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Purpose@#This study aimed to confirm the decision-making patterns for life-sustaining treatment (LST) and analyze medical service utilization changes after enforcement of the Life-Sustaining Treatment Decision-Making Act. @*Materials and Methods@#Of 1,237 patients who completed legal forms for life-sustaining treatment (hereafter called the LST form) at three academic hospitals and died at the same institutions, 1,018 cancer patients were included. Medical service utilization and costs were analyzed using claims data. @*Results@#The median time to death from completion of the LST form was three days (range, 0 to 248 days). Of these, 517 people died within two days of completing the document, and 36.1% of all patients prepared the LST form themselves. The frequency of use of the intensive care unit, continuous renal replacement therapy, and mechanical ventilation was significantly higher when the families filled out the form without knowing the patient’s intention. In the top 10% of the medical expense groups, the decision-makers for LST were family members rather than patients (28% patients vs. 32% family members who knew and 40% family members who did not know the patient’s intention). @*Conclusion@#The cancer patient’s own decision-making rather than the family’s decision was associated with earlier decision-making, less use of some critical treatments (except chemotherapy) and expensive evaluations, and a trend toward lower medical costs.
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Tables and figures are commonly adopted methods for presenting specific data or statistical analysis results. Figures can be used to display characteristics and distributions of data, allowing for intuitive understanding through visualization and thus making it easier to interpret the statistical results. To maximize the positive aspects of figure presentation and increase the accuracy of the content, in this article, the authors will describe how to choose an appropriate figure type and the necessary components to include. Additionally, this article includes examples of figures that are commonly used in research and their essential components using virtual data.
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This article introduces a crossover design that is often used in clinical studies, with the advantage of comparing treatment effects within one study subject. In particular, the advantages and disadvantages of the two-period, two-sequence crossover design (2 × 2 or AB/BA crossover design), which is widely used in clinical practice, are identified, and the elements necessary for analysis are introduced. This article explains the carryover effect, period effect, sequence effect, and period-by-treatment interaction in a crossover design and examines the analysis commands of SAS along with example data. After confirming the carryover effect using a general linear model, the treatment effect is analyzed using a linear mixed effect model.
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Background@#There is a debate regarding the safety of etomidate. We evaluated the effects of etomidate on mortality in a large cohort of critical care patients. @*Methods@#This retrospective matched-cohort study was performed using the Medical Information Mart for Intensive Care version 3 (MIMIC-III) database. Among 12,526 adult patients who were prescribed etomidate or propofol on the first day of mechanical ventilation, 625 patients administered etomidate were statistically matched with 6,250 patients administered propofol. The primary outcome measures were all-cause in-hospital mortality, 48-hour survival, cardiovascular morbidity, and infectious morbidity. Logistic regression analysis with stepwise selection of variables was performed to examine the dose–mortality relationship of etomidate. @*Results@#All-cause in-hospital mortality was 1.84 times higher in the etomidate cohort (OR, 1.84; 98.75% CI, 1.42, 2.37). Compared to the propofol cohort, the etomidate cohort showed 57% lower odds of 48-hour survival (0.43 [0.27, 0.73]), no difference in odds of cardiovascular morbidity (0.86 [0.66, 1.12]), and 1.77 times higher odds of infectious morbidity (1.77 [1.35, 2.31]). Additionally, the odds of mortality increased by 1.36 times per 0.1 mg/kg of etomidate (1.36 [95% CI: 1.23, 1.49]). @*Conclusions@#Etomidate is a poor choice as a hypnotic drug on the first day of mechanical ventilation, as it is associated with a dose-dependent increase in all-cause mortality, and does not improve survival for the first 48 h.
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The aim of this paper is to introduce basic concepts and methods for calculating sample size in animal studies. At the planning stage of clinical studies, the determination of the sample size is a very important process to show the validity, accuracy, and reliability of the study. However, not all studies require a sample size to be calculated. Before conducting the study, it is essential to determine whether the study objectives suggest a pilot and exploratory study, as well as the purpose of testing the hypothesis of interest. Since most animal experiments are pilot and exploratory studies, it would be more appropriate to review other considerations for conducting an experiment while maintaining scientific and qualitative levels rather than sample size estimation. Sample size is calculated in various situations in animal studies. Therefore, it can be estimated according to the situations and objectives through the methods of precision analysis, power analysis, and so on. In some cases, nonparametric methods can be employed if the assumptions of normality is not met or a small sample is available for the study.
