Risk factors of suicide attempt among people with suicidal ideation in South Korea: a cross-sectional study.

BACKGROUND: Suicide is a serious public health concern worldwide, and the fourth leading cause of death in Korea. Few studies have focused on risk factors for suicide attempt among people with suicidal ideation. The aim of the present study was to investigate the risk factors and develop prediction models for suicide attempt among people with suicidal ideation in the Korean population. METHOD: This study included 1567 men and 3726 women aged 20 years and older who had suicidal ideation from the Korea National Health and Nutrition Examination Survey from 2007 to 2012. Among them, 106 men and 188 women attempted suicide. Multivariate logistic regression analysis with backward stepwise elimination was performed to find risk factors for suicide attempt. Sub-group analysis, dividing participants into under 50 and at least 50 years old was also performed. RESULTS: Among people with suicidal ideation, age, education, cancer, and depressive disorder were selected as risk factors for suicide attempt in men. Age, education, national basic livelihood security, daily activity limitation, depressive disorder, stress, smoking, and regular exercise were selected in women. Area under curves of our prediction models in men and women were 0.728 and 0.716, respectively. CONCLUSIONS: It is important to pay attention to populations with suicidal ideation and the risk factors mentioned above. Prediction models using the determined risk factors could be useful to detect high-risk groups early for suicide attempt among people with suicidal ideation. It is necessary to develop specific action plans for these high-risk groups to prevent suicide.

Increased fragility fracture risk in Korean women who snore: a 10-year population-based prospective cohort study.

BACKGROUND: Snoring is frequently associated with obstructive sleep apnea (OSA). Previous studies have shown that bone mineral density was significantly lower in patients with OSA than in controls; however, these studies did not focus on fractures. Fragility fractures can lead to long-term disabilities and a decrease in quality of life. The present study aimed to investigate the association between snoring and fragility fractures. METHODS: This study included 2969 men and 3220 women aged 40 years and older from the Ansung and Ansan cohort studies in Korea. During a 10-year follow-up period, 129 and 273 fracture cases were reported in men and women, respectively. RESULTS: Severe snoring (6-7 nights per week or sleep disturbance by snoring in the next room) was a statistically significant risk factor for fracture (p = 0.006, hazard ratio 1.68, 95% confidence interval 1.16-2.43) after adjusting for covariates related to fragility fracture in women. However, both snoring and severe snoring groups did not show significant associations with the fracture risk in men. CONCLUSIONS: Thus, information on the frequency of snoring in women may improve the accuracy of fragility fracture risk prediction, which can help in deciding whether intervention or treatment is necessary.

Intraoperative Diagnosis Support Tool for Serous Ovarian Tumors Based on Microarray Data Using Multicategory Machine Learning.

OBJECTIVES: Serous borderline ovarian tumors (SBOTs) are a subtype of serous ovarian carcinoma with atypical proliferation. Frozen-section diagnosis has been used as an intraoperative diagnosis tool in supporting the fertility-sparing surgery by diagnosing SBOTs with accuracy of 48% to 79%. Using DNA microarray technology, we designed multicategory classification models to support frozen-section diagnosis within 30 minutes. MATERIALS AND METHODS: We systematically evaluated 6 machine learning algorithms and 3 feature selection methods using 5-fold cross-validation and a grid search on microarray data obtained from the National Center for Biotechnology Information. To validate the models and selected biomarkers, expression profiles were analyzed in tissue samples obtained from the Yonsei University College of Medicine. RESULTS: The best accuracy of the optimal machine learning model was 97.3%. In addition, 5 features, including the expression of the putative biomarkers SNTN and AOX1, were selected to differentiate between normal, SBOT, and serous ovarian carcinoma groups. Different expression levels of SNTN and AOX1 were validated by real-time quantitative reverse-transcription polymerase chain reaction, Western blotting, and immunohistochemistry. A multinomial logistic regression model using SNTN and AOX1 alone was used to construct a simple-to-use equation that gave a diagnostic test accuracy of 91.9%. CONCLUSIONS: We identified 2 biomarkers, SNTN and AOX1, that are likely involved in the pathogenesis and progression of ovarian tumors. An accurate diagnosis of ovarian tumor subclasses by application of the equation in conjunction with expression analysis of SNTN and AOX1 would offer a new accurate diagnosis tool in conjunction with frozen-section diagnosis within 30 minutes.

