation, and identify the concepts and structure of the parent theory to use in derivation; modify and redefine the concepts and structure of the parent theory to create a derived theory. In the literature review process, relevant findings were synthesized to support the propositions of the derived theory. Results: The Theory of Uncertainty on COVID-19 was derived from the Uncertainty in Illness Theory to make it relevant and applicable to a specific aspect of uncertainty on COVID-19, health-related uncertainty perceived by a person who has not contracted COVID-19. It is a middle-range theory targeting the general population and consists of a linear and unidirectional model centered on three themes: antecedents of uncertainty, appraisal of uncertainty, and coping with uncertainty. Conclusion The Theory of Uncertainty on COVID-19 will be able to contribute to efforts to manage perceived uncertainty on pandemic diseases and improve individual biopsychosocial health in the future.

Purpose: The purpose of this study is to develop the Theory of Uncertainty on COVID-19 using the strategy of theory derivation. Methods: Theory derivation was carried out in the following steps: review the literature to explore the phenomena related to uncertainty on COVID-19; select a parent theory that provides valuable concepts and a useful structure for derivation, and identify the concepts and structure of the parent theory to use in derivation; modify and redefine the concepts and structure of the parent theory to create a derived theory. In the literature review process, relevant findings were synthesized to support the propositions of the derived theory. Results: The Theory of Uncertainty on COVID-19 was derived from the Uncertainty in Illness Theory to make it relevant and applicable to a specific aspect of uncertainty on COVID-19, health-related uncertainty perceived by a person who has not contracted COVID-19. It is a middle-range theory targeting the general population and consists of a linear and unidirectional model centered on three themes: antecedents of uncertainty, appraisal of uncertainty, and coping with uncertainty. Conclusion The Theory of Uncertainty on COVID-19 will be able to contribute to efforts to manage perceived uncertainty on pandemic diseases and improve individual biopsychosocial health in the future.

Purpose: The purpose of this study is to develop the Theory of Uncertainty on COVID-19 using the strategy of theory derivation. Methods: Theory derivation was carried out in the following steps: review the literature to explore the phenomena related to uncertainty on COVID-19; select a parent theory that provides valuable concepts and a useful structure for derivation, and identify the concepts and structure of the parent theory to use in derivation; modify and redefine the concepts and structure of the parent theory to create a derived theory. In the literature review process, relevant findings were synthesized to support the propositions of the derived theory. Results: The Theory of Uncertainty on COVID-19 was derived from the Uncertainty in Illness Theory to make it relevant and applicable to a specific aspect of uncertainty on COVID-19, health-related uncertainty perceived by a person who has not contracted COVID-19. It is a middle-range theory targeting the general population and consists of a linear and unidirectional model centered on three themes: antecedents of uncertainty, appraisal of uncertainty, and coping with uncertainty. Conclusion The Theory of Uncertainty on COVID-19 will be able to contribute to efforts to manage perceived uncertainty on pandemic diseases and improve individual biopsychosocial health in the future.

Purpose: Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers (ARBs) are frequently employed to counteract the detrimental effects of proteinuria on glomerular diseases. However, the effects of ARBs remain poorly examined in pediatric patients with immunoglobulin A (IgA) nephropathy. Herein, we evaluated the efficacy and safety of losartan, an ARB, in pediatric IgA nephropathy with proteinuria. Methods: This prospective, single-arm, multicenter study included children with IgA nephropathy exhibiting proteinuria. Changes in proteinuria, blood pressure, and kidney function were prospectively evaluated before and 4 and 24 weeks after losartan administration. The primary endpoint was the difference in proteinuria between baseline and 24 weeks. Results: In total, 29 patients were enrolled and received losartan treatment. The full analysis set included 28 patients who received losartan at least once and had pre- and post-urinary protein to creatinine ratio measurements (n=28). The per-protocol analysis group included 22 patients who completed all scheduled visits without any serious violations during the study period. In both groups, the mean log (urine protein to creatinine ratio) value decreased significantly at 6 months. After 24 weeks, the urinary protein to creatinine ratio decreased by more than 50% in approximately 40% of the patients. The glomerular filtration rate was not significantly altered during the observation period. Conclusions Losartan decreased proteinuria without decreasing kidney function in patients with IgA nephropathy over 24 weeks. Losartan could be safely employed to reduce proteinuria in this patient population. ClinicalTrials.gov trial registration (NCT0223277)

Background/Aims: The prospective Crohn’s Disease Clinical Network and Cohort Study is a nationwide multicenter cohort study of patients with Crohn’s disease (CD) in Korea, aiming to prospectively investigate the clinical features and long-term prognosis associated with CD. Methods: Patients diagnosed with CD between January 2009 and September 2019 were prospectively enrolled. They were divided into two cohorts according to the year of diagnosis: cohort 1 (diagnosed between 2009 and 2011) versus cohort 2 (between 2012 and 2019). Results: A total of 1,175 patients were included, and the median follow-up duration was 68 months (interquartile range, 39.0 to 91.0 months). The treatment-free durations for thiopurines (p<0.001) and anti-tumor necrosis factor agents (p=0.018) of cohort 2 were shorter than those of cohort 1. Among 887 patients with B1 behavior at diagnosis, 149 patients (16.8%) progressed to either B2 or B3 behavior during follow-up. Early use of thiopurine was associated with a reduced risk of behavioral progression (adjusted hazard ratio [aHR], 0.69; 95% confidence interval [CI], 0.50 to 0.90), and family history of inflammatory bowel disease was associated with an increased risk of behavioral progression (aHR, 2.29; 95% CI, 1.16 to 4.50). One hundred forty-one patients (12.0%) underwent intestinal resection, and the intestinal resection-free survival time was significantly longer in cohort 2 than in cohort 1 (p=0.003). The early use of thiopurines (aHR, 0.35;95% CI, 0.23 to 0.51) was independently associated with a reduced risk of intestinal resection. Conclusions The prognosis of CD in Korea appears to have improved over time, as evidenced by the decreasing intestinal resection rate. Early use of thiopurines was associated with an improved prognosis represented by a reduced risk of intestinal resection.

