Impact of Comprehensive Primary Care in Patients With Complex Chronic Diseases: Nationwide Cohort Database Analysis in Korea.

BACKGROUND: More comprehensive healthcare services should be provided to patients with complex chronic diseases to better manage their complex care needs. This study examined the effectiveness of comprehensive primary care in patients with complex chronic diseases. METHODS: We obtained 2002-2019 data from the National Health Insurance Sample Cohort Database. Participants were individuals aged ≥ 30 years with at least two of the following diseases: hypertension, diabetes mellitus, and hyperlipidemia. Doctors' offices were classified into specialized, functional, and gray-zone based on patient composition and major diagnostic categories. The Cox proportional hazard model was used to examine the association between office type and hospital admission due to all-causes, severe cardiovascular or cerebrovascular diseases (CVDs), hypertension, diabetes mellitus, or hyperlipidemia. RESULTS: The mean patient age was 60.3 years; 55.8% were females. Among the 24,906 patients, 12.8%, 38.3%, and 49.0% visited specialized, functional, and gray-zone offices, respectively. Patients visiting functional offices had a lower risk of all-cause admission (hazard ratio [HR], 0.935; 95% confidence interval [CI], 0.895-0.976) and CVD-related admission (HR, 0.908; 95% CI, 0.844-0.977) than those visiting specialized offices. However, the admission risks for hypertension, diabetes mellitus, and hyperlipidemia were not significantly different among office types. CONCLUSION: This study provides evidence of the effectiveness of primary care in functional doctors' offices for patients with complex chronic diseases beyond a single chronic disease and suggests the need for policies to strengthen functional offices providing comprehensive care.

Trends in telemedicine utilization for mental illness during the COVID-19 pandemic: an analysis of a nationwide database in Korea.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has worsened mental health and reduced access to mental health services. During the pandemic, the demand for telemedicine has increased and related laws have been enacted. This study aimed to investigate telemedicine use for cases of major mental illnesses during the COVID-19 pandemic and to compare the characteristics of patients who received telemedicine service with those of patients who received in-person care. METHODS: This population-based, cross-sectional, observational study was based on health insurance claims data, and included 2,749,872 patients who received outpatient treatment for mental illness from February 24, 2020 to June 30, 2022. Logistic regression was performed to assess the relationships between patient characteristics and telemedicine service use. Patients who received telemedicine services were analyzed in subgroups of each mental illness. RESULTS: During the study period, 80,157 patients (2.9%), with an average age of 63 years, received at least one telemedicine treatment. There was a predominance of women and medical aid recipients. The lowest proportion of telemedicine treatments was for depression (2.1%), and the highest was for dementia (6.7%). The proportion of patients receiving telemedicine in long-term care hospitals was high (22.6%), with the highest odds ratio (OR) (5.84), compared with that in tertiary or general hospitals, followed by that in psychiatric hospitals and clinics. The proportions were high in the departments of internal medicine, neurology, and psychiatry. Patients aged > 80 years received most telemedicine treatment (OR: 1.23) across all diagnoses. Cases of dementia and other mental disorders had higher ORs (2.60 and 2.36, respectively) compared with cases of depression. Except for dementia and behavioral/emotional disorders, hospitalization increased the probability of telemedicine treatment. Comorbidities were positively associated with telemedicine treatment. CONCLUSIONS: Older people and people with other physical illnesses were more likely to use telemedicine treatments temporarily provided during the pandemic. Telemedicine maintained continuity of treatment for patients with dementia and severe mental illnesses. Telemedicine can be useful for filling the medical gaps for vulnerable populations other than those with mild mental illnesses. This aspect should be considered for the future establishment of telemedicine systems.

A Study on the Effective Ratio of Fat to Stromal Vascular Fraction for Cell-Assisted Lipotransfer.

