Comparison of survival prediction models for pancreatic cancer: Cox model versus machine learning models

A survival prediction model has recently been developed to evaluate the prognosis of resected nonmetastatic pancreatic ductal adenocarcinoma based on a Cox model using two nationwide databases: Surveillance, Epidemiology and End Results (SEER) and Korea Tumor Registry System-Biliary Pancreas (KOTUS-BP). In this study, we applied two machine learning methods—random survival forests (RSF) and support vector machines (SVM)—for survival analysis and compared their prediction performance using the SEER and KOTUS-BP datasets. Three schemes were used for model development and evaluation. First, we utilized data from SEER for model development and used data from KOTUS-BP for external evaluation. Second, these two datasets were swapped by taking data from KOTUS-BP for model development and data from SEER for external evaluation. Finally, we mixed these two datasets half and half and utilized the mixed datasets for model development and validation. We used 9,624 patients from SEER and 3,281 patients from KOTUS-BP to construct a prediction model with seven covariates: age, sex, histologic differentiation, adjuvant treatment, resection margin status, and the American Joint Committee on Cancer 8th edition T-stage and N-stage. Comparing the three schemes, the performance of the Cox model, RSF, and SVM was better when using the mixed datasets than when using the unmixed datasets. When using the mixed datasets, the C-index, 1-year, 2-year, and 3-year time-dependent areas under the curve for the Cox model were 0.644, 0.698, 0.680, and 0.687, respectively. The Cox model performed slightly better than RSF and SVM.

Effects of Health-Related Quality of Life on Suicidal Ideation and Depression among Older Korean Adults: A Cross-Sectional Study

Objective@#The aim of this study was to investigate the prevalence of depression and suicidal ideation among older Korean adults and the predictors of suicidal ideation. @*Methods@#We analyzed data from 5,604 Koreans aged 65 or older collected by the Korea National Health and Nutrition Examination Survey in 2012–2016, an annual national, cross-sectional, epidemiologic study of the Korean population. A chi-square test was used to assess differences in socio-demographic characteristics by suicidal ideation. Psychological variables, self-rated physical health, and the five dimensions of the Korean version of the EQ-5D (EuroQoL) were compared between four subgroups categorized according to the presence/absence of suicidal ideation and depression. Multiple logistic regression was used to estimate the predictive power of health-related quality of life variables, as well as physical and psychological factors regarding suicidal ideation. @*Results@#Overall, 11.5% of the sample reported suicidal ideation, and 20.0% of the suicidal ideation group were diagnosed with depression. Respondents with suicidal ideation had significantly lower levels of health-related quality of life than those without suicidal ideation. EQ-5D self-control (OR=1.42), anxiety/depression (OR=2.32), depression (OR=2.07), and self-rated physical health (OR=1.36) were found to significantly predict suicidal ideation. @*Conclusion@#Suicidal ideation without depression was prevalent among older Koreans. Self-control, anxiety/depression of EQ-5D, selfrated physical health, and depression predicted suicidal ideation. Interventions to screen older Koreans for early detection of suicide risk and prevention strategies should consider evaluating each EQ-5D dimension.

Effects of a low-FODMAP enteral formula on diarrhea on patients in the intensive care unit

BACKGROUND/OBJECTIVES@#A dietary restriction on the intake of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) has been reported to be effective in the treatment of gastrointestinal (GI) tract complications. Enteral nutrition (EN) is widely used for patients who cannot obtain their nutritional requirements orally, but many studies have reported EN complications, especially diarrhea, in up to 50% of patients. @*SUBJECTS/METHODS@#We performed a single-center, non-randomized, controlled trial to determine the effects of a low-FODMAP enteral formula on GI complications in patients in intensive care units (ICUs). Patients in the ICU who needed EN (n = 66) were alternately assigned to the low-FODMAP group (n = 33) or the high-FODMAP group (n = 33). @*RESULTS@#Anthropometric and biochemical parameters were measured, and stool assessment was performed using King's Stool Chart. We excluded patients who received laxatives, GI motility agents, proton pump inhibitors, antifungal agents, and antibiotics other than β-lactams. There were no differences in GI symptoms during 7 days of intervention, including bowel sound, abdominal distension, and vomiting between the 2 groups. However, diarrhea was more frequent in the high-FODMAP group (7/33 patients) than the lowFODMAP group (1/33 patients) (P = 0.044). @*CONCLUSIONS@#Our results suggest that a low-FODMAP enteral formula may be a practical therapeutic approach for patients who exhibit enteral formula complications. Our study warrants further randomized clinical trials and multicenter trials.

