Association with Combined Occupational Hazards Exposure and Risk of Metabolic Syndrome: A Workers' Health Examination Cohort 2012–2021

Background@#This study aimed to evaluate the association between exposure to occupational hazards and the metabolic syndrome. A secondary objective was to analyze the additive and multiplicative effects of exposure to risk factors. @*Methods@#This retrospective cohort was based on 31,615 health examinees at the Pusan National University Yangsan Hospital in Republic of Korea from 2012–2021. Demographic and behavior-related risk factors were treated as confounding factors, whereas three physical factors, 19 organic solvents and aerosols, and 13 metals and dust were considered occupational risk factors. Time-dependent Cox regression analysis was used to calculate hazard ratios. @*Results@#The risk of metabolic syndrome was significantly higher in night shift workers (hazard ratio = 1.45: 95% confidence interval = 1.36–1.54) and workers who were exposed to noise (1.15:1.07–1.24). Exposure to some other risk factors was also significantly associated with a higher risk of metabolic syndrome. They were dimethylformamide, acetonitrile, trichloroethylene, xylene, styrene, toluene, dichloromethane, copper, antimony, lead, copper, iron, welding fume, and manganese. Among the 28 significant pairs, 19 exhibited both positive additive and multiplicative effects. @*Conclusions@#Exposure to single or combined occupational risk factors may increase the risk of developing metabolic syndrome. Working conditions should be monitored and improved to reduce exposure to occupational hazards and prevent the development of the metabolic syndrome.

An Introduction to Causal Mediation Analysis With a Comparison of 2 R Packages / 예방의학회지

Traditional mediation analysis, which relies on linear regression models, has faced criticism due to its limited suitability for cases involving different types of variables and complex covariates, such as interactions. This can result in unclear definitions of direct and indirect effects. As an alternative, causal mediation analysis using the counterfactual framework has been introduced to provide clearer definitions of direct and indirect effects while allowing for more flexible modeling methods. However, the conceptual understanding of this approach based on the counterfactual framework remains challenging for applied researchers. To address this issue, the present article was written to highlight and illustrate the definitions of causal estimands, including controlled direct effect, natural direct effect, and natural indirect effect, based on the key concept of nested counterfactuals. Furthermore, we recommend using 2 R packages, ‘medflex’ and ‘mediation’, to perform causal mediation analysis and provide public health examples. The article also offers caveats and guidelines for accurate interpretation of the results.

Directed acyclic graphs for clinical research: a tutorial

Directed acyclic graphs (DAGs) are useful tools for visualizing the hypothesized causal structures in an intuitive way and selecting relevant confounders in causal inference. However, in spite of their increasing use in clinical and surgical research, the causal graphs might also be misused by a lack of understanding of the central principles. In this article, we aim to introduce the basic terminology and fundamental rules of DAGs, and DAGitty, a user-friendly program that easily displays DAGs. Specifically, we describe how to determine variables that should or should not be adjusted based on the backdoor criterion with examples. In addition, the occurrence of the various types of biases is discussed with caveats, including the problem caused by the traditional approach using p-values for confounder selection. Moreover, a detailed guide to DAGitty is provided with practical examples regarding minimally invasive surgery. Essentially, the primary benefit of DAGs is to aid researchers in clarifying the research questions and the corresponding designs based on the domain knowledge. With these strengths, we propose that the use of DAGs may contribute to rigorous research designs, and lead to transparency and reproducibility in research on minimally invasive surgery.

Application of Standardization for Causal Inference in Observational Studies: A Step-by-step Tutorial for Analysis Using R Software / 예방의학회지

Epidemiological studies typically examine the causal effect of exposure on a health outcome. Standardization is one of the most straightforward methods for estimating causal estimands. However, compared to inverse probability weighting, there is a lack of user-centric explanations for implementing standardization to estimate causal estimands. This paper explains the standardization method using basic R functions only and how it is linked to the R package stdReg, which can be used to implement the same procedure. We provide a step-by-step tutorial for estimating causal risk differences, causal risk ratios, and causal odds ratios based on standardization. We also discuss how to carry out subgroup analysis in detail.

Effect of intravenous dexamethasone on the duration of postoperative analgesia for popliteal sciatic nerve block: a randomized, double-blind, placebo-controlled study / 대한마취과학회지

Background@#Intravenous (IV) dexamethasone prolongs the duration of a peripheral nerve block; however, there is little available information about its optimal effective dose. This study aimed to evaluate the effects of three different doses of IV dexamethasone on the duration of postoperative analgesia to determine the optimal effective dose for a sciatic nerve block. @*Methods@#Patients scheduled for foot and ankle surgery were randomly assigned to receive normal saline or IV dexamethasone (2.5 mg, 5 mg, or 10 mg). An ultrasound-guided popliteal sciatic nerve block was performed using 0.75% ropivacaine (20 ml) before general anesthesia. The duration of postoperative analgesia was the primary outcome, and pain scores, use of rescue analgesia, onset time, adverse effects, and patient satisfaction were assessed as secondary outcomes. @*Results@#Compared with the control group, the postoperative analgesic duration of the sciatic nerve block was prolonged in groups receiving IV dexamethasone 10 mg (P < 0.001), but not in the groups receiving IV dexamethasone 2.5 mg or 5 mg. The use of rescue analgesics was significantly different among the four groups 24 h postoperatively (P = 0.001) and similar thereafter. However, pain scores were not significantly different among the four groups 24 h postoperatively. There were no statistically significant differences in the other secondary outcomes among the four groups. @*Conclusions@#This study demonstrated that compared to the controls, only IV dexamethasone 10 mg increased the duration of postoperative analgesia following a sciatic nerve block for foot and ankle surgery without the occurrence of adverse events.