BACKGROUND: Fat grafting, used for soft tissue augmentation during aesthetic or reconstructive plastic surgery, has disadvantages of low efficiency and unpredictable resorption rate. As an alternative, cell-assisted lipotransfer (CAL) is widely used because of its simplicity and low fat resorption rate. However, relevant studies on optimal CAL parameters are still lacking. Here, we aimed to identify the most effective ratio of fat to stromal vascular fraction (SVF) for CAL. METHODS: We designed two experimental paradigms. The first involved four groups of mice, each group injected with varying ratios of fat and SVF purified from different amounts of fat from a fixed amount of harvested fat. The second experiment involved four groups of mice, each injected with varying amounts of SVF mixed with a fixed amount of fat tissue. The amount of surviving fat in both experiments was compared 8 weeks after fat transplantation. RESULTS: In the first experiment, the group injected with only fat, without consuming any of the harvested fat for SVF purification, showed the greatest mean volume and weight. In the second experiment, groups with 1:1 or more ratio of fat to SVF showed greater volume and weight than the group without SVF. Notably, a ratio of 1:1 did not give significantly different results than higher ratios. CONCLUSIONS: Thus, when a limited amount of fat tissue is available, using all of it for grafting is the most effective. However, if an adequate amount is available, using a fat-to-SVF ratio of 1:1 is the most efficient. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Administration of encapsulated L-tryptophan improves duodenal starch digestion and increases gastrointestinal hormones secretions in beef cattle.

OBJECTIVE: This study investigated the effects of oral administration of rumen-protected L-tryptophan (RPL-T) on duodenal starch digestion and gastrointestinal hormones (GIH) secretions using Hanwoo beef steers as the animal models. METHODS: Four steers (423±24 kg) fitted with ruminal and duodenal cannulas were employed in a crossover design replicated twice. Treatments were control (basal diet) and RPL-T (basal diet+191.1 mg/kg body weight [BW]) group. Blood and duodenal samples were collected to measure serum GIH levels and pancreatic α-amylase activity at day 0, 1, 3, and 5 (-30, 30, 90, 150, and 210 min) of the study. Samples from each segment of the gastrointestinal tract were collected via ruminal and duodenal cannulas and were used to determine soluble protein and the starch digestion rate at days 6 (-30, 180, 360, and 540 min) and 8 (-30, 90, 270, and 450 min) of the experiment. RESULTS: No significant difference in ruminal pH, NH3-N, and total volatile fatty acid including the levels of acetate, propionate, butyrate, isobutyrate, valerate, isovalerate, and the acetate-to-propionate ratio was observed between groups (p>0.05). Crude protein uptake was higher and feces starch content was lower in RPL-T group than the control group (p<0.05). The D-glucose contents of feces in RPL-T group decreased at day 5 compared to those in the control group (p<0.05), however, no change was found at day 0, 1, or 3 compared to the control group (p>0.05). Serum cholecystokinin (CCK), melatonin, duodenal pancreatic α-amylase activity, and starch digestion were significantly higher in RPL-T group than the control group (p<0.05). CONCLUSION: Taken together, oral administration of RPL-T at the rate of 191.1 mg/kg BW consistently increased CCK concentration, pancreatic α-amylase activity in duodenal fluids, and starch digestion rate in the small intestine and thus found to be beneficial.

Prospectively identifying older adults at risk for potentially avoidable hospitalizations in Korea using population-based data.

OBJECTIVE: The purpose of this study is to develop and validate a prediction model to identify older adults at risk for potentially avoidable hospitalizations (PAHs) using variables readily available in routinely collected health administrative data. DESIGN: Population-based, retrospective observational study using National Health Insurance Service-National Sample Cohort (NHIS-NSC) data. SETTING: Primary care settings in South Korea. PARTICIPANTS: The sample includes 113 612 older NHI beneficiaries in the year 2011, among which 2856 had one or more PAHs in 2012. METHODS: We examined multi-dimensional risk factors of PAHs in the base year and developed and validated prediction models of hospitalization risk using the following year. The predictive power of the developed models was examined with samples generated by the bootstrap method. The performance of the final model was evaluated with further test statistics at different risk thresholds. MAIN OUTCOME MEASURE: Predicting PAHs. RESULTS: The c-statistic of the final predictive model was 0.784 (CI: 0.769-0.799). The final model including all selected predictors showed the greatest marginal improvement (integrated discrimination improvement of 365%) compared to the base model. The positive predictive value was good. CONCLUSIONS: Our prediction model based on health administrative data can assist the insurer and practitioners to proactively identify and intervene with older adults at risk for a PAH.