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This article introduces a crossover design that is often used in clinical studies, with the advantage of comparing treatment effects within one study subject. In particular, the advantages and disadvantages of the two-period, two-sequence crossover design (2 × 2 or AB/BA crossover design), which is widely used in clinical practice, are identified, and the elements necessary for analysis are introduced. This article explains the carryover effect, period effect, sequence effect, and period-by-treatment interaction in a crossover design and examines the analysis commands of SAS along with example data. After confirming the carryover effect using a general linear model, the treatment effect is analyzed using a linear mixed effect model.
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Background@#There is a debate regarding the safety of etomidate. We evaluated the effects of etomidate on mortality in a large cohort of critical care patients. @*Methods@#This retrospective matched-cohort study was performed using the Medical Information Mart for Intensive Care version 3 (MIMIC-III) database. Among 12,526 adult patients who were prescribed etomidate or propofol on the first day of mechanical ventilation, 625 patients administered etomidate were statistically matched with 6,250 patients administered propofol. The primary outcome measures were all-cause in-hospital mortality, 48-hour survival, cardiovascular morbidity, and infectious morbidity. Logistic regression analysis with stepwise selection of variables was performed to examine the dose–mortality relationship of etomidate. @*Results@#All-cause in-hospital mortality was 1.84 times higher in the etomidate cohort (OR, 1.84; 98.75% CI, 1.42, 2.37). Compared to the propofol cohort, the etomidate cohort showed 57% lower odds of 48-hour survival (0.43 [0.27, 0.73]), no difference in odds of cardiovascular morbidity (0.86 [0.66, 1.12]), and 1.77 times higher odds of infectious morbidity (1.77 [1.35, 2.31]). Additionally, the odds of mortality increased by 1.36 times per 0.1 mg/kg of etomidate (1.36 [95% CI: 1.23, 1.49]). @*Conclusions@#Etomidate is a poor choice as a hypnotic drug on the first day of mechanical ventilation, as it is associated with a dose-dependent increase in all-cause mortality, and does not improve survival for the first 48 h.
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Background@#Uncontrolled blood pressure (BP) is relatively common despite treatment with antihypertensive medication. This study aimed to investigate factors associated with uncontrolled systolic BP (SBP) and diastolic BP (DBP) separately in hypertensive patients with high medication adherence in Korea. @*Methods@#This population-based cross-sectional study included 3,236 participants in the Korea National Health and Nutrition Examination Survey from 2013 to 2015. Hypertensive patients with high medication adherence were defined when they stated that they were taking antihypertensive medication daily. “Uncontrolled SBP and DBP” were defined as SBP ≥140 mm Hg and DBP ≥90 mm Hg, respectively. Data were analyzed using logistic regression to determine the association between uncontrolled SBP or DBP and various factors. @*Results@#The prevalence of uncontrolled SBP and uncontrolled DBP was 23.3%, and 9.0%, respectively. In multivariate analysis, uncontrolled SBP was positively associated with older age, female sex, blue-collar occupation or no work (vs. white-collar), presence of a spouse, short sleep duration, frequent heavy alcohol drinking, longer hypertension duration, diabetes, stroke, and missing antihypertensive medication on the examination day, but negatively associated with high stress. Uncontrolled DBP was positively associated with frequent heavy alcohol drinking, but negatively associated with older age, blue-collar occupation or no work (vs. white-collar), and diabetes. @*Conclusion@#After excluding low medication adherence, we identified various factors associated with uncontrolled SBP or DBP in Korean adults with treated hypertension. There were differences between factors associated with uncontrolled SBP or DBP. Separate analysis of SBP and DBP may help understand the factors involved in BP control.
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The Appendix of this article contained an error throughout in which an incorrect symbol was used for the assignment.
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Randomized controlled trial is widely accepted as the best design for evaluating the efficacy of a new treatment because of the advantages of randomization (random allocation). Randomization eliminates accidental bias, including selection bias, and provides a base for allowing the use of probability theory. Despite its importance, randomization has not been properly understood. This article introduces the different randomization methods with examples: simple randomization; block randomization; adaptive randomization, including minimization; and response-adaptive randomization. Ethics related to randomization are also discussed. The study is helpful in understanding the basic concepts of randomization and how to use R software.
