The Burden of Cancer in Korea during 2012: Findings from a Prevalence-Based Approach

Comparison of Disability-Adjusted Life Years (DALYs) and Economic Burden on People With Drug-Susceptible Tuberculosis and Multidrug-Resistant Tuberculosis in Korea

In the future, tuberculosis (TB) will place a heavy burden on the aging population in Korea. To prepare for this crisis, it is important to analyze the disease burden trend of drug-susceptible tuberculosis (DS-TB) and multidrug-resistant tuberculosis (MDR-TB). Measuring disability-adjusted life years (DALYs) and economic burden on MDR-TB patients can help reduce the incidence of TB. Accordingly, in this study, we measured the DALYs and economic burden on DS-TB and MDR-TB patients in 2014-2017 using a combination of National Health Insurance claims data, Annual Report on the Notified TB data, and Statistics Korea's mortality data. The incidence-based DALY approach implemented involved the summation of years of life lost and years lived with disability. For measuring economic burden, direct and indirect costs incurred by patients were totaled. From 2014 to 2017, DALYs per 100,000 people with DS-TB were 56, 49, 46, and 40, respectively, and DALYs per 100,000 people with MDR-TB were 3, 2, 2, and 2, respectively. The economic burden for the DS-TB population from 2014 to 2017 was $143.89 million, $136.36 million, $122.85 million, and $116.62 million, respectively, while that for MDR-TB was $413.44 million, $380.25 million, $376.46 million and $408.14 million, respectively. The results showed a decreasing trend in DALYs and economic burden for DS-TB, whereas MDR-TB was still found to be burdensome without a specific trend. With respect to age, the economic burden for both DS-TB and MDR-TB was higher among men than among women till ≤ 79 years. Conversely, the economic burden for women aged ≥80 years was higher as compared to their male counterparts. In conclusion, the incidence and spread of TB in all areas of society must be suppressed through intensive management of MDR-TB in the older population. We hope that the national TB management project will proceed efficiently when the infectious disease management system is biased to one side due to the COVID-19 pandemic.

DALY Estimation Approaches: Understanding and Using the Incidence-based Approach and the Prevalence-based Approach

Disability-adjusted life-year (DALY) estimates may vary according to factors such as the standard life expectancy, age weighting, time preference and discount rate, calculation of disability weights, and selection of the estimation method. DALY estimation methods are divided into the following 3 approaches: the incidence-based approach, the pure prevalence-based approach, and the hybrid approach. These 3 DALY estimation approaches each reflect different perspectives on the burden of disease using unique characteristics, based on which the selection of a suitable approach may vary by the purpose of the study. The Global Burden of Disease studies, which previously estimated DALYs using the incidence-based approach, switched to using the hybrid approach in 2010, while the National Burden of Disease studies in Korea still mainly apply the incidence-based approach. In order to increase comparability with other international burden of disease studies, more DALY studies using the prevalence-based approach need to be conducted in Korea. However, with the limitations of the hybrid approach in mind, it is necessary to conduct more research using a disease classification system suitable for Korea. Furthermore, more detailed and valid data sources should be established before conducting studies using a broader variety of DALY estimation approaches. This review study will help researchers on burden of disease use an appropriate DALY estimation approach and will contribute to enhancing researchers’ ability to critically interpret burden of disease studies.

Estimation of Years Lived with Disability Using a Prevalence-Based Approach: Application to Major Psychiatric Disease in Korea

To help develop policies concerning the prevention of psychiatric disease in Korea, we reviewed the literature on this topic in different countries and used a prevalence-based approach to estimate the years lived with disability (YLDs) in Korean patients with major psychiatric diseases. We calculated YLDs by extracting data on the number of patients with mild, moderate, and severe cases of schizophrenia, bipolar disorder, and major depressive disorder, as classified by International Statistical Classification of Disease (ICD) codes. YLDs were highest for patients with major depressive disorder (1190.6; 73.9%), schizophrenia (303.3; 18.8%) and bipolar disorder (117.9; 7.3%). Men had higher YLDs for schizophrenia, 2502 (20-24 years); bipolar disorder, 477 (40-44 years); and major depressive disorder, 2034 (75-79 years). Women had higher YLDs for schizophrenia, 484 (45-49 years); bipolar disorder, 214 (≥80 years); and major depressive disorder, 3541 (75-79 years). The prevalence-based approach and severity distribution is useful for estimating long-term psychiatric disease burden and YLDs. However, YLD-estimation studies must compensate for the shortcomings of the ICD-10 by referencing the Diagnostic and Statistical Manual of Mental Disorders 5th edition, as well as updating the disability weight score according to disease severity.