Effects of feeding level on nutrient digestibility and enteric methane production in growing goats (Capra hircus hircus) and Sika deer (Cervus nippon hortulorum)

Objective: Two experiments were conducted to determine the effects of feeding level on nutrient digestibility and enteric methane (CH4) emissions in growing goats and Sika deer. METHODS: Three growing male goats (initial body weight [BW] of 22.4±0.9 kg) and three growing male deer (initial BW of 20.2±4.8 kg) were each allotted to a respiration-metabolism chamber for an adaptation period of 7 d and a data collection period of 3 d. An experimental diet was offered to each animal at one of three feeding levels (1.5%, 2.0%, and 2.5% of BW) in a 3×3 Latin square design. The chambers were used for measuring enteric CH4 emission. RESULTS: Nutrient digestibility decreased linearly in goats as feeding level increased, whereas Sika deer digestibility was not affected by feeding level. The enteric production of CH4 expressed as g/kg dry matter intake (DMI), g/kg organic matter intake, and % of gross energy intake decreased linearly with increased feeding level in goats; however, that of Sika deer was not affected by feeding level. Six equations were estimated for predicting the enteric CH4 emission from goats and Sika deer. For goat, equation 1 was found to be of the highest accuracy: CH4 (g/d) = 6.2 (±14.1)+10.2 (±7.01)×DMI (kg/d)+0.0048 (±0.0275)×dry matter digestibility (DMD, g/kg)-0.0070 (±0.0187)×neutral detergent fiber digestibility (NDFD; g/kg). For Sika deer, equation 4 was found to be of the highest accuracy: CH4 (g/d) = -13.0 (±30.8)+29.4 (±3.93)×DMI (kg/d)+0.046 (0.094)×DMD (g/kg)-0.0363 (±0.0636)×NDFD (g/kg). CONCLUSION: Increasing the feeding level increased CH4 production in both goats and Sika deer, and predictive models of enteric CH4 production by goats and Sika deer were estimated.

Dementia is a risk factor for major adverse cardiac and cerebrovascular events in elderly Korean patients initiating hemodialysis: a Korean national population-based study.

BACKGROUND: Dementia is common in end-stage renal disease (ESRD) patients on hemodialysis (HD) and is associated with worse outcomes. This study aimed to investigate the risk of major adverse cardiac and cerebrovascular event (MACCE) in elderly patients with dementia initiating HD. METHODS: Using the database from the Health Insurance Review & Assessment Service, we analyzed 10,171 patients aged 65 years or older who had initiated dialysis from 2005 to 2008. MACCE was defined as a composite outcome of all-cause mortality, nonfatal acute myocardial infarction, target vessel revascularization, and nonfatal ischemic and hemorrhagic stroke. The Kaplan-Meier method and Cox proportional hazards model were used, and further comparisons using propensity-score matching at 1:2 ratio were also performed. RESULTS: A total of 303 elderly patients (3.0%) had dementia at initiating HD. During follow-up, dementia was a significant predictor of MACCE after adjustment for confounding variables. In addition, further analyzed in the propensity-score matched groups, dementia was an independent predictor of both nonfatal ischemic stroke and all-cause mortality. CONCLUSIONS: Dementia is an independent risk factor for mortality and ischemic stroke in elderly ESRD patients initiating HD. Patients with dementia who start dialysis should be closely monitored to reduce the risk of mortality and ischemic stroke.