Effect of intravenous dexamethasone on the duration of postoperative analgesia for popliteal sciatic nerve block: a randomized, double-blind, placebo-controlled study / 대한마취과학회지

Background@#Intravenous (IV) dexamethasone prolongs the duration of a peripheral nerve block; however, there is little available information about its optimal effective dose. This study aimed to evaluate the effects of three different doses of IV dexamethasone on the duration of postoperative analgesia to determine the optimal effective dose for a sciatic nerve block. @*Methods@#Patients scheduled for foot and ankle surgery were randomly assigned to receive normal saline or IV dexamethasone (2.5 mg, 5 mg, or 10 mg). An ultrasound-guided popliteal sciatic nerve block was performed using 0.75% ropivacaine (20 ml) before general anesthesia. The duration of postoperative analgesia was the primary outcome, and pain scores, use of rescue analgesia, onset time, adverse effects, and patient satisfaction were assessed as secondary outcomes. @*Results@#Compared with the control group, the postoperative analgesic duration of the sciatic nerve block was prolonged in groups receiving IV dexamethasone 10 mg (P < 0.001), but not in the groups receiving IV dexamethasone 2.5 mg or 5 mg. The use of rescue analgesics was significantly different among the four groups 24 h postoperatively (P = 0.001) and similar thereafter. However, pain scores were not significantly different among the four groups 24 h postoperatively. There were no statistically significant differences in the other secondary outcomes among the four groups. @*Conclusions@#This study demonstrated that compared to the controls, only IV dexamethasone 10 mg increased the duration of postoperative analgesia following a sciatic nerve block for foot and ankle surgery without the occurrence of adverse events.

Diagnostic Accuracy of Percutaneous Transthoracic Needle Lung Biopsies: A Multicenter Study

OBJECTIVE: To measure the diagnostic accuracy of percutaneous transthoracic needle lung biopsies (PTNBs) on the basis of the intention-to-diagnose principle and identify risk factors for diagnostic failure of PTNBs in a multi-institutional setting. MATERIALS AND METHODS: A total of 9384 initial PTNBs performed in 9239 patients (mean patient age, 65 years [range, 20–99 years]) from January 2010 to December 2014 were included. The accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of PTNBs for diagnosis of malignancy were measured. The proportion of diagnostic failures was measured, and their risk factors were identified. RESULTS: The overall accuracy, sensitivity, specificity, PPV, and NPV were 91.1% (95% confidence interval [CI], 90.6–91.7%), 92.5% (95% CI, 91.9–93.1%), 86.5% (95% CI, 85.0–87.9%), 99.2% (95% CI, 99.0–99.4%), and 84.3% (95% CI, 82.7–85.8%), respectively. The proportion of diagnostic failures was 8.9% (831 of 9384; 95% CI, 8.3–9.4%). The independent risk factors for diagnostic failures were lesions ≤ 1 cm in size (adjusted odds ratio [AOR], 1.86; 95% CI, 1.23–2.81), lesion size 1.1–2 cm (1.75; 1.45–2.11), subsolid lesions (1.81; 1.32–2.49), use of fine needle aspiration only (2.43; 1.80–3.28), final diagnosis of benign lesions (2.18; 1.84–2.58), and final diagnosis of lymphomas (10.66; 6.21–18.30). Use of cone-beam CT (AOR, 0.31; 95% CI, 0.13–0.75) and conventional CT-guidance (0.55; 0.32–0.94) reduced diagnostic failures. CONCLUSION: The accuracy of PTNB for diagnosis of malignancy was fairly high in our large-scale multi-institutional cohort. The identified risk factors for diagnostic failure may help reduce diagnostic failure and interpret the biopsy results.