Estimating the disease burden of lung cancer attributable to residential radon exposure in Korea during 2006-2015: A socio-economic approach

Estimating the lung cancer disease burden can provide evidence for public health practitioners, researchers, and policymakers. This study uses claim data from lung cancer patients for 2006-2015 from the Korean National Health Insurance Service to estimate the lung cancer burdens attributable to residential radon in Korea using disability-adjusted life years (DALY) and patients' annual economic burden with societal perspectives using the cost-of-illness (COI) method. The number of patients increased during our study period (from 35,866 to 59,168). The disease burden and that attributable to residential radon, respectively, increased from 517.57 to 695.74 and 64.62 (95%; CIs 61.33-67.69) to 86.99 (95%; CIs 82.7-91.1) DALYs per 100,000 patients. The percentage of years lost due to disability among the DALY doubled from 8% to 17%. The cost for all the patients was US$2.33 billion, with US$292 (95%; CIs 278-306) million attributable to residential radon. During the last decade, the lung cancer disease burden increased by 1.34 times, with a doubled percentage of non-fatal burden and average annual growth rate of 9.5% of the total cost. Hence, the burden and cost of lung cancer in Korean provinces have been steadily increasing. The findings could be used as input data for future cost-effectiveness analysis of policies regarding radon reduction.

Lifetime survival and medical costs of lung cancer: a semi-parametric estimation from South Korea

Background

It is essential to have information on the disease burden of lung cancer at an individual level throughout the life; however, few such results have been reported. Thus, this study aimed to assess the lifetime disease burden in patients with lung cancer by assessing various factors, such as survival, years of life lost (YLL) and medical expenditure in South Korea based on real-world data and extrapolation.

Methods

Newly diagnosed lung cancer patients (n = 2919) in 2004–2010 were selected and observed until the end of 2015 using nationwide reimbursement claim database. The patients were categorised into the Surgery group, Chemo and/or Radiotherapy group (CTx/RTx), and Surgery+CTx/RTx according to their treatment modality. Age- and sex-matched control subjects were selected from among general population using the life table. The survival and cost data after diagnosis were analysed by a semi-parametric method, the Kaplan–Meier analysis for the first 100 months and rolling extrapolation algorithm for 101–300 months. YLL were derived from the difference in survival between patients and controls.

Results

Lifetime estimates (standard error) were 4.5 (0.2) years for patients and 14.5 (0.1) years for controls and the derived YLL duration was 10.0 (0.2) years. Lifetime survival years showed the following trend: Surgery (14.2 years) > Surgery+CTx/RTx (8.5 years) > CTx/RTx group (3.0 years), and YLL were increased as lifetime survival years decreased (2.3, 8.7, 12.2 years, respectively). The mean lifetime medical cost was estimated at 30,857 USD/patient. Patients in the Surgery group paid higher treatment cost in first year after diagnosis, but the overall mean cost per year was lower at 4359 USD compared with 7075USD of Surgery+CTx/RTx or 7626USD of CTx/RTx group.

Conclusions

Lung cancer has resulted in about 10 years of life lost in overall patients. The losses were associated with treatment modality, and the results indicated that diagnosing lung cancer in patients with low stage disease eligible for surgery is beneficial for reducing disease burden in terms of survival and treatment cost per year throughout the life.

Estimating Disability-Adjusted Life Years due to Tuberculosis in Korea through to the Year 2040

Despite efforts to reduce its incidence, tuberculosis continues to burden the rapidly aging Korean society. This study aimed to investigate the current trend of tuberculosis burden in Korea and its projections to 2040. We used National Health Insurance claims data to calculate the disability-adjusted life years due to tuberculosis in Korea. Disability-adjusted life years were measured by summing the years of life lost and the years lived with disability using an incidence-based approach. We modeled the incidence rates using a time-series model for the projection of disability-adjusted life years accrued from 2020 to 2040. The total disability-adjusted life years due to tuberculosis were 69, 64, 59, and 49 disability-adjusted life years/100,000 population in 2014, 2015, 2016, and 2017, respectively. In both sexes, disability-adjusted life years were the highest in those aged ≥80 years. Projected disability-adjusted life years showed a descending trend from 38 disability-adjusted life years/100,000 in 2020, to 14 disability-adjusted life years/100,000 in 2040. Conversely, the projected disability-adjusted life years increased among females aged ≥80 years. Although the tuberculosis burden in Korea is decreasing, a high burden remains among the elderly. Therefore, interventions targeting those vulnerable are required.

