Joinpoint Regression About Injury Mortality and Hospitalization in Korea

Background@#Injury is a social problem that causes health and property losses, and it is important to identify the size and trend of injury for efficient prevention and management.Therefore, this study analyzed the trends in injury mortality and hospitalization rates from 2005 to 2019 in Korea. @*Methods@#Using mortality data by Statistics Korea and Korea National Hospital Discharge In-depth injury survey by the Korea Disease Control and Prevention Agency (KDCA), age standardized rates were calculated for death and hospitalization to analyze trends and annual changes with the joinpoint regression model. In addition, annual changes in the hospitalization rate of the transport accident and fall injuries by age group were analyzed, which are the major causes of injuries. @*Results@#From 2005 to 2019, the injury mortality rate has been on the decline, but the injury hospitalization rate has been on the rise. The annual rate of change varied depending on the injury mechanism, but the mortality rate tended to decrease or remain similar level, while the rate of hospitalization has steadily increased. In addition, by age group, injury mortality and hospitalization rates were high in the elderly. In particular, the hospitalization rate of the elderly was higher when comparing the hospitalization rate of the children in transport accidents and falls. Pedestrian transport accidents tended to decrease under the age of 15, but remained similar for those aged 65 and older, and bicycle accidents tended to increase in both groups. In addition, hospitalization rates were higher in the fall, with both groups showing a statistically significant increase in hospitalization rates caused by falls. @*Conclusion@#This study analyzed the trend of injury mortality and hospitalization and found that transport accidents and falls may vary depending on the means or age of the accident.Since injury is a big social problem that is a burden of disease, safety education and legal sanctions for injury prevention should be further improved in the future, especially by prioritizing vulnerable groups by age and detailed mechanisms of injury.

Recalcitrant Low Back Pain Diagnosed as Hypophosphatemic Osteomalacia Induced by Antiviral Medication

We report a rare case of anti-viral agent induced hypophosphatemic osteomalacia presented with localized and radicular pain. A 51-year-old man, who had been taking adefovir for chronic hepatitis, had experienced low back pain radiating to his right thigh for 2 years. With impression of lumbar disc herniation, he underwent magnetic resonance imaging and found multi-level disc herniation with facet joint synovial cysts. He received transforaminal epidural steroid injections, however, symptoms did not improve. To find other possible causes, additional tests were performed. Blood tests revealed hypophosphatemia and increased serum alkaline phosphatase, and osteoporosis was noted in dual-energy X-ray absorptiometry with multiple hot uptakes in bone scan. After replacement of adefovir to entecavir and supplement of phosphate and vitamin D, phosphate level and the clinical symptoms were improved. This is the first to report the presentation of osteomalacia due to anti-viral agent as radicular low back pain with facet synovial cysts.

Evaluation and improvement of adherence to medication

Medication adherence refers to the extent to which a patient takes medication according to prescription. In many cases, adherence to medication is defined as the proportion of prescribed drugs taken as prescribed over a certain period. However, there is no satisfactory level of adherence that can be applied uniformly to all diseases and medications. Patients with poor adherence experience worsening of conditions, complications, and increased risk for death, which increases medical expenses. Therefore, to improve medication adherence, healthcare providers should try to identify poor adherence, adjust prescriptions to optimize treatment according to the patient’s lifestyle, and educate patients to help them understand the value of medical treatment and the effects of adherence. The most practical way to identify poor adherence during clinical visits is by asking patients about their medication adherence in a non-judgmental manner. Reducing the number of doses is more effective than reducing the number of tablets to increase compliance. It is necessary to adopt innovative methods based on information technology in our healthcare system because of the labor-intensive nature of educational intervention to improve adherence.

Erratum: Correction of the Text in the Article “Funding”: Incidence-Based versus Prevalence-Based Approaches on Measuring Disability-Adjusted Life Years for Injury

This notice corrects the grant number in funding information.

