Seon Ha Kim

Comparing the psychometric properties of the EQ-5D-3L and EQ-5D-5L in cancer patients in Korea

PurposeThis study was conducted to assess the redistribution properties of the EQ-5D-3L when using the EQ-5D-5L and to compare the validity, informativity, and reliability of both EQ-5D-3L and EQ-5D-5L in Korean cancer patients.MethodsPatients visiting one ambulatory cancer center self-administered the two versions of the EQ-5D and the EORTC QLQ-C30 questionnaire. Redistribution properties in each dimension of EQ-5D were analyzed between EQ-5D-3L and EQ-5D-5L. Informativity was evaluated using the Shannon entropy and ceiling effect. Convergent validity was evaluated by comparing the EQ-VAS, ECOG performance status, and EORTC QLQ-C30 subscales. Reliability was also evaluated in terms of test–retest reliability.ResultsAll levels of the EQ-5D-3L substantially partitioned into associated levels of the EQ-5D-5L. The average inconsistency rate of the two versions was 3.5%. Absolute informativity was higher for the EQ-5D-5L than for the EQ-5D-3L, but their informative efficiency tended to be similar. The proportion of ‘perfect health’ (11111) decreased from 16.8% in the EQ-5D-3L to 9.7% in the EQ-5D-5L. EQ-5D-5L demonstrated similar or higher correlations with the EQ-VAS, ECOG performance status, and EORTC QLQ-C30, than the EQ-5D-3L. The intraclass correlation coefficient of the EQ-5D-5L index was 0.77.ConclusionsThe EQ-5D-5L had greater informativity and lower rate in the ceiling effect than those values of the EQ-5D-3L. The EQ-5D-5L showed good construct validity and reasonable reliability. Therefore, considering these findings, the EQ-5D-5L may be preferable to the EQ-5D-3L.

Mapping EORTC QLQ-C30 onto EQ-5D for the assessment of cancer patients

BackgroundThe European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) is the instrument most frequently used to measure quality of life in cancer patients, whereas the EQ-5D is widely used to measure and evaluate general health status. Although the EORTC QLQ-C30 has been mapped to EQ-5D utilities, those studies were limited to patients with a single type of cancer. The present study aimed to develop a mapping relationship between the EORTC QLQ-C30 and EQ-5D-based utility values at the individual level.MethodsThe model was derived using patients with different types of cancer who were receiving chemotherapy. The external validation set comprised outpatients with colon cancer. Ordinary least squares regression was used to estimate the EQ-5D index from the EORTC QLQ-C30 results. The predictability, goodness of fit, and signs of the estimated coefficients of the model were assessed. Predictive ability was determined by calculating the mean absolute error, the estimated proportions with absolute errors > 0.05 and > 0.1, and the root-mean-squared error (RMSE).ResultsA model that included global health, physical, role, emotional functions, and pain was optimal, with a mean absolute error of 0.069 and an RMSE of 0.095 (normalized RMSE, 8.1%). The explanatory power of this model was 51.6%. The mean absolute error was higher for modeled patients in poor health.ConclusionsThis mapping algorithm enabled the EORTC QLQ-C30 to be converted to the EQ-5D utility index to assess cancer patients in Korea.

Right ventricular dysfunction as an echocardiographic prognostic factor in hemodynamically stable patients with acute pulmonary embolism: a meta-analysis

BackgroundWe investigated whether right ventricular dysfunction (RVD) as assessed by echocardiogram can be used as a prognostic factor in hemodynamically stable patients with acute pulmonary embolism (PE). Short-term mortality has been investigated only in small studies and the results have been controversial.MethodsA PubMed search was conducted using two keywords, “pulmonary embolism” and “echocardiogram”, for articles published between January 1st 1998 and December 31st 2011. Out of 991 articles, after careful review, we found 12 articles that investigated the implications of RVD as assessed by echocardiogram in predicting short-term mortality for hemodynamically stable patients with acute PE. We conducted a meta-analysis of these data to identify whether the presence of RVD increased short-term mortality.ResultsAmong 3283 hemodynamically stable patients with acute PE, 1223 patients (37.3%) had RVD, as assessed by echocardiogram, while 2060 patients (62.7%) had normal right ventricular function. Short-term mortality was reported in 167 (13.7%) out of 1223 patients with RVD and in 134 (6.5%) out of 2060 patients without RVD. Hemodynamically stable patients with acute PE who had RVD as assessed by echocardiogram had a 2.29-fold increase in short-term mortality (odds ratio 2.29, 95% confidence interval 1.61-3.26) compared with patients without RVD.ConclusionsIn hemodynamically stable patients with acute PE, RVD as assessed by echocardiogram increases short-term mortality by 2.29 times. Consideration should be given to obtaining echocardiogram to identify high-risk patients even if they are hemodynamically stable.