The Expression of Adipogenic Genes in Adipose Tissues of Feedlot Steers Fed Supplementary Palm Oil or Soybean Oil.

We hypothesized that supplementing finishing diets with palm oil would promote adipogenic gene expression and stearoyl-CoA desaturase (SCD) gene expression in subcutaneous (s.c.) and intramuscular (i.m.) adipose tissues of feedlot steers. Eighteen Angus and Angus crossbred steers were assigned to three groups of 6 steers and fed a basal diet (control), with 3% palm oil, or with 3% soybean oil, for 70 d, top-dressed daily. Tailhead s.c. adipose tissue was obtained by biopsy at 14 d before the initiation of dietary treatments and at 35 d of dietary treatments. At slaughter, after 70 d of dietary treatment, tailhead s.c. adipose tissue and i.m. adipose tissue were obtained from the longissimus thoracis muscle. Palm oil increased plasma palmitic acid and soybean oil increased plasma linoleic acid and α-linolenic acid relative to the initial sampling time. Expression of AMP-activated protein kinase alpha (AMPKα) and peroxisome proliferator-activated receptor gamma (PPARγ) increased between the initial and intermediate biopsies and declined thereafter (p<0.03). SCD gene expression did not change between the initial and intermediate biopsies but declined by over 75% by the final period (p = 0.04), and G-coupled protein receptor 43 (GPR43) gene expression was unaffected by diet or time on trial. Soybean oil decreased (p = 0.01) PPARγ gene expression at the intermediate sample time. At the terminal sample time, PPARγ and SCD gene expression was less in i.m. adipose tissue than in s.c. adipose tissue (p<0.05). AMPKα gene expression was less in s.c. adipose tissue of palm oil-fed steers than in control steers (p = 0.04) and CCAAT enhancer binding protein-beta (CEBPß) gene expression was less in s.c. and i.m. adipose tissues of palm oil-fed steers than in soybean oil-fed steers (p<0.03). Soybean oil decreased SCD gene expression in s.c. adipose tissue (p = 0.05); SCD gene expression in palm oil-fed steers was intermediate between control and soybean oil-fed steers. Contrary to our original hypothesis, palm oil did not promote adipogenic gene expression in s.c. and i.m. adipose tissue.

Effect of the Schroth method of emphasis of active holding on Cobb's angle in patients with scoliosis: a case report.

[Purpose] The purpose of this study was to examine the effect of the Schroth method (three-dimensional convergence exercise) of emphasis of active holding on pain and Cobb's angle in patients with scoliosis. [Subjects and Methods] It applied the Schroth method program of emphasis of active holding individually to three subjects three time per week for 15 weeks. All subject were measured Cobb's angle and pain. [Results] After 15 weeks, pain and Cobb's angle decreased compared to values before. [Conclusion] These results demonstrate the benefit of the Schroth exercise program of emphasis of active holding on decreasing pain and Cobb's angle in patients with idiopathic scoliosis.

Mycobacterium tuberculosis Eis protein initiates suppression of host immune responses by acetylation of DUSP16/MKP-7.