Parathyroid hormone, calcium, and sodium bridging between osteoporosis and hypertension in postmenopausal Korean women.

The coexistence of osteoporosis and hypertension, which are considered distinct diseases, has been widely reported. In addition, daily intake of calcium and sodium, as well as parathyroid hormone levels (PTH), is known to be associated with osteoporosis and hypertension. This study aimed to determine the association of low calcium intake, high sodium intake, and PTH levels with osteoporosis and hypertension in postmenopausal Korean women. Data for postmenopausal Korean women aged 50 years or older were obtained from the Korea National Health and Nutrition Examination Survey 2008-2011. Osteoporosis was diagnosed using dual energy X-ray absorptiometry, while hypertension was diagnosed using blood pressure data. The odds ratios for osteoporosis and hypertension were calculated using logistic regression analysis for quartiles of the daily calcium intake, daily sodium intake, and PTH levels. Women with hypertension had a high coexistence of osteoporosis (43.6 vs. 36.5 %; P = 0.022), and vice versa (21.1 vs. 16.6 %; P = 0.022). PTH was significantly associated with osteoporosis and hypertension, and a high intake of calcium was strongly correlated with a low incidence of osteoporosis. This is the first study to report the characteristics of postmenopausal Korean women who have high dietary sodium intake and low dietary calcium intake, in association with the incidence of osteoporosis and hypertension. Osteoporosis and hypertension were strongly associated with each other, and PTH appears to be a key mediator of both diseases, suggesting a possible pathogenic link.

Exposure of Surgeons to Magnetic Fields during Laparoscopic and Robotic Gynecologic Surgeries.

STUDY OBJECTIVE: To measure and compare levels of extremely-low-frequency magnetic field (ELF-MF) exposure to surgeons during laparoscopic and robotic gynecologic surgeries. DESIGN: Prospective case-control study. DESIGN CLASSIFICATION: Canadian Task Force I. SETTING: Gynecologic surgeries at the Yonsei University Health System in Seoul, Korea from July to October in 2014. PATIENTS: Ten laparoscopic gynecologic surgeries and 10 robotic gynecologic surgeries. INTERVENTION: The intensity of ELF-MF exposure to surgeons was measured every 4 seconds during 10 laparoscopic gynecologic surgeries and 10 robotic gynecologic surgeries using portable ELF-MF measuring devices with logging capability. MEASUREMENT AND MAIN RESULTS: The mean ELF-MF exposures were .1 ± .1 mG for laparoscopic gynecologic surgeries and .3 ± .1 mG for robotic gynecologic surgeries. ELF-MF exposure levels to surgeons during robotic gynecologic surgery were significantly higher than those during laparoscopic gynecologic surgery (p < .001) after adjustment for duration of measurement. CONCLUSION: The present study demonstrated low levels of ELF-MF exposure to surgeons during robotic gynecologic surgery and conventional laparoscopic surgery, hoping to alleviate concerns regarding the hazards of MF exposure posed to surgeons and hospital staff.

Effects of short-term radiation emitted by WCDMA mobile phones on teenagers and adults.

BACKGROUND: With the rapid increasing use of third generation (3 G) mobile phones, social concerns have arisen concerning the possible health effects of radio frequency-electromagnetic fields (RF-EMFs) emitted by wideband code division multiple access (WCDMA) mobile phones in humans. The number of people, who complain of various symptoms such as headache, dizziness, and fatigue, has also increased. Recently, the importance of researches on teenagers has been on the rise. However, very few provocation studies have examined the health effects of WCDMA mobile phone radiation on teenagers. METHODS: In this double-blind study, two volunteer groups of 26 adults and 26 teenagers were simultaneously investigated by measuring physiological changes in heart rate, respiration rate, and heart rate variability for autonomic nervous system (ANS), eight subjective symptoms, and perception of RF-EMFs during sham and real exposure sessions to verify its effects on adults and teenagers. Experiments were conducted using a dummy phone containing a WCDMA module (average power, 250 mW at 1950 MHz; specific absorption rate, 1.57 W/kg) within a headset placed on the head for 32 min. RESULTS: Short-term WCDMA RF-EMFs generated no significant changes in ANS, subjective symptoms or the percentages of those who believed they were being exposed in either group. CONCLUSIONS: Considering the analyzed physiological data, the subjective symptoms surveyed, and the percentages of those who believed they were being exposed, 32 min of RF radiation emitted by WCDMA mobile phones demonstrated no effects in either adult or teenager subjects.