National practice patterns and direct medical costs for prostate cancer in Korea across a 10 year period: a nationwide population-based study using a national health insurance database

BACKGROUND

A complete enumeration study was conducted to evaluate trends in national practice patterns and direct medical costs for prostate cancer (PCa) in Korea over a 10-year retrospective period using data from the Korean National Health Insurance Service.

METHODS

Reimbursement records for 874,924 patients diagnosed between 2002 and 2014 with primary PCa according to the International Classification of Disease (ICD) 10th revision code C61 were accessed. To assess direct medical costs for patients newly diagnosed after 2005, data from 68,596 patients managed between January 2005 and 31 December 2014 were evaluated.

RESULTS

From 2005 to 2014, the total number of PCa patients showed a 2.6-fold increase. Surgery and androgen deprivation therapy were the most common first-line treatment, alone or within the context of combined therapy. Surgery as a monotherapy was performed in 23.5% of patients in 2005, and in 39.4% of patients in 2014. From 2008, the rate of robot-assisted RP rose sharply, showing a similar rate to open RP in 2014. Average total treatment costs in the 12 months post-diagnosis were around 10 million Korean won. Average annual treatment costs thereafter were around 5 million Korean won. Out-of-pocket expenditure was highest in the first year post-diagnosis, and ranged from 12 to 17% thereafter.

CONCLUSIONS

Between 2005 and 2014, a substantial change was observed in the national practice pattern for PCa in Korea. The present data provide a reliable overview of treatment patterns and medical costs for PCa in Korea.

The Korean National Burden of Disease Study: from Evidence to Policy

Following the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD), disability-adjusted life years (DALYs) have been widely used as a summary measure of population health. The DALY metric is a comprehensive measurement of population health, enabling comparison among groups. However, the available data and reliance on estimates to supplement the data gap require contextualization at the national level, and the outcomes of which are more appropriate for national policymakers. The Korean National Burden of Disease (KNBD) study was initiated by the Research and Development Project of the Ministry of Health and Welfare, funded by a 5-year grant from 2013, to contextualize the GBD method to the Korean population. Here, we provide a comprehensive overview of the KNBD study with its achievements and challenges and discuss the implications for public health policies.

Disability Weights Measurement for 289 Causes of Disease Considering Disease Severity in Korea

BACKGROUND

For the Korean Burden of Disease (KBD) 2015 study, we have amended disability weights for causes of disease adapting the methodology of the KBD disability weight 2012 study.

METHODS

We conducted a self-administered web-based survey in Korea using ranking five causes of disease. A total of 605 physicians and medical college students who were attending in third or fourth grade of a regular course performed the survey. We converted the ranked data into paired comparison data and ran a probit regression. The predicted probabilities for each cause of disease were calculated from the coefficient estimates of the probit regression. 'Being dead (1)' and 'Full health (0)' were utilized as anchor points to rescale the predicted probability on a scale from 0 to 1.

RESULTS

As a result, disability weights for a total of 289 causes of disease were estimated. In particular, we calculated the disability weights of 60 causes of disease considering severity level. These results show that prejudice about the severity of cause of disease itself can affect the estimation of disability weight, when estimating the disability weight for causes of disease without consideration of severity. Furthermore, we have shown that disability weights can be estimated based on a ranking method which can maximize efficiency of data collection.

CONCLUSION

Disability weights from this study can be used to estimate disability adjusted life year and healthy life expectancy. Furthermore, we expected that the use of the ranking method will increase gradually in disability weight studies.

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

BACKGROUND

Injury represents an important aspect of disease that affects everyone at some point in their lives. To better understand and prevent these injuries, various analytical methods have been developed to assess both the magnitude and features of injury burden. In this study, we attempted to estimate the injury burden of Korea in 2014 by comparing the prevalence-based approach used by the Global Burden of Diseases (GBD) team and the World Health Organization against an alternative incidence-based approach, and to assess the different implications of these measurements.

