Korean National Health Insurance Claims Research Articles

Relationship between tamoxifen and cataracts: a nationwide cohort study of women in South Korea

Although prospective randomized clinical trials have reported that the use of prophylactic tamoxifen in patients at a high risk of breast cancer is associated with an increased risk of cataracts development, such findings are inconsistent. This study aimed to clarify the relationship between adjuvant tamoxifen use and cataracts risk using a nationwide longitudinal population-based registry. This retrospective cohort study was conducted using the Korean National Health Insurance claims database over a 15-year period (January 2007-December 2021). Data from all female patients diagnosed with ductal carcinoma in situ (DCIS) between 2009 and 2015 were extracted. We evaluated the incidence of cataracts diagnosis and surgery after adjuvant tamoxifen administration in patients with DCIS. A total of 43,434 patients who met the inclusion criteria were diagnosed with DCIS between 2009 and 2015. Data from 2849 patients receiving tamoxifen and 1615 patients not receiving tamoxifen were analyzed before matching. After matching for comorbidities, type of breast surgery, and age, both groups consisted of 1597 patients. Both before and after matching, adjuvant tamoxifen was not a significant factor for an increased risk of cataracts diagnosis alone or with surgery. Our study showed that adjuvant tamoxifen was not a risk factor for increased cataracts diagnosis and surgery in patients with DCIS. This finding provides a basis for physicians to reduce their ocular toxicity concerns regarding the risk of patients developing cataracts by tamoxifen treatment.

Disparities in the Diagnosis and Treatment of Bile Duct Cancer in People with Disabilities: A National Cohort Study in South Korea.

We aimed to evaluate the impacts of disability on the diagnosis, treatment, and prognosis of bile duct cancer (BDC) according to the severity and type of disability. Patients diagnosed with BDC were selected from an age- and sex-matched population (1:3 ratio) with or without disabilities from the National Disability Database, the Korean Central Cancer Registry, and the Korean National Health Insurance claims database. The cohort included 15,065 patients with BDC, with a significantly lower rate in those with severe disabilities than in people without or with mild disabilities (110.6 vs. 136.5 vs. 147.6 per 105 persons, respectively). People with severe disabilities were diagnosed with BDC at an earlier age but were less likely to undergo surgery (adjusted odds ratio (aOR) = 0.52, 95% confidence interval (CI): 0.45-0.61) or chemotherapy (aOR = 0.76, 95% CI: 0.61-0.95) compared to those without disabilities. This trend was more evident in patients with mental disabilities. The overall and cancer-specific mortality rates were higher in patients (especially women) with disabilities than in those without. There needs systemic approach to ensure equal access to quality cancer care for people with disabilities.

Incidence of Sturge-Weber Syndrome and Risk of Secondary Glaucoma: A Nationwide Population-based Study Using a Rare Disease Registry

To determine Sturge-Weber syndrome (SWS) incidence and secondary glaucoma risk. Nationwide retrospective cohort study. The Korean National Health Insurance (NHI) claims database from 2002 to 2019 along with the registration-program database for rare intractable diseases (ie, the rare disease registry) were accessed to identify ophthalmologist/neurologist-confirmed SWS patients. SWS incidence was estimated in a same-birth-year population (ie, a birth cohort) from 2002 to 2009. Among the SWS patients born between 2002 and 2019, the incidence of SWS-associated glaucoma was estimated. During the 18-year observational period, a total of 1049 patients were registered as SWS. The mean birth-cohort SWS incidence was 3.08 (95% CI 2.52-3.64) per 100000 people per year, with an approximate female-to-male ratio of 0.97:1. Among the 217 SWS patients born between 2002 and 2019, secondary glaucoma arose in 18 (8.3%) cases, including 12 males (66.7%). Among these 18 SWS-associated glaucoma cases, 15 (83.3%) were diagnosed before 1 year of age, and the other 3 (16.7%) between age 1 and 2 years. Among the 660 SWS patients under age 40 years during the study period, SWS-associated glaucoma was identified in 79 (12.0%) cases. Neurologic manifestations such as epilepsy, hemiparesis, and mental retardation did not significantly differ between SWS patients with and those without secondary glaucoma. This study identified birth-cohort SWS incidence and determined secondary-glaucoma risk in a population of East Asian ethnicity. These data could help to promote better understanding of the epidemiologic features of SWS patients.