Incidence-Based versus Prevalence-Based Approaches on Measuring Disability-Adjusted Life Years for Injury

BACKGROUND@#Injury represents an important aspect of disease that affects everyone at some point in their lives. To better understand and prevent these injuries, various analytical methods have been developed to assess both the magnitude and features of injury burden. In this study, we attempted to estimate the injury burden of Korea in 2014 by comparing the prevalence-based approach used by the Global Burden of Diseases (GBD) team and the World Health Organization against an alternative incidence-based approach, and to assess the different implications of these measurements.@*METHODS@#The 10th Korean National Hospital Discharge survey data and causes of death statistics in 2014 were used as data sources. Years of life lost (YLL), years lived with disability (YLD) and disability-adjusted life years (DALYs) were calculated using both the incidence- and prevalence-based approaches. The Korean Classification of Diseases (KCD) version 5 diagnostic codes were used to classify the mechanism of injury.@*RESULTS@#The prevalence-based injury burden tended to be higher (1,670,229 DALYs) than the incidence-based injury burden (1,544,467 DALYs). The elderly population exhibited a higher prevalence-based YLD and DALY relative to incidence-based outcomes. In order of significance, the three most common causes of injury as calculated using an incidence-based approach were road injury, fall, and self-harm, compared with a prevalence-based method, which identified self-harm, road injury, and falls as the most common injuries.@*CONCLUSION@#An appropriate prevention program is needed for injuries with potential to cause long-lasting morbidity. Accordingly, a tailored injury-prevention strategy should be developed for each high-risk group.

Requirements for Cerebrovascular Surgery in Comprehensive Stroke Centers in South Korea

OBJECTIVE: Cerebrovascular disease (CVD) was the third most common cause of death in South Korea in 2014. Evidence from abroad suggests that comprehensive stroke centers play an important role in improving the mortality rate of stroke. However, surgical treatment for CVD is currently slightly neglected by national policy, and there is still regional imbalance in this regard. For this reason, we conducted a survey on the necessity of, and the requirements for, establishing regional comprehensive cerebrovascular surgery centers (CCVSCs).METHODS: This investigation was performed using the questionnaire survey method. The questionnaire was consisted with two sections. The first concerned the respondent’s opinion regarding the current status of demand and the regional imbalance of cerebrovascular surgery in South Korea. The second section asked about the requirements for establishing regional CCVSCs. We sent the questionnaire to 100 board members of the Korean Society of Cerebrovascular Surgeons.RESULTS: Most experts agreed that cerebrovascular surgery patients were concentrated in large hospitals in the capital area, and 83.6% of respondents agreed that it was necessary to alleviate the regional imbalance of cerebrovascular surgery. With regards to personnel, over 90% of respondents answered that at least two neuro-vascular surgeons and two neuro-interventionists are necessary to establish a CCVSC. Regarding facilities, almost all respondents stated that each CCVSC would require a neuro-intensive care unit and hybrid operating room. The survey asked the respondents about 13 specific neurovascular surgical procedures and whether they were necessary for a regional CCVSC. In the questions about the necessity of cerebrovascular surgical equipment, all seven pieces of equipment were considered essential by all respondents. A further five pieces of equipment were considered necessary on site: computed tomographic angiography, magnetic resonance angiography, conventional angiography, surgical microscope, and surgical navigation. Our results may provide a basis for future policy regarding treatment of cerebrovascular disease, including surgery.CONCLUSION: Raising the comprehensiveness of treatment at a regional level would lower the national disease burden. Policies should be drafted regarding comprehensive treatment including surgery for cerebrovascular disease, and related support plans should be implemented.

