The reliability of clinical measurements is critical to medical research and clinical practice. Newly proposed methods are assessed in terms of their reliability, which includes their repeatability, intra- and interobserver reproducibility. In general, new methods that provide repeatable and reproducible results are compared with established methods used clinically. This paper describes common statistical methods for assessing reliability and agreement between methods, including the intraclass correlation coefficient, coefficient of variation, Bland-Altman plot, limits of agreement, percent agreement, and the kappa statistic. These methods are more appropriate for estimating reliability than hypothesis testing or simple correlation methods. However, some methods of reliability, especially unscaled ones, do not clearly define the acceptable level of error in real size and unit. The Bland-Altman plot is more useful for method comparison studies as it assesses the relationship between the differences and the magnitude of paired measurements, bias (as mean difference), and degree of agreement (as limits of agreement) between two methods or conditions (e.g., observers). Caution should be used when handling heteroscedasticity of difference between two measurements, employing the means of repeated measurements by method in methods comparison studies, and comparing reliability between different studies. Additionally, independence in the measuring processes, the combined use of different forms of estimating, clear descriptions of the calculations used to produce indices, and clinical acceptability should be emphasized when assessing reliability and method comparison studies.
Bias (Epidemiology) ; Methods* ; Reproducibility of Results

Objective: We examined the performance of attention tests related to suicidal ideation in mood disorder patients and to explain the differenceof attention test performance in relation to suicidal ideation after controlling clinical and psychological variables of mood disorderpatients. Methods: Seventy-three in- and outpatients with major depressive disorder (n=41) or bipolar disorder (n=32) completed a self-ratingquestionnaire assessing socio-demographic characteristics, and clinical and psychological variables. Comprehensive Attention Test(CAT) also was conducted. Results: Thirty-three patients were the high-suicidal ideation (SI) group, and forty patients were the low-SI group. The errors of commission(CEs) of visual sustained attention in the high-SI group was 6.3 times higher on average than that of the low-SI group. Aftercontrolling for sex, age, and diagnosis, a higher number of CEs on visual sustained attention tasks predicted higher SI score. However,after controlling for sex, age, diagnosis, and depressive mood, this predictive ability was no longer observed. Conclusion This study showed that CE on the visual sustained attention task seems to influence suicidal ideation as a result of interactionwith depressive symptoms. Psychiatry Investig 2020;17(4):374-381

OBJECTIVES: People who have chronic diseases, as well as gait imbalance or psychiatric drug use, may be susceptible to injuries from falls and slips. The purpose of this study was to evaluate the effect of musculoskeletal diseases on incidental fall-related injuries among adults in Korea. METHODS: We analyzed data from the 4th Korea National Health and Nutrition Examination Survey (2007-2009), which are national data obtained by a rolling survey sampling method. The 1-year incidence of fall-related injuries was defined by health service utilization within the last year due to injury occurring after a slip and fall, and musculoskeletal diseases included osteoarthritis, rheumatoid arthritis, osteoporosis, and back pain. To evaluate the effects of preexisting musculoskeletal diseases, adults diagnosed before the last year were considered the exposed group, and adults who had never been diagnosed were the unexposed group. RESULTS: The weighted lifetime prevalence of musculoskeletal disease was 32 540 per 100 000 persons. Musculoskeletal diseases were associated with a higher risk of fall-related injury after adjustment for sex, age, residence, household income, education, occupation, visual disturbance, paralysis due to stroke, and medication for depression (odds ratio [OR], 1.41; 95% confidence interval [CI], 1.03 to 1.93). As the number of comorbid musculoskeletal diseases increased, the risk of fall-induced injuries increased (p-value for trend <0.001). In particular, patients who had any musculoskeletal condition were at much higher risk of recurrent fall-related injuries (OR, 6.20; 95% CI, 1.06 to 36.08). CONCLUSIONS: One must take into account the risk of fall-related injuries and provide prevention strategies among adults who have musculoskeletal diseases.
Accidental Falls/*statistics & numerical data ; Adolescent ; Adult ; Age Factors ; Aged ; Arthritis, Rheumatoid/complications/epidemiology ; Back Pain/complications/epidemiology ; Female ; Health Surveys ; Humans ; Incidence ; Male ; Middle Aged ; Musculoskeletal Diseases/*complications ; Osteoarthritis/complications/epidemiology ; Osteoporosis/complications/epidemiology ; Republic of Korea/epidemiology ; Risk Factors ; Sex Factors ; Socioeconomic Factors ; Young Adult

