Assessment of thirty-day readmission rate, timing, causes and predictors after hospitalization with COVID-19

BACKGROUND

There are limited data on the characteristics of 30-day readmission after hospitalization with coronavirus disease 2019 (COVID-19).

OBJECTIVES

To examine the rate, timing, causes, predictors and outcomes of 30-day readmission after COVID-19 hospitalization.

METHODS

From 13 March to 9 April 2020, all patients hospitalized with COVID-19 and discharged alive were included in this retrospective observational study. Multivariable logistic regression was used to identify the predictors of 30-day readmission, and a restricted cubic spline function was utilized to assess the linearity of the association between continuous predictors and 30-day readmission.

RESULTS

A total of 1062 patients were included in the analysis, with a median follow-up time of 62 days. The mean age of patients was 56.5 years, and 40.5% were women. At the end of the study, a total of 48 (4.5%) patients were readmitted within 30 days of discharge, and a median time to readmission was 5 days. The most common primary diagnosis of 30-day readmission was a hypoxic respiratory failure (68.8%) followed by thromboembolism (12.5%) and sepsis (6.3%). The patients with a peak serum creatinine level of ≥1.29 mg/dL during the index hospitalization, compared to those with a creatinine of <1.29 mg/dL, had 2.4 times increased risk of 30-day readmission (adjusted odds ratio: 2.41; 95% CI: 1.23-4.74). The mortality rate during the readmission was 22.9%.

CONCLUSION

With 4.5% of the thirty-day readmission rate, COVID-19 survivors were readmitted early after hospital discharge, mainly due to morbidities of COVID-19. One in five readmitted COVID-19 survivors died during their readmission.

Expedited Safety Reporting to Sponsors Through the Implementation of an Alert System for Clinical Trial Management at an Academic Medical Center: Retrospective Design Study

Background

Early detection or notification of adverse event (AE) occurrences during clinical trials is essential to ensure patient safety. Clinical trials take advantage of innovative strategies, clinical designs, and state-of-the-art technologies to evaluate efficacy and safety, however, early awareness of AE occurrences by investigators still needs to be systematically improved.

Objective

This study aimed to build a system to promptly inform investigators when clinical trial participants make unscheduled visits to the emergency room or other departments within the hospital.

Methods

We developed the Adverse Event Awareness System (AEAS), which promptly informs investigators and study coordinators of AE occurrences by automatically sending text messages when study participants make unscheduled visits to the emergency department or other clinics at our center. We established the AEAS in July 2015 in the clinical trial management system. We compared the AE reporting timeline data of 305 AE occurrences from 74 clinical trials between the preinitiative period (December 2014-June 2015) and the postinitiative period (July 2015-June 2016) in terms of three AE awareness performance indicators: onset to awareness, awareness to reporting, and onset to reporting.

Results

A total of 305 initial AE reports from 74 clinical trials were included. All three AE awareness performance indicators were significantly lower in the postinitiative period. Specifically, the onset-to-reporting times were significantly shorter in the postinitiative period (median 1 day [IQR 0-1], mean rank 140.04 [SD 75.35]) than in the preinitiative period (median 1 day [IQR 0-4], mean rank 173.82 [SD 91.07], P≤.001). In the phase subgroup analysis, the awareness-to-reporting and onset-to-reporting indicators of phase 1 studies were significantly lower in the postinitiative than in the preinitiative period (preinitiative: median 1 day, mean rank of awareness to reporting 47.94, vs postinitiative: median 0 days, mean rank of awareness to reporting 35.75, P=.01; and preinitiative: median 1 day, mean rank of onset to reporting 47.4, vs postinitiative: median 1 day, mean rank of onset to reporting 35.99, P=.03). The risk-level subgroup analysis found that the onset-to-reporting time for low- and high-risk studies significantly decreased postinitiative (preinitiative: median 4 days, mean rank of low-risk studies 18.73, vs postinitiative: median 1 day, mean rank of low-risk studies 11.76, P=.02; and preinitiative: median 1 day, mean rank of high-risk studies 117.36, vs postinitiative: median 1 day, mean rank of high-risk studies 97.27, P=.01). In particular, onset to reporting was reduced more in the low-risk trial than in the high-risk trial (low-risk: median 4-0 days, vs high-risk: median 1-1 day).

Conclusions

We demonstrated that a real-time automatic alert system can effectively improve safety reporting timelines. The improvements were prominent in phase 1 and in low- and high-risk clinical trials. These findings suggest that an information technology-driven automatic alert system effectively improves safety reporting timelines, which may enhance patient safety.

Cigarette Smoking Preferentially Affects Intracranial Vessels in Young Males: A Propensity-Score Matching Analysis

Purpose

Cigarette smoking (CS) is one of the major risk factors of cerebral atherosclerotic disease, however, its level of contribution to extracranial and intracranial atherosclerotic stenosis (ECAS and ICAS) was not fully revealed yet. The purpose of our study was to assess the association of CS to cerebral atherosclerosis along with other risk factors.