Risk of revision in UKA versus HTO: a nationwide propensity score-matched study.

Our study aims to investigate the incidence rate and risk factors for subsequent revision in patients treated with UKA compared with those treated with HTO. In this retrospective nationwide cohort study, we used data from the Korean National Health Insurance claims database from January 1, 2009 to December 31, 2017. We compared patients who had undergone UKA or HTO as the primary surgical procedure longer than two years prior. We used multivariable logistic regression models to compare risk of revision between the groups after propensity matching with inverse probability of treatment weighting (IPTW). Revision was defined as conversion to total knee arthroplasty (TKA) after primary UKA or HTO. In this study, 73,902 patients with UKA and 72,215 patients with HTO were identified after applying IPTW. The risk of revision during the entire study period was higher for patients with HTO than for patients with UKA (adjusted hazard ratio [HR] = 1.42). Kaplan-Meier 8-years survival was 96.8% in the UKA group and 95.1% in the HTO group. Patients with HTO who were at higher risk of revision had advanced age (60-69years [HR = 2.17, 95% CI 1.76-2.67] and 70-79years [HR = 2.89, 95% CI 1.81-4.62]), female sex (HR = 1.41, 95% CI 1.19-1.66), CHF (HR = 3.12, 95% CI 1.25-7.78), COPD (HR = 1.68, 95% CI 1.34-2.10), PVD (HR = 1.75, 95% CI 1.10-2.78), and CVA or TIA (HR = 1.87, 95% CI 1.13-3.08) compared with those with UKA. Risk of revision was higher for patients with HTO than for patients with UKA. Risk factors for subsequent revision in patients with HTO were advanced age (60-69, 70-79), female sex, and comorbidities such as CHF, COPD, PVD, CVA, or TIA. However, orthopedic surgeons should also consider that TKA conversion from UKA has higher risk of revision than TKA conversion from HTO before choosing between UKA and HTO.

Marked Reduction in the Risk of Dementia in Patients with Breast Cancer: A Nationwide Population-Based Cohort Study.

An inverse relationship between cancer and neurodegenerative disease, which presents the possibility of a reduced risk of dementia in cancer patients, has been suggested previously. However, a nationwide longitudinal population-based study of specific types of cancer with due consideration of treatment effects has not been conducted. This nationwide population-based cohort study used data obtained in a 12-year period (January 2007- December 2018) in the Korean National Health Insurance claims database. All female breast cancer patients (age ≥ 50 years) diagnosed between 2009 and 2010 were included after excluding those with physician visits for any cancer during a 2-year period (2007-2008). Patients with senile cataract constituted the control group. The main study outcome was the risk of developing dementia. From a total of 90,396 and 85,906 patients with breast cancer and cataract, respectively, patients without behavior codes were excluded. Data for 15,407 breast cancer patients and 7,020 controls were analyzed before matching. After matching for comorbidities and age, either group comprised 2,252 patients. The median follow-up time was 104.1±24.0 months after matching. After matching, breast cancer was a predictor of a lower risk of for dementia (hazard ratio, 0.091; 95% confidence interval, 0.075 to 0.111; p < 0.001). In breast cancer patients, receiving chemotherapy and endocrine therapy did not significantly affect the incidence of dementia. Breast cancer was associated with a remarkably decreased risk of dementia. The findings strongly suggest an inverse relationship between cancer and neurodegeneration, regardless of the adverse effects of cancer treatment on cognitive function.

Risk of developing depression from endocrine treatment: A nationwide cohort study of women administered treatment for breast cancer in South Korea.