BACKGROUND/AIMS: Helicobacter pylori (H. pylori) is causally associated with gastritis and peptic ulcer diseases. Recent data have demonstrated that triple therapy with amoxicillin, clarithromycin, and a proton pump inhibitor has an eradication rate of only 74~76% and new therapeutic protocols may be necessary. The aim of this study was to investigate the effects of Lactobacillus as supplementation to anti-H. pylori regimens on H. pylori eradication rates and therapy-associated side effects. MATERIALS AND METHODS: The PubMed, Medline and Korean Medical Database were searched in January 2012, with no language restrictions, for randomized controlled trials; additional references were obtained from reviewed articles. We included trials comparing Lactobacillus supplementation to placebo or no treatment during anti-H. pylori regimens. Meta-analysis was performed with Review Manager. RESULTS: Eleven trials involving a total of 1,107 participants met the inclusion criteria. Compared with placebo or no intervention, Lactobacillus given along with anti-H. pylori regimens significantly increased the eradication rate [84.7% vs. 78.8%, odds ratio (OR) 1.75, 95% confidence interval (CI) 1.26~2.42] and reduced the risk of overall H. pylori therapy related adverse effects (35.4% vs. 48.6%, OR 0.56, 95% CI 0.38~0.81), particularly of diarrhea (7.5% vs. 20.6%, OR 0.31, 95% CI 0.18~0.54), bloating (19.2% vs. 29.9%, OR 0.53, 95% CI 0.32~0.88) and taste disturbance (17.6% vs. 34.8%, OR 0.37, 95% CI 0.21~0.64). There were no significant differences between groups in the risk of other adverse effects. CONCLUSIONS: Our review suggests that supplementation with Lactobacilli could be effective in increasing eradication rates of anti-H. pylori therapy. Furthermore, Lactobacilli showed a positive impact on some H. pylori therapy-related side effects, particularly diarrhea, bloating and taste disturbance.
Amoxicillin ; Clarithromycin ; Diarrhea ; Gastritis ; Helicobacter ; Helicobacter pylori ; Lactobacillus ; Odds Ratio ; Peptic Ulcer ; Proton Pumps

PURPOSE: Although the overall incidence of hepatitis A in Korea has been decreasing recently, the adolescents born before the introduction of the hepatitis A vaccine remain to be highly vulnerable to outbreak. This study examines the unvaccinated adolescents' and their parents' knowledge and health beliefs toward hepatitis A vaccination. METHODS: Healthy adolescents aged 13-19 years old who had no previous history of hepatitis A vaccine and hepatitis A infection, and their parents or legal guardians were the subjects of the study. The survey was conducted using a structured questionnaire based on the Health Belief Model, and examined the subjects' demographics, knowledge, and health beliefs (i.e., perceived susceptibility, severity, benefits, and barriers). RESULTS: We included 157 adolescents and their parents/guardians (mean age: 16.0+/-1.6 and 45.6+/-4.7 years, respectively). The average knowledge item score for adolescents and parents was 6.4+/-3.7 and 7.3+/-3.4 (out of 18), respectively. Similarly, average Health Belief Model item scores were: susceptibility, 5.6+/-1.6 and 5.9+/-1.7 (range: 2-10); severity, 16.3+/-4.1 and 18.3+/-3.6 (range:5-25); benefits, 19.7+/-3.3 and 20.6+/-2.1 (range:5-25); and barriers, 41.3+/-8.9 and 39.0+/-9.1 (range:7-85). The major reason for not undergoing hepatitis A vaccination was lack of knowledge about its importance. CONCLUSIONS: Refresher health lectures about hepatitis A and the vaccine are needed by both the adolescents and their parents. Furthermore, the inclusion of hepatitis A vaccine in the national immunization program should be considered to reduce the risk of hepatitis A outbreak and to raise the vaccination coverage among the adolescents in Korea.
Adolescent ; Demography ; Hepatitis A Vaccines ; Hepatitis A* ; Hepatitis* ; Humans ; Immunization Programs ; Incidence ; Korea ; Lectures ; Legal Guardians ; Parents* ; Surveys and Questionnaires ; Vaccination*