Validity and reliability of the EQ-5D for cancer patients in Korea

PurposeThe purpose of this study was to assess the validity and reliability of the Korean version of the EQ-5D health questionnaire for use in patients with cancer in Korea.MethodsPatients with colorectal cancer were recruited from one ambulatory cancer center. Each participant consecutively self-administered the EQ-5D, the EORTC QLQ-C30, and the Short Form-36 (SF-36). Discriminatory ability was evaluated by comparing the SF-36 subscales with their corresponding EQ-5D dimensions. Convergent validity was assessed by examining the correlations between the EQ-5D index, EORTC QLQ-C30 subscales, and SF-36 scale and summary scores. Test-retest reliability was also evaluated.ResultsSubjects reporting problems in each EQ-5D dimension showed lower scores on all SF-36 subscales. As expected, the relationships were stronger between the EQ-5D functional dimensions and physical function on the EORTC QLQ-C30 and between the EQ-5D anxiety/depression dimension and emotional function on the EORTC QLQ-C30. The EQ-5D index and SF-36 scales were moderately or highly correlated. intraclass correlation coefficient of the EQ-5D index was 0.45.ConclusionsThe Korean version of the EQ-5D may be a valid tool for assessing the health-related quality of life of patients with cancer. However, further research is needed to determine the reliability of the Korean EQ-5D over different time intervals and disease conditions.

Psychometric Properties of the Korean Short Form-36 Health Survey Version 2 for Assessing the General Population

PURPOSE To evaluate the psychometric properties of the Korean short form-36 health survey version 2 for assessing the general population and to provide normative data on the general population. METHODS Six hundred members of the general Korean population were recruited using a multistage quota sampling method. Data quality was evaluated in terms of the completeness of the data and the response consistency index. Each psychometric property was evaluated using descriptive statistics, item internal consistency, item discriminant validity, known-group validity, internal consistency reliability, and exploratory factor analysis. RESULTS The rate of missing data was low, and the rate of consistent responses was similar to conventional criteria. Item internal consistency was acceptable across all scales, whilst item discriminant validity was satisfactory for five of the eight scales. Social functioning was the least acceptable in terms of not only item discriminant validity but also item consistency reliability (Cronbachs alpha = .64). Test-retest Pearson correlation coefficients ranged from .54 to .80. In known group comparison, male sex, age <60 years, high educational status, and the absence of any comorbidities were associated with higher scores than their counterparts. Item factor analysis yields the presence of six factors, accounting for 68.8% of the variance. CONCLUSION The findings of this study generally support the use of the Korean short form-36 version 2 for evaluating the general population, although caution is recommended when interpreting the vitality, social functioning, and mental health scales. Further research is needed in Korea.

Model for Assessing Cardiovascular Risk in a Korean Population

Background—A model for predicting cardiovascular disease in Asian populations is limited. Methods and Results—In total, 57 393 consecutive asymptomatic Korean individuals aged 30 to 80 years without a prior history of cardiovascular disease who underwent a general health examination were enrolled. Subjects were randomly classified into the train (n=45 914) and validation (n=11 479) cohorts. Thirty-one possible risk factors were assessed. The cardiovascular event was a composite of cardiovascular death, myocardial infarction, and stroke. In the train cohort, the C-index (95% confidence interval) and Akaike Information Criterion were used to develop the best-fitting prediction model. In the validation cohort, the predicted versus the observed cardiovascular event rates were compared by the C-index and Nam and D’Agostino &khgr;2 statistics. During a median follow-up period of 3.1 (interquartile range, 1.9–4.3) years, 458 subjects had 474 cardiovascular events. In the train cohort, the best-fitting model consisted of age, diabetes mellitus, hypertension, current smoking, family history of coronary heart disease, white blood cell, creatinine, glycohemoglobin, atrial fibrillation, blood pressure, and cholesterol (C-index =0.757 [0.726–0.788] and Akaike Information Criterion =7207). When this model was tested in the validation cohort, it performed well in terms of discrimination and calibration abilities (C-index=0.760 [0.693–0.828] and Nam and D’Agostino &khgr;2 statistic =0.001 for 3 years; C-index=0.782 [0.719–0.846] and Nam and D’Agostino &khgr;2 statistic=1.037 for 5 years). Conclusions—A risk model based on traditional clinical and biomarkers has a feasible model performance in predicting cardiovascular events in an asymptomatic Korean population.