BackgroundAlthough previous studies demonstrated no association between depression and tamoxifen in patients with breast cancer, there is still a limited amount of long-term follow-up data. This study aimed to evaluate the relationship between endocrine treatment and the risk of depression.MethodsThis nationwide population-based cohort study used data obtained over a 14-year period (January 2007 to December 2021) from the Korean National Health Insurance claims database. All female patients with breast cancer were included. We examined the incidence of depression in patients who underwent endocrine treatment, and those who did not undergo endocrine treatment constituted the control group.ResultsThe data from 11,109 patients who underwent endocrine treatment and 6,615 control patients between 2009 and 2010 were analyzed. After performing matching for comorbidities and age, both groups comprised 6,532 patients. The median follow-up were 119.71 months. Before and after matching was performed, the endocrine treatment was not a significant risk factor for developing depression (p=0.7295 and p=0.2668, respectively), nor was it a significant factor for an increased risk for suicide attempt (p=0.6381 and p=0.8366, respectively).ConclusionsUsing a real-world population-based cohort, this study demonstrated that there is no evidence that the endocrine treatment increases the risk of depression.

Changes in the Mean and Variance of the Numbers of Medical Visits for Allergic Diseases before and during the COVID-19 Pandemic in Korea.

The implementation of precautionary measures, such as wearing a mask and social distancing, may have affected allergic diseases during the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to compare the numbers of medical visits for allergic diseases before and during the COVID-19 pandemic. Data were obtained from the Korean National Health Insurance claims database. Monthly numbers of patients for four allergic diseases, i.e., allergic rhinitis (AR), asthma, atopic dermatitis (AD), and allergic conjunctivitis (AC), were evaluated using ICD-10 codes and compared between the ‘before COVID-19’ period from January 2018 to February 2020, and the ‘during COVID-19’ period from March 2020 to June 2021, since the first COVID-19 patient was detected on 20 January 2020, in Korea. Subgroup analyses were performed according to age and sex. The mean numbers of medical visits for AR and asthma were significantly greater before COVID-19 than those during COVID-19 (both p < 0.001). The variance in the number of medical visits for asthma decreased during the COVID-19 pandemic. However, the mean number of medical visits for AD increased slightly during COVID-19 and that for AC did not change before and during the COVID-19 pandemic. In subgroup analyses, the results showed a similar pattern to that of the total number of participants, regardless of age and sex. In conclusion, medical visits for AR and asthma significantly decreased during the COVID-19 pandemic, regardless of age and sex.

National prescription patterns of antidepressants among patients with amyotrophic lateral sclerosis: An analysis of the Korean National Health Insurance database.

The current status of antidepressant use in patients with amyotrophic lateral sclerosis (ALS), such as the prevalence and factors associated with it, has not been systematically investigated. We aimed to analyze the prevalence and patterns of antidepressant prescriptions in patients with ALS and depression, and to identify factors associated with antidepressant prescriptions after the diagnosis of ALS. The data of patients with ALS and the prescription of antidepressants were retrieved from the Korean National Health Insurance claims data. A multivariate logistic regression model was used to identify factors associated with antidepressant prescriptions. In total, 533 of 2955 patients had depressive disorders, and 426 were prescribed antidepressants. Selective serotonin reuptake inhibitors and tricyclic antidepressants were the most frequently prescribed drugs. Adjusted odds ratios (ORs) were 1.379 for the prescription of antidepressants in females. For various age groups, compared with those aged 80 years and older, adjusted ORs were 1.889 for those in their 70s, 2.319 for those in their 60s, 2.872 for those in their 50s, 2.854 for those in their 40s, and 3.363 for those under 40 years of age. Adjusted ORs were 1.662 for patients with a history of a psychiatric disorder and 1.861 for those with a history of psychiatric pharmacotherapy (all P < .05). Most patients with ALS who had depression received antidepressant prescriptions. In young females with a previous psychiatric disorder or pharmacotherapy, an in-depth evaluation for a depressive disorder should be performed.

Recurrence Rates and Its Associated Factors after Early Spinal Instrumentation for Pyogenic Spondylodiscitis: A Nationwide Cohort Study of 2148 Patients.