Heart disease is one of the major cause of death in diabetic patients, but the thogenesis of diabetic cardio-myopathy remains unclear. In this experiment, to sess the significance of G protein signaling pathways in the pathogenesis of abetic cardiomyopathy, we analyzed the expression of G proteins and the tivities of second messenger dependent protein kinases: cAMP-dependent protein nase (PKA), DAG-mediated protein kinase C (PKC), and calmodulin dependent otein kinase II (CaM kinase II) in the streptozotocin induced diabetic rat art. The expression of Galphaq was increased by slightly over 10% (P<0.05) in abetic rat heart, while Galphas, Galphai, and Gbeta remained unchanged. The A activity in the heart did not change significantly but increased by 27%<0.01) in the liver. Insulin treatment did not restore the increased activity the liver. Total PKC activity in the heart was increased by 56% (P<0.01), and sulin treatment did not restore such increase. The CaM kinase II activity in e heart remained at the same level but was slightly increased in the liver 4% increase, P<0.05). These findings of increased expression of Galphaq in the reptozotocin-diabetic rat heart that are reflected by the increased level of C activity and insensitivity to insulin demonstrate that alteration of Galphaq y underlie, at least partly, the cardiac dysfunction that is associated with abetes. Copyright 2000 Academic Press.
Animal ; Ca(2+)-Calmodulin Dependent Protein Kinase/metabolism ; Cyclic AMP-Dependent Protein Kinases/metabolism ; Diabetes Mellitus, Experimental/metabolism* ; Diabetes Mellitus, Experimental/drug therapy ; Diabetes Mellitus, Experimental/chemically induced ; GTP-Binding Proteins/metabolism* ; Insulin/pharmacology ; Liver/metabolism ; Liver/drug effects ; Male ; Myocardium/metabolism* ; Protein Kinase C/metabolism ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Streptozocin

Hepatitis A can cause serious illness among adolescents and adults with low vaccination coverage. Even though hepatitis A vaccine is one of the strong candidates for Korean national immunization program, adolescents aged older than 12 yr would not benefit. Our purpose was to assess the willingness and analyze the correlates of Korean mothers for hepatitis A (HepA) vaccination to develop strategies for HepA vaccination. A national telephone survey on 800 mothers with children aged 7-18 yr was conducted with random-digit dialing method. Sixty-two percent and 92% of the mothers reported that they were willing to HepA vaccination at current cost and at half of the current cost, respectively. However, at current cost, only 79% wished to vaccinate their child in an epidemic and 32% wished to vaccinate promptly. Having two or more children, not having future plans to send the child overseas, and low family income were significantly associated with not willing to HepA vaccination. Low perception of the susceptibility for hepatitis A and perception of the current cost as barrier increased the odds of unwillingness to vaccination at current cost and to prompt vaccination. The mothers' willingness to HepA vaccination for the children aged 7-18 yr in Korea was not very high at current cost and associated socioeconomic status and health-belief. Targeted intervention or strategies are needed to increase the HepA vaccination rate among children in Korea.
Adolescent ; Adult ; Child ; Demography ; Female ; Health Status ; Health Surveys ; Hepatitis A/economics/*prevention & control ; Hepatitis A Vaccines/economics/*immunology ; Humans ; Interviews as Topic ; Male ; Middle Aged ; Mothers/psychology ; Republic of Korea ; Social Class ; *Vaccination

PURPOSE: Serum level of 25-hydroxyvitamin D (25-OHD) is considered as the most appropriate marker of vitamin D status. However, only a few studies have investigated the relationship between 25-OHD and parathyroid hormone (PTH) in children. To this end, this study was aimed at evaluating the lowest 25-OHD level that suppresses the production of parathyroid hormone in children. METHODS: A retrospective record review was performed for children aged 0.2 to 18 years (n=193; 106 boys and 87 girls) who underwent simultaneous measurements of serum 25-OHD and PTH levels between January 2010 and June 2014. RESULTS: The inflection point of serum 25-OHD level for maximal suppression of PTH was at 18.0 ng/mL (95% confidence interval, 14.3–21.7 ng/mL). The median PTH level of the children with 25-OHD levels of <18.0 ng/mL was higher than that of children with 25-OHD levels ≥ 18.0 ng/mL (P<0.0001). The median calcium level of children with 25-OHD levels<18.0 ng/mL was lower than that of children with 25-OHD levels≥18.0 ng/mL (P=0.0001). The frequency of hyperparathyroidism was higher in the children with 25-OHD levels<18.0 ng/mL than in the children with 25-OHD levels≥18.0 ng/mL (P<0.0001). Hypocalcemia was more prevalent in the children with 25-OHD levels<18.0 ng/mL than in the children with 25-OHD levels≥18.0 ng/mL (P<0.0001). CONCLUSION: These data suggest that a vitamin D level of 18.0 ng/mL could be the criterion for 25-OHD deficiency in children at the inflection point of the maximal suppression of PTH.
Calcium ; Child* ; Humans ; Hyperparathyroidism ; Hypocalcemia ; Parathyroid Hormone* ; Retrospective Studies ; Vitamin D ; Vitamin D Deficiency

