Incidence of Influenza Among Childhood Cancer Survivors in South Korea: A Population-based Retrospective Analysis.

BACKGROUND/AIM: We quantified the incidence, and identified risk factors for influenza infection among childhood cancer survivors in South Korea, an at-risk population. PATIENTS AND METHODS: Nationwide health insurance claims data were used to assess the frequency of influenza among childhood cancer survivors (aged <20 years) diagnosed between January 2009 and April 2016. A multivariable logistic regression was constructed to identify risk factors for influenza. RESULTS: Of 6,457 children cancer survivors, 1,704 (27.0%) were diagnosed with influenza. Influenza was common in children <5 years old and infections were highest between late October and April. Over 60% of influenza treatment claims came from private clinics. Risk factors for influenza included age <9 years. CONCLUSION: Childhood cancer survivors are particularly at-risk for influenza infection during the traditional influenza season. Identifying risks for influenza infection will help to establish countermeasures for reducing the influenza infections in at-risk cancer surviving children.

Psychological distress among prostate cancer survivors in South Korea: A nationwide population-based, longitudinal study.

AIM: This time-dependent study aimed to analyze the prevalence of psychological distress in prostate cancer survivors by using claims data in South Korea. METHODS: In a nationwide cohort, 32 005 patients were identified who were diagnosed with prostate cancer between January 2010 and December 2014. We referred the diagnostic codes of mental disorders as psychological distress. We categorized the prevalence of psychological distress based on age and specific times before and after the cancer diagnosis. RESULTS: The median age at diagnosis of prostate cancer was 70 years. Among 32 005 patients, 3074 (9.6%) were diagnosed at least once with a mental disorder between 1 year before the cancer diagnosis and the last follow-up. Among the first diagnoses of each patient, the common mental disorders were anxiety (39.1%) and depression (33.0%). In the total cohort, there were 54 666 claims for mental disorders and over 48.0% (26 256) were for depression. The frequency of psychological distress peaked just before cancer diagnosis. Anxiety was frequent before diagnosis of prostate cancer, whereas depression was frequent after diagnosis. Although stress reaction/adjustment disorders were relatively high in the younger group, depression was relatively high in the elderly group. CONCLUSION: Psychological distress in prostate cancer survivors showed different patterns of prevalence between before and after cancer diagnosis, as well as between age groups. Timely diagnosis and intervention for mental health could promote quality of life for prostate cancer survivors.

Metabolic comorbidities and medical institution utilization among breast cancer survivors: a national population-based study.

BACKGROUND/AIMS: We investigated metabolic comorbidity status and patterns of medical institution utilization among breast cancer survivors using medical claims data from the Health Insurance Review and Assessment Service (HIRA). METHODS: Using claims data obtained from the HIRA, we selected breast cancer survivors between 2010 and 2015. Descriptive statistics were calculated to determine the frequency of metabolic comorbidities, as well as to analyze patterns of medical institution utilization in accordance with disease status. RESULTS: A total of 89,953 breast cancer survivors were identified. Among these, 12,364 (13.7%) had hypercholesterolemia, 20,754 (23.1%) had hypertension (HTN), and 11,102 (12.3%) had diabetes mellitus (DM). In particular, more than half of breast cancer survivors older than 60 years had HTN, and other diseases sharply increased beginning at age 50 years. For HTN, a total of 531,292 claims were submitted; more than 80% (n = 473,737) were from primary medical institutions, whereas only 2.4% (n = 12,551) were from tertiary medical institutions. The number of claims submitted for DM was 231,526; those from primary medical institutions accounted for 68.5% (n = 158,566), whereas claims from tertiary medical institutions accounted for 12.0% (n = 27,693). In subgroup analyses, the utilization of secondary and tertiary medical institutions was higher among patients with severe diseases and those diagnosed following their breast cancer diagnosis. CONCLUSION: More than 10% of breast cancer survivors were diagnosed with a metabolic comorbidity. Through analysis of medical institution utilization patterns, we ascertained that a communication system linking secondary and tertiary medical institutions with primary medical institutions is needed.