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BACKGROUND: Mesenchymal stem cells (MSCs) can be used for a wide range of therapeutic applications because of not only their differentiation potential but also their ability to secrete bioactive factors. Recently, several studies have suggested the use of human embryonic stem cell-derived MSCs (hE-MSCs) as an alternative for regenerative cellular therapy due to mass production of MSCs from a single donor. METHODS: We generated hE-MSCs from embryonic stem cell lines, SNUhES3, and analyzed immune properties of these cells. Also, we evaluated the in-vivo therapeutic potential of hE-MSCs in immune-mediated inflammatory skin disease. RESULTS: The cell showed the suppression of immunity associated with allogenic peripheral blood mononuclear cells in mixed lymphocyte response assay. We also detected that cytokines and growth factor related to the immune response were secreted from these cells. To assessed the in-vivo therapeutic potential of hE-MSCs in immune-mediated inflammatory skin disease, we used imiquimod (IMQ)-induced skin psoriasis mouse model. The score of clinical skin was significantly reduced in the hE-MSCs treated group compared with control IMQ group. In histological analysis, the IMQ-induced epidermal thickness was significantly decreased by hE-MSCs treatment. It was correlated with splenomegaly induced by IMQ which was also improved in the hE-MSCs. Moreover, IMQ-induced inflammatory cytokines; Th1 cytokines (TNF-α, IFN-α, IFN-γ,and IL-27) and Th17 cytokines (IL-17A and IL-23), in the serum and skin showed marked inhibition by hEMSCs. CONCLUSION: These results suggested that hE-MSCs have a potency of immune modulation in psoriasis, which might be the key factor for the improved psoriasis.
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Animales , Humanos , Ratones , Citocinas , Células Madre Embrionarias , Linfocitos , Células Madre Mesenquimatosas , Psoriasis , Enfermedades de la Piel , Piel , Esplenomegalia , Donantes de TejidosRESUMEN
Randomized controlled trial is widely accepted as the best design for evaluating the efficacy of a new treatment because of the advantages of randomization (random allocation). Randomization eliminates accidental bias, including selection bias, and provides a base for allowing the use of probability theory. Despite its importance, randomization has not been properly understood. This article introduces the different randomization methods with examples: simple randomization; block randomization; adaptive randomization, including minimization; and response-adaptive randomization. Ethics related to randomization are also discussed. The study is helpful in understanding the basic concepts of randomization and how to use R software.
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Sesgo , Ética , Teoría de la Probabilidad , Distribución Aleatoria , Sesgo de SelecciónRESUMEN
The Appendix of this article contained an error throughout in which an incorrect symbol was used for the assignment.
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Mendelian randomization (MR) in epidemiology is the use of genetic variants as instrumental variables (IVs) in non-experimental design to make causality of a modifiable exposure on an outcome or disease. It assesses the causal effect between risk factor and a clinical outcome. The main reason to approach MR is to avoid the problem of residual confounding. There is no association between the genotype of early pregnancy and the disease, and the genotype of an individual cannot be changed. For this reason, it results with randomly assigned case-control studies can be set by regressing the measurements. IVs in MR are used genetic variants for estimating the causality. Usually an outcome is a disease and an exposure is risk factor, intermediate phenotype which may be a biomarker. The choice of the genetic variable as IV (Z) is essential to a successful in MR analysis. MR is named ‘Mendelian deconfounding’ as it gives to estimate of the causality free from biases due to confounding (C). To estimate unbiased estimation of the causality of the exposure (X) on the clinically relevant outcome (Y), Z has the 3 core assumptions (A1-A3). A1) Z is independent of C; A2) Z is associated with X; and A3) Z is independent of Y given X and C; The purpose of this review provides an overview of the MR analysis and is to explain that using an IV is proposed as an alternative statistical method to estimate causal effect of exposure and outcome under controlling for a confounder.