Comparison of Energy Requirements of Patients with Brain Injury of the Intensive Care Unit: Indirect Calorimetry vs. Predictive Equations

Purpose@#The metabolic activity and demand usually increase in seriously ill patients, especially in patients with a brain injury (BI). These nutritional demands have been traditionally satisfied using predictive equations (PEs). Recently, indirect calorimetry (IC) has been used widely because it is more accurate than other methods. This study measured the energy expenditures (EE) using IC (GE, CARESCAPE B650, Helsinki, Finland) and calculated the PEs simultaneously in patients with BI. @*Methods@#This study was conducted on 55 patients with a BI for three years (2017.7∼2020.8), who were mechanically ventilated within a hospital for ≤seven days. The EE values using IC were measured once in each patient, and the EE values using PE were calculated using 5 PEs (ESPEN, Harris-Benedict, HB; Frankenfield, FK; Penn state, PS; and Faisy) at the same time.The 55 patients were divided into two groups, acute group (39 patients; ≤3 hospital days group, AG) and subacute group (16 patients; ＞3 hospital days group, SG) according to the time, and the values were obtained. @*Results@#There were no differences in the patient’s characteristics between the two groups, including age, gender, severity of the condition (Simplified Acute Physiology Score II), and anthropometric parameters. In AG, the energy expenditure values using PEs were significantly lower than those using IC in the three PEs (IC 1,712.0±476 kcal, ESPEN 1,558.6±324 kcal, P=0.038, HB 1,582.4±273 kcal, P=0.037, PS 1,530.8±340 kcal, P=0.005). In SG, the EE value using PEs did not differ significantly from that using IC. @*Conclusion@#An accurate assessment of EE is critical for seriously ill patients. These results showed that the previously well-known PEs might not be correct, particularly in acute patients with BI. Therefore, it is recommended that the EE values be obtained using IC, at least in acute patients with BI.

Comparison of Energy Requirements of Patients with Brain Injury of the Intensive Care Unit: Indirect Calorimetry vs. Predictive Equations

Purpose@#The metabolic activity and demand usually increase in seriously ill patients, especially in patients with a brain injury (BI). These nutritional demands have been traditionally satisfied using predictive equations (PEs). Recently, indirect calorimetry (IC) has been used widely because it is more accurate than other methods. This study measured the energy expenditures (EE) using IC (GE, CARESCAPE B650, Helsinki, Finland) and calculated the PEs simultaneously in patients with BI. @*Methods@#This study was conducted on 55 patients with a BI for three years (2017.7∼2020.8), who were mechanically ventilated within a hospital for ≤seven days. The EE values using IC were measured once in each patient, and the EE values using PE were calculated using 5 PEs (ESPEN, Harris-Benedict, HB; Frankenfield, FK; Penn state, PS; and Faisy) at the same time.The 55 patients were divided into two groups, acute group (39 patients; ≤3 hospital days group, AG) and subacute group (16 patients; ＞3 hospital days group, SG) according to the time, and the values were obtained. @*Results@#There were no differences in the patient’s characteristics between the two groups, including age, gender, severity of the condition (Simplified Acute Physiology Score II), and anthropometric parameters. In AG, the energy expenditure values using PEs were significantly lower than those using IC in the three PEs (IC 1,712.0±476 kcal, ESPEN 1,558.6±324 kcal, P=0.038, HB 1,582.4±273 kcal, P=0.037, PS 1,530.8±340 kcal, P=0.005). In SG, the EE value using PEs did not differ significantly from that using IC. @*Conclusion@#An accurate assessment of EE is critical for seriously ill patients. These results showed that the previously well-known PEs might not be correct, particularly in acute patients with BI. Therefore, it is recommended that the EE values be obtained using IC, at least in acute patients with BI.