Requirements for Cerebrovascular Surgery in Comprehensive Stroke Centers in South Korea

OBJECTIVE: Cerebrovascular disease (CVD) was the third most common cause of death in South Korea in 2014. Evidence from abroad suggests that comprehensive stroke centers play an important role in improving the mortality rate of stroke. However, surgical treatment for CVD is currently slightly neglected by national policy, and there is still regional imbalance in this regard. For this reason, we conducted a survey on the necessity of, and the requirements for, establishing regional comprehensive cerebrovascular surgery centers (CCVSCs). METHODS: This investigation was performed using the questionnaire survey method. The questionnaire was consisted with two sections. The first concerned the respondent’s opinion regarding the current status of demand and the regional imbalance of cerebrovascular surgery in South Korea. The second section asked about the requirements for establishing regional CCVSCs. We sent the questionnaire to 100 board members of the Korean Society of Cerebrovascular Surgeons. RESULTS: Most experts agreed that cerebrovascular surgery patients were concentrated in large hospitals in the capital area, and 83.6% of respondents agreed that it was necessary to alleviate the regional imbalance of cerebrovascular surgery. With regards to personnel, over 90% of respondents answered that at least two neuro-vascular surgeons and two neuro-interventionists are necessary to establish a CCVSC. Regarding facilities, almost all respondents stated that each CCVSC would require a neuro-intensive care unit and hybrid operating room. The survey asked the respondents about 13 specific neurovascular surgical procedures and whether they were necessary for a regional CCVSC. In the questions about the necessity of cerebrovascular surgical equipment, all seven pieces of equipment were considered essential by all respondents. A further five pieces of equipment were considered necessary on site: computed tomographic angiography, magnetic resonance angiography, conventional angiography, surgical microscope, and surgical navigation. Our results may provide a basis for future policy regarding treatment of cerebrovascular disease, including surgery. CONCLUSION: Raising the comprehensiveness of treatment at a regional level would lower the national disease burden. Policies should be drafted regarding comprehensive treatment including surgery for cerebrovascular disease, and related support plans should be implemented.

Oral Administration of Glycine and Leucine Dipeptides Improves Skin Hydration and Elasticity in UVB-Irradiated Hairless Mice

Placenta is a special organ that contains many nutrients such as growth factors, minerals, and bioactive peptides. Dipeptides of glycine and leucine are major components of porcine placenta extracts (PPE) that has been used as an alternative of human placenta extracts. In this study, we investigated whether major peptides of PPE, Glycyl-L-Leucine (Gly-Leu), L-Leucyl-Glycine (Leu-Gly), and L-Leucyl-L-Leucine (Leu-Leu), affect skin hydration and elasticity in vitro and in vivo. We found that Gly-Leu and Leu-Gly dipeptides induced the expression of transglutaminase 1 in normal human epidermal keratinocytes (NHEKs) whereas Leu-Leu dipeptides did not. Treatment with Gly-Leu or Leu-Gly significantly increased hyaluronan (HA) synthesis in NHEKs and the upregulation of hyaluronan synthase 2 (HAS2) mRNA level was confirmed. In addition, elastase activity was inhibited in NHEKs treated with Gly-Leu or Leu-Gly dipeptides. Oral administration of Gly-Leu or Leu-Gly dipeptides increased skin hydration and elasticity in UVB-irradiated hairless mice. The significant upregulation of HA in UVB-irradiated hairless mice was observed in response to oral administration of Gly-Leu or Leu-Gly. These results suggest that the major dipeptides of porcine placenta, Gly-Leu and Leu-Gly, are potentially active ingredients for skin moisturization formulations.

The Effect of Balloon Dilatation and/or Botulinum Toxin Injection on the Severe Dysphagic Patients with Cricopharyngeal Dysfunction: Case Series / 대한연하장애학회지

OBJECTIVE: To investigate changes of swallowing function after ballooning dilatation (BD) and the Botox injection (BI) into the cricopharyngeus muscle in patients with severe dysphagia. METHOD: Nine severe dysphagic patients with cricopharyngeal dysfunction (CPD) who underwent BD and/or BI into the cricopharyngeal muscle were retrospectively reviewd. Patients who had severe dysphagia (Functional Oral Intake Scale (FOIS)≤2) after at least 3 months of the conventional swallowing therapy were included by a thorough review of medical records with videofluoroscopic swallowing study (VFSS). Before and after several interventions (BD and/or BI), swallowing function was evaluated using VFSS. RESULT: Among 9 patients, 5 underwent both BD and BI, and the other 4 patients underwent only BD. Four among 9 cases showed that interventions were effective. Of the 5 cases with both BD and BI, 2 cases were effective for treatment of CPD. In all the effective 4 cases, pyriform sinus residue seemed to be related with FOIS. Of those cases, one case had long-term effect (more than 4 months) and the other 3 case had short term effect (less than 4 months). CONCLUSION: Interventions were effective in 4 among 9 cases with severe CPD and the therapeutic effect was sustained for more than 4 months. The results suggest that in CPD patients, the BD or BI into UES could be considered in selected patients.

