LIVIVO - Search results -

Search results

Result 1 - 10 of total 15

Search options

Article ; Online: Application of Standardization for Causal Inference in Observational Studies

Sangwon Lee / Woojoo Lee

Journal of Preventive Medicine and Public Health, Vol 55, Iss 2, Pp 116-

A Step-by-step Tutorial for Analysis Using R Software

2022 Volume 124

Abstract: 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 ... ...

Abstract	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.
Keywords	standardization ; causality ; observational study ; confounding factors ; epidemiology ; Medicine ; R ; Public aspects of medicine ; RA1-1270
Language	English
Publishing date	2022-03-01T00:00:00Z
Publisher	Korean Society for Preventive Medicine
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Model-Based Approach for Designing an Efficient Bioequivalence Study for Highly Variable Drugs

Eunjung Song / Woojoo Lee / Bo-Hyung Kim

Pharmaceuticals, Vol 14, Iss 1101, p

2021 Volume 1101

Abstract: The statistical procedures as outlined by the European Medicines Agency (EMA) and United States Food and Drug Administration (FDA) guidelines for bioequivalence testing of highly variable drugs (HVDs) are complex. Additionally, the sample size is ... ...

Abstract	The statistical procedures as outlined by the European Medicines Agency (EMA) and United States Food and Drug Administration (FDA) guidelines for bioequivalence testing of highly variable drugs (HVDs) are complex. Additionally, the sample size is affected by clinical study designs or practical real-world problems, such as dropout rate or study budget. To overcome these difficulties, we propose a model-based approach for the selection of a study design with a sample size that satisfies the bioequivalence criteria using simulation studies based on a pharmacokinetic (PK) model. The designed approach was implemented using a simulation procedure considering some conventionally measured factors, such as geometric mean ratio and within-subject coefficient of variation, with various PK information important in determining bioequivalence. All simulation results were assessed according to the EMA and FDA guidelines. Furthermore, power calculations from simulation results were interpreted with regard to PK characteristics and compared among 2 × 2, 3 × 3, and 2 × 4 crossover designs to determine the efficient design considering appropriate sample size and duration of the clinical study. The proposed approach can be applied to bioequivalence studies of all drugs. However, the current study was targeted at HVDs, which are highly likely to require detailed decision making for sample size and study design.
Keywords	highly variable drugs ; reference-scaled average bioequivalence ; pharmacokinetic model ; Medicine ; R ; Pharmacy and materia medica ; RS1-441
Subject code	310
Language	English
Publishing date	2021-10-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Association with Combined Occupational Hazards Exposure and Risk of Metabolic Syndrome

Dongmug Kang / Eun-Soo Lee / Tae-Kyoung Kim / Yoon-Ji Kim / Seungho Lee / Woojoo Lee / Hyunman Sim / Se-Yeong Kim

Safety and Health at Work, Vol 14, Iss 3, Pp 279-

A Workers' Health Examination Cohort 2012–2021

2023 Volume 286

Abstract: 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 ... ...

Abstract	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.
Keywords	Heavymetal exposure ; Lifestyle disease ; Occupational risk factors ; Organic solvents exposure ; Worker's health cohort ; Public aspects of medicine ; RA1-1270
Subject code	610
Language	English
Publishing date	2023-09-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: The Association between Community Water Fluoridation and Bone Diseases

Naae Lee / Sungchan Kang / Woojoo Lee / Seung-sik Hwang

International Journal of Environmental Research and Public Health, Vol 17, Iss 9170, p

A Natural Experiment in Cheongju, Korea

2020 Volume 9170

Abstract: The present study aimed to investigate the association between bone diseases and community water fluoridation (CWF). An ecological study with a natural experiment design was conducted in Cheongju, South Korea, from 1 January 2004 to 31 December 2013. The ...

Abstract	The present study aimed to investigate the association between bone diseases and community water fluoridation (CWF). An ecological study with a natural experiment design was conducted in Cheongju, South Korea, from 1 January 2004 to 31 December 2013. The community water fluoridation program was implemented in Cheongju and divided into CWF and non-CWF areas. To observe adverse health effects related to bone diseases, we conducted a spatio-temporal analysis of the prevalence of hip fracture, osteoporosis, and bone cancer in residents who have lived in CWF and non-CWF areas using National Health Insurance Service data. First, we used standardized incidence ratios to estimate the disease risk. Second, the hierarchical Bayesian Poisson spatio-temporal regression model was used to investigate the association between the selected bone diseases and CWF considering space and time interaction. The method for Bayesian estimation was based on the R-integrated nested Laplace approximation (INLA). Comparing the CWF area with the non-CWF area, there was no clear evidence that exposure to CWF increased health risks at the town level in Cheongju since CWF was terminated after 2004. The posterior relative risks (RR) of hip fracture was 0.95 (95% confidence intervals 0.87, 1.05) and osteoporosis was 0.94 (0.87, 1.02). The RR in bone cancer was a little high because the sample size very small compared to the other bone diseases (RR = 1.20 (0.89, 1.61)). The relative risk of selected bone diseases (hip fractures, osteoporosis, and bone cancer) increased over time but did not increase in the CWF area compared to non-CWF areas. CWF has been used to reduce dental caries in all population groups and is known for its cost-effectiveness. These findings suggest that CWF is not associated with adverse health risks related to bone diseases. This study provides scientific evidence based on a natural experiment design. It is necessary to continue research on the well-designed epidemiological studies and develop public health prevention ...
Keywords	community water fluoridation ; adverse health effect ; bone diseases ; natural experiment ; spatio-temporal analysis ; Medicine ; R
Language	English
Publishing date	2020-12-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Diagnostic accuracy of SOX11 immunohistochemistry in mantle cell lymphoma