The Distribution of Weight Status according to Familial Socioeconomic Status in Korean Adolescents: The Twelfth Korea Youth Risk Behavior Web-based Survey, 2016

BACKGROUND: The influence of socioeconomic status (SES) on weight status varies depending on the countries' levels of social and economic development. There are many studies on a risk of adolescent obesity according to familial SES in Korea. However, it is not clarified what effects familial SES has on a risk of underweight in Korean adolescents. This study investigated the distribution of weight status including obesity and underweight according to familial SES in Korean adolescents. METHODS: This cross-sectional study involved 63,741 adolescents who participated in the 2016 Korea Youth Risk Behavior Wed-based Survey. The data on height, weight, familial SES, current smoking status, current alcohol intake, physical activity, breakfast skipping, perceived stress, depressive mood, and living with family were obtained through online questionnaires. The assessment of familial SES was based on perceived household economic status and parental education level. RESULTS: In boys, low household economic status was related to a high proportion of obesity (odds ratio [OR] 1.14, 95% confidence interval [CI] 1.04–1.25) and underweight (OR 1.31, 95% CI 1.14–1.51). Girls with low household economic status were more likely to be obese (OR 1.81, 95% CI 1.61–2.03) and overweight (OR 1.41, 95% CI 1.23–1.60) but, although not statistically significant, less likely to be underweight (OR 0.88, 95% CI 0.75–1.04). CONCLUSIONS: This study showed that adolescents with low familial SES were at a high risk of obesity and underweight. A risk of underweight was increased in boys with low familial SES but in girls with high familial SES.

Regional difference in spontaneous firing inhibition by GABA(A) and GABA(B) receptors in nigral dopamine neurons

GABAergic control over dopamine (DA) neurons in the substantia nigra is crucial for determining firing rates and patterns. Although GABA activates both GABA(A) and GABA(B) receptors distributed throughout the somatodendritic tree, it is currently unclear how regional GABA receptors in the soma and dendritic compartments regulate spontaneous firing. Therefore, the objective of this study was to determine actions of regional GABA receptors on spontaneous firing in acutely dissociated DA neurons from the rat using patch-clamp and local GABA-uncaging techniques. Agonists and antagonists experiments showed that activation of either GABA(A) receptors or GABA(B) receptors in DA neurons is enough to completely abolish spontaneous firing. Local GABA-uncaging along the somatodendritic tree revealed that activation of regional GABA receptors limited within the soma, proximal, or distal dendritic region, can completely suppress spontaneous firing. However, activation of either GABA(A) or GABA(B) receptor equally suppressed spontaneous firing in the soma, whereas GABA(B) receptor inhibited spontaneous firing more strongly than GABA(A) receptor in the proximal and distal dendrites. These regional differences of GABA signals between the soma and dendritic compartments could contribute to our understanding of many diverse and complex actions of GABA in midbrain DA neurons.

The Distribution of Weight Status according to Familial Socioeconomic Status in Korean Adolescents: The Twelfth Korea Youth Risk Behavior Web-based Survey, 2016

BACKGROUND@#The influence of socioeconomic status (SES) on weight status varies depending on the countries' levels of social and economic development. There are many studies on a risk of adolescent obesity according to familial SES in Korea. However, it is not clarified what effects familial SES has on a risk of underweight in Korean adolescents. This study investigated the distribution of weight status including obesity and underweight according to familial SES in Korean adolescents.@*METHODS@#This cross-sectional study involved 63,741 adolescents who participated in the 2016 Korea Youth Risk Behavior Wed-based Survey. The data on height, weight, familial SES, current smoking status, current alcohol intake, physical activity, breakfast skipping, perceived stress, depressive mood, and living with family were obtained through online questionnaires. The assessment of familial SES was based on perceived household economic status and parental education level.@*RESULTS@#In boys, low household economic status was related to a high proportion of obesity (odds ratio [OR] 1.14, 95% confidence interval [CI] 1.04–1.25) and underweight (OR 1.31, 95% CI 1.14–1.51). Girls with low household economic status were more likely to be obese (OR 1.81, 95% CI 1.61–2.03) and overweight (OR 1.41, 95% CI 1.23–1.60) but, although not statistically significant, less likely to be underweight (OR 0.88, 95% CI 0.75–1.04).@*CONCLUSIONS@#This study showed that adolescents with low familial SES were at a high risk of obesity and underweight. A risk of underweight was increased in boys with low familial SES but in girls with high familial SES.