Effects of 60 Hz magnetic fields on teenagers and adults.

BACKGROUND: As use of electrical devices has increased, social concerns about the possible effects of 60 Hz electromagnetic fields on human health have increased. Accordingly, the number of people who complain of various symptoms such as headache and insomnia has risen. Many previous studies of the effects of extremely low frequency (ELF) magnetic field exposure on children have focused on the occurrence of childhood leukaemia and central nervous system cancers. However, very few provocation studies have examined the health effects of ELF magnetic fields on teenagers. METHODS: In this double-blind study, we simultaneously investigated physiological changes (heart rate, respiration rate, and heart rate variability), subjective symptoms, and magnetic field perception to determine the reliable effects of 60 Hz 12.5 µT magnetic fields on teenagers. Two volunteer groups of 30 adults and 30 teenagers were tested with exposure to sham and real magnetic fields for 32 min. RESULTS: ELF magnetic field exposure did not have any effects on the physiological parameters or eight subjective symptoms in either group. Neither group correctly perceived the magnetic fields. CONCLUSIONS: Physiological data were analysed, subjective symptoms surveyed, and the percentages of those who believed they were being exposed were measured. No effects were observed in adults or teenagers resulting from 32 min of 60 Hz 12.5 µT magnetic field exposure.

Effects of radiation emitted by WCDMA mobile phones on electromagnetic hypersensitive subjects.

BACKGROUND: With the use of the third generation (3 G) mobile phones on the rise, social concerns have arisen concerning the possible health effects of radio frequency-electromagnetic fields (RF-EMFs) emitted by wideband code division multiple access (WCDMA) mobile phones in humans. The number of people with self-reported electromagnetic hypersensitivity (EHS), who complain of various subjective symptoms such as headache, dizziness and fatigue, has also increased. However, the origins of EHS remain unclear. METHODS: In this double-blind study, two volunteer groups of 17 EHS and 20 non-EHS subjects were simultaneously investigated for physiological changes (heart rate, heart rate variability, and respiration rate), eight subjective symptoms, and perception of RF-EMFs during real and sham exposure sessions. Experiments were conducted using a dummy phone containing a WCDMA module (average power, 24 dBm at 1950 MHz; specific absorption rate, 1.57 W/kg) within a headset placed on the head for 32 min. RESULTS: WCDMA RF-EMFs generated no physiological changes or subjective symptoms in either group. There was no evidence that EHS subjects perceived RF-EMFs better than non-EHS subjects. CONCLUSIONS: Considering the analyzed physiological data, the subjective symptoms surveyed, and the percentages of those who believed they were being exposed, 32 min of RF radiation emitted by WCDMA mobile phones demonstrated no effects in either EHS or non-EHS subjects.

Origins of electromagnetic hypersensitivity to 60 Hz magnetic fields: A provocation study.

With increasing electrical device usage, social concerns about the possible effects of 60 Hz electromagnetic fields on human health have increased. The number of people with self-attributed electromagnetic hypersensitivity (EHS) who complain of various subjective symptoms such as headache and insomnia has also increased. However, it is unclear whether EHS results from physiological or other origins. In this double-blinded study, we simultaneously investigated physiological changes (heart rate, respiration rate, and heart rate variability), subjective symptoms, and perception of the magnetic field to assess origins of the subjective symptoms. Two volunteer groups of 15 self-reported EHS and 16 non-EHS individuals were tested with exposure to sham and real (60 Hz, 12.5 µT) magnetic fields for 30 min. Magnetic field exposure did not have any effects on physiological parameters or eight subjective symptoms in either group. There was also no evidence that the EHS group perceived the magnetic field better than the non-EHS group. In conclusion, the subjective symptoms did not result from the 60 Hz, 12.5 µT magnetic field exposures but from other non-physiological factors.

Medial meniscus root tear refixation: comparison of clinical, radiologic, and arthroscopic findings with medial meniscectomy.