Prevalence of Endocrine Disorders in Childhood Brain Tumor Survivors in South Korea.

BACKGROUND/AIM: This longitudinal study aimed to analyze the prevalence of endocrine disorders in childhood brain tumor survivors in South Korea using claims data. PATIENTS AND METHODS: We identified in 1,058 patients from a nationwide cohort of patients diagnosed with brain tumors between January 1st 2009 to March 29th 2016. Multivariable logistic regression was used to evaluate associations between clinical factors and endocrine disorders. RESULTS: After a median follow-up of 60.0 months, 393 (37.1%) patients had at least 1 endocrine disorder. The commonest endocrine disorders were hypopituitarism (17.4%) and hypothyroidism (6.1%). Female gender (odds ratio(OR)=1.45, p=0.005) and age <10 years (OR=1.65, p=0.001) conferred a higher risk. Patients who received radiotherapy were more likely to have endocrine disorders compared to those who did not (OR=1.79, p<0.001). CONCLUSION: Regular assessment of endocrine function and timely interventions are necessary for childhood brain tumor survivors with a risk of endocrine disorders.

Cancer risk after renal transplantation in South Korea: a nationwide population-based study.

BACKGROUND: This study aimed to evaluate patterns of posttransplant malignancies among renal transplant recipients (RTRs) in South Korea using nationwide data. METHODS: The nationwide cohort assessed in this study included RTRs from January 1, 2010, to December 31, 2014. We analyzed cancer incidence during the time course after renal transplantation. Additionally, we calculated standardized incidence ratios (SIRs) to evaluate the risk of malignancies in RTRs. RESULTS: A total of 1343 RTRs (871 males and 472 females, mean age 48.5 ± 11.6 years) were assessed. Among them, 104 (7.7%) developed malignancies after transplantation, most commonly in the thyroid cancer (23.1%). The SIR for all cancers was 3.54; particularly, the SIRs for renal cancer, myeloma, and non-Hodgkin lymphoma were 16.31, 24.02, and 28.64, respectively. Females showed a higher risk of malignancy than males (SIRs: 4.04 for women and 3.26 for men). The median interval between transplantation and malignancy diagnosis was 27.2 months (range 12.3-54.8 months). CONCLUSIONS: RTRs in South Korea demonstrated a high risk of malignancy after transplantation compared with the general population. This indicates that close surveillance and routine screening for cancer in RTRs are needed.

Psychiatric comorbidities among patients undergoing liver transplantation in South Korea: a nationwide population-based study.

OBJECTIVES: The aim of this study was to analyze the prevalence of mental disorders in patients undergoing liver transplantation (LT) based on claims data from the Health Insurance Review and Assessment Service (HIRA) in South Korea. METHODS: We confirmed mental disorders in a nationwide cohort of 3758 patients receiving LT between January 2010 and December 2014. We categorized the prevalence of mental disorders based on patient age at the time of LT. RESULTS: A total of 288 patients for LT were diagnosed with a mental disorder 1 year before their cancer diagnosis. Of those patients, depression was present in 90 (31.25%) and anxiety in 92 (31.9%) patients at the first diagnosis. The overall frequency of mental disorders peaked just before LT, and substance abuse was the most prevalent mental disorder before LT. The risk of mental disorders after LT was significantly lower in those with hepatocellular carcinoma (HCC) than in those without HCC (hazard ratio = 1.70, p < 0.001). CONCLUSIONS: Mental disorders in patients receiving LT showed different patterns of prevalence depending on age at the time of surgery and the nature of underlying diseases. Personalized intervention based on patient characteristics could improve the quality of life.

Psychiatric comorbidities among ovarian cancer survivors in South Korea: A nationwide population-based, longitudinal study.

