The impact of overactive bladder on health-related quality of life in Korea: based on the results of a Korean Community Health Survey.

PURPOSE: This study aimed to assess the impact of overactive bladder on health-related quality of life (HRQoL) in a community-based sample of Korean population. METHODS: The data of adults aged 19 and over that who participated in the 2012 Korean Community Health Survey were analyzed. Overactive bladder severity was classified as normal, mild, moderate, or severe using the Overactive Bladder Symptom scores, and HRQoL was evaluated using EQ-5D-3L. Relations between HRQoL and the severities and symptoms of OAB were investigated. Sampling weighted adjusted multiple regression analysis was performed to determine the effect of OAB symptom severity on HRQoL. RESULTS: Of the 226,867 study subjects, 12,303 (5.4%) had OAB, and 552 (0.2%) had an OABSS of ≥ 12, indicating severe OAB. The problem -reporting rate significantly increased in all EQ-5D-3L dimensions as OAB severity increased. After adjusting for other variables, OAB severity had a significant effect on EQ-5D-3L index. Urge incontinence had greatest impact on quality of life. CONCLUSIONS: As the severity of OAB increased from mild to severe, quality of life decreased significantly. OAB was found to negatively affect HRQoL.

Exploring health-related quality of life and frailty in older adults based on the Korean Frailty and Aging Cohort Study.

PURPOSE: The study aimed to analyze the association between frailty and health-related quality of life (HRQOL) based on the Korean Frailty and Aging Cohort Study. METHODS: In this cross-sectional study, 2905 adults aged 70 to 84 years were enrolled. Frailty was determined according to the Fried frailty index. HRQOL was measured using the 5-level EuroQol questionnaire (EQ-5D-5L) and the 12-item Short-Form Health Survey version 2 (SF-12). Hierarchical linear regressions were conducted to examine the relationship between frailty and HRQOL and a logistic regression analysis was performed to estimate odds ratios of frailty status in the scores of the lowest quartiles in each scale. RESULTS: Of the total respondents, 7.8% were frail, 47.0% were pre-frail, and 45.2% were robust. Frail respondents had significantly lower HRQOL scores than robust respondents, especially for EQ-5D-5L utility weights (0.74 vs 0.93). Frailty was strongly associated with decreased HRQOL in both physical and mental component summary of SF-12 (p < 0.001). Both pre-frail and frail states were related to greater odds of scoring in the bottom 25% of HRQOL scales compared to the non-frail state (p < 0.0001). CONCLUSION: Frailty was associated with declined HRQOL in Korean older adults. This result recommends raising awareness about identifying and preventing frailty for better quality of life in the Korean elderly population.

Estimation of population-based utility weights for health states of chronic kidney disease, dialysis and kidney transplantation.

AIM: This study aimed to determine the utility of chronic kidney disease (CKD)-related health states in the Korean general population by using the standard gamble (SG) method. METHODS: Seven hypothetical CKD-related health states were developed and revised based on previous publications. Data from 242 individuals from the Korean general population were obtained via computer-assisted personal interviews and used to evaluate the CKD-related health states by using the visual analogue scale (VAS) and SG methods. Mean and median utility values were calculated for each health state. To assess the reliability of the valuation, some samples were retested and evaluated using intraclass correlation coefficients (ICC). RESULTS: In all health states, the utility weights from SG were higher than those from VAS. The difference in utility values between the two valuation methods ranged from 0.258 to 0.308. The utility value of CKD grade 3 was the highest and that of peritoneal dialysis (PD) was the lowest. The utility weights tended to decrease in accordance with the progression of CKD. CKD grade 3 was assigned a SG utility value of 0.878, whereas PD was assigned 0.507. The SG utility values of predialysis end-stage renal disease, haemodialysis, kidney transplantation (KT), and post-KT recovery states were 0.666, 0.547, 0.748 and 0.827, respectively. The mean ICC (SD) at the individual level was 0.746 (0.281) for the SG scores. CONCLUSION: Our results could be used to measure the burden of kidney disease or to evaluate the economic efficiency of CKD-related interventions.

