PurposeThe purpose of this study was to estimate the clinical utilization of radiation therapy (RT) in Korea between 2011 and 2015.Materials and MethodsWe analyzed the claims data from the Health Insurance Review and Assessment Service to estimate the clinical utilization of RT. The source population consisted of all patients who had any of the International Classification of Diseases 10th revision cancer diagnoses (C00-C97) and those with diagnostic codes D00-D48, who were also associated with at least one of the procedure codes related to RT.ResultsThe total number of patients who received RT in 2011, 2012, 2013, 2014, and 2015 were 54,810, 59,435, 61,839, 64,062, and 66,183, respectively. Among them, the total numbers of male and female patients were 24,946/29,864 in 2011, 27,211/32,224 in 2012, 28,111/33,728 in 2013, 29,312/34,750 in 2014, and 30,266/35,917 in 2015. The utilization rate of RT in cancer patients has also increased steadily over the same period from 25% to 30%. The five cancers that were most frequently treated with RT between 2011 and 2012 were breast, lung, colorectal, liver, and uterine cervical cancers. However, the fifth most common cancer treated with RT that replaced uterine cervical cancer in 2013 was prostate cancer. More than half of cancer patients (64%) were treated with RT in the capital area (Seoul, Gyeonggi, and Incheon).ConclusionThe total number of patients who underwent RT increased steadily from 2011 to 2015 in Korea. The utilization rate of RT in cancer patients is also increasing.

Prediction of outcome after stroke may help clinicians provide effective management and plan long-term care. We aimed to develop and validate a score for predicting good functional outcome available for hospitals after ischemic stroke using linked data. A total of 22,005 patients with acute ischemic stroke from the Clinical Research Center for Stroke Registry between July 2007 and December 2014 were included in the derivation group. We assessed functional outcomes using a modified Rankin scale (mRS) score at 3 months after ischemic stroke. We identified predictors related to good 3-month outcome (mRS score ≤ 2) and developed a score. External validations (geographic and temporal validations) of the developed model were performed. The prediction model performance was assessed using the area under the receiver operating characteristic curve (AUC) and the calibration test. Stroke severity, sex, stroke mechanism, age, pre-stroke mRS, and thrombolysis/thrombectomy treatment were identified as predictors for 3-month good functional outcomes in the S-SMART score (total 34 points). Patients with higher S-SMART scores had an increased likelihood of a good outcome. The AUC of the prediction score was 0.805 (0.798-0.811) in the derivation group and 0.812 (0.795-0.830) in the geographic validation group for good functional outcome. The AUC of the model was 0.812 (0.771-0.854) for the temporal validation group. Moreover, they had good calibration. The S-SMART score is a valid and useful tool to predict good functional outcome following ischemic stroke. This prediction model may assist in the estimation of outcomes to determine care plans after stroke.

Background: Neurocritical care by dedicated neurointensivists may improve outcomes of critically ill patients with severe brain injury. In this study, we aimed to validate whether neurointensive care could improve the outcome in patients with critically ill acute ischemic stroke using the linked big dataset on stroke in Korea. Methods: We included 1,405 acute ischemic stroke patients with mechanical ventilator support in the intensive care unit after an index stroke. Patients were retrieved from linking the Clinical Research Center for Stroke Registry and the Health Insurance Review and Assessment Service data from the period between January 2007 and December 2014. The outcomes were mortality at discharge and at 3 months after an index stroke. The main outcomes were compared between the centers with and without dedicated neurointensivists. Results: Among the included patients, 303 (21.6%) were admitted to the centers with dedicated neurointensivists. The patients treated by dedicated neurointensivists had significantly lower in-hospital mortality (18.3% vs. 26.8%, P = 0.002) as well as lower mortality at 3-month (38.0% vs. 49.1%, P < 0.001) than those who were treated without neurointensivists. After adjusting for confounders, a treatment without neurointensivists was independently associated with higher in-hospital mortality (odds ratio [OR], 1.59; 95% confidence intervals [CIs], 1.13-2.25; P = 0.008) and 3-month mortality (OR, 1.48; 95% CIs, 1.12-1.95; P = 0.005). Conclusion: Treatment by dedicated neurointensivists is associated with lower in-hospital and 3-month mortality using the linked big datasets for stroke in Korea. This finding stresses the importance of neurointensivists in treating patients with severe ischemic stroke.