PURPOSE: To investigate the clinical, radiologic, and arthroscopic findings of pullout repair in medial meniscus root tear (MRT) and to compare the results of pullout repair and partial meniscectomy. METHODS: This study enrolled 58 consecutive patients with medial MRT who underwent partial meniscectomy (M group, n = 28) or pullout repair (R group, n = 30) between September 2003 and August 2007. The patients were evaluated by the Lysholm knee score, International Knee Documentation Committee (IKDC) subjective knee score, joint space narrowing, and Kellgren-Lawrence grade on simple radiographs. Medial meniscal extrusion and the state of the meniscus and articular cartilage on magnetic resonance imaging (MRI) were documented. We performed second-look arthroscopy in 14 patients with pullout repair and evaluated fixation strength and hoop tension of the meniscus and the state of the articular cartilage. RESULTS: There were no differences in demographic data (age, sex, and body mass index) between the 2 groups. The mean follow-up was 48.5 months in the R group and 46.1 in the M group. Lysholm and IKDC scores improved significantly in both groups (P < .05). However, the R group had better Lysholm and IKDC scores and less joint space narrowing and progression of the Kellgren-Lawrence grade than the M group did (P < .05). In a subgroup analysis of the R group, medial meniscal extrusion on MRI decreased from 3.13 to 2.94 mm. Of the patients, 28 (93.3%) showed complete or partial healing of the meniscus. On MRI, 6 (20%) showed arthrosis progression. On second-look arthroscopic examinations in 14 patients in the R group, 9 (64.3%) showed normal fixation strength, 10 (71.4%) had normal restoration of hoop tension, 5 (35.7%) showed arthrosis progression, and 2 (6.7%) had repeat tears of the meniscus. CONCLUSIONS: Arthroscopic pullout repair of a medial MRT gave significantly better clinical and radiologic results than partial meniscectomy, and sound healing with restoration of hoop tension of the meniscus was observed on MRI and second-look arthroscopy. We propose that this method is an effective treatment for medial MRT. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Cancer Testis Antigen, NOL4, Is an Immunogenic Antigen Specifically Expressed in Small-Cell Lung Cancer.

To identify cancer/testis (CT) antigens and immunogenic proteins, immunoscreening of testicular and small-cell lung cancer cell line NCI-H889 cDNA libraries was performed using serum obtained from a small-cell lung cancer (SCLC) patient. We obtained 113 positive cDNA clones comprised of 74 different genes, designated KP-SCLC-1 through KP-SCLC-74. Of these genes, 59 genes were found to be related to cancers by EMBASE analysis. Three of these antigens, including KP-SCLC-29 (NOL4), KP-SCLC-59 (CCDC83), and KP-SCLC-69 (KIF20B), were CT antigens. RT-PCR and western blot analysis showed that NOL4 was frequently present in small-cell lung cancer cell lines (8/9, 8/9). In addition, NOL4 mRNA was weakly, or at a low frequency, or not detected in various cancer cell lines. Our results reveal that NOL4 was expressed at protein levels in small-cell lung cancer tissues (10/10) but not detected in lung adenocarcinoma and squamous cell carcinoma by immunohistochemical analysis. Serological response to NOL4 was also evaluated by western blot assay using NOL4 recombinant protein. A humoral response against NOL4 proteins was detected in 75% (33/44) of small-cell lung cancer patients and in 65% (13/20) of healthy donors by a serological western blot assay. These data suggest that NOL4 is a specific target that may be useful for diagnosis and immunotherapy in SCLC.

Intensity of extremely low-frequency electromagnetic fields produced in operating rooms during surgery at the standing position of anesthesiologists.

BACKGROUND: Numerous electronic devices have been introduced into operating rooms. Although little is known about the relationship between exposure to electromagnetic fields and health hazards, several studies have demonstrated causal relationships between electromagnetic fields exposure and various symptoms, cancers, and other diseases. METHODS: This study was approved by the Institutional Review Board. The intensity of extremely low-frequency electromagnetic fields was measured during surgery with the extremely low-frequency electromagnetic field strength measurement system at the standing position of anesthesiologists in 18 operating rooms and analyzed with EMDEX analysis and graphical program (EMCALC 95; ENERTECH, Campbell, CA). RESULTS: The average measurement duration per operating room per day was 7.41 +/- 0.70 h (mean +/- SD). The average sample number of measurements was 888.11 +/- 82.75 per operating room. The average magnetic field was 5.83 +/- 5.23 milliGuass (mG) (range, 0.10-33.80 mG), with 70% of these levels 2 mG or greater. CONCLUSIONS: The authors' results indicate that anesthesiologists in operating rooms are exposed to extremely low-frequency electromagnetic field levels that exceed magnetic field intensity of 2 mG recommended by the Swedish Board for Technical Accreditation for production by computer monitors and detected 30 cm from them. It currently is not clear if this exposure has health effects on anesthesiologists and other operating room personnel.