A cross sectional survey on health-related quality of life among parents of children with allergic symptoms using the EQ-5D-5L.

Object: This study aims to evaluate the HRQOL of parents of children with allergic diseases using the EQ-5D-5L. Methods: The subjects of the study were parents of children enrolled in primary schools and daycare centers. The EQ-5D-5L was self-administered in the sample population, and demographic and health information of their children were collected. We assessed the difference in EQ-5D-5L index and EQ-VAS of parents by the prevalence of allergic symptoms (wheezing, runny or blocked nose, and itchy rash) in their children in the past 12 months. In addition, we examined the difference in parents' EQ-5D-5L index and EQ-VAS score, based on the number of allergic symptoms of their children. Results: Of the 23,837 completed questionnaires, 22,904 were analyzed. There were significant differences in HRQOL between parents of children with and without allergic symptoms. There was a considerable difference in proportion of problem reporting in the "pain/discomfort" and "anxiety/depression" dimensions compared with the remaining dimensions of the EQ-5D-5L. Among three allergic symptoms, the HRQOL of parents of children with asthmatic symptoms was lowest at 0.936 on the EQ-5D-5L index and 79.3 on the EQ-VAS score. As the number of allergic symptoms of children increased, QOL of parents significantly decreased. Conclusions: Parents of children with allergic symptoms showed lower HRQOL than those parents whose children did not. The EQ-5D-5L instrument appeared to be useful to evaluate the HRQOL of parents of children with allergic diseases.

Health-related quality of life in adult males with lower urinary tract symptoms.

PURPOSE: To assess the status and impact of lower urinary tract symptoms (LUTS) on health-related quality of life (HRQoL) in a community-based sample of Korean adult males. METHODS: We analyzed the data of 101,606 adult males aged ≥ 19 years of age obtained during the 2011 Korean Community Health Survey. Subject data were assessed for LUTS and HRQoL using international prostate symptom scores, and EuroQol-five-dimensions three-level version (EQ-5D-3L) and EuroQol-visual analogue scale (EQ-VAS) scores. RESULTS: Of the 101,606 subjects, 53,323 (52.5%) reported having at least one LUTS and 3116 (3.1%) had an IPSS of ≥ 20, indicating severe LUTS. In those aged 19-39 years, 28.7% (8343/29,072) reported they had mild to severe LUTS. The prevalence of LUTS was high among those aged 40-59 years (47.7%), 60-79 years (80.5%), and ≥ 80 years (91.2%). In addition, EQ-5D-3L and EQ-VAS scores decreased as LUTS severity and frequency increased. CONCLUSIONS: Adult men of all ages with mild to severe LUTS have poorer health statuses and quality of life. Even among young males, LUTS severity and was found to negatively affect HRQoL.

Cost-utility analysis of the National Health Screening Program for chronic kidney disease in Korea.

AIM: Although a National Health Screening Program (NHSP) for chronic kidney disease (CKD) has been implemented in Korea since 2002, its cost-effectiveness has never been determined. This study aimed to estimate the cost-utility of NHSP for CKD in Korea. METHODS: A Markov decision analytic model was constructed to compare CKD screening strategies of the NHSP with no screening. We developed a model that simulated disease progression in a cohort aged 20-120 years or death from the societal perspective. RESULTS: Biannual screening starting at age 40 for CKD by proteinuria (dipstick) and estimated glomerular filtration ratio had an ICUR of $66 874/QALY relative to no screening. The targeted screening strategy had an ICUR of $37 812/QALY and $40 787/QALY for persons with diabetes and hypertension, respectively. ICURs improved with lower cost strategies. The most influential parameter that might make screening more cost-effective was the effectiveness of treatment on CKD to decrease disease progression and mortality. CONCLUSIONS: The Korean NHSP for CKD is more cost-effective for patients with diabetes or hypertension than the general population, consistent with prior studies. Although it is too early to conclude the cost-effectiveness of the Korean NHSP for CKD, this study provides evidence that is useful in evaluating the cost-effectiveness of CKD interventions.