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Embarazo , Sesgo , Estudios de Casos y Controles , Epidemiología , Genotipo , Análisis de la Aleatorización Mendeliana , Métodos , Epidemiología Molecular , Fenotipo , Distribución Aleatoria , Factores de RiesgoRESUMEN
Appropriate prescription writing is one of the critical medical processes affecting the quality of public health care. However, this is a complex task for newly qualified intern doctors because of its complex characteristics requiring sufficient knowledge of medications and principles of clinical pharmacology, skills of diagnosis and communication, and critical judgment. This study aims to gather data on the current status of undergraduate prescribing education in South Korea. Two surveys were administered in this study: survey A to 26 medical schools in South Korea to gather information on the status of undergraduate education in clinical pharmacology; and survey B to 244 intern doctors in large hospitals to gather their opinions regarding prescribing education and ability. In survey A, half of the responding institutions provided prescribing education via various formats of classes over two curriculums including lecture, applied practice, group discussions, computer-utilized training, and workshops. In survey B, we found that intern doctors have the least confidence when prescribing drugs for special patient populations, especially pregnant women. These intern doctors believed that a case-based practical training or group discussion class would be an effective approach to supplement their prescribing education concurrently or after the clerkship in medical schools or right before starting intern training with a core drug list. The results of the present study may help instructors in charge of prescribing education when communicating and cooperating with each other to improve undergraduate prescribing education and the quality of national medical care.
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Femenino , Humanos , Curriculum , Diagnóstico , Educación , Educación Médica , Práctica de Grupo , Juicio , Corea (Geográfico) , Farmacología Clínica , Mujeres Embarazadas , Prescripciones , Salud Pública , Facultades de Medicina , EscrituraRESUMEN
PURPOSE: Postcholecystectomy syndrome (PCS) is characterized by abdominal symptoms following gallbladder removal. However, there is no consensus for the definition or treatment for PCS. The purpose of this study was to define PCS among various symptoms after laparoscopic cholecystectomy, and to identify risk factors affecting PCS. METHODS: This study was conducted at Dongguk University Ilsan Hospital and Chung-Ang University Hospital (2012–2013). Outcomes were assessed using European Organization for Research and Treatment of Cancer QLQ–C30 questionnaire. Symptom cluster for determining PCS was made by factor analysis. Cluster analysis evaluating risk factors of PCS was made by Ward methods and Dentogram. RESULTS: Factor analysis revealed three distinct symptom clusters, those are ‘insomnia and financial difficulties (eigenvalue, 1.707; Cronbach α, 0.190),’‘appetite loss and constipation (eigenvalue, 1.413; Cronbach α, 0.480),’ and ‘right upper quadrant (RUQ) pain and diarrhea (eigenvalue, 1.245; Cronbach α, 0.315).’ Among these symptom clusters, the cluster of ‘RUQ pain and diarrhea’ was determined as PCS. However, we could not find any risk factors between high symptomatic group and low symptomatic group. CONCLUSION: PCS could consist of RUQ pain and diarrhea. Well-designed prospective trials are needed to determine risk factors of PCS.
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Colecistectomía , Colecistectomía Laparoscópica , Consenso , Estreñimiento , Diarrea , Vesícula Biliar , Síndrome Poscolecistectomía , Estudios Prospectivos , Calidad de Vida , Factores de RiesgoRESUMEN
PURPOSE: In the present study, the visual discomfort induced by smart mobile devices was assessed in normal and healthy adults. METHODS: Fifty-nine volunteers (age, 38.16 ± 10.23 years; male : female = 19 : 40) were exposed to tablet computer screen stimuli (iPad Air, Apple Inc.) for 1 hour. Participants watched a movie or played a computer game on the tablet computer. Visual fatigue and discomfort were assessed using an asthenopia questionnaire, tear film break-up time, and total ocular wavefront aberration before and after viewing smart mobile devices. RESULTS: Based on the questionnaire, viewing smart mobile devices for 1 hour significantly increased mean total asthenopia score from 19.59 ± 8.58 to 22.68 ± 9.39 (p < 0.001). Specifically, the scores for five items (tired eyes, sore/aching eyes, irritated eyes, watery eyes, and hot/burning eye) were significantly increased by viewing smart mobile devices. Tear film break-up time significantly decreased from 5.09 ± 1.52 seconds to 4.63 ± 1.34 seconds (p = 0.003). However, total ocular wavefront aberration was unchanged. CONCLUSIONS: Visual fatigue and discomfort were significantly induced by viewing smart mobile devices, even though the devices were equipped with state-of-the-art display technology.