Influence of the Swallowing Posture and Liquid Thickness on the Ease of Pill Swallowing in Healthy Adults / 대한연하장애학회지

OBJECTIVE: To investigate the influence of the swallowing posture and liquid thickness on the easiness of pill swallowing in healthy adults. METHOD: The subjects were 12 healthy young group (19-40 years) and 10 elderly group (65- years). Each subject was examined under videofluoroscopy while swallowing barium-containing placebo pills with six different methods: free fluid with neutral (FN), chin down (FD), chin up (FU), head rotated to left (FL), head rotated to right postures (FR), and thickened fluid with neutral posture (TN). The subjects rated their ease of pill swallowing on a 5-point Likert scale. Time variables were evaluated from the videofluoroscopy images. RESULT: FD, FU and FL were rated significantly less comfortable than FN for pill swallowing. Duration from the start signal to the mandible angle and to laryngeal elevation was significantly prolonged with FD and FL compared to FN. Duration from the start signal to the upper esophageal sphincter was significantly prolonged with FD compared to FN. There were no significant differences on either easiness of swallowing or the time variables between FN and TN. Duration from the start signal to the mandible angle and to the upper esophageal sphincter was significantly longer in the elderly group than the young group with all swallowing methods except FU. In the elderly group, duration from the start signal to laryngeal elevation was significantly shorter with FU than FN. CONCLUSION: Chin down posture is uncomfortable and prolong swallowing time during pill swallowing. In the neutral posture, pill swallowing with thickened fluid is comparable to that with free fluid. Chin up posture may shorten pill swallowing time in elderly.

Public Awareness of Stroke and Its Predicting Factors in Korea: a National Public Telephone Survey, 2012 and 2014

The aim of this study was to investigate time trends in the public awareness of stroke and its predicting factors. The target population was 9,600 community-dwelling adults, aged 19–79 years, in 16 metropolitan cities and provinces in Korea. The survey samples in 2012 and 2014 were selected separately (entirely different sets of subjects) using a proportionate quota sampling method. Information concerning knowledge of stroke and demographics was collected by trained telephone interviewers using random digit dialing. After excluding subjects with a non-response or refusal to answer any question, the analyses included 8,191 subjects in 2012 and 8,127 subjects in 2014. Respondents’ awareness of stroke warning signs (numbness or weakness, difficulty speaking or understanding speech, dizziness, visual impairment, and severe headache) was highest for difficulty speaking or understanding speech (80.9% in 2012 and 86.4% in 2014). There were significant increases in the proportion of respondents understanding the appropriate action (i.e., calling an ambulance) at the time of stroke occurrence (59.6% to 67.1%), and in the proportion aware of the general need for prompt treatment (86.7% to 89.8%). In multivariable logistic regression analysis, older age, higher education level, higher household income, current non-smoking, exposure to stroke-related public relations materials, and experience of stroke education were significantly associated with both high knowledge of stroke warning signs and awareness of the need for prompt treatment. Between 2012 and 2014, the public’s awareness of stroke increased significantly. More specialized interventions, including public relations materials and education, should focus on subgroups who have lower stroke knowledge.