Woojoo Lee / Eun Shin / Bo-Hyung Kim / Hyunchul Kim

PLoS ONE, Vol 14, Iss 11, p e

A meta-analysis.

2019 Volume 0225096

Abstract: SOX11 is a transcription factor that is normally expressed in the fetal brain and has also been detected in some malignant tumors, including mantle cell lymphoma (MCL). MCL is a mature B-cell lymphoma that characteristically expresses cyclin D1, which ... ...

Abstract	SOX11 is a transcription factor that is normally expressed in the fetal brain and has also been detected in some malignant tumors, including mantle cell lymphoma (MCL). MCL is a mature B-cell lymphoma that characteristically expresses cyclin D1, which has been used as a diagnostic tumor marker. SOX11 has also recently emerged as a tumor marker for MCL, particularly in cyclin D1-negative MCLs and to distinguish between MCLs and other cyclin D1-positive lymphomas. In this study, we evaluated the diagnostic accuracy of SOX11 immunohistochemistry for the diagnosis of MCL using a meta-analysis. A comprehensive literature search was performed using the PubMED, EMBASE, and Cochrane library through May 9, 2018. In total, 14 studies were included in our meta-analysis. The sensitivity, specificity, and area under the curve calculated from the summary receiver operator characteristic were 0.9, 0.95, and 0.934, respectively. Effect sizes of log positive likelihood ratios, log negative likelihood ratios, and log diagnostic odds ratios were 2.67, -2.12, and 5.27, respectively. Statistically significant substantial heterogeneity was observed for specificity (I2 = 95%), but not for sensitivity. Subgroup analysis and meta-regression were performed to explain the heterogeneity in specificity and showed that the proportions of Burkitt's lymphoma, lymphoblastic lymphoma, and hairy cell leukemia were significant covariates among studies using rabbit polyclonal antibodies. Overall, this meta-analysis showed that SOX11 was a useful diagnostic marker for MCL, with the clone MRQ-58 mouse monoclonal antibody showing particularly robust performance.
Keywords	Medicine ; R ; Science ; Q
Subject code	610
Language	English
Publishing date	2019-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Effectiveness of bystander cardiopulmonary resuscitation in improving the survival and neurological recovery of patients with out-of-hospital cardiac arrest

Joongyub Lee / Woojoo Lee / Yu Jin Lee / Hyunman Sim / Won Kyung Lee

PLoS ONE, Vol 15, Iss 12, p e

A nationwide patient cohort study.

2020 Volume 0243757

Abstract: Introduction Few studies have focused on enhancing causality and yielding unbiased estimates on the effectiveness of bystander cardiopulmonary resuscitation (BCPR) on the outcomes of out-of-hospital cardiac arrest (OHCA) in a real-world setting. ... ...

Abstract	Introduction Few studies have focused on enhancing causality and yielding unbiased estimates on the effectiveness of bystander cardiopulmonary resuscitation (BCPR) on the outcomes of out-of-hospital cardiac arrest (OHCA) in a real-world setting. Therefore, this study evaluated the effect of BCPR on the outcomes of OHCA and its differences according to the characteristics of OHCA. Methods This study enrolled all patients with OHCA of cardiac etiology treated by emergency medical services (EMS) in Korea from 2012 to 2015. The endpoints were survival and neurological recovery at discharge, and the main exposure was BCPR conducted by a layperson. The effect of BCPR was analyzed after adjusting for confounders, determined using a directed acyclic graph, by inverse probability of treatment weighting (IPTW) and model-based standardization (STR). Moreover, differences in subgroups and time trends were evaluated. Results Among 10,505 eligible patients after excluding those with missing data on BCPR, 7,721 patients received BCPR, accounting for 74.3% of EMS-treated OHCA patients. BCPR increased the odds of survival and good neurological recovery at discharge by 1.67- (95% confidence interval (CI): 1.44-1.93) and 1.93- (95% CI: 1.56-2.39) fold, respectively, in the IPTW analysis. These findings were comparable to those obtained with STR. The odds ratios were 2.39 (95% CI: 1.91-2.94) and 2.70 (95% CI: 1.94-3.41), respectively, in the sensitivity analysis of the missing BCPR information considering confounders and the outcome variable. However, the effect of qualified BCPR was not evenly distributed, and it did not increase with time. BCPR was likely to be more effective in male patients aged <65 years, those who experienced an OHCA in a private place or non-capital region, and those with shockable rhythm at the scene. Conclusion Based on data from a nationwide registry, the estimated effect of BCPR on survival and neurological recovery was moderate and did not improve from 2012 to 2015.
Keywords	Medicine ; R ; Science ; Q
Subject code	616
Language	English
Publishing date	2020-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: The importance of investing in data, models, experiments, team science, and public trust to help policymakers prepare for the next pandemic.