Estimating Lifetime Duration of Diabetes by Age and Gender in the Korean Population Using a Markov Model.

BACKGROUND: Duration of type 2 diabetes is clinically important. Duration of morbidity is an independent and critical predictor of developing its complications. This study aims to explore an applicability of a Markov model to estimate the duration of diabetes in the Korean population. METHODS: We constructed the Markov model with two Markov states, diabetes and death, for estimation of duration of diabetes. The cycle of the Markov model was 1 year. Each diabetes onset by 5 years was considered from 30 to 85 years old or above. The endpoint of the Markov was 100 years old. Type 2 diabetes was operationally defined using the 10th revision of International Statistical Classification of Diseases and prescriptions of anti-diabetic drugs from the National Health Insurance Services-National Sample cohort. In each incident and existing prevalence cases, survival probabilities were obtained. Durations of diabetes from the Markov model were compared with those from the DisMod II program. Reductions of life expectancy due to diabetes were defined as differences of life expectancies between diabetic patients and the general public. Sensitivity analyses were also conducted using a cure rate and 95% confidence interval of survival probability. RESULTS: The duration of diabetes gradually decreased with incident age in both genders. In the early 30s, the duration was the largest at 48.9 and 41.9 years in women and men, respectively. In the average incident age group of type 2 diabetes, the late 50s, the reduction of life expectancy due to diabetes was estimated to be about two years in both genders. As annual cure probabilities increased, the durations of diabetes were reduced. CONCLUSION: This study estimated the duration of diabetes using a Markov model. The model seems to work well and diabetes could reduce life expectancy by about 2 years on average. This approach could be useful to estimate the duration of illness, calculate disability-adjusted life years, and conduct economic evaluation studies on interventions for diabetic patients.

Disease severity-based evaluation of utility weights for lung cancer-related health states in Korea.

BACKGROUND: Utility weight, a measure of health-related quality of life, is used in disease burden measurements and economic evaluations. In this study, we used the visual analogue scale (VAS) and standard gamble (SG) method to determine the utility weights of lung cancer health states in South Korea from a societal perspective. METHODS: Six hypothetical health states for lung cancer or a related health state reflective of disease severity were developed: 1) Stage I, 2) Stage II, 3) Stage IIIa, 4) Stage IIIB, 5) Stage IV, and 6) Pulmonary nodule. The description of each health state description was divided into four parts: diagnosis, symptoms, treatment, and progression and prognosis. A total of 515 representative adult Korean participants used a VAS and SG to evaluate these six health states via face-to-face computer-assisted interviews. The means, standard deviations, and median utility weights of the six health states were estimated by valuation method. RESULTS: The two valuation methods of the scenarios yielded the same mean utility rankings. Pulmonary nodule received the highest rank (VAS, 0.66 and SG, 0.83), whereas Stage 4 was assigned the lowest rank (VAS, 0.09 and SG, 0.31). For all health states, the mean utility weights calculated using the SG were greater than those calculated using the VAS. The differences between the utility weights obtained using the two valuation methods ranged from 0.14 (Stage I) to 0.22 (Stage IV). The two approaches tended to yield larger differences for more severe stages. CONCLUSIONS: This study determined utilities for squamous cell lung cancer that will be useful for estimating the burden of lung cancer and for conducting economic evaluations of lung cancer interventions.

Health-related quality of life by allergy symptoms in elementary school students.