The intracellular pathogen Mycobacterium tuberculosis (Mtb) causes tuberculosis. Enhanced intracellular survival (Eis) protein, secreted by Mtb, enhances survival of Mycobacterium smegmatis (Msm) in macrophages. Mtb Eis was shown to suppress host immune defenses by negatively modulating autophagy, inflammation, and cell death through JNK-dependent inhibition of reactive oxygen species (ROS) generation. Mtb Eis was recently demonstrated to contribute to drug resistance by acetylating multiple amines of aminoglycosides. However, the mechanism of enhanced intracellular survival by Mtb Eis remains unanswered. Therefore, we have characterized both Mtb and Msm Eis proteins biochemically and structurally. We have discovered that Mtb Eis is an efficient N(ε)-acetyltransferase, rapidly acetylating Lys55 of dual-specificity protein phosphatase 16 (DUSP16)/mitogen-activated protein kinase phosphatase-7 (MKP-7), a JNK-specific phosphatase. In contrast, Msm Eis is more efficient as an N(α)-acetyltransferase. We also show that Msm Eis acetylates aminoglycosides as readily as Mtb Eis. Furthermore, Mtb Eis, but not Msm Eis, inhibits LPS-induced JNK phosphorylation. This functional difference against DUSP16/MKP-7 can be understood by comparing the structures of two Eis proteins. The active site of Mtb Eis with a narrow channel seems more suitable for sequence-specific recognition of the protein substrate than the pocket-shaped active site of Msm Eis. We propose that Mtb Eis initiates the inhibition of JNK-dependent autophagy, phagosome maturation, and ROS generation by acetylating DUSP16/MKP-7. Our work thus provides insight into the mechanism of suppressing host immune responses and enhancing mycobacterial survival within macrophages by Mtb Eis.

Knowledge about dementia in South Korean nursing students: a cross-sectional survey.

BACKGROUND: The number of individuals with dementia is increasing substantially due to South Korea's rapidly aging society. Undergraduate nursing students need to have adequate knowledge about dementia to deliver appropriate nursing services. The purpose of this study was to assess the knowledge about dementia among undergraduate nursing students. METHODS: A total of 148 students ranging from freshmen to seniors at a nursing university participated in this study. Data were collected through self-reports using 12-item questionnaires with true/false responses. Knowledge levels about the general characteristics including demographic categories and dementia- related education and training were determined. Factors affecting the score of dementia knowledge were also investigated. RESULTS: The average score and standard deviation for knowledge about dementia were 10.26 and 1.24 out of 12 points. They had relatively low knowledge about the "prevention and treatment" and "causes" of dementia, with overall correct rate of 78.6 % and 85.4 %, respectively. Higher level of knowledge about dementia was associated with increase in grade level (p < 0.001), experience in education on dementia (p = 0.01), previous experience in caring for people with dementia during clinical practice (p < 0.001), and acquiring information on dementia (p = 0.02). Factors that influenced knowledge about dementia included grade level and experience in caring for dementia patients during clinical practice. CONCLUSIONS: This study showed that the level of knowledge about dementia among nursing students was reasonably good. Integrating dementia education and clinical experience into the curricula of undergraduates could improve knowledge about the causes, prevention, and treatment methods for dementia.

Incidence, prevalence, and survival of moyamoya disease in Korea: a nationwide, population-based study.

BACKGROUND AND PURPOSE: There is a scarcity of information on the epidemiology and natural course of moyamoya disease. The aim of this study was to investigate the nationwide epidemiological features of moyamoya disease in Korea, including incidence, prevalence, and survival. METHODS: We used the data from nationwide, population-based Health Insurance Review and Assessment Service claims database and Rare Intractable Disease registration program, which includes physician-certified diagnoses based on uniform criteria for moyamoya disease from 2007 to 2011. Age-specific incidence and prevalence were calculated, and survival was examined using Kaplan-Meier method. RESULTS: The total number of patients with moyamoya disease was 8154 in 2011, with a female-to-male ratio of 1.8. The incidence from 2007 to 2011 was 1.7 to 2.3/10(5), and the prevalence in 2011 was 16.1/10(5). In total, 66.3% of patients aged 0 to 14 years underwent surgery, whereas only 21.5% in the older than 15 years age group underwent surgery. The 1- and 5-year survival rates of adult patients were 96.9% and 92.9%, respectively, and of child patients were 99.6% and 99.3%, respectively. CONCLUSIONS: The prevalence and incidence presented in this study are higher than those in previous studies. This study demonstrates that the burden of moyamoya disease in Korea is substantial.

A population-based approach indicates an overall higher patient mortality with peritoneal dialysis compared to hemodialysis in Korea.