BACKGROUND: As the population with chronic degenerative disease or functional impairment has increased in terms of the advanced aging society, the inevitability of home health services for the homebound have been augmented as a token of the trend toward the nuclear family along with the family capacity of care declined. For the past several years, home nursing service facilities have been enlarged and partially have been fulfilling these requirements. However, there are a great number of demands for home health service by physicians. Thereupon, we designed the following study to observe the cases of home visits by a medical office practice and to provide some information about the need of the home visit and its clinical features. METHODS: The study was conducted reviewing currently remained 84 data of home visit records at a home-visit- specialized medical office practice for 10 months in 1999. Its information collected was as below: patient's sex, age, frequency and duration of visit, distance to visit location, reason being homebound, and reason for visit. RESULTS: Of the reviewed records of 84 patients, comprised of 356 home visits, the median age of the patients was 67.5 years. They were visited 2 times as a median and with a median duration of 4 days. Physician drove a median distance of 6.1km one-way. Most common diagnoses were cancer and cerebrovascular diseases, equally with 10.8%. Reasons for being homebound were neurologic problem (28.6%), frail elderly (21.4%), terminal illness (20.2%) in order. Sixty two patients (73.8%) were permanently homebound and 12 patients (14.3%) were not. Reasons for visits were routine follow-up (42.1%) and evaluation of a new problem (19.9%) in the chronic homebound and terminal illness care (17.1%). While 102 visits (28.6%) should have begun by doctor-based visit, 233 visits (65.4%) including routine follow-up could be considered to be replaced for home nursing services. Even out of 233 visits, not all could be replaced and some should remain as physician's regular follow-up. CONCLUSION: There were needs of home visit in both permanent and transient homebound patients, in cases of exacerbation, new problem and routine follow-up of chronic homebound patients, and also in acute illness of previously healthy persons. To meet the needs of homebound patients in seeing the physician, and to offer adequate health services, the physician's role should be acknowledged in home nursing service, and home visit by physician should be institutionalized and carried into effect.
Aged ; Aging ; Diagnosis ; Follow-Up Studies ; Frail Elderly ; Health Services ; Home Nursing ; House Calls* ; Humans ; Nuclear Family ; Physician's Role ; Seoul*

To examine the relationship between birth characteristics and childhood cancer mortality, a retrospective cohort study of Korean children was conducted using data collected by the national birth register between 1995 and 2006, which were then individually linked to death data. A cohort of 6,479,406 children was followed from birth until their death or until December 31, 2006. Poisson regression analyses were used to calculate rate ratios of childhood cancer deaths according to birth characteristics. A total of 1,469 cancer deaths were noted and the childhood cancer mortality rate was found to be 3.43 per 100,000 person-years in Korea during the period of 1995-2006. The birth characteristics examined in this study (i.e. , birth weight, gestational age, multiple births, parental ages, and number of siblings) were generally found to be not significantly associated with childhood cancer mortality, and the associations did not vary meaningfully with gender nor with cancer sites. However, among children aged 5-11 yr, higher birth weight was associated with elevated childhood cancer mortality (rate ratio = 1.28, 95% confidence interval 1.04-1.58). Our results offer no overall associations between childhood cancer mortality and birth characteristics, but suggest that the association may be specific to age group.
Birth Weight ; Child ; Child, Preschool ; Cohort Studies ; Gestational Age ; Humans ; Multiple Birth Offspring ; Neoplasms/*mortality ; Parents ; Republic of Korea ; Retrospective Studies ; Risk Factors ; Siblings ; Socioeconomic Factors