Recent studies have consistently reported the safety and effectiveness of early spinal instrumentation for pyogenic spondylodiscitis. However, none of these studies investigated the recurrence rate or associated factors based on this specific group of patients. Recurrence prediction models that are not based on a homogenous cohort of patients undergoing early spinal instrumentation show theoretical limitations for clinical use. A nationwide, population-based, retrospective cohort study using a claims database was planned to investigate the recurrence rate and its associated factors in patients who underwent early instrumented spinal fusion surgery for pyogenic spondylodiscitis. We used data from the Korean National Health Insurance claims database collected between 2014 and 2018. A total of 2148 patients who underwent early (within 6 weeks after the diagnosis) instrumented spinal fusion surgery for pyogenic spondylodiscitis were included, including 1925 patients (90%) without recurrence and 223 patients (10%) with recurrence. Logistic regression models were used to identify factors associated with recurrence, and sensitivity analysis was performed according to two different definitions for recurrence: shorter (2 weeks or more) and longer (6 weeks or more) periods of antibiotic therapy for recurrence. The recurrence rates in our cohort were 14.1%, 10.4%, and 8.0% at 2, 4, and 6 weeks, respectively, in relation to the duration of antibiotic treatment for recurrence. We identified age 60–69 years (OR = 2.42), age > 70 years (OR = 2.29), posterior thoracic approach (OR = 1.85), multiple surgical approaches (OR = 4.17), use of a cage (OR = 1.66), transfusion (OR = 2.55), antibiotics for resistant organisms (OR = 2.55), and systemic steroid treatment over 2 weeks (OR = 2.27) as the factors associated with recurrence. The recurrence rates and associated factors from our first population-based and the largest clinical study can be practically used as a reasonable reference and provide clinicians with an acceptable tool for the comprehensive risk assessment for recurrence after early spinal instrumentation for pyogenic spondylodiscitis.

Early Reoperation Rates and Its Risk Factors after Instrumented Spinal Fusion Surgery for Degenerative Spinal Disease: A Nationwide Cohort Study of 65,355 Patients.

Reoperation is a major concern in spinal fusion surgery for degenerative spinal disease. Earlier reported reoperation rates were confined to a specific spinal region without comprehensive analysis, and their prediction models for reoperation were not statistically validated. Our study aimed to present reasonable base rates for reoperation according to all possible risk factors and build a validated prediction model for early reoperation. In our nationwide population-based cohort study, data between 2014 and 2016 were obtained from the Korean National Health Insurance claims database. Patients older than 19 years who underwent instrumented spinal fusion surgery for degenerative spinal diseases were included. The patients were divided into cases (patients who underwent reoperation) and controls (patients who did not undergo reoperation), and risk factors for reoperation were determined by multivariable analysis. The estimates of all statistical models were internally validated using bootstrap samples, and sensitivity analyses were additionally performed to validate the estimates by comparing the two prediction models (models for 1st-year and 3rd-year reoperation). The study included 65,355 patients: 2939 (4.5%) who underwent reoperation within 3 years after the index surgery and 62,146 controls. Reoperation rates were significantly different according to the type of surgical approach and the spinal region. The third-year reoperation rates were 5.3% in the combined lumbar approach, 5.2% in the posterior lumbar approach, 5.0% in the anterior lumbar approach, 3.0% in the posterior thoracic approach, 2.8% in the posterior cervical approach, 2.6% in the anterior cervical approach, and 1.6% in the combined cervical approach. Multivariable analysis identified older age, male sex, hospital type, comorbidities, allogeneic transfusion, longer use of steroids, cages, and types of surgical approaches as risk factors for reoperation. Clinicians can conduct comprehensive risk assessment of early reoperation in patients who will undergo instrumented spinal fusion surgery for degenerative spinal disease using this model.

Statins and the risk of gastric, colorectal, and esophageal cancer incidence and mortality: a cohort study based on data from the Korean national health insurance claims database.