Hypersensitivity to RF fields emitted from CDMA cellular phones: a provocation study.

With the number of cellular phone users rapidly increasing, there is a considerable amount of public concern regarding the effects that electromagnetic fields (EMFs) from cellular phones have on health. People with self-attributed electromagnetic hypersensitivity (EHS) complain of subjective symptoms such as headaches, insomnia, and memory loss, and attribute these symptoms to radio frequency (RF) radiation from cellular phones and/or base stations. However, EHS is difficult to diagnose because it relies on a person's subjective judgment. Various provocation studies have been conducted on EHS caused by Global System for Mobile Communications (GSM) phones in which heart rate and blood pressure or subjective symptoms were investigated. However, there have been few sham-controlled provocation studies on EHS with Code Division Multiple Access (CDMA) phones where physiological parameters, subjective symptoms, and perception of RF radiation for EHS and non-EHS groups were simultaneously investigated. In this study, two volunteer groups of 18 self-reported EHS and 19 non-EHS persons were tested for both sham and real RF exposure from CDMA cellular phones with a 300 mW maximum exposure that lasted half an hour. We investigated not only the physiological parameters such as heart rate, respiration rate, and heart rate variability (HRV), but also various subjective symptoms and the perception of EMF. In conclusion, RF exposure did not have any effects on physiological parameters or subjective symptoms in either group. As for EMF perception, there was no evidence that the EHS group better perceived EMF than the non-EHS group.

The possibility of the combination of OCT and fundus images for improving the diagnostic accuracy of deep learning for age-related macular degeneration: a preliminary experiment.

Recently, researchers have built new deep learning (DL) models using a single image modality to diagnose age-related macular degeneration (AMD). Retinal fundus and optical coherence tomography (OCT) images in clinical settings are the most important modalities investigating AMD. Whether concomitant use of fundus and OCT data in DL technique is beneficial has not been so clearly identified. This experimental analysis used OCT and fundus image data of postmortems from the Project Macula. The DL based on OCT, fundus, and combination of OCT and fundus were invented to diagnose AMD. These models consisted of pre-trained VGG-19 and transfer learning using random forest. Following the data augmentation and training process, the DL using OCT alone showed diagnostic efficiency with area under the curve (AUC) of 0.906 (95% confidence interval, 0.891-0.921) and 82.6% (81.0-84.3%) accuracy rate. The DL using fundus alone exhibited AUC of 0.914 (0.900-0.928) and 83.5% (81.8-85.0%) accuracy rate. Combined usage of the fundus with OCT increased the diagnostic power with AUC of 0.969 (0.956-0.979) and 90.5% (89.2-91.8%) accuracy rate. The Delong test showed that the DL using both OCT and fundus data outperformed the DL using OCT alone (P value < 0.001) and fundus image alone (P value < 0.001). This multimodal random forest model showed even better performance than a restricted Boltzmann machine (P value = 0.002) and deep belief network algorithms (P value = 0.042). According to Duncan's multiple range test, the multimodal methods significantly improved the performance obtained by the single-modal methods. In this preliminary study, a multimodal DL algorithm based on the combination of OCT and fundus image raised the diagnostic accuracy compared to this data alone. Future diagnostic DL needs to adopt the multimodal process to combine various types of imaging for a more precise AMD diagnosis. Graphical abstract The basic architectural structure of the tested multimodal deep learning model based on pre-trained deep convolutional neural network and random forest using the combination of OCT and fundus image.

Ten-year prediction of suicide death using Cox regression and machine learning in a nationwide retrospective cohort study in South Korea.