Background: We sought to compare the performance of three commercially available automated urine sediment analyzers that represent the current urine sediment analysis technology. Methods: A total of 232 patient samples were analyzed using manual microscopy and three automated analyzers: IRIS Iq200 (Beckman Coulter, USA), UF-1000i (Sysmex, Japan), and Cobas u701 (Roche, Switzerland). We analyzed precision, linearity, carry-over, concordance rate, and agreement between the three analyzers and manual microscopy. Results: The repeatability and within-laboratory precision showed results similar to those of previous studies. All analyzers showed excellent linearity. The carry-over rates were within 1%. The correlation coefficient (r) between the three analyzers and manual microscopy was good. Regarding red blood cell (RBC), the UF-1000i showed a better concordance rate (90.52%) with manual microscopy than the other two analyzers and the agreement was substantial for UF-1000i (κ=0.63) and IRIS Iq200 (κ=0.61). Regarding white blood cell (WBC), Cobas u701 showed the best concordance rate (96.55%) and the agreement was moderate for IRIS Iq200 (κ=0.57) and Cobas u701 (κ=0.56), and fair for UF-1000i (κ=0.47). Regarding epithelial cell (EPI), IRIS Iq200 showed the highest concordance rate (99.2%) and the agreement was moderate for IRIS Iq200 (κ=0.59) and Cobas u701 (κ=0.54), and fair for UF-1000i (κ=0.40). Conclusions IRIS Iq200 offered the best agreement with manual microscopy for WBC and EPI count, while UF-1000i showed a better agreement for RBC count. The agreement is insufficient for fully replacing the manual microscopy.

PURPOSE: Data are lacking on the association between the allergic rhinitis (AR) phenotype and sensitization to specific allergens or bronchial hyperresponsiveness (BHR) in children. We here investigated risk factors and comorbidities, including sensitization to specific allergens and BHR, for the AR phenotype by AR and its Impact on Asthma (ARIA) classification in a general population-based birth cohort study. METHODS: We enrolled 606 children aged 7 years from the Panel Study of Korean Children. The AR phenotype was assigned in accordance with the ARIA classification in children. Skin prick tests and Provocholine provocation test were performed. Risk factors and comorbidities for AR phenotypes were then analyzed. RESULTS: The prevalence of mild and moderate to severe AR in our study cohort was 37.2% and 8.8%, respectively. Recent use of analgesics or antipyretics and current cat ownership were associated with the risk of mild persistent AR. Sensitizations to Dermatophagoides Pteronyssinus (Der p), Japanese hop and cat were associated with moderate to severe persistent AR. Children with moderate to severe AR had a higher risk of current asthma and BHR compared to mild AR cases (adjusted odds ratio [aOR], 5.26; 95% confidence interval [CI], 1.77–15.62). Moderate to severe AR with allergic sensitization was associated with the highest risk of BHR (aOR, 11.77; 95% CI, 3.40–40.74). CONCLUSIONS: Moderate to severe-persistent AR is more closely related to respiratory comorbidities and sensitizations than mild AR. Stratifying the AR phenotype by ARIA classification may assist in disease management.
Allergens ; Analgesics ; Animals ; Antipyretics ; Asian Continental Ancestry Group ; Asthma ; Bronchial Hyperreactivity ; Cats ; Child ; Classification ; Cohort Studies ; Comorbidity ; Dermatophagoides pteronyssinus ; Disease Management ; Humans ; Methacholine Chloride ; Odds Ratio ; Ownership ; Parturition ; Phenotype ; Prevalence ; Rhinitis, Allergic ; Risk Factors ; Skin

Background: We sought to compare the performance of three commercially available automated urine sediment analyzers that represent the current urine sediment analysis technology. Methods: A total of 232 patient samples were analyzed using manual microscopy and three automated analyzers: IRIS Iq200 (Beckman Coulter, USA), UF-1000i (Sysmex, Japan), and Cobas u701 (Roche, Switzerland). We analyzed precision, linearity, carry-over, concordance rate, and agreement between the three analyzers and manual microscopy. Results: The repeatability and within-laboratory precision showed results similar to those of previous studies. All analyzers showed excellent linearity. The carry-over rates were within 1%. The correlation coefficient (r) between the three analyzers and manual microscopy was good. Regarding red blood cell (RBC), the UF-1000i showed a better concordance rate (90.52%) with manual microscopy than the other two analyzers and the agreement was substantial for UF-1000i (κ=0.63) and IRIS Iq200 (κ=0.61). Regarding white blood cell (WBC), Cobas u701 showed the best concordance rate (96.55%) and the agreement was moderate for IRIS Iq200 (κ=0.57) and Cobas u701 (κ=0.56), and fair for UF-1000i (κ=0.47). Regarding epithelial cell (EPI), IRIS Iq200 showed the highest concordance rate (99.2%) and the agreement was moderate for IRIS Iq200 (κ=0.59) and Cobas u701 (κ=0.54), and fair for UF-1000i (κ=0.40). Conclusions IRIS Iq200 offered the best agreement with manual microscopy for WBC and EPI count, while UF-1000i showed a better agreement for RBC count. The agreement is insufficient for fully replacing the manual microscopy.