To date, only a few large-scale studies have measured the effect of dialysis modality on mortality in Asian populations. Here, we sought to compare survival between incident hemodialysis (HD) and peritoneal dialysis (PD) patients using the Korean Health Insurance Review & Assessment Service database. This enabled us to perform a population-based complete survey that included 32,280 incident dialysis patients and followed them for a median of 26.5 months. To reduce biases due to nonrandomization, we first matched 7049 patient pairs with similar propensity scores. Using the log-rank test, we found the mortality rate in PD patients was significantly higher than that in HD patients. Subsequent subgroup analyses indicated that in older patients (55 years and older), with the exception of the subgroup of patients with no comorbidities and the subgroup of patients with malignancy, PD was consistently associated with a higher mortality rate. In younger patients (under 55 years), regardless of the covariates, the survival rate of PD patients was comparable to that of HD patients. Thus, while the overall mortality rate was higher in incident PD patients, mortality rates of some incident PD and HD patients were comparable in Korea.

Abomasal infusion of arginine stimulates SCD and C/EBPß gene expression, and decreases CPT1ß gene expression in bovine adipose tissue independent of conjugated linoleic acid.

Based on previous research with bovine peadipocytes, we hypothesized that infusion of arginine into the abomasum of Angus steers stimulates stearoyl-CoA desaturase (SCD) gene expression in bovine subcutaneous (s.c.) adipose tissue, and that this would be attenuated by conjugated linoleic acid (CLA). Growing Angus steers were infused abomasally with L-arginine 50 g/day; n = 13; provided as L-arginine HCl) or L-alanine (isonitrogenous control, 100 g/day; n = 11) for 14 days. For the subsequent 14 days, half of the steers in each amino acid group were infused with CLA (100 g/day). Body weight gain and average daily gain were unaffected (P > 0.15) by infusion of arginine or CLA into the abomasum. The plasma concentrations of cis-9, trans-11 and trans-10, cis-12 CLA were increased CLA infusion (P = 0.001) and infusion of arginine increased plasma arginine (P = 0.01). Compared with day 0, fatty acid synthase, glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase enzyme activities in s.c. adipose tissue increased by day 14 in steers infused with either alanine or arginine (all P < 0.01). NADP-MDH activity was higher (P = 0.01) in steers infused with arginine than in steers infused with arginine plus CLA by day 28, but lipid synthesis in vitro from glucose and acetate was unaffected by infusion of either arginine or CLA (P > 0.40). By day 28, C/EBPß and SCD gene expression was higher, and CPT1ß gene expression was lower, in s.c. adipose tissue of steers infused with arginine than in steers infused with alanine (±CLA) (P = 0.05). CLA decreased adipose tissue oleic acid (18:1n-9) in alanine- or arginine-infused steers (P = 0.05), although CLA had no effect on SCD gene expression. The data indicate that supplemental arginine promotes adipogenic gene expression and may promote lipid accumulation in bovine adipose tissue. L-Arginine may beneficially improve beef quality for human consumption.

Characterization of ambrette seed oil and its mode of action in bacteria.

In the present study, chemical composition and the antibacterial mechanism of ambrette seed oil are investigated. Chemical composition of the oil was analysed by gas chromatography-mass spectrometry (GC-MS). Thirty-five compounds were identified and the major compounds were found to be farnesol acetate (51.45%) and ambrettolide (12.96%). The antibacterial activity was performed by well diffusion assay and the mechanisms were studied by measuring the alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and protein leakage assays. The antibacterial effect of the ambrette seed oil showed inhibitory effect against Bacillus subtilis, Staphylococcus aureus and Enterococcus faecalis. The LDH activity was high in all tested bacteria compared with control, whereas the ALP and protein concentrations were also increased in E. faecalis. Molecular docking revealed the ligands farnesol acetate and ambrettolide had satisfactory binding energy towards the beta lactamase TEM-72 and dihydrofolate reductase (DHFR) protein. Due to its better antibacterial properties, the ambrette seed oil could be used as a source of antibacterial agents.