This study investigated the association between the use of statins, the incidence of gastric, colorectal, and esophageal cancers, and mortality between January 2005 and June 2013 in South Korea. We compared patients aged 45-70years statin users for at least 6months to non-statin users matched by age and sex, from 2004 to June 2013 using the National Health Insurance database. Main outcomes were gastric, colorectal, and esophageal cancer incidence and mortality. Cox proportional hazard regression was used to calculate the adjusted hazard ratios (aHRs) and 95% confidence intervals (95% CIs) among overall cohort and matched cohort after propensity score matching with a 1:1 ratio. Out of 1,008,101 people, 20,473 incident cancers, 3938 cancer deaths occurred and 7669 incident cancer, 1438 cancer death in matched cohort. The aHRs for the association between the risk of cancers and statin use were 0.7 (95% CI 0.65-0.74) for gastric cancer, 0.73 (95% CI 0.69-0.78) for colorectal cancer, and 0.55 (95% CI 0.43-0.71) for esophageal cancer. There were associations between statin use and decreased gastric cancer mortality (HR 0.46, 95% CI 0.52-0.57), colorectal cancer mortality (HR 0.43, 95% CI 0.36-0.51), and esophageal cancer mortality (HR 0.41, 95% CI 0.27-0.50) in the overall cohort and this pattern was similar in the matched cohort. Statin use for at least 6months was significantly associated with a lower risk of stomach, colorectal, and esophageal cancer incidence as well as cancer mortality after a diagnosis.

Validity of the diagnosis of diabetic microvascular complications in Korean national health insurance claim data

Background: There is inadequate information on the validation of diabetic microvascular complications in the Korean National Health Insurance Service data set. We aimed to validate the diagnostic algorithms regarding the nephropathy, neuropathy, and retinopathy of diabetes.Methods: From various secondary and tertiary medical centers, we selected 6,493 patients aged ≥ 40 years who were diagnosed with diabetic microvascular complications more than once based on codes in the 10th version of the International Classification of Diseases (ICD-10). During 2019 and 2020, we randomly selected the diagnoses of 200 patients, 100 from each of two hospitals. The positive predictive value (PPV), negative predictive value, error rate, sensitivity, and specificity were determined for each diabetic microvascular complication according to the ICD-10 codes, laboratory findings, diagnostic studies, and treatment procedure codes.Results: Among the 200 patients who visited the hospital more than once and had the diagnostic codes of diabetic microvascular complications, 142, 110, and 154 patients were confirmed to have the gold standard of diabetic nephropathy (PPV, 71.0%), diabetic neuropathy (PPV, 55.0%), and diabetic retinopathy (PPV, 77.0%), respectively. The PPV and specificity of diabetic nephropathy (PPV, 71.0–81.4%; specificity, 10.3–53.4%), diabetic neuropathy (PPV, 55.0–81.3%; specificity, 66.7–76.7%) and diabetic retinopathy (PPV, 77.0–96.6%; specificity, 2.2–89.1%) increased after combining them with the laboratory findings, diagnostic studies, and treatment procedures codes. These change trends were observed similarly for both hospitals.Conclusions: Defining diabetic microvascular complications using ICD-10 codes and their related examination codes may be a feasible method for studying diabetic complications.

Comparative analysis of cardio-cerebrovascular complications in immigrants and native-born Koreans with diabetes: Risk factors and perspectives

BackgroundGiven the rapidly increasing number of immigrants, it is crucial to address health care issues involving immigrants to facilitate their safe and secure settlement. Especially for common chronic diseases, such as diabetes, immigrants face more complex obstacles to manage their chronic conditions than do native-born residents. Therefore, we aimed to assess differences in the incidence and associated risk factors of cardio-cerebrovascular (CCV) complications of immigrants compared with native-born Koreans with diabetes.MethodsImmigrants and native-born Koreans who had new diagnosis of diabetes and simultaneously received anti-diabetic prescriptions in 2012 were defined by using Korean National Health Insurance Claim Database(KNHICD). CCV complications were assessed at a 3-year follow-up from the index date. We assessed differences in the CCV complications and risk factors using multiple cox regression models.ResultsIn total, 4,008 patients (668 of immigrants and 3,340 of native-born Koreans) who had newly diagnosed diabetes and simultaneously received anti-diabetic prescriptions in 2012 were selected. Immigrants with diabetes were at a 1.39 times higher risk of having CCV complications than native-born Koreans with diabetes (95% CI: 1.021–1.881). Patients who had a usual sources of care (USC) presented a significantly reduced risk of cardio-cerebrovascular complication (HR: 0.452; 95% CI: 0.342–0.598) in both immigrants and native Koreans. In subgroup analysis in immigrants, patients having USC showed decreased risk of CCV incidence (HR: 0.35, 95% CI: 0.175–0.703), whereas >60 years old and Charlson comorbidity index (CCI) score >1 presented increased risk of CCV complications.ConclusionImmigrants with diabetes have a higher risk of CCV complications than native-born Koreans with diabetes. However, having a USC significantly decreased the risk of CCV complications. Therefore, the utilization of USC will benefit to reduce diabetic complications in immigrants as well as reduction of overall health care cost burden, it would be necessary to implement USC in diabetes care at the initial disease stage.