Characteristics of Dysphagia in Severe Traumatic Brain Injury Patients: A Comparison With Stroke Patients

OBJECTIVE: To compare the swallowing characteristics of dysphagic patients with traumatic brain injury (TBI) with those of dysphagic stroke patients. METHODS: Forty-one patients with TBI were selected from medical records (between December 2004 to March 2013) and matched to patients with stroke (n=41) based on age, sex, and disease duration. Patients' swallowing characteristics were analyzed retrospectively using a videofluoroscopic swallowing study (VFSS) and compared between both groups. Following thorough review of medical records, patients who had a history of diseases that could affect swallowing function at the time of the study were excluded. Dysphagia characteristics and severity were evaluated using the American Speech-Language-Hearing Association National Outcome Measurement System swallowing scale, clinical dysphagia scale, and the videofluoroscopic dysphagia scale. RESULTS: There was a significant difference in radiological lesion location (p=0.024) between the two groups. The most common VFSS finding was aspiration or penetration, followed by decreased laryngeal elevation and reduced epiglottis inversion. Swallowing function, VFSS findings, or quantified dysphagia severity showed no significant differences between the groups. In a subgroup analysis of TBI patients, the incidence of tube feeding was higher in patients with surgical intervention than in those without (p=0.011). CONCLUSION: The swallowing characteristics of dysphagic patients after TBI were comparable to those of dysphagic stroke patients. Common VFSS findings comprised aspiration or penetration, decreased laryngeal elevation, and reduced epiglottis inversion. Patients who underwent surgical intervention after TBI were at high risk of tube feeding requirement.

Disability-adjusted Life Years for 313 Diseases and Injuries: the 2012 Korean Burden of Disease Study

This study is part of a 5-year research project on the national burden of diseases, injuries, and risk factors in Korea. Using disability-adjusted life years (DALYs), a metric introduced by the 1990 Global Burden of Disease (GBD) project, we performed a comprehensive and detailed assessment of the magnitude and distribution of both fatal and non-fatal health problems in the Korean population. The concept and general approach were consistent with the original GBD study, with some methodological modifications to make the study more suitable for Korea. We computed DALYs for 313 causes in both sexes and nine age groups using the entire population's medical records and newly generated Korean disability weights. In 2012, the dominant disease burden was non-communicable diseases, which accounted for 85.21% of total DALYs, while injuries accounted for 7.77% and communicable, maternal, neonatal, and nutritional disorders for 7.02%. Of the total DALYs, 88.67% were from years lived with disability and 11.32% were from years of life lost due to premature mortality. Diabetes mellitus was the leading cause of DALYs, followed by low back pain, chronic obstructive pulmonary disease, ischemic heart disease, ischemic stroke, cirrhosis of the liver, falls, osteoarthritis, motorized vehicle with three or more wheels, and self-harm. The results reported here identify key health challenges and opportunities for future health interventions and policy changes, and provide information that will help assess the major public health issues in Korea, a nation faced with one of the world's most rapidly ageing populations.

Disability-adjusted Life Years (DALYs) for Mental and Substance Use Disorders in the Korean Burden of Disease Study 2012

The purpose of this study was to estimate the national burden of mental substance disorders on medical care utilization in Korea using National Health Insurance System (NHIS) data and updated disability weight, in terms of disability-adjusted life years (DALYs). For each of the 24 disorders, the incident years lived with disability (YLDs) was calculated, using NHIS data to estimate prevalence and incidence rates. The DisMod-II software program was used to model duration and remission. The years of life lost (YLLs) due to premature death were calculated from causes of death statistics. DALYs were computed as the sum of YLDs and YLLs, and time discounting and age weighting were applied. The year examined was 2012, and the subjects were divided into 9 groups according to age. In 2012, the Korean burden of mental and substance use disorders was 945,391 DALYs. More than 98% of DALYs were from YLDs, and the burden in females was greater than that in males, though the burden in males aged less than 19 years old was greater than that in females. Unipolar depressive disorders, schizophrenia, and anxiety disorders were found to be major diseases that accounted for more than 70% of the burden, and most DALYs occurred in their 30–59. Mental and substance use disorders accounted for 6.2% of the total burden of disease and were found to be the 7th greatest burden of disease. Therefore, mental and substance use disorders need to be embraced by mainstream health care with resources commensurate with the burden.