Antibacterial, anti-inflammatory and probiotic potential of Enterococcus hirae isolated from the rumen of Bos primigenius.

In the present study bacterial strains were isolated from the rumen fluids of Bos primigenius and investigated their in vitro probiotic properties with potent antibacterial activity and anti-inflammatory effects. 9 g positive bacterial isolates were obtained and three isolates could able to tolerate gastric conditions, high bile salt concentrations and exhibited significant bactericidal effect against the enteric pathogens Vibrio cholera, Enterococcus faecalis, Enterobacter aerogens, Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi. Moreover it showed above 70% cell surface hydrophobicity, significant low-invasion ability and potential adherence capacity in Caco-2 cells when compared with the control. The proinflammatory cytokines (TNF-α) was greatly reduced in rumen bacteria treatment and ARBS-1 modulate the immune response by activating the IL-4 secretion in parallel to TNF-α suppression. The 16s rRNA gene sequence of the active isolates were identified as Enterococcus hirae (ARBS-1), Pediococcus acidilactici (ARBS-4) and Bacillus licheniformis (ARBS-7). This study revealed the probiotic bactericidal properties of E. hirae obtained from the rumen of B. primigenius with potential antibacterial and anti-inflammatory effects. Future studies with the strains may yield some novel probiotic product for livestock's.

Adjusting for Confounders in Outcome Studies Using the Korea National Health Insurance Claim Database: A Review of Methods and Applications.

OBJECTIVES: Adjusting for potential confounders is crucial for producing valuable evidence in outcome studies. Although numerous studies have been published using the Korea National Health Insurance Claim Database, no study has critically reviewed the methods used to adjust for confounders. This study aimed to review these studies and suggest methods and applications to adjust for confounders. METHODS: We conducted a literature search of electronic databases, including PubMed and Embase, from January 1, 2021 to December 31, 2022. In total, 278 studies were retrieved. Eligibility criteria were published in English and outcome studies. A literature search and article screening were independently performed by 2 authors and finally, 173 of 278 studies were included. RESULTS: Thirty-nine studies used matching at the study design stage, and 171 adjusted for confounders using regression analysis or propensity scores at the analysis stage. Of these, 125 conducted regression analyses based on the study questions. Propensity score matching was the most common method involving propensity scores. A total of 171 studies included age and/or sex as confounders. Comorbidities and healthcare utilization, including medications and procedures, were used as confounders in 146 and 82 studies, respectively. CONCLUSIONS: This is the first review to address the methods and applications used to adjust for confounders in recently published studies. Our results indicate that all studies adjusted for confounders with appropriate study designs and statistical methodologies; however, a thorough understanding and careful application of confounding variables are required to avoid erroneous results.

Trends in Regional Disparities in Cardiovascular Surgery and Mortality in Korea: A National Cross-sectional Study.

OBJECTIVES: Regional disparities in cardiovascular care in Korea have led to uneven patient outcomes. Despite the growing need for and access to procedures, few studies have linked regional service availability to mortality rates. This study analyzed regional variation in the utilization of major cardiovascular procedures and their associations with short-term mortality to provide better evidence regarding the relationship between healthcare resource distribution and patient survival. METHODS: A cross-sectional study was conducted using nationwide claims data for patients who underwent coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), stent insertion, or aortic aneurysm resection in 2022. Regional variation was assessed by the relevance index (RI). The associations between the regional RI and 30-day mortality were analyzed. RESULTS: The RI was lowest for aortic aneurysm resection (mean, 26.2; standard deviation, 26.1), indicating the most uneven regional distribution among the surgical procedures. Patients undergoing this procedure in regions with higher RIs showed significantly lower 30-day mortality (adjusted odds ratio [aOR], 0.73; 95% confidence interval, 0.55 to 0.96; p=0.026) versus those with lower RIs. This suggests that cardiovascular surgery regional availability, as measured by RI, has an impact on mortality rates for certain complex surgical procedures. The RI was not associated with significant mortality differences for more widely available procedures like CABG (aOR, 0.96), PCI (aOR, 1.00), or stent insertion (aOR, 0.91). CONCLUSIONS: Significant regional variation and underutilization of cardiovascular surgery were found, with reduced access linked to worse mortality for complex procedures. Disparities should be addressed through collaboration among hospitals and policy efforts to improve outcomes.