BACKGROUND: Globally, allergic diseases are very common in childhood and may affect children's quality of life. This study aimed to explore health-related quality of life of elementary school students with allergy symptoms using the EQ-5D-Y and to examine the validity and feasibility of the EQ-5D-Y. METHODS: The study subjects were the students within 50 elementary schools which voluntarily participated in research project. In this sample population, the EQ-5D-Y questionnaire was self-administered by the students, and demographic and health information were collected from the student's parents. The parents' information was used to investigate the proportion of students with allergic symptoms (wheezing, runny or blocked nose, and itchy rash) in the past 12 months. In addition, we analyzed the correlation of symptom reporting and EQ-5D-Y including EQ-VAS. RESULTS: The overall return was 9117 responses, of which 198 (2.2%) lacked responses on the EQ-5D-Y dimension and 1258 (13.8%) on the VAS score. There were significant differences in symptom reporting in all EQ-5D-Y dimensions between groups with or without allergic symptoms. Particularly, there was a large difference in reporting rates in 'having pain or discomfort' and 'feeling worried, sad or unhappy' dimensions. As the number of allergic symptoms increased, in all dimensions also the problem reporting rate tended to increase. CONCLUSIONS: As expected, the presence of allergic symptoms is inversely correlated with the quality of life of children. The EQ-5D-Y instrument proved to be useful in terms of feasibility and construct validity in assessing the quality of life of Korean elementary school students.

Estimation of utility weights for major liver diseases according to disease severity in Korea.

BACKGROUND: The global burden of liver diseases, such as hepatocellular carcinoma and liver cirrhosis, is substantial. In this study, we estimated utility weights of liver disease-related health states in the general population using a visual analogue scale (VAS) and the standard gamble (SG) method. METHODS: Depictions of standardized health states related to major liver diseases were developed based on patient education materials and previous publications. To fully reflect disease progression from diagnosis to prognosis, each health state comprised four parts: diagnosis, symptoms, treatment, and progression and prognosis. A total of 407 participants from the Korean general population evaluated the health states using the VAS and SG methods in computer-assisted personal interviews. After excluding illogical responses, mean utility weights were calculated for each health state. RESULTS: The utility weights for health states were significantly different according to the existence of inconsistency in general. According to the VAS results, the health state with the highest utility was 'Chronic hepatitis B virus infection' (0.64), whereas the health state with the lowest utility was 'Hepatocellular carcinoma that requires palliative therapy' (0.17). Similarly, the SG results revealed that the health state with the highest utility was 'Chronic hepatitis B virus infection' (0.85), and the health state with the lowest utility was 'Hepatocellular carcinoma that requires palliative therapy' (0.40). CONCLUSIONS: The estimated utility weights in this study will be useful to measure the burden of liver diseases and evaluate cost-utility of programs for reducing the burden of liver diseases.

Feasibility, comparability, and reliability of the standard gamble compared with the rating scale and time trade-off techniques in Korean population.

PURPOSE: The standard gamble (SG) method is the gold standard for valuing health states as a utility, although it is accepted that it is difficult to valuate health states. This study was conducted in order to compare the SG with the rating scale (RS) and time trade-off (TTO) techniques in terms of their feasibility, comparability, and reliability in a valuation survey of the general Korean population. METHODS: Five-hundred members of the general Korean population were recruited using a multi-stage quota sampling method in Seoul and its surrounding areas, Korea. Respondents evaluated 9 EQ-5D-5L health states using a visual analogue scale (VAS), SG, and TTO during a personal interview. Feasibility was assessed in aspects of the level of difficulty, administration time, and inconsistent responses. Comparability was evaluated using intraclass correlation coefficient (ICC) and the Bland-Altman approach. Test-retest reliability was analyzed using the ICC. RESULTS: Of the three methods, VAS was the easiest and quickest method to respond. The SG method did not differ significantly compared to the TTO method in administration time as well as the level of difficulty. The SG and TTO values were highly correlated (r = 0.992), and the average mean difference between the SG and the TTO values was 0.034. The ICCs of the VAS, SG, and TTO scores were 0.906, 0.841, and 0.827, respectively. CONCLUSIONS: This study suggests that the SG method compared with the VAS and TTO method was feasible and offered a reliable tool for population-based, health state valuation studies in Korea.

Estimation of utility weights for human papilloma virus-related health states according to disease severity.