PURPOSE: The aim of this time-dependent study was to analyze the prevalence of mental disorders in ovarian cancer survivors using claims data in South Korea. MATERIALS AND METHODS: We confirmed mental disorders in a nationwide cohort of 9763 patients who were diagnosed with ovarian cancer between January 1, 2010 and December 31, 2014. We categorized the prevalence of mental disorders based on the age and the time of diagnosis. RESULTS: A total of 821 ovarian cancer patients were diagnosed with a mental disorder, 1 year prior to the cancer diagnosis. Of those patients, 311 were diagnosed with depression (37.9%) and 245 with anxiety (29.8%) during their first visit. The overall frequency of mental disorders peaked within 2 months after the cancer diagnosis. The highest rate of increase after diagnosis was noted in stress reaction/adjustment disorders. While depression was relatively high (40.4%) in the younger age group under 60 years, anxiety was higher (39.4%) in the elderly group over 60 years old. Age was a significant predictive factor for mental disorders (P = 0.002), and patients over 50 years were at a higher risk for mental disorders (hazard ratio: 1.29, P = 0.002). CONCLUSION: Mental disorders in ovarian cancer survivors showed different patterns of prevalence depending on age at the time of diagnosis and the nature of disease. Timely diagnosis and intervention for psychological distress could increase the quality of life for ovarian cancer survivors.

Ambient temperature and hospital admissions for acute kidney injury: A time-series analysis.

Some studies have suggested that high ambient temperatures are a risk factor for kidney-related diseases. However, none have examined the association between ambient temperature and acute kidney injury (AKI). This study aimed to examine the association between daily mean temperature and AKI and identify high-risk subgroups in this association. We obtained health insurance claim data from the Health Insurance Review and Assessment Service (HIRA) for 24,800 admitted cases of AKI during the period 2007-2014 in Seoul, Korea. Using a time-series design and piecewise linear regression models, we estimated the percentage change in AKI admissions associated with daily mean temperature after controlling for relevant covariates. Daily mean temperature and AKI admissions displayed an inverse association in the cold season and a nonlinear relationship with a flexion point around 28.8°C in the warm season. AKI admissions increased by 23.3% (95% confidence interval [CI]: 14.3, 33.0) per 1°C increase in mean temperature above the 28.8°C flexion point in the warm season. The estimates were greatest among men with hypertension (55.1%; 95% CI: 25.1, 92.2). However, we did not observe significant increases in AKI admissions associated with ambient temperature in the cold season (0.4% [95% CI: -0.1, 0.9] per 1°C decrease in mean temperature). Our results suggest that hospital admissions for AKI increase in association with high temperature, particularly among men with hypertension in the warm season. Thus, early detection of AKI during heat wave periods is crucial. Our findings also provide evidence for the local government to target populations vulnerable to high ambient temperatures.

Second primary cancer after liver transplantation in hepatocellular carcinoma: a nationwide population-based study.

PURPOSE: The aim of this study is to evaluate prevalence of second primary cancer (SPC) among hepatocellular carcinoma (HCC) patients after liver transplantation (LT) by using nationwide claims data from South Korea. MATERIALS AND METHODS: The nationwide cohort included patients who were diagnosed with HCC and received LT from 1 January 2010 to 31 December 2014. We analyzed frequency and standardized incidence ratios (SIRs) to estimate the risk of SPC in HCC patients after LT. RESULTS: A total of 2462 patients who were diagnosed with HCC and received LT were confirmed. Of these patients, 103 (4.2%) developed SPC after LT; the most common cancer site was lung (16.5%). Patients with HCC receiving LT had high risk of SPC [SIR 2.79, 95% confidence interval (CI) 2.27-3.38], particularly lymphoma (SIR 9.26), myeloma (SIR 10.60), and bladder cancer (SIR 7.19). The 12-, 24-, 36-, and 48-month overall survival for patients with HCC after LT was 92.7, 87.8, 84.6, and 82.1%, respectively. CONCLUSIONS: HCC patients with LT had longer life expectancy and higher risk for SPC compared with the general population. Therefore, close surveillance for SPC is important in patients with HCC receiving LT.