METHODS

The 10th Korean National Hospital Discharge survey data and causes of death statistics in 2014 were used as data sources. Years of life lost (YLL), years lived with disability (YLD) and disability-adjusted life years (DALYs) were calculated using both the incidence- and prevalence-based approaches. The Korean Classification of Diseases (KCD) version 5 diagnostic codes were used to classify the mechanism of injury.

RESULTS

The prevalence-based injury burden tended to be higher (1,670,229 DALYs) than the incidence-based injury burden (1,544,467 DALYs). The elderly population exhibited a higher prevalence-based YLD and DALY relative to incidence-based outcomes. In order of significance, the three most common causes of injury as calculated using an incidence-based approach were road injury, fall, and self-harm, compared with a prevalence-based method, which identified self-harm, road injury, and falls as the most common injuries.

CONCLUSION

An appropriate prevention program is needed for injuries with potential to cause long-lasting morbidity. Accordingly, a tailored injury-prevention strategy should be developed for each high-risk group.

Trend analysis of major cancer statistics according to sex and severity levels in Korea

Existing epidemiologic reports or studies of cancer statistics in Korea lack sufficient data on cancer severity distributions and observed survival rates. This study analyzed trends in major cancer statistics according to sex and severity levels in Korea from 2006 to 2013. We included eight cancers (hepatocellular carcinoma, and thyroid, colorectal, gastric, lung, prostate, breast, and cervical cancer), using Korea Central Cancer Registry data. Severity level was classified by Surveillance, Epidemiology, and End Results (SEER) stage as follows: localized, regional, distant, or unknown. Numbers of incident cancer cases from 2006 to 2013 were described by sex and SEER stage. We estimated up to 8-year observed survival rates of major cancers by sex and SEER stage, and provided prevalence rates by sex and SEER stage in 2011, 2012, and 2013. Although increases in new cancer cases are slowing and the total number of incident cancer cases in 2013 decreased for the first time since 2006, the number of prevalent cancer cases was 663,530 in 2013, an increase of 13.3% compared to 2011. Among the five cancers affecting both sexes, sex-related differences in 5-year observed survival rates for lung cancer were greatest in the localized stage (men, 31.9%; women, 48.1%), regional stage (men, 20.0%; women, 31.3%), and unknown stage (men, 24.3%; women, 37.5%). The sum of the proportions of localized and regional stages for thyroid and breast cancer was over 90% in 2013, while the sum of the proportions of localized and regional stages for lung cancer was only 56.7% in 2013. Differences in observed survival rates between men and women were prominent in lung cancer for all SEER stages. The reported epidemiologic data from this study can be used to obtain a more valid measure of cancer burden using a summary measure of population health.

Occupational Burden of Asbestos-Related Diseases in Korea, 1998-2013: Asbestosis, Mesothelioma, Lung Cancer, Laryngeal Cancer, and Ovarian Cancer

BACKGROUND

Asbestos exposure causes asbestos-related diseases (ARDs) including asbestosis, malignant mesothelioma, lung cancer, laryngeal cancer, and ovarian cancer. Although Korea used substantial amounts of asbestos in the past, no study has focused on its occupational burden of disease (OBD). Therefore, this study aimed to determine the OBDs of ARDs in Korea.

METHODS

The CARcinogen Exposure (CAREX) database was used to determine the proportion of exposed population. Relative risks for lung cancer, laryngeal cancer, and ovarian cancer were used to determine the population-attributable fraction. Data for deaths caused by ARDs during 1998-2013 were obtained from the World Health Organization mortality database. The potential years of life lost (PYLL) and annual average PYLL (APYLL) indicated OBDs.

RESULTS

In Korea, the number of ARD-attributable deaths and PYLL due to all ARDs during 1998-2013 were 4,492 and 71,763.7, respectively. The number of attributable deaths and PYLL due to asbestosis, malignant mesothelioma, lung cancer, laryngeal cancer, and ovarian cancer were 37 and 554.2, 808 and 15,877.0, 3,256 and 47,375.9, 120 and 1,605.5, and 271 and 6,331.1, respectively; additionally, the APYLL were 15.0, 19.7, 14.6, 13.4, and 23.4, respectively, and the average age at death was 70.4, 62.6, 69.1, 69.9, and 61.8, respectively. Our study showed that although the use of asbestos has ceased in Korea, the incidence of ARDs tends to increase.