Suicide death and other-cause mortality in psychiatric patients: A South Korean study using nationwide claims data.

INTRODUCTION: It is well-known that suicide and excess mortality are high in patients with psychiatric illnesses and this has long been an important issue in the field of mental health. We aim to investigate suicide and other-cause deaths in patients with psychiatric illnesses. METHODS: This retrospective, population-based cohort was based on the National Health Insurance claims data of the first admission with a principal diagnosis of major psychiatric disorder between 2010 and 2011, and followed up to 2020. A total of 95,855 participants were enrolled. Suicide and other-cause mortality were assessed through Log-rank test and Kaplan-Meier curve. RESULTS: There were 95,855 patients, with an average age of 48.2 years. The number of suicide deaths and other-cause deaths was 2408 (288.1 per 100,000 person-years) and 15,192 (1817.6 per 100,000 person-years), respectively. The rate of healthcare utilization prior to suicide was 95.0 %, and the rate of utilization prior to one week before suicide was 43.5 %. The risk of suicide was highest in patients with depression, followed by alcohol use disorder, schizophrenia, and bipolar disorder. CONCLUSIONS: This study revealed various factors related to healthcare utilization associated with suicide and other-cause deaths in psychiatric patients. Educating frontline healthcare professionals, psychiatrists, emergency department personnel, and general practice doctors using such as Gatekeeper program is important to prevent suicides.

Feasibility of extracting cancer stage and metastasis codes from health insurance claims of outpatients and expressibility in ICD-11: a cross-sectional study using national health insurance data from South Korea.

OBJECTIVES: This study aimed to evaluate the incidence of health insurance claims recording the cancer stage and TNM codes representing tumor extension size (T), lymph node metastasis (N), and distant metastasis (M) for patients diagnosed with cancer and to determine whether this extracted data could be applied to the new ICD-11 codes. DESIGN: A cross-sectional study design was used, with the units of analysis as individual outpatients. Two dependent variables were extraction feasibility of cancer stage and TNM metastasis information from each claim. Expressibility of the two variables in ICD-11 was descriptively analysed. SETTING AND PARTICIPANTS: The study was conducted in South Korea and study participants were outpatients: lung cancer (LC) (46616), stomach cancer (SC) (50103) and colorectal cancer (CC) (54707). The data set consisted of the first health insurance claim of each patient visiting a hospital from 1 July to 31 December 2021. RESULTS: The absolute extraction success rates for cancer stage based on claims with cancer stage was 33.3%. The rates for stage for LC, SC and CC were 30.1%, 35.5% and 34.0%, respectively. The rate for TNM was 11.0%. The relative extraction success rates for stage compared with that for CC (the reference group) were lower for patients with LC (adjusted OR (aOR), 0.803; 95% CI 0.782 to 0.825; p<0.0001) but higher for SC (aOR 1.073; 95% CI 1.046 to 1.101; p<0.0001). The rates of TNM compared that for CC were 40.7% lower for LC (aOR, 0.593; 95% CI 0.569 to 0.617; p<0.0001) and 43.0% lower for SC (aOR 0.570; 95% CI 0.548 to 0.593; p<0.0001). There were limits to expressibility in ICD-11 regarding the detailed cancer stage and TNM metastasis codes. CONCLUSION: Extracting cancer stage and TNM codes from health insurance claims were feasible, but expressibility in ICD-11 codes was limited. WHO may need to create specific cancer stage and TNM extension codes for ICD-11 due to the absence of current rules in ICD-11.