BACKGROUND: Death by suicide is a preventable public health concern worldwide. The aim of this study is to investigate the probability of suicide death using baseline characteristics and simple medical facility visit history data using Cox regression, support vector machines (SVMs), and deep neural networks (DNNs). METHOD: This study included 819,951 subjects in the National Health Insurance Service (NHIS)-Cohort Sample Database from 2004 to 2013. The dataset was divided randomly into two independent training and validation groups. To improve the performance of predicting suicide death, we applied SVM and DNN to the same training set as the Cox regression model. RESULTS: Among the study population, 2546 people died by intentional self-harm during the follow-up time. Sex, age, type of insurance, household income, disability, and medical records of eight ICD-10 codes (including mental and behavioural disorders) were selected by a Cox regression model with backward stepwise elimination. The area of under the curve (AUC) of Cox regression (0.688), SVM (0.687), and DNN (0.683) were approximately the same. The group with top .5% of predicted probability had hazard ratio of 26.21 compared to that with the lowest 10% of predicted probability. LIMITATIONS: This study is limited by the lack of information on suicidal ideation and attempts, other potential covariates such as information of medication and subcategory ICD-10 codes. Moreover, predictors from the prior 12-24 months of the date of death could be expected to show better performances than predictors from up to 10 years ago. CONCLUSIONS: We suggest a 10-year probability prediction model for suicide death using general characteristics and simple insurance data, which are annually conducted by the Korean government. Suicide death prevention might be enhanced by our prediction model.

A new method for accurate and fast measurement of 3D eye movements.

Videooculography (VOG) is an eye movement measurement method used in the objective evaluation of vestibulo-ocular reflexes (VOR). An important requirement of VOG is to accurately estimate pupil center and ocular torsion, irrespective of drooping eyelids, eyelashes, corneal reflection, and blinking. Finding the accurate center of the pupil is particularly important in three-dimensional VOG, since otherwise, significant errors can occur in measuring torsional eye movement. A fast algorithm was proposed to accurately ascertain the pupil center, in spite of the complicating factors mentioned above. In this study, real-time three-dimensional VOG, which can measure horizontal, vertical, and torsional eye movements and calculate the pupil radius, was implemented using the proposed method. When the pupil radius was determined, the vertical position was measured within an error margin of less than 3%, even though only 10% of the pupil was visible. The time required to measure both three-dimensional eye movements and the pupil radius was less than 16 ms. Thus, eye movements can be measured in real-time. The resolutions of horizontal, vertical, and torsional eye movement were 0.2 degrees, 0.2 degrees, and 0.1 degrees, respectively, with maximum ranges of +/- 35 degrees, +/- 25 degrees, and +/- 18 degrees.

ATLS Hypovolemic Shock Classification by Prediction of Blood Loss in Rats Using Regression Models.

In our previous study, our input data set consisted of 78 rats, the blood loss in percent as a dependent variable, and 11 independent variables (heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse pressure, respiration rate, temperature, perfusion index, lactate concentration, shock index, and new index (lactate concentration/perfusion)). The machine learning methods for multicategory classification were applied to a rat model in acute hemorrhage to predict the four Advanced Trauma Life Support (ATLS) hypovolemic shock classes for triage in our previous study. However, multicategory classification is much more difficult and complicated than binary classification. We introduce a simple approach for classifying ATLS hypovolaemic shock class by predicting blood loss in percent using support vector regression and multivariate linear regression (MLR). We also compared the performance of the classification models using absolute and relative vital signs. The accuracies of support vector regression and MLR models with relative values by predicting blood loss in percent were 88.5% and 84.6%, respectively. These were better than the best accuracy of 80.8% of the direct multicategory classification using the support vector machine one-versus-one model in our previous study for the same validation data set. Moreover, the simple MLR models with both absolute and relative values could provide possibility of the future clinical decision support system for ATLS classification. The perfusion index and new index were more appropriate with relative changes than absolute values.

Patient exposure to extremely low-frequency magnetic fields during laparoscopic and robotic surgeries.

BACKGROUND: Laparoscopic and robotic surgeries require many electronic devices, and the hazard of extremely low-frequency magnetic fields (ELF-MFs) from these devices to humans remains uncertain. This study aimed to measure and compare patients' exposure levels to ELF-MFs in laparoscopic and robotic surgeries. METHODS: The intensity of ELF-MF exposure to patients was measured every 10 s during 30 laparoscopic surgeries and 30 robotic surgeries using portable ELF-MF measuring devices with logging capabilities. RESULTS: The mean ELF-MF exposures were 0.11 ± 0.07 µT for laparoscopic surgeries and 0.12 ± 0.10 µT for robotic surgeries. There were no significant differences between the laparoscopic and robotic surgeries. CONCLUSIONS: Patients' mean ELF-MF exposure levels in laparoscopic and robotic surgeries were lower than 0.2 µT, which is considered safe according to previous studies. However, because many medical devices have been implemented for multiple purposes in hospitals, the MF environment in hospitals regarding patient health should not be overlooked. Copyright © 2015 John Wiley & Sons, Ltd.

