Cost-Effectiveness of All-Oral Regimens for the Treatment of Multidrug-Resistant Tuberculosis in Korea: Comparison With Conventional Injectable-Containing Regimens.

BACKGROUND: Regimens for the treatment of multidrug-resistant tuberculosis (MDR-TB) have been changed from injectable-containing regimens to all-oral regimens. The economic effectiveness of new all-oral regimens compared with conventional injectable-containing regimens was scarcely evaluated. This study was conducted to compare the cost-effectiveness between all-oral longer-course regimens (the oral regimen group) and conventional injectable-containing regimens (the control group) to treat newly diagnosed MDR-TB patients. METHODS: A health economic analysis over lifetime horizon (20 years) from the perspective of the healthcare system in Korea was conducted. We developed a combined simulation model of a decision tree model (initial two years) and two Markov models (remaining 18 years, six-month cycle length) to calculate the incremental cost-effectiveness ratio (ICER) between the two groups. The transition probabilities and cost in each cycle were assumed based on the published data and the analysis of health big data that combined country-level claims data and TB registry in 2013-2018. RESULTS: The oral regimen group was assumed to spend 20,778 USD more and lived 1.093 years or 1.056 quality-adjusted life year (QALY) longer than the control group. The ICER of the base case was calculated to be 19,007 USD/life year gained and 19,674 USD/QALY. The results of sensitivity analyses showed that base case results were very robust and stable, and the oral regimen was cost-effective with a 100% probability for a willingness to pay more than 21,250 USD/QALY. CONCLUSION: This study confirmed that the new all-oral longer regimens for the treatment of MDR-TB were cost-effective in replacing conventional injectable-containing regimens.

Real-world association of adherence with outcomes and economic burden in patients with tuberculosis from South Korea claims data.

Objectives: We analyzed tuberculosis (TB)-related costs according to treatment adherence, as well as the association between treatment adherence, treatment outcomes, and costs related to drug-susceptible TB in South Korea. Methods: Patients who had newly treated TB in South Korea between 2006 and 2015 were selected from nationwide sample claims data and categorized into adherent and non-adherent groups using the proportion of days TB drugs covered. Patients were followed-up from the initiation of TB treatment. The mean five-year cumulative costs per patient were estimated according to adherence. Moreover, we evaluated the relative ratios to identify cost drivers such as adherence, treatment outcomes, and baseline characteristics using generalized linear models. Four treatment outcomes were included: treatment completion, loss to follow-up, death, and the initiation of multidrug-resistant TB treatment. Results: Out of the 3,799 new patients with TB, 2,662 were adherent, and 1,137 were non-adherent. Five years after initiating TB treatment, the mean TB-related costs were USD 2,270 and USD 2,694 in the adherent and non-adherent groups, respectively. The TB-related monthly cost per patient was also lower in the adherent than in the non-adherent (relative ratio = 0.89, 95% CI 0.92-0.98), while patients who were lost to follow-up spent more on TB-related costs (2.52, 2.24-2.83) compared to those who completed the treatment. Conclusion: Non-adherent patients with TB spend more on treatment costs while they have poorer outcomes compared to adherent patients with TB. Improving patient adherence may lead to effective treatment outcomes and reduce the economic burden of TB. Policymakers and providers should consider commitment programs to improve patient's adherence.

Survival and medical costs of melanoma patients with subsequent cancer diagnoses: A South Korean population-based retrospective cohort study.

AIM: Subsequent cancers (SCs) after melanoma diagnosis further increases the risks of mortality and medical costs. This population-based analysis aimed to evaluate risk factors for SC, mortality, and medical costs of melanoma patients with SC. METHODS: A retrospective cohort analysis was conducted using a nationwide claims database during 2002-2017 in South Korea. SC was defined as having other types of cancer diagnoses other than subsequent melanoma during-up to 5 years after melanoma diagnosis. Melanoma patients were divided into patients with and without SC, and the overall and subgroup survival rates, the risk of developing SC, and the total medical costs were analyzed using a Kaplan-Meier method and regressions. RESULTS: A total of 3740 melanoma patients were included in the analysis (mean age, 62.3 ± 15.4 y; 47.2% men), and 2273 patients (1157 within 2 months, 756 after 2 months of melanoma diagnosis) had SC. Higher Charlson comorbidity index score and male sex significantly increased the risk of developing SC. Five-year survival rate and cumulative medical costs were 62.3% (95% confidence interval [CI], 60.8-63.9) and $21,413, respectively, in all patients. Patients with SC diagnosed after 2 months showed the lowest survival rate of 47.8% (95% CI, 44.3-51.4) and the highest costs of $27,081, showing a mortality hazard ratio of 1.65 (range, 1.46-1.86) and a cost ratio of 1.189 (range, 1.112-1.271) compared with those without SC. CONCLUSION: This study presented survival outcomes and medical costs in melanoma patients and confirmed that SC after the first diagnosis of melanoma significantly increased disease burden in terms of mortality and medical costs.