Richard Grieve / Youqi Yang / Sam Abbott / Giridhara R Babu / Malay Bhattacharyya / Natalie Dean / Stephen Evans / Nicholas Jewell / Sinéad M Langan / Woojoo Lee / Geert Molenberghs / Liam Smeeth / Elizabeth Williamson / Bhramar Mukherjee

PLOS Global Public Health, Vol 3, Iss 11, p e

2023 Volume 0002601

Abstract: The COVID-19 pandemic has brought about valuable insights regarding models, data, and experiments. In this narrative review, we summarised the existing literature on these three themes, exploring the challenges of providing forecasts, the requirement for ...

Abstract	The COVID-19 pandemic has brought about valuable insights regarding models, data, and experiments. In this narrative review, we summarised the existing literature on these three themes, exploring the challenges of providing forecasts, the requirement for real-time linkage of health-related datasets, and the role of 'experimentation' in evaluating interventions. This literature review encourages us to broaden our perspective for the future, acknowledging the significance of investing in models, data, and experimentation, but also to invest in areas that are conceptually more abstract: the value of 'team science', the need for public trust in science, and in establishing processes for using science in policy. Policy-makers rely on model forecasts early in a pandemic when there is little data, and it is vital to communicate the assumptions, limitations, and uncertainties (theme 1). Linked routine data can provide critical information, for example, in establishing risk factors for adverse outcomes but are often not available quickly enough to make a real-time impact. The interoperability of data resources internationally is required to facilitate sharing across jurisdictions (theme 2). Randomised controlled trials (RCTs) provided timely evidence on the efficacy and safety of vaccinations and pharmaceuticals but were largely conducted in higher income countries, restricting generalisability to low- and middle-income countries (LMIC). Trials for non-pharmaceutical interventions (NPIs) were almost non-existent which was a missed opportunity (theme 3). Building on these themes from the narrative review, we underscore the importance of three other areas that need investment for effective evidence-driven policy-making. The COVID-19 response relied on strong multidisciplinary research infrastructures, but funders and academic institutions need to do more to incentivise team science (4). To enhance public trust in the use of scientific evidence for policy, researchers and policy-makers must work together to clearly ...
Keywords	Public aspects of medicine ; RA1-1270
Subject code	306
Language	English
Publishing date	2023-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article: Sensitivity analysis on the ecological bias for Seoul tuberculosis data

Song, Eunjung / Soeun Kim / Seungsik Hwang / Woojoo Lee

Environmental and ecological statistics. 2018 Sept., v. 25, no. 3

2018

Abstract: In ecological studies, researchers often try to convey the analysis results to individual level based on aggregate data. In order to do this correctly, the possibility of ecological bias should be studied and addressed. One of the key ideas used to ... ...

Abstract	In ecological studies, researchers often try to convey the analysis results to individual level based on aggregate data. In order to do this correctly, the possibility of ecological bias should be studied and addressed. One of the key ideas used to address the ecological bias issue is to derive the ecological model from the individual model and to check whether the parameter of interest in the individual model is identifiable in the ecological model. However, the procedure depends on unverifiable assumptions, and we recommend checking how sensitive the results are to these unverifiable assumptions. We analyzed the tuberculosis data that was collected in Seoul in 2005 using a spatial ecological regression model for the aggregate count data with spatial correlation, and found that the deprivation index is likely to have a small positive effect on the occurrence risk of tuberculosis in individual level in Seoul. We considered this finding in various aspects by performing in depth sensitivity analyses. In particular, our findings are shown to be robust to the distribution assumptions for the individual exposure and missing binary covariate across various scenarios.
Keywords	models ; regression analysis ; risk ; tuberculosis
Language	English
Dates of publication	2018-09
Size	p. 341-362.
Publishing place	Springer US
Document type	Article
ZDB-ID	2000906-9
ISSN	1573-3009 ; 1352-8505
ISSN (online)	1573-3009
ISSN	1352-8505
DOI	10.1007/s10651-018-0408-4
Database	NAL-Catalogue (AGRICOLA)