Restarting anticoagulant therapy after intracranial hemorrhage in patients with atrial fibrillation: A nationwide retrospective cohort study.

Resuming anticoagulation after an intracranial hemorrhage (ICH) poses a clinical conundrum. The absence of relevant guidelines has led to wide variations in the decision on resuming anticoagulation therapies after ICH. This study aimed to evaluate the risks of an anticoagulation therapy on severe thrombotic events (STE) and severe hemorrhage events (SHE) in Korea and compare the effects of novel direct oral anticoagulants (NOACs) and warfarin in patients with AF. This study was performed using the Korean national health insurance claims data obtained between 2002 and 2017 from individuals who had recently survived an ICH with comorbid AF. The endpoints of this study were STE and SHE. Anticoagulants, antiplatelet agents, and non-antithrombotic users were analyzed for survival with propensity score matching. Among the 4,964 participants analyzed, 878 (17.7%) and 2,070 (41.7%) used anticoagulant and antiplatelet agents, respectively. Anticoagulant (hazard ratio [HR] for STE: 0.385, P<0.0001; HR for SHE: 0.578, P<0.0001) or antiplatelet users (HR for STE: 0.545, P<0.0001; HR for SHE: 0.637, P<0.0001) had a lower risk of STE and SHE than non-antithrombotic users. Anticoagulation 6-8weeks post-ICH showed a tendency of the lowest risk of all-cause mortality (HR: 0.614, P=0.0552). However, there was no difference in the risk between the anticoagulant and antiplatelet users. Further, NOACs were associated with a lower risk of STEs than warfarin (HR, 0.263; P<0.0001). Our results showed that in patients with AF, resuming anticoagulants and antiplatelets after ICH improved the STEs and SHEs. Further, NOAC had additional benefits as compared to warfarin.

Safety of laparoscopic surgery during pregnancy: a Korean nationwide population-based study.

The optimal surgical approach to perform during pregnancy is still controversial. This study evaluated pregnancy and operative outcomes in women undergoing an appendectomy or cholecystectomy during pregnancy, and compared them between the laparoscopic and open approach using nationwide population-based data. Between 2009 and 2019, a total of 2941 pregnant women with procedure codes for an appendectomy or cholecystectomy were extracted from the Korean National Health Insurance claims data (laparoscopy: 1504; open: 1437). Surgical outcomes [length of stay (LOS), anesthesia time, 30-day readmission rates, transfusion rates, second laparotomy, and 30-day mortality rates] and pregnancy outcomes (live birth rate, overall and spontaneous abortion rates, threatened abortion rate, type of delivery, preterm labor, stillbirth, fetal screening abnormalities, and intrauterine growth retardation) were compared between the open and laparoscopic groups. The laparoscopic group had a significantly shorter LOS than the open group, and transfusions were less frequent in the laparoscopic group. Mortality, 30-day readmission rates, and second laparotomy were not statistically significant between the two groups. There were no significant differences in fetal loss and live birth rates between the two groups in all gestational ages. Preterm labor within 30days of surgery was more frequent in the laparoscopy group than in the open surgery group, especially for those in their first and third trimesters. Open procedures were associated with an increased rate of cesarean sections. Laparoscopic surgery was found to be feasible and safe without adverse postoperative outcomes. Careful observation of postoperative preterm labor is necessary, especially for women who undergo laparoscopic surgery in their first and third trimesters.

Associations of stroke with all-cause and cause-specific mortality: A population-based matched cohort study.