Influenza Among Breast Cancer Survivors in South Korea: A Nationwide Population-Based Study.

BACKGROUND/AIM: In this study, we analyzed the prevalence of influenza disease in breast cancer survivors using claims data from the Health Insurance Review and Assessment Service (HIRA) in South Korea. PATIENTS AND METHODS: We defined influenza among a nationwide cohort of 87,843 patients who were diagnosed with breast cancer and underwent surgery from January 1, 2010 to December 31, 2014, based on HIRA claim data. Descriptive statistics were calculated to estimate the frequency of influenza disease using diagnostic code and utilization pattern at medical institutions. RESULTS: Two thousand four hundred breast cancer survivors (2.7%) were diagnosed with influenza. The overall frequency of influenza increased from November (n=98) and peaked in February (n=1,745). Over 60% (2,693) of claims for influenza disease treatment were in the clinic, whereas general hospitals accounted for 22.0% (873). Among 3,967 claims, admission rate was 7.6% (n=301) and the average length of hospitalization was 4.7 days. Elderly breast cancer survivors over 70 years old had the longest length of hospitalization at 5.9 days. CONCLUSION: Breast cancer survivors are more susceptible to influenza than non-cancer survivors. It is important not only to raise the vaccination rate among young cancer survivors, but also to quickly identify symptoms and begin treatment for flu in elderly cancer survivors.

Psychiatric comorbidities among breast cancer survivors in South Korea: a nationwide population-based study.

PURPOSE: The aim of this study was to analyze the prevalence of mental disorders in breast cancer survivors using claims data from the Health Insurance Review and Assessment Service in South Korea. We also analyzed patterns of mental disorders with respect to the time of diagnosis and age. MATERIALS AND METHODS: We confirmed mental disorders in a nationwide cohort of 87,843 people who were diagnosed with invasive breast cancer and underwent surgery between January 1, 2010 and December 31, 2014. We investigated the prevalence of mental disorders according to the time of diagnosis and age group. We also examined the utilization patterns of medical institutions and medical departments. RESULT: From one year before a breast cancer diagnosis, 8430 patients were diagnosed with a mental disorder. Of those patients, 3256 were diagnosed with depression (38.6%) and 2739 with anxiety (32.5%). The overall frequency of mental disorders peaked within one month after the cancer diagnosis. The highest rate of increase after diagnosis was noted in stress reaction/adjustment disorders. Depression was relatively high in the young age group, and anxiety was high in the elderly group. In total, there were 59,111 claims for mental disorders. Over 70% (43,788) of claims for mental disorder treatment were from a psychiatry medical department. CONCLUSION: Mental disorders in breast cancer survivors showed different patterns of prevalence according to time, age, and disease. Early intervention could be effective in controlling symptoms of mental disorder and could increase the quality of life for cancer survivors.

A guide for the utilization of Health Insurance Review and Assessment Service National Patient Samples.

The claims data of the Health Insurance Review and Assessment Service (HIRA) is an important source of information for healthcare service research. The claims data of HIRA is collected when healthcare service providers submit a claim to HIRA to be reimbursed for a service that they provided to patients. To improve the accessibility of healthcare service researchers to claims data of HIRA, HIRA has developed the Patient Samples which are extracted using a stratified randomized sampling method. The Patient Samples of HIRA consist of five tables: a table for general information (Table 20) containing socio-demographic information such as gender, age and medical aid, indicators for inpatient and outpatient services; a table for specific information on healthcare services provided (Table 30); a table for diagnostic information (Table 40); a table for outpatient prescriptions (Table 53) and a table for information on healthcare service providers (Table of providers). Researchers who are interested in using the Patient Sample data for research can apply via HIRA's website (https://www.hira.or.kr).