Full text online

Accessible to users with ZB MED library card

Order via subito

This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

Details ▾
- Full text online
- Order with fees

Article ; Online: Hygroscopic properties of particulate matter and effects of their interactions with weather on visibility

Wan-Sik Won / Rosy Oh / Woojoo Lee / Sungkwan Ku / Pei-Chen Su / Yong-Jin Yoon

Scientific Reports, Vol 11, Iss 1, Pp 1-

2021 Volume 12

Abstract: Abstract The hygroscopic property of particulate matter (PM) influencing light scattering and absorption is vital for determining visibility and accurate sensing of PM using a low-cost sensor. In this study, we examined the hygroscopic properties of ... ...

Abstract	Abstract The hygroscopic property of particulate matter (PM) influencing light scattering and absorption is vital for determining visibility and accurate sensing of PM using a low-cost sensor. In this study, we examined the hygroscopic properties of coarse PM (CPM) and fine PM (FPM; PM2.5) and the effects of their interactions with weather factors on visibility. A censored regression model was built to investigate the relationships between CPM and PM2.5 concentrations and weather observations. Based on the observed and modeled visibility, we computed the optical hygroscopic growth factor, $$f\left( {RH} \right)$$ f RH , and the hygroscopic mass growth, $$GM_{VIS}$$ G M VIS , which were applied to PM2.5 field measurement using a low-cost PM sensor in two different regions. The results revealed that the CPM and PM2.5 concentrations negatively affect visibility according to the weather type, with substantial modulation of the interaction between the relative humidity (RH) and PM2.5. The modeled $$f\left( {RH} \right)$$ f RH agreed well with the observed $$f\left( {RH} \right)$$ f RH in the RH range of the haze and mist. Finally, the RH-adjusted PM2.5 concentrations based on the visibility-derived hygroscopic mass growth showed the accuracy of the low-cost PM sensor improved. These findings demonstrate that in addition to visibility prediction, relationships between PMs and meteorological variables influence light scattering PM sensing.
Keywords	Medicine ; R ; Science ; Q
Language	English
Publishing date	2021-08-01T00:00:00Z
Publisher	Nature Portfolio
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Perception and expectations of personal sound amplification products in Korea

Jae Sang Han / Yeonji Kim / Moo Kyun Park / Jae-Jun Song / Il Joon Moon / Woojoo Lee / Young Sang Cho / Jae-Hyun Seo / Yong-Ho Park

PLoS ONE, Vol 17, Iss 5, p e

A hospital-based, multi-center, cross-sectional survey.

2022 Volume 0269123

Abstract: Objectives The objective of this study was to investigate current perception and expected price of personal sound amplification products (PSAPs) and to analyze influencing factors through multi-center hospital-based surveys of outpatients, caregivers, ... ...

Abstract	Objectives The objective of this study was to investigate current perception and expected price of personal sound amplification products (PSAPs) and to analyze influencing factors through multi-center hospital-based surveys of outpatients, caregivers, and hearing experts. Methods A multi-center exploratory cross-sectional study was conducted in two groups of respondents with two separate surveys: 1) a perception survey of patients and caregivers who visited an otorhinolaryngology outpatient clinic in 5 general hospitals and 2) an opinion survey of hearing specialists about the expected price of PSAPs. A total of 197 outpatient visitors responded to the perception survey, and 42 hearing specialists responded to the opinion survey. Results Overall perception score (18 questions) was 3.04 (95% CI, 3.00-3.09). When 5 categories of perception (knowledge, needs, cost, expectation, and information categories) were analyzed, cost and expectation showed the highest scores of 3.33 (95% CI, 3.21-3.44) and 3.33 (95% CI, 3.27-3.40), respectively, and needs showed the lowest score of 2.23 (95% CI, 1.97-2.49). The ≥ 60-year-old group showed significantly higher perception of PSAPs (P = 0.002), and the individuals with greater severity of subjective hearing loss showed significantly higher perception of PSAPs (P = 0.002). The expected price of PSAPs of the outpatient visitors was 933.9 USD (95% CI, 811.9-1056.0) per ear. Mean expected price of PSAPs of hearing specialists was 291.3 USD (95% CI, 238.2-344.3) per ear. Conclusion The perception rate of PSAPs was very low, and there was a discrepancy in the expected price of PSAPs between patients/caregivers and hearing experts. Hearing specialists should make effort to improve perception of PSAPs.
Keywords	Medicine ; R ; Science ; Q
Subject code	390
Language	English
Publishing date	2022-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Order via subito

Full text online

More links

Kategorien

Inter-library loan at ZB MED

Full text online

More links

Kategorien

Inter-library loan at ZB MED