This study aimed to assess the specific associations between stroke and all-cause and cause-specific mortality among Korean adults. We used data extracted from the Korean National Health Insurance claims database from 2002 to 2013, including information on individuals with or without stroke aged 20years and older. Patients with intracerebral hemorrhage, ischemic stroke or unspecified stroke were classified as stroke patients, while a reference population matched in terms of sex and age were also selected. The outcomes were all-cause mortality, natural causes of death (i.e. all natural causes, death by stroke and death by other diseases) and suicide. Survival analysis was performed using the Cox proportional hazards model. Of the 73150 eligible participants-including 14630 stroke patients and 58520 age- and sex-matched controls-11121 (15.2%) died during the study period. Of them, 10513 participants (94.5%) died of natural causes, including 1653 (14.5%) who died due to stroke and 8860 (79.7%) who died due to other diseases. Two hundred and fifty patients (2.2%) died by suicide. Stroke patients showed higher adjusted hazard ratios (HR) for all-cause (HR=6.48, 95% CI, 3.87-10.86), all-natural-cause (HR=2.68, 95% CI, 2.53-2.84), stroke (HR=21.16, 95% CI, 17.49-25.61), other disease (HR=1.69, 95% CI, 1.58-1.81) and suicide mortality (HR=3.34, 95% CI, 2.24-4.98) than those without stroke. The effect size of stroke for suicide mortality was greater than that for other causes of mortality (except stroke mortality). Stroke was associated with a higher risk of all-cause, natural cause and suicide mortality; stroke was more strongly associated with risk of suicide mortality than with any mortality for any other causes. From a policy standpoint, these results suggest the need for greater supportive care to prevent unnatural deaths among stroke patients.

A Comparison of the Anesthetic Methods for Recurrence Rates of Bladder Cancer after Transurethral Resection of Bladder Tumors Using National Health Insurance Claims Data of South Korea.

Bladder cancers have high recurrence rates and are usually removed via transurethral resection of bladder tumor (TURBT). Recently, some reports showed that the anesthetic method may affect the recurrence rates of bladder cancers. The purpose of this population-based study was to compare the effect of anesthetic methods with the recurrence rates of bladder cancers in South Korea. A total of 4439 patients were reviewed retrospectively using the data of the Korean National Health Insurance (NHI) claims database from January 2007 to December 2011. Patients were divided into 2 groups who received general (n = 3767) and regional anesthesia (n = 582), and were followed up until September 2017. Propensity score matching was conducted to reduce the effect of confounding factors. After using propensity score matching with a multivariable Cox regression model, age (p < 0.001), sex (p < 0.001), hypertension (p = 0.003), diabetes mellitus (p = 0.001), and renal disease (p < 0.001) were significantly associated with bladder cancer recurrence. However, there were no significant differences in the recurrence rates of bladder cancers in patients who received general anesthesia and spinal anesthesia for TURBTs. This study revealed that there is no relationship between the anesthetic method and bladder cancer recurrence. Either general anesthesia or regional anesthesia can be used depending on the situation in patients receiving TURBT. Future prospective studies are warranted to confirm the association between the anesthetic method and the recurrence rates of bladder cancer.

A comparative study of 21,194 UKAs and 49,270 HTOs for the risk of unanticipated events in mid-age patients from the national claims data in South Korea

BackgroundBoth high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are well-established treatments for medial knee osteoarthritis (OA). However, over the past 20 years, results of comparisons of long-term survival rates and outcomes have remained controversial. Furthermore, in patients at the boundary age, from 50 to 70 years, considering age as a treatment indication, selecting a surgical method is difficult. Therefore, we aimed to investigate conversion rates to total knee arthroplasty (TKA) and perioperative adverse outcomes between the two surgical methods in mid-age patients.MethodsWe extracted data from the Korean National Health Insurance claims database. A total of 70,464 patients aged between 50 and 70 years, considered as mid-age patients were included in the final study population. We used a multivariable Cox proportional hazard regression model, adjusting for potential confounders such as age, sex, insurance type, region of residence, hospital type, comorbidities, and the Charlson comorbidity Index (CCI).ResultsOf the 70,464 patients, 21,194 were treated with UKA and 49,270 were treated with HTO. HTO showed a higher risk of revision than UKA at five, and 10 years and during the whole observation period. The incidence of deep vein thromboembolism, and surgical site infection was significantly higher in UKA than in HTO.ConclusionsIt is important to choose an appropriate surgical method considering that UKA has better results in terms of long-term survival rates but may have a higher incidence of various complications.