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.

Cost-effectiveness of Bariatric Surgery for People with Morbid Obesity in South Korea.

OBJECTIVE: This study aimed to evaluate the cost-effectiveness of bariatric surgery (BS) compared to non-surgical treatment (NST) in Korean people with morbid obesity according to comorbidities and body mass index (BMI) severity. METHODS: The target cohort was people with morbid obesity, defined as BMI of ≥ 35 kg/m2, or obese people with BMI of 30-34.9 kg/m2 having obesity-related comorbidities. A decision-tree model for 1-year obesity treatment and Markov model for the rest of life were used. In the decision-tree model, the comorbidity remission rate and BMI change after 1-year treatment were decided based on a prospective clinical trial. In the Markov model, the transition probabilities were calculated considering the BMI level and age. The starting age of 20 years, a cycle length of 1 year, a time horizon of 80 years, and a 5% discount rate were applied for the base case from the healthcare system perspective. RESULTS: In the base case, BS improved quality-adjusted life years (QALYs) and was the cost-effective option in total cohort (incremental cost-effectiveness ratio of BS vs. NST was 674 USD/QALY). It was shown to be cost-effective in all subgroup analyses based on BMI level. In particular, BS was a dominant alternative for the subgroup with basal BMI of 35.0-37.4 kg/m2. Various sensitivity analyses showed the robustness of results indicating the cost-effectiveness of BS. CONCLUSION: BS at BMI of > 30 kg/m2 was more effective than NST for a reduction in BMI and remission of obesity-related comorbidities and was cost-effective in Korea.

Economic burden of lung cancer: A retrospective cohort study in South Korea, 2002-2015.

We evaluated the survival rates and medical expenditure in patients with lung cancer using a nationwide claims database in South Korea. A retrospective observational cohort study design was used, and 2,919 lung cancer patients and their matched controls were included. Medical expenditures were analyzed with the Kaplan-Meier sample average method, and patients were categorized into 4 groups by operation and primary treatment method (i.e. Patients with operation: OP = surgery, OP+CTx/RTx = surgery with anti-cancer drugs or radiotherapy; Patients without operation: CTx/RTx = anti-cancer drugs or radiotherapy, Supportive treatment). The 5-year medical expenditure per case was highest in the OP+CTx/RTx group ($36,013), followed by the CTx/RTx ($23,134), OP ($22,686), and supportive treatment group ($3,700). Lung cancer-related anti-cancer drug therapy was the major cost driver, with an average 53% share across all patients. Generalized linear regression revealed that monthly medical expenditure in lung cancer patients, after adjustment for follow-up month, was approximately 3.1-4.3 times higher than that in the control group (cost ratio for OP = 3.116, OP+CTx/RTx = 3.566, CTx/RTx = 4.340, supportive treatment = 4.157). The monthly medical expenditure at end of life was estimated at $2,139 for all decedents, and approximately a quarter of patients had received chemotherapy in the last 3 months. In conclusion, this study presented the quantified treatment costs of lung cancer on various aspects compared with matched controls according to the treatment of choice. In this study, patients with operation incurred lower lifetime treatment costs than patients with CTx/RTx or supportive treatment, indicating that the economic burden of lung cancer was affected by treatment method. Further studies including both cancer stage and treatment modality are needed to confirm these results and to provide more information on the economic burden according to disease severity.

Cost-effectiveness of Pharmaceutical Interventions to Prevent Osteoporotic Fractures in Postmenopausal Women with Osteopenia.

BACKGROUND: To assess the cost-effectiveness of drug therapy to prevent osteoporotic fractures in postmenopausal women with osteopenia in Korea. METHODS: A Markov cohort simulation was conducted for lifetime with a hypothetical cohort of postmenopausal women with osteopenia and without prior fractures. They were assumed to receive calcium/vitamin D supplements only or drug therapy (i.e., raloxifene or risedronate) along with calcium/vitamin D for 5 years. The Markov model includes fracture-specific and non-fracture specific health states (i.e. breast cancer and venous thromboembolism), and all-cause death. Published literature was used to determine the model parameters. Local data were used to estimate the baseline incidence rates of fracture in those with osteopenia and the costs associated with each health state. RESULTS: From a societal perspective, the estimated incremental cost-effectiveness ratios (ICERs) for the base cases that had T-scores between -2.0 and -2.4 and began drug therapy at the age of 55, 60, or 65 years were $16,472, $6,741, and -$13,982 per quality-adjusted life year (QALY) gained, respectively. Sensitivity analyses for medication compliance, risk of death following vertebral fracture, and relaxing definition of osteopenia resulted in ICERs reached to $24,227 per QALY gained. CONCLUSIONS: ICERs for the base case and sensitivity analyses remained within the World Health Organization's willingness-to-pay threshold, which is less than per-capita gross domestic product in Korea (about $25,700). Thus, we conclude that drug therapy for osteopenia would be a cost-effective intervention, and we recommend that the Korean National Health Insurance expand its coverage to include drug therapy for osteopenia.