BACKGROUND: A cost-utility study of a human papilloma virus (HPV) vaccine requires that the utility weights for HPV-related health states (i.e., cervical intraepithelial neoplasia (CIN), cervical cancer, and condyloma) be evaluated. The aim of the present study was to determine the utility weights for HPV-related health states. METHODS: Hypothetical standardised health states related to HPV were developed based on patient education material and previous publications. To fully reflect disease progression from diagnosis to prognosis, each health state comprised four parts (diagnosis, symptoms, treatment, and progression and prognosis). Nine-hundred members from the Korean general population evaluated the HPV-related health states using a visual analogue scale (VAS) and a standard gamble (SG) approach, which were administered face-to-face via computer-assisted interview. The mean utility values were calculated for each HPV-related health state. RESULTS: According to the VAS, the highest utility (0.73) was HPV-positive status, followed by condyloma (0.66), and CIN grade I (0.61). The lowest utility (0.18) was cervical cancer requiring chemotherapy without surgery, followed by cervical cancer requiring chemoradiation therapy (0.42). SG revealed that the highest utility (0.83) was HPV-positive status, followed by condyloma (0.78), and CIN grade I (0.77). The lowest utility (0.43) was cervical cancer requiring chemotherapy without surgery, followed by cervical cancer requiring chemoradiation therapy (0.60). CONCLUSIONS: This study was based on a large sample derived from the general Korean population; therefore, the calculated utility weights might be useful for evaluating the economic benefit of cancer screening and HPV vaccination programs.

The EQ-5D-5L valuation study in Korea.

PURPOSE: This study aimed to estimate Korean preference weights for EQ-5D-5L based on values elicited from Korean population by applying the EuroQol Valuation Technology (EQ-VT) program and the standard protocol by the EuroQol Group. METHODS: The multistage quota sampling method was used to recruit 1085 subjects from the general population in Korea. Each respondent valuated 10 health states using the composite time trade-off (cTTO) and 7 health states using discrete choice experiment. The EQ-VT program was developed by the EuroQol Group and translated into Korean with the Korean research team. Computer-assisted, face-to-face interviews were conducted. A range of predictive models were explored using cTTO. The most appropriate model was determined after assessing goodness of fit, logical consistency, and parsimony. RESULTS: Of 3206 contacted, 1085 subjects completed interviews (33.8 %) and 1080 were used for modeling. A model with dummy variables for each level of severity and dimension and a term that picked up whether any dimension in the state was at level 4 or 5 was selected as the best predictive model. All coefficients of the final model were statistically significant and logically consistent. In addition, it was parsimonious. This model had mean absolute error of 0.027, and the absolute error for all 86 health states was below 0.1. CONCLUSIONS: The final model built in this study appears to predict the utilities of the states which were valuated directly. This model could be used to interpolate quality weights for all EQ-5D-5L health states.

Disability-Adjusted Life Years for Maternal, Neonatal, and Nutritional Disorders in Korea.

Maternal and child health is an important issue throughout the world. Given their impact on maternal and child health, nutritional issues need to be carefully addressed. Accordingly, the effect of maternal, child, and nutritional disorders on disability-adjusted life years (DALYs) should be calculated. The present study used DALYs to estimate the burden of disease of maternal, neonatal, and nutritional disorders in the Korean population in 2012. For this purpose, we used claim data of the Korean National Health Insurance Service, DisMod II, and death data of the Statistics Korea and adhered to incidence-based DALY estimation methodology. The total DALYs per 100,000 population were 376 in maternal disorders, 64 in neonatal disorders, and 58 in nutritional deficiencies. The leading causes of DALYs were abortion in maternal disorders, preterm birth complications in neonatal disorders, and iron-deficiency anemia in nutritional deficiencies. Our findings shed light on the considerable burden of maternal, neonatal, and nutritional conditions, emphasizing the need for health care policies that can reduce morbidity and mortality.

Effect of nurse staffing variation and hospital resource utilization.