Association Between Metabolic Syndrome and Incident Fractures in Korean Men: A 3-Year Follow-Up Observational Study Using National Health Insurance Claims Data

CONTEXT Although the prevalence of both metabolic syndrome (MetS) and fractures increases with advancing age, studies on possible associations between these conditions in men are limited and the results are inconsistent. OBJECTIVE The objective of the study was to clarify the impact of MetS on the male risk of incident fractures. DESIGN AND SETTING This was a large, longitudinal study with an average 3-year follow-up period. PARTICIPANTS Korean men (n = 16 078) aged 50 years or older who had undergone comprehensive routine health examinations participated in the study. MAIN OUTCOME MEASURES Incident fractures found after baseline examinations were identified using selected International Classification of Diseases, tenth revision, codes in the nationwide claims database of the Health Insurance Review and Assessment Service of Korea. RESULTS In total, 158 men (1.0%) developed incident fractures. The fracture event rates for subjects with and without MetS were 26.2 and 35.7 per 10 000 person-years, respectively. After adjustment for potential confounders, subjects with MetS had a much lower risk of incident fractures than subjects without MetS (hazard ratio 0.662, 95% confidence interval 0.445-0.986). Furthermore, subjects with three and four or more MetS components had a 49.4% and 50.4% lower risk, respectively, of incident fractures compared with the subjects without any MetS components. Importantly, additional adjustment for body mass index eliminated the statistical significance of these associations. CONCLUSION Our current results indicate that the beneficial effects of MetS in reducing fracture risk could be explained by the general obesity that accompanies MetS, although other related factors, such as greater padding effect, peripheral aromatization, or adipokine changes, may also contribute.

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.

Association between C-reactive Protein and Type of Coronary Arterial Plaque in Asymptomatic Patients: Assessment with Coronary CT Angiography

PURPOSE To determine whether C-reactive protein is associated with the type of coronary plaque seen at computed tomographic (CT) angiography. MATERIALS AND METHODS The institutional review board approved this retrospective study, and the need for informed consent was waived. C-reactive protein levels were measured in 2653 asymptomatic subjects (mean age ± standard deviation, 54.7 years ± 9.2; 1811 men) who underwent self-referred coronary CT angiography as part of a general health checkup. The presence of coronary plaque, plaque type (calcified, mixed calcified, or noncalcified), stenosis degree, and number of involved segments were evaluated. Subjects with one type of plaque (calcified plaque, mixed plaque, and noncalcified plaque groups) and two or more types of plaque (multiple lesions group) were analyzed separately. Multivariate logistic regression analysis was used to evaluate the association between increasing C-reactive protein levels and plaque type. RESULTS Coronary plaque was found in 1150 of the 2653 subjects (43.3%): calcified plaque (n = 604, 22.8%), mixed plaque (n = 67, 2.5%), noncalcified plaque (n = 208, 7.8%), and multiple lesions (n = 271, 10.2%). The C-reactive protein cutoff value of the fourth quartile was 1.2 mg/L (11.4 nmol/L), and all types of coronary plaque were increased in the higher quartile of the C-reactive protein levels. Multivariate logistic regression analysis showed that a higher C-reactive protein level was an independent predictor for the presence of noncalcified plaque (fourth vs first quartile group, odds ratio = 1.70, P = .025) and significant (50% and higher) coronary stenosis (odds ratio = 1.76, P = .020) after adjustment for traditional risk factors for coronary artery disease. CONCLUSION C-reactive protein is associated with noncalcified coronary arterial plaque, as seen at coronary CT angiography in asymptomatic patients after adjustment for traditional risk factors.

Clinical impact and cost-effectiveness of coronary computed tomography angiography or exercise electrocardiogram in individuals without known cardiovascular disease.

AbstractIt is not clear whether screening by coronary computed tomographic angiography (CCTA) and/or exercise electrocardiogram (ECG) can improve clinical outcomes and reduce costs in individuals without known cardiovascular disease (CVD).In total, 71,811 consecutive individuals without known CVD who underwent general health examinations were enrolled. Using propensity-score matching according to screening tests, 1-year clinical outcomes and 6-month total and coronary artery disease–related medical costs were analyzed in separate groups: group 1 (CCTA [n = 2578] vs no screening [n = 5146]), group 2 (exercise ECG [n = 2898] vs no screening [n = 5796]), and group 3 (CCTA and exercise ECG [n = 2003] vs no screening [n = 4006]).There were no significant differences in the composite outcome of death, myocardial infarction, and stroke in each matched group: group 1 (0.35% vs 0.45%, P = 0.501), group 2 (0.14% vs 0.28%, P = 0.157), and group 3 (0.25% vs 0.27%, P = 0.858). However, revascularization was more frequent in the CCTA screening groups: group 1 (2.02% vs 0.45%, P < 0.001) and group 3 (1.40% vs 0.45%, P < 0.001). Matched screening groups had higher 6-month total and coronary artery disease–related medical costs: group 1 (