Background: Optimal antithrombotic regimens to prevent recurrent stroke in patients with ischemic stroke due to AF and atherosclerotic large-vessel stenosis remains unknown. Aims: This study aimed to evaluate the effect of multiple antithrombotic therapies on outcomes at 1-year after ischemic stroke due to two or more causes. Methods: Based on the linked data, we identified 862 patients with ischemic stroke due to AF and large artery atherosclerosis in the relevant arteries. These patients were categorized into three groups, according to their antithrombotic therapies at discharge after ischemic stroke: those receiving 1) antiplatelet agents, 2) oral anticoagulants (OAC), and 3) antiplatelet agents plus OAC. The study outcomes were recurrent ischemic stroke, composite outcomes, including ischemic stroke, myocardial infarction, intracerebral hemorrhage and death, and major bleeding after 1 year. Inverse probability of treatment weighting (IPTW) was used to balance the three groups using propensity scores. Results: Among 862 patients (mean age: 72.6 years, men: 58.4%), 169 (19.6%) were treated with antiplatelet agents, 405 (47.0%) were treated with OAC, and 288 (33.4%) were treated with antiplatelet agents and OAC. After applying IPTW, only OAC had a significant beneficial effect on the 1-year composite outcome (hazard ratio [HR]: 0.37, 95% confidence interval [CI]: 0.23–0.60, P < 0.001) and death (HR: 0.35, [95% CI: 0.19–0.63], P < 0.001). Patients treated with a combination of antiplatelet agents and OAC had an increased risk of major bleeding complications (HR: 5.27, [95% CI: 1.31–21.16], P = 0.019) compared with those treated with antiplatelet agents alone. However, there was no significant difference in the risk of 1-year recurrent stroke among the three groups. Conclusion: This study demonstrated that OAC monotherapy was associated with lower risks of composite outcome and death in patients at 1-year after ischemic stroke due to AF and atherosclerotic stenosis. In addition, the combination of an antiplatelet agent and OAC had a high risk of major bleeding.

Background and purpose The ticlopidine/Ginkgo biloba ext. combination drug (Yuclid) is used as an antiplatelet agent for prevention of vascular events since its approval in 2008. The purpose of this study is to explore the safety of ticlopidine/Ginkgo biloba combination, mainly regarding the incidence of neutropenia, through a post-marketing surveillance study. Methods From March 2009 to October 2015, a total of 4839 subjects had been enrolled in this study. The enrollments were conducted by 152 doctors of 89 hospitals according to the regulations for post-marketing surveillance programs in Korea. If a subject was administered the drug once, he/she was included in the safety analysis set for any adverse events and bleedings, and the primary safety evaluation regarding neutropenia was conducted in subjects who completed 3-month blood test follow-up. We predefined that 1% reduction in neutropenia incidence by ticlopidine/Ginkgo biloba ext. combination from the previously reported incidence of ticlopidine of 2.3% was clinically meaningful. Results Among the safety analysis set of 4831 patients (99.8% of the enrolled subjects), 3150 (65.1%) completed evaluation for neutropenia at 3 months which is the primary safety endpoint. The major causes of dropout were no follow-up visit at 3 months (n = 1016) and violation of the follow-up period (n = 503). Nine patients experienced neutropenia (Absolute neutrophil count [ANC] ≤ 1200mm 3 ) and the estimated cumulative incidence at 3 months is 0.29% (95% confidence interval, 0.13%– 0.54%). Severe neutropenia (ANC ≤ 450mm 3 ) did not occur in any patients. Conclusions The incidence of neutropenia with addition of Ginkgo biloba ext. to ticlopidine may be lower than the previously reported incidence of neutropenia with ticlopidine, which needs to be confirmed in randomized controlled trials.