In this study, we examined the effect of variations in nurse staffing levels on the length of stay and medical expenses of patients who underwent hip or knee surgeries. A cross-sectional study was conducted using the National Health Insurance database and hospital surveys from 2010. Patient length of stay and medical expenses by nurse staffing level and skill mix were compared after adjusting for hospital and patient characteristics. Nurse staffing was measured based on staffing grade, the bed-to-registered nurse/nurse aid ratio, the bed-to-nursing personnel ratio, and the RN proportion. Generalized estimation models were used to analyze the associations. Decreased nurse staffing was consistently associated with increased length of stay, regardless of nurse staffing measures. The medical expenses associated with the lowest staffing level were approximately $US 1142.2 more than those associated with the highest staffing level. The study results suggest that maintaining a high nurse staffing level could be a cost-effective strategy for government and insurers, as well as for patients. We propose that policy makers implement more efficient nurse staffing strategies.

Estimating quality-adjusted life-year loss due to noncommunicable diseases in Korean adults through to the year 2040.

OBJECTIVES: To estimate the loss in quality-adjusted life-years (QALYs) in Korean adults due to 13 noncommunicable diseases (NCDs) in 2010 and predict changes in QALY loss through to the year 2040. METHODS: Thirteen NCDs (hypertension, diabetes mellitus, hyperlipidemia, stroke, myocardial infarction, angina, arthritis, osteoporosis, asthma, allergic rhinitis, atopic dermatitis, cataract, and depression) were selected from the Korean Community Health Survey 2010. The EuroQol five-dimensional questionnaire index from the Korean Community Health Survey 2010 and the Korean valuation set were used to estimate utility weights according to sex, age, and disease. Morbidity data were also obtained from the Korean Community Health Survey 2010. Mortality data according to disease and life expectancy were retrieved from the Korean Statistical Information Service. To predict future QALY loss, future population projection data from the Korean Statistical Information Service were used as substitutes for 2010 population size. RESULTS: Among the assessed 13 NCDs, the largest total QALY loss was for hypertension (513,113 QALYs; units are omitted hereafter), followed by arthritis (509,317) and stroke (431,049). The largest QALY loss due to mortality was stroke (306,733), whereas the largest QALY loss due to morbidity was arthritis (502,513). By applying the middle estimate of future population, the largest increase in total QALY loss between 2010 and 2040 was for hypertension (840,582), followed by stroke (719,076) and diabetes mellitus (474,607). CONCLUSIONS: Hypertension, arthritis, and stroke are important in terms of total QALY loss, which will continuous to increase because of aging. These results could be used to develop cost-effective interventions that reduce the burden of NCDs.

Serum Triglyceride Levels and Cardiovascular Disease Events in Koreans.

OBJECTIVES: Hypercholesterolemia, especially elevated levels of LDL-cholesterol, is a well-known risk factor for cardiovascular disease (CVD). However, the role of triglycerides in CVD risk remains controversial. METHODS: We enrolled 86,476 individuals who had undergone a general health checkup at Asan Medical Center between January 2007 and June 2011. After exclusion criteria were applied to the total cohort, 76,434 participants were included. CVD events and death were gathered from the nationwide health insurance claims database and death certificates using ICD-10 codes. RESULTS: Age- and sex-adjusted odds ratios (ORs) of the higher triglyceride group were significantly increased: 1.52 (95% CI: 1.27-1.82) for major CVD events, 1.53 (95% CI: 1.24-1.88) for major ischemic heart disease events, and 1.49 (95% CI: 1.37-1.63) for overall CVD events. After adjustment for multiple risk factors including HDL-cholesterol, ORs for overall CVD events were significantly increased in the higher triglyceride group. When the analysis was stratified according to BMI, hypertension, and glycemic status at baseline, age- and sex-adjusted ORs for the outcomes were significantly increased in the higher triglyceride group with nonobese, normotensive, or nondiabetic subjects. CONCLUSIONS: Hypertriglyceridemia is independently associated with an increased risk for CVD, especially in nonobese, normotensive, or nondiabetic individuals.