Simple Scoring System and Artificial Neural Network for Knee Osteoarthritis Risk Prediction: A Cross-Sectional Study.

BACKGROUND: Knee osteoarthritis (OA) is the most common joint disease of adults worldwide. Since the treatments for advanced radiographic knee OA are limited, clinicians face a significant challenge of identifying patients who are at high risk of OA in a timely and appropriate way. Therefore, we developed a simple self-assessment scoring system and an improved artificial neural network (ANN) model for knee OA. METHODS: The Fifth Korea National Health and Nutrition Examination Surveys (KNHANES V-1) data were used to develop a scoring system and ANN for radiographic knee OA. A logistic regression analysis was used to determine the predictors of the scoring system. The ANN was constructed using 1777 participants and validated internally on 888 participants in the KNHANES V-1. The predictors of the scoring system were selected as the inputs of the ANN. External validation was performed using 4731 participants in the Osteoarthritis Initiative (OAI). Area under the curve (AUC) of the receiver operating characteristic was calculated to compare the prediction models. RESULTS: The scoring system and ANN were built using the independent predictors including sex, age, body mass index, educational status, hypertension, moderate physical activity, and knee pain. In the internal validation, both scoring system and ANN predicted radiographic knee OA (AUC 0.73 versus 0.81, p<0.001) and symptomatic knee OA (AUC 0.88 versus 0.94, p<0.001) with good discriminative ability. In the external validation, both scoring system and ANN showed lower discriminative ability in predicting radiographic knee OA (AUC 0.62 versus 0.67, p<0.001) and symptomatic knee OA (AUC 0.70 versus 0.76, p<0.001). CONCLUSIONS: The self-assessment scoring system may be useful for identifying the adults at high risk for knee OA. The performance of the scoring system is improved significantly by the ANN. We provided an ANN calculator to simply predict the knee OA risk.

Development of a Screening Tool for Predicting Adverse Outcomes of Gestational Diabetes Mellitus: A Retrospective Cohort Study.

Gestational diabetes mellitus (GDM) is a common disease in pregnancy causing maternal and fetal complications. To prevent these adverse outcomes, optimal screening and diagnostic criteria must be adequate, timely, and efficient. This study suggests a novel approach that is practical, efficient, and patient- and clinician-friendly in predicting adverse outcomes of GDM. The authors conducted a retrospective cohort study via medical record review of patients admitted between March 2001 and April 2013 at the Severance Hospital, Seoul, South Korea. Patients diagnosed by a conventional 2-step method were evaluated according to the presence of adverse outcomes (neonatal hypoglycemia, hyperbilirubinemia, and hyperinsulinemia; admission to the neonatal intensive care unit; large for gestational age; gestational insulin therapy; and gestational hypertension). Of 802 women who had an abnormal 50-g, 1-hour glucose challenge test, 306 were diagnosed with GDM and 496 did not have GDM (false-positive group). In the GDM group, 218 women (71.2%) had adverse outcomes. In contrast, 240 women (48.4%) in the false-positive group had adverse outcomes. Women with adverse outcomes had a significantly higher body mass index (BMI) at entry (P = 0.03) and fasting blood glucose (FBG) (P = 0.03). Our logistic regression model derived from 2 variables, BMI at entry and FBG, predicted GDM adverse outcome with an area under the curve of 0.642, accuracy of 61.3%, sensitivity of 57.2%, and specificity of 66.9% compared with the conventional 2-step method with an area under the curve of 0.610, accuracy of 59.1%, sensitivity of 47.6%, and specificity of 74.4%. Our model performed better in predicting GDM adverse outcomes than the conventional 2-step method using only BMI at entry and FBG. Moreover, our model represents a practical, inexpensive, efficient, reproducible, easy, and patient- and clinician-friendly approach.