CONCLUSION

Therefore, efforts to reduce future OBDs of ARDs, including early detection and proper management of ARDs, are needed in Korea.

Prediction of organ-confined disease after robot-assisted radical prostatectomy in patients with clinically locally-advanced prostate cancer

BACKGROUND

Little is known about the preoperative predictive factors that could identify subsets of favorable patients who can be possibly cured with robot-assisted radical prostatectomy (RARP) alone in locally advanced prostate cancer (LAPCa). Our study was designed to identify clinical predictors of pathologic organ-confined disease (pOCD) in RARP setting.

METHODS

Between 2007 and 2013, clinicopathological and oncological data from 273 consecutive men undergoing robot-assisted RP with extended PLND for clinically LAPCa were reviewed in a single-institution, retrospectively. After exclusion of patients who received neoadjuvant hormone treatment before surgery, 186 subjects satisfied the final inclusion criteria.

RESULTS

Fourty-three patients (23.1% of total cohort) with preoperative clinically LAPCa patients were down-staged to pOCD following RARP. Preoperative prostate-specific antigen (PSA) level, preoperative PSAD, positive core percent, maximal tumor volume in any core, and biopsy Gleason score were significantly associated with down-staging into pOCD following RARP. Multivariate logistic regression analysis revealed that lower preoperative PSA (≤10 ng/mL) and maximal tumor volume in any core (≤70%) were independent predictors of pOCD following RARP.

CONCLUSIONS

Approximately 23% of preoperative clinically LAPCa patients were down-staged to pOCD following RARP. Preoperative PSA and maximal tumor volume in any biopsy core might be useful clinical predictors of pOCD in clinically LAPCa patients in RARP setting.

Strategies for Appropriate Patient-centered Care to Decrease the Nationwide Cost of Cancers in Korea

In terms of years of life lost to premature mortality, cancer imposes the highest burden in Korea. In order to reduce the burden of cancer, the Korean government has implemented cancer control programs aiming to reduce cancer incidence, to increase survival rates, and to decrease cancer mortality. However, these programs may paradoxically increase the cost burden. For examples, a cancer screening program for early detection could bring about over-diagnosis and over-treatment, and supplying medical services in a paternalistic manner could lead to defensive medicine or futile care. As a practical measure to reduce the cost burden of cancer, appropriate cancer care should be established. Ensuring appropriateness requires patient-doctor communication to ensure that utility values are shared and that autonomous decisions are made regarding medical services. Thus, strategies for reducing the cost burden of cancer through ensuring appropriate patient-centered care include introducing value-based medicine, conducting cost-utility studies, and developing patient decision aids.

Association between Nutrient Intake and Metabolic Syndrome in Patients with Colorectal Cancer

The purpose of this study was to investigate the difference of nutritional status according to metabolic syndrome in colorectal cancer patients. The subjects were divided into 2 groups (metabolic syndrome group and normal group) according to the presence or absence of metabolic syndrome in 143 patients diagnosed with colorectal cancer, and their lifestyle and nutritional status were analyzed. Recall method was used for the dietary survey, and metabolic syndrome was defined as the presence of 3 or more of waist circumference, fasting blood glucose, triglyceride, high-density lipoprotein (HDL)-cholesterol, and blood pressure. This study showed that the metabolic syndrome group had a low age, a high body mass index (BMI), and a high drinking rate. The intake of energy, protein, fat, calcium, and phosphorus was significantly higher in the metabolic syndrome group than in the normal group, and the intake of β-carotene, vitamin C, and folic acid was significantly low. The intake of cholesterol, fatty acid, saturated fatty acid, and polyunsaturated fatty acid was also higher in the metabolic syndrome group. Higher BMI, alcohol consumption, intake of fat, total fatty acid or saturated fatty acid increased the risk of metabolic syndrome, but fiber, vitamin C, or folic acid intake lowered the risk.Weight management and balanced nutritional intake should be emphasized to prevent metabolic syndrome and to improve the condition in patients with colorectal cancer.