Estimation of minimally important differences in the EQ-5D and SF-6D indices and their utility in stroke.

BACKGROUND: The aim of the present study was to estimate minimally important differences (MIDs) in EQ-5D and SF-6D indices and to explore the responsiveness of EQ-5D and SF-6D indices in stroke. METHODS: We used observational longitudinal survey data of EQ-5D and SF-36 that were administered to stroke patients at baseline and at 10 months. A range of MIDs for both indexes was estimated using anchor-based approaches. The modified Rankin scale and the Barthel index were used as an anchor. RESULTS: The MID estimates for EQ-5D ranged from 0.08 to 0.12 and those for SF-6D ranged from 0.04 to 0.14 in stroke patients. The MID values for these two utility measures differed in absolute magnitude, as the SF-6D index has wider range that that of the EQ-5D index. CONCLUSIONS: The MID values for these two utility measures differed in absolute magnitude, as the SF-6D index has wider range that that of the EQ-5D index. These MID estimates may assist the interpretation of health related quality of life assessments related to health care intervention in stroke patients.

Validity and reliability of EQ-5D-3L for breast cancer patients in Korea.

BACKGROUND: Recently, breast cancer incidence and prevalence has been increasing. Patients' health related quality of life is important considerations in the treatment of breast cancer. The EQ-5D-3L is one of most popular instruments to measure health related quality of life. This study was aimed to evaluate the validity and reliability of EQ-5D-3L in post-operative breast cancer patients from Korea. METHODS: A total of 827 patients visiting the ambulatory cancer center of 1 tertiary hospital after breast cancer surgery self-administered the EQ-5D-3L and Functional Assessment of Cancer Therapy-Breast Cancer (FACT-B). We evaluated known-group validity using differences in the EQ-5D-3L index and EQ-VAS score according to demographic and clinical data. The discriminatory ability of the EQ-5D-3L was determined by comparing the mean FACT-B subscale scores between subjects with no problems and subjects with moderate or severe problems in each EQ-5D-3L dimension. Construct validity was evaluated by Pearson correlation coefficients among the EQ-5D-3L index and FACT-B subscales, respectively. Reliability was assessed in terms of test-retest reliability using Cohen's kappa value and intra-class correlation coefficient (ICC). RESULTS: The EQ-5D-3L index and EQ-VAS score were higher in the educated, current radiotherapy and unmarried groups. The correlation of EQ-5D-3L index and subscales for the FACT-B was highest in physical well-being (r = 0.553) and lowest in social well-being (r = 0.199). For reliability, the Kappa values' range was from 0.32 to 0.70, and ICCs of the EQ-5D-3L index and EQ-VAS scores were 0.70 and 0.48, respectively. CONCLUSIONS: This study indicated that the EQ-5D-3L could be a valid health related quality of life instrument for postoperative breast cancer patients.

Utility estimation of hypothetical chronic obstructive pulmonary disease health states by the general population and health professionals.

PURPOSE: This study attempted to estimate the utility weights for hypothetical chronic obstructive pulmonary disease (COPD) health states, including the effect of exacerbation, and based on utilities elicited from a representative sample using the time trade-off (TTO). METHODS: A total of 200 study subjects were recruited using a quota sampling method in Seoul, Korea. Ten COPD health profiles were described reflecting the severity of COPD and the extent of exacerbation. Respondents evaluated each health state using a visual analogue scale and TTO during a personal interview. TTO values were estimated using a linear mixed model, and the model performance was evaluated in terms of its predictive ability and goodness of fit. RESULTS: The estimated TTO values were 0.824 in moderate, 0.646 in severe, and 0.305 in very severe COPD health states. The estimated utility decrements in TTO varied from 0.082 for a non-serious exacerbation to 0.228 for one non-serious plus one serious exacerbation per year. The mean absolute error of the TTO model was 0.008, and the generalized R(2) was 0.86. CONCLUSION: The social preference of various COPD health states and the utility decrement due to exacerbation can be useful for the economic evaluation of COPD intervention in Korea.