Prescribed drugs and polypharmacy in healthcare service users in South Korea: an analysis based on National Health Insurance Claims data.

OBJECTIVE: This study was conducted to analyze and compare the exposure to individually prescribed drugs and the prevalence of polypharmacy according to age group and concomitant disease in South Korea. METHODS: The use of prescribed drugs was evaluated according to average numbers of prescription drugs used daily during a year or month, using the Korean Health Insurance Claims Database, which is representative of over 90% of citizens, in 2010 and 2011. The use of prescribed drugs was also analyzed according to concomitant diseases and age. Polypharmacy was defined as the use of 5 or more drugs daily during a specific observation period, and proportions of polypharmacy users were calculated according to comorbidity and age group. RESULTS: The annual average numbers of daily used prescription drugs in 2010 and 2011 were 0.3 (SD = 0.5), 0.4 (SD = 0.7), 1.2 (SD = 1.5), and 2.3 (SD = 2.0) for people aged < 20 years, 20-49 years, 50-64 years, and ≥ 65 years, respectively. Proportions of individuals demonstrating polypharmacy increased with age and were 9.5% and 44.1% for elderly individuals in the year- and month-based analyses, respectively. The annual average number of daily medications used increased by ~2 drugs in the concomitant disease group, and the higher mortality group used a higher number of prescribed drugs than the lower mortality group. CONCLUSIONS: The results highlight the elevated burden of multi-medication in elderly patients, and the study found that prescribed drug use increased with age and the number of concomitant diseases.

Cost-effectiveness of Bedaquiline for the Treatment of Multidrug-resistant Tuberculosis in the Republic of Korea.

PURPOSE: Bedaquiline is a new drug used for the treatment of multidrug-resistant tuberculosis (MDR-TB). This study aimed to evaluate the cost-effectiveness of adding bedaquiline to a standard regimen (SR) for treating patients with MDR-TB, including extensively drug-resistant (XDR)-TB, in the Republic of Korea. METHODS: A cohort-based decision-analytic model developed in a previously published study from the United Kingdom was used, with a 20-year time horizon and a 5% discount rate for cost and effectiveness, to evaluate the incremental cost-effectiveness ratios of bedaquiline + SR and SR only. The key parameters regarding the clinical data were available via the published Phase II trial of bedaquiline. Additional parameters for recurrence, cure status, loss to follow-up, surgery, death, cost, and health utility were based on Korean data if available; otherwise the international literature data were applied. Univariate and probabilistic sensitivity analyses were conducted. FINDINGS: Based on the analysis, a patient on bedaquiline + SR would gain 1.20 quality-adjusted life-years (QALYs) at 13,961,659 Korean won (KRW) (1100 KRW = US $1) of additional cost compared with a patient administered SR only, with an incremental cost/utility ratio of 11,638,656 KRW/QALY. Bedaquiline + SR had an 80% probability of being cost-effective, at a willingness-to-pay threshold of 26 million KRW, compared with SR only. IMPLICATIONS: The results of this study suggest that, in the Republic of Korea, bedaquiline, as a part of combination therapy with SR, is a cost-effective option for the treatment of MDR-TB (including XDR-TB) compared with SR only.

Clinical and Economic Burden of Visual Impairment in an Aging Society of South Korea.

Whereas the incidence of visual impairment and blindness (VI&B) is decreasing, the total number of VI&B is increasing due to the growth of elderly population. To compare the clinical and economic outcomes of patients with and without VI&B (ie, cases and controls) in Korea, a case-control study was performed using the Health Insurance Review and Assessment Service-National Patients Sample data. Cases had higher prevalence for all of the Charlson Comorbidity Index components, depression, fracture, and injury as well as eye diseases compared to age- and sex-matched controls. In regression after adjustment of concomitant diseases, cases had 2.7 times (95% confidence interval = 2.3-3.2) higher medical expenditure than controls. The results of this study confirm that patients with VI&B have significantly higher direct medical expenditures and concomitant diseases than those without VI&B and highlight the need for a public health strategy to reduce potentially avoidable costs attributed to VI&B.