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Adulto , Femenino , Humanos , Masculino , Astenopía , Computadoras de Mano , Síndromes de Ojo Seco , Lágrimas , Juegos de Video , VoluntariosRESUMEN
BACKGROUND/AIMS: Capsule endoscopy (CE) is widely used. However, CE has limitations including incomplete examination, inadequate bowel preparation, and retention. The aim of this study was to estimate the indications for and detection, completion, and retention rates of small intestine CE based on the 10-year data from the Korean Capsule Endoscopy Registry. METHODS: Twenty-four hospitals participated in this study. Clinical information, such as reasons for CE, method and quality of bowel preparation, and incomplete examination and capsule retention rates, was collected and analyzed. RESULTS: A total of 2,914 CEs were registered. The most common reason for CE was obscure gastrointestinal bleeding (59%). Significant lesions were detected in 66% of cases. Positive CE diagnosis occurred in 63% of cases. The preparation method did not significantly affect the quality of bowel preparation for CE. The overall incomplete rate was 33%, and was high in the elderly and those with poor bowel preparation. Capsule retention was 3% and high in patients with small bowel tumors and Crohn's disease and in children under 10 years of age. CONCLUSIONS: CE is a valuable technique; while the overall detection rate is high, incompletion and retention rates are also relatively high. CE should be carefully considered in the elderly and children less than 10 years of age, as well as in patients with small bowel tumors and Crohn's disease.
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Anciano , Niño , Humanos , Endoscopía Capsular , Enfermedad de Crohn , Diagnóstico , Hemorragia , Intestino DelgadoRESUMEN
General epidemiological data regarding herpes zoster (HZ) are necessary for treatment and prevention of this disease. In addition, epidemiological data can play an important role in evaluating the efficacy and impact of vaccination. Though several epidemiological studies of HZ in Korea have been conducted, they usually depend on hospital-based data and may not be representative of HZ characteristics all over Korea. The purpose of this study was to evaluate the incidence and other epidemiological features of HZ in the general Korean population. We used population-based medical records from the Health Insurance Review & Assessment Service, which includes 50,908,646 medical insurance subscribers, to calculate the incidence of HZ. Also, we analyzed an age-stratified random sample of 1,375,842 individuals to study descriptive epidemiologic characteristics of HZ in Korea in 2011. We observed that the incidence of HZ was 10.4 per 1,000 person-years and was strongly correlated with age. Sex had a major influence on HZ incidence; overall, there were 12.6 cases per 1,000 person years in women and 8.3 cases per 1,000 person years in men. There was no difference in incidence according to the locality and season.
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Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Adulto Joven , Distribución por Edad , Herpes Zóster/diagnóstico , Hospitalización/estadística & datos numéricos , Prevalencia , República de Corea/epidemiología , Factores de Riesgo , Estaciones del Año , Distribución por SexoRESUMEN
BACKGROUND AND OBJECTIVES: Metabolic syndrome and high sodium intake are associated with frequent cardiovascular events. Few studies have estimated sodium intake in subjects with metabolic syndrome by 24-hour urine sodium excretion. We evaluated sodium intake in individuals with metabolic syndrome. SUBJECTS AND METHODS: Participants were recruited by random selection and through advertisement. Twenty four-hour urine collection, ambulatory blood pressure measurements, and blood test were performed. Sodium intake was estimated by 24-hour urine sodium excretion. Participants receiving antihypertensive medications were excluded from analysis. RESULTS: Among the 463 participants recruited, subjects with metabolic syndrome had higher levels of 24-hour urine sodium excretion than subjects without metabolic syndrome (p=0.0001). There was a significant relationship between the number of metabolic syndrome factors and 24-hour urine sodium excretion (p=0.001). The proportion of subjects with metabolic syndrome was increased across the tertile groups of 24-hour urine sodium excretion (p<0.0001). The association of high sodium intake and metabolic syndrome was significant only among women. Among the factors related to metabolic syndrome, body mass index had an independent association with 24-hour urine sodium excretion (p<0.0001). CONCLUSION: Women with metabolic syndrome exhibited significantly higher sodium intake, suggesting that dietary education to reduce sodium consumption should be emphasized for women with metabolic syndrome.