Blood Pressure Reference Values for Normal Weight Korean Children and Adolescents: Data from The Korea National Health and Nutrition Examination Survey 1998–2016: The Korean Working Group of Pediatric Hypertension

BACKGROUND AND OBJECTIVES: Hypertension is becoming one of the most common health conditions in children and adolescents due to increasing childhood obesity. We aimed to provide the auscultatory blood pressure (BP) normative reference values for Korean non-overweight children and adolescents. METHODS: BP measurements in children and adolescents aged 10 to 18 years were performed in the Korean National Health and Nutrition Examination Survey (KNHANES) from 1998 to 2016. BP was measured using a mercury sphygmomanometer. Sex-, age- and height-specific systolic BP (SBP) and diastolic BP (DBP) percentiles were calculated in the non-overweight children (n=10,442). We used the General Additive Model for Location Scale and Shape method to calculate BP percentiles. RESULTS: The 50th, 90th, 95th, and 99th percentiles of SBP and DBP tables and graphs of non-overweight children and adolescents aged 10 to 18 years were presented by age and height percentiles. We found that the SBP and DBP at the 95th percentile were well correlated with height. The BP tables presented by height contained BP values from 124 cm to 190 cm for boys and from 120 cm to 178 cm for girls. Boys had higher SBP and DBP. CONCLUSIONS: We provided the sex-, age- and height-specific auscultatory BP values using the KNHANES big data. These may be useful in diagnosis and treatment of hypertension in Korean children and adolescents.

Blood Pressure Reference Values for Normal Weight Korean Children and Adolescents: Data from The Korea National Health and Nutrition Examination Survey 1998–2016: The Korean Working Group of Pediatric Hypertension

BACKGROUND AND OBJECTIVES@#Hypertension is becoming one of the most common health conditions in children and adolescents due to increasing childhood obesity. We aimed to provide the auscultatory blood pressure (BP) normative reference values for Korean non-overweight children and adolescents.@*METHODS@#BP measurements in children and adolescents aged 10 to 18 years were performed in the Korean National Health and Nutrition Examination Survey (KNHANES) from 1998 to 2016. BP was measured using a mercury sphygmomanometer. Sex-, age- and height-specific systolic BP (SBP) and diastolic BP (DBP) percentiles were calculated in the non-overweight children (n=10,442). We used the General Additive Model for Location Scale and Shape method to calculate BP percentiles.@*RESULTS@#The 50th, 90th, 95th, and 99th percentiles of SBP and DBP tables and graphs of non-overweight children and adolescents aged 10 to 18 years were presented by age and height percentiles. We found that the SBP and DBP at the 95th percentile were well correlated with height. The BP tables presented by height contained BP values from 124 cm to 190 cm for boys and from 120 cm to 178 cm for girls. Boys had higher SBP and DBP.@*CONCLUSIONS@#We provided the sex-, age- and height-specific auscultatory BP values using the KNHANES big data. These may be useful in diagnosis and treatment of hypertension in Korean children and adolescents.

Comparative Assessment of Diagnostic Performances of Two Commercial Rapid Diagnostic Test Kits for Detection of Plasmodium spp. in Ugandan Patients with Malaria

Prompt diagnosis of malaria cases with rapid diagnostic tests (RDTs) has been widely adopted as an effective malaria diagnostic tool in many malaria endemic countries, primarily due to their easy operation, fast result output, and straightforward interpretation. However, there has been controversy about the diagnostic accuracy of RDTs. This study was conducted to evaluate the diagnostic performances of the 2 commercially available malaria RDT kits, RapiGEN Malaria Ag Pf/Pv (pLDH/pLDH) and Asan EasyTestTM Malaria Ag Pf/Pv (HRP-2/pLDH) for their abilities to detect Plasmodium species in blood samples collected from Ugandan patients with malaria. To evaluate the diagnostic performances of these 2 RDT kits, 229 blood samples were tested for malaria infection by microscopic examination and a species-specific nested polymerase chain reaction. The detection sensitivities for P. falciparum of Malaria Ag Pf/Pv (pLDH/pLDH) and Asan EasyTestTM Malaria Ag Pf/Pv (HRP-2/pLDH) were 87.83% and 89.57%, respectively. The specificities of the 2 RDTs were 100% for P. falciparum and mixed P. falciparum/P. vivax infections. These results suggest that the 2 RDT kits showed reasonable levels of diagnostic performances for detection of the malaria parasites from Ugandan patients. However, neither kit could effectively detect P. falciparum infections with low parasitaemia ( < 500 parasites/μl).

Community-Acquired Necrotizing Pneumonia Caused by ST72-SCCmec Type IV-Methicillin-Resistant Staphylococcus aureus in Korea / 결핵및호흡기질환

Methcillin-resistant Staphylococcus aureus (MRSA) has emerged as an important cause of community-acquired infections, which has been recently designated as community-associated (CA) MRSA. Panton-Valentine leukocidin (PVL)-negative multilocus sequence type 72 (ST72)-staphylococcal cassette chromosome mec (SCCmec) type IV has been reported as the predominat CA-MRSA strain in Korea and is commonly associated with skin and soft tissue infections in addition to healthcare-associated pneumonia. However, community-acquired pneumonia (CAP) for this strain has not yet been reported. We hereby report two cases of CAP caused by PVL-negative ST72-SCCmec type IV strain in patients who had no risk factors for MRSA acquisition. While CA-MRSA infections are not yet prevalent in Korea, our cases suggest that CA-MRSA should be considered in cases of severe CAP, especially for cases associated with necrotizing pneumonia.