Association between birth weight and neurodevelopmental disorders assessed using the Korean National Health Insurance Service claims data

The risk of neurodevelopmental disorders in low birth weight (LBW) infants has gained recognition but remains debatable. We investigated the risk of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in school-aged children according to their birth weight. We conducted a retrospective cohort study using the Korean National Health Insurance claims data of 2,143,652 children who were born between 2008 and 2012. Gestational age of infants was not available; thus, outcomes were not adjusted with it. Not only infants with birth weights of < 1.5 kg, but also 2.0–2.4 kg and 1.5–1.9 kg were associated with having ADHD; odds ratio (OR), 1.41 (95% confidence interval [CI] 1.33–1.50), and 1.49 (95% CI 1.33–1.66), respectively. The OR in infants with birth weights of 2.0–2.4 kg and 1.5–1.9 kg was 1.91 (95% CI 1.79–2.05) and 3.25 (95% CI 2.95–3.59), respectively, indicating increased odds of having ASD. Subgroup analysis for children without perinatal diseases showed similar results. In this national cohort, infants with birth weights of < 2.5 kg were associated with ADHD and ASD, regardless of perinatal history. Children born with LBW need detailed clinical follow-up.

Risk Factors for Postoperative Deep Infection after Instrumented Spinal Fusion Surgeries for Degenerative Spinal Disease: A Nationwide Cohort Study of 194,036 Patients

Previous studies to identify risk factors for postoperative deep infection following instrumented spinal fusion surgery for degenerative spinal disease are based on insufficient information and have limited use in clinical practice. This study aims to fill this gap by assessing the risk factors and their adjusted relative risks through a comprehensive analysis, including all core information. In this nationwide, population-based, cohort study, data were obtained from the Korean National Health Insurance claims database between 1 January 2014, and 31 December 2018. This study included a cohort of 194,036 patients older than 19 years, who underwent instrumented spinal fusion surgery for degenerative spinal disease. We divided this population into cases (patients with postoperative deep infection) and controls (patients without postoperative deep infection); risk factors for postoperative deep infection were determined by multivariable analysis. The definition of postoperative deep infection varied, and sensitivity analyses were performed according to each definition. The estimates of all the statistical models were internally validated using bootstrap samples. The study included 767 patients (0.39%) with postoperative deep spinal infections and 193,269 controls. The final multivariable model identified the following variables as significant risk factors for postoperative deep infection: age between 60–69 years (OR = 1.6 [1.1–2.3]); age between 70–79 years (OR = 1.7 [1.2–2.5]); age > 80 years (OR = 2.1 [1.3–3.2]); male sex (OR = 1.7 [1.5–2.0]); rural residence (OR = 1.3 [1.1–1.5]); anterior cervical approach (OR = 0.2 [0.1–0.3]); posterior cervical approach (OR = 0.5 [0.2–1.0]); multiple approaches (OR = 1.4 [1.2–1.6]); cerebrovascular disease (OR = 1.5 [1.2–1.8]); peripheral vascular disease (OR = 1.3 [1.1–1.5]); chronic pulmonary disease (OR = 1.2 [1.0–1.4]); rheumatologic disease (OR = 1.6 [1.3–2.1]); liver disease (OR = 1.4 [1.1–1.7]); diabetes (OR = 1.5 [1.3–1.7]); hemiplegia or paraplegia (OR = 2.2 [1.5–3.3]); allogenous transfusion (OR = 1.6 [1.3–1.8]); and use of systemic steroids over 2 weeks (OR = 1.5 [1.1–2.0]). Our results, which are based on homogenous patient groups, provide clinicians with an acceptable tool for comprehensive risk assessment of postoperative deep infection in patients who will undergo instrumented spinal fusion surgery for degenerative spinal disease.