Disability-Adjusted Life Years (DALYs) for Injuries Using Death Certificates and Hospital Discharge Survey by the Korean Burden of Disease Study 2012

A system for assessing the burdens imposed by disease and injury was developed to meet healthcare, priority setting, and policy planning needs. The first such system, the Global Burden of Disease (GBD), was implemented in 1990. However, problems associated with limited data and assumed disability weightings remain to be resolved. The purpose of the present study was to estimate national burdens of injuries in Korea using more reliable data and disability weightings. The incidences of injuries were estimated using the Korean National Hospital Discharge Survey and the mortality data from the Korean National Statistical Office in 2010. Additionally, durations of injuries and age at injury onset were used to calculate disability-adjusted life years (DALY) using disability weightings derived from the Korean Burden of Disease (KBD) study. Korea had 1,581,072 DALYs resulting from injuries (3,170 per 100,000), which was 22.9% higher than found by the GBD 2010 study. Males had almost twice as heavy an injury burden as females. Road injury, fall, and self-harm ranked 1st, 2nd, and 3rd in terms of burden of injury in 2010. Total injury burden peaked in the forties, while burden per person declined gradually from early adulthood. We hope that this study contributes to the reliable evaluation of injury burden and a better understanding of injury-related health status using nation-specific, dependable data.

Modifying Effect of Heat Waves on the Relationship between Temperature and Mortality

Studies conducted to evaluate temporal trends of heat-related mortality have not considered the effects of heat waves; although it is known they can affect mortality and act as a modifying factor. After adjusting for long-term trends and seasonality, the effects of temperature on non-accidental deaths in Seoul and Busan (inland and coastal cities, respectively) were analyzed using a generalized additive model of Poisson distribution. We evaluated temporal trends of heat-related mortalities in four periods (1991-1995, 1996-2000, 2001-2005, and 2006-2012). The effects of temperature on mortality were evaluated according to the occurrence of a heat wave and results were compared in the two cities. The effect of temperature on mortality was the greatest in 1991-1995 in Seoul; no significant change was observed in Busan. When we stratified the study period by heat wave status, the risk increase in mortality was 15.9% per 1℃ during years with a heat wave in Seoul, which was much higher than 0.31% increase observed during years without a heat wave. On the other hand, Busan showed a linear relationship between temperature and mortality and no significant difference between years with or without a heat wave. Variations in the relationship between temperature and mortality could be misunderstood if heat waves are not considered. Furthermore, heterogeneity was found in the modifying effect of heat waves on heat-related mortality in inland and coastal cities. The findings of this study help understand relations between temperature and mortality.

Impact of Childbearing Decisions on Family Size of Korean Women with Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) predominantly affects women in their reproductive years and has a significant impact on childbearing. We investigated the influence of personal decision on family size among Korean women with SLE and factors that affect the decisions. A case-control study comparing childbearing history and decisions of 112 SLE patients and 135 controls was performed. Women with SLE participating in the Network for Lupus Clinical Research in South Korea and matching controls between ages of 18-45, who are/were married or living with a partner were included. Data regarding socio-demographics, reproductive history, and childbearing decisions were collected through a survey using a standardized questionnaire and medical record review. More women with SLE reported at least one pregnancy (85.7% vs. 71.9%, P = 0.009) or at least one live birth (85.7% vs. 71.9%, P = 0.003) compared with controls. Mean number of pregnancies was significantly higher (2.4 ± 1.6 vs. 1.4 ± 1.3, P < 0.001), and mean number of live births was significantly lower in women with SLE (1.2 ± 0.8 vs. 1.6 ± 0.8, P < 0.001). Significantly more women with SLE made the decision not to have children compared with controls (54.5% vs. 40.7%, P = 0.031), and health-related concerns were the major cause of the decision. Other socio-demographic factors did not influence the decision to limit childbearing in SLE women. The disease-related concerns had significant impact on family size and childbearing decisions among Korean women with SLE.

Crystallization of Local Anesthetics When Mixed With Corticosteroid Solutions

OBJECTIVE: To evaluate at which pH level various local anesthetics precipitate, and to confirm which combination of corticosteroid and local anesthetic crystallizes. METHODS: Each of ropivacaine-HCl, bupivacaine-HCl, and lidocaine-HCl was mixed with 4 different concentrations of NaOH solutions. Also, each of the three local anesthetics was mixed with the same volume of 3 corticosteroid solutions (triamcinolone acetonide, dexamethasone sodium phosphate, and betamethasone sodium phosphate). Precipitation of the local anesthetics (or not) was observed, by the naked eye and by microscope. The pH of each solution and the size of the precipitated crystal were measured. RESULTS: Alkalinized with NaOH to a certain value of pH, local anesthetics precipitated (ropivacaine pH 6.9, bupivacaine pH 7.7, and lidocaine pH 12.9). Precipitation was observed as a cloudy appearance by the naked eye and as the aggregation of small particles (300 µm, pH 7.5). Ropivacaine with dexamethasone sodium phosphate also precipitated, but it was only observable by microscope (a few crystals of 10-100 µm, pH 7.0). Bupivacaine with betamethasone sodium phosphate formed precipitates of non-aggregated smaller particles (<10 µm, pH 7.7). Lidocaine mixed with corticosteroids did not precipitate. CONCLUSION: Ropivacaine and bupivacaine can precipitate by alkalinization at a physiological pH, and therefore also produce crystals at a physiological pH when they are mixed with betamethasone sodium phosphate. Thus, the potential risk should be noted for their use in interventions, such as epidural steroid injections.

Diagnosis and Clinical Course of Unexplained Dysphagia

OBJECTIVE: To investigate the final diagnosis of patients with unexplained dysphagia and the clinical and laboratory findings supporting the diagnosis. METHODS: We retrospectively analyzed 143 patients with dysphagia of unclear etiology who underwent a videofluoroscopic swallowing study (VFSS). The medical records were reviewed, and patients with a previous history of diseases that could affect swallowing were categorized into a missed group. The remaining patients were divided into an abnormal or normal VFSS group based on the VFSS findings. The clinical course and final diagnosis of each patient were examined. RESULTS: Among the 143 patients, 62 (43%) had a previous history of diseases that could affect swallowing. Of the remaining 81 patients, 58 (72.5%) had normal VFSS findings and 23 (27.5%) had abnormal VFSS findings. A clear cause of dysphagia was not identified in 9 of the 23 patients. In patients in whom a cause was determined, myopathy was the most common cause (n=6), followed by laryngeal neuropathy (n=4) and drug-induced dysphagia (n=3). The mean ages of the patients in the normal and abnormal VFSS groups differed significantly (62.52±15.00 vs. 76.83±10.24 years, respectively; p<0.001 by Student t-test). CONCLUSION: Careful history taking and physical examination are the most important approaches for evaluating patients with unexplained swallowing difficulty. Even if VFSS findings are normal in the pharyngeal phase, some patients may need additional examinations. Electrodiagnostic studies and laboratory tests should be considered for patients with abnormal VFSS findings.

Risks of Lung Cancer due to Radon Exposure among the Regions of Korea

Radon is likely the second most common cause of lung cancer after smoking. We estimated the lung cancer risk due to radon using common risk models. Based on national radon survey data, we estimated the population-attributable fraction (PAF) and the number of lung cancer deaths attributable to radon. The exposure-age duration (EAD) and exposure-age concentration (EAC) models were used. The regional average indoor radon concentration was 37.5 95 Bq/m3. The PAF for lung cancer was 8.3% (European Pooling Study model), 13.5% in males and 20.4% in females by EAD model, and 19.5% in males and 28.2% in females by EAC model. Due to differences in smoking by gender, the PAF of radon-induced lung cancer deaths was higher in females. In the Republic of Korea, the risk of radon is not widely recognized. Thus, information about radon health risks is important and efforts are needed to decrease the associated health problems.