Materials and Methods

All consecutive patients who were angiographically confirmed with severe symptomatic cerebral atherosclerotic disease between January 2002 and December 2012 were included in this study. Multivariate logistic regression analyses were performed to identify risk factors for ECAS and ICAS. Thereafter, CS group were compared to non-CS group in the entire study population and in a propensity-score matched population with two different age-subgroups.

Results

Of 1709 enrolled patients, 794 (46.5%) had extracranial (EC) lesions and the other 915 (53.5%) had intracranial (IC) lesions. CS group had more EC lesions (55.8% vs. 35.3%, P<0.001) whereas young age group (<50 years) had more IC lesion (84.5% vs. 47.6%, P<0.001). In multivariate analysis, seven variables including CS, male, old age, coronary heart disease, higher erythrocyte sedimentation rate, multiple lesions, and anterior lesion were independently associated with ECAS. In the propensity-score matched CS group had significant more EC lesion compared to non-CS group (65.7% vs. 47.9%) only in the old age subgroup.

Conclusion

In contrast to a significant association between CS and severe symptomatic ECAS shown in old population, young patients did not show this association and showed relatively higher preference of ICAS.

Risk factors for developing Mycobacterium kansasii lung disease: A case-control study in Korea

Previous studies have suggested that development of Mycobacterium kansasii lung disease (MKLD) was associated with COPD, pneumoconiosis, aging, male, immunosuppression, alcohol, malignancy, and certain occupations such as mining and sandblasting. However, previous studies were outdated and used non-comparative statistical methods. We aimed to determine the current risk factors for developing MKLD in Korea by using appropriate statistical techniques.Eighty-six MKLD patients were identified through a search of the Ulsan University Hospital database between January 2010 and December 2014. These cases were matched with 172 controls who had normal respiratory systems in a health examination during the same period (matching variables, age and sex; case: control ratio of 1:2). Clinical and demographic characteristics were gathered by reviewing the medical record and telephone survey. Multivariate logistic regression analyses were performed to evaluate risk factors for developing MKLD.Multivariate analysis showed that occupation in heavy industries (adjusted odds ratio (aOR) 6.41, 95% confidence interval (CI) 2.19-18.74, P = .001) and low body mass index (BMI) (aOR [per kg/m] 0.73, 95% CI 0.63-0.85, P < .001) were independent risk factors for development of MKLD. Educational attainment more than high school was associated with a lower risk of MKLD development (aOR 0.22, 95% CI 0.08-0.63, P = .005).Employees in heavy industry and low BMI are independent risk factors for development of MKLD in Korea.

Reliability of fast magnetic resonance imaging for acute ischemic stroke patients using a 1.5-T scanner

OBJECTIVES

To determine whether fast scanned MRI using a 1.5-T scanner is a reliable method for the detection and characterization of acute ischemic stroke in comparison with conventional MRI.

METHODS

From May 2015 to June 2016, 862 patients (FLAIR, n = 482; GRE, n = 380; MRA, n = 190) were prospectively enrolled in the study, with informed consent and under institutional review board approval. The patients underwent both fast (EPI-FLAIR, ETL-FLAIR, TR-FLAIR, EPI-GRE, parallel-GRE, fast CE-MRA) and conventional MRI (FLAIR, GRE, time-of-flight MRA, fast CE-MRA). Two neuroradiologists independently assessed agreements in acute and chronic ischemic hyperintensity, hyperintense vessels (FLAIR), microbleeds, susceptibility vessel signs, hemorrhagic transformation (GRE), stenosis (MRA), and image quality (all MRI), between fast and conventional MRI. Agreements between fast and conventional MRI were evaluated by generalized estimating equations. Z-scores were used for comparisons of the percentage agreement among fast FLAIR sequences and fast GRE sequences and between conventional and fast MRA.

RESULTS

Agreements of more than 80% were achieved between fast and conventional MRI (ETL-FLAIR, 96%; TR-FLAIR, 97%; EPI-GRE, 96%; parallel-GRE, 98%; fast CE-MRA, 86%). ETL- and TR-FLAIR were significantly superior to EPI-FLAIR in the detection of acute ischemic hyperintensity and hyperintense vessels, while parallel-GRE was significantly superior to EPI-GRE in the detection of susceptibility vessel sign (p value < 0.05 for all). There were no significant differences in the other scores and image qualities (p value > 0.05).

CONCLUSIONS

Fast MRI at 1.5 T is a reliable method for the detection and characterization of acute ischemic stroke in comparison with conventional MRI.

KEY POINTS

• Fast MRI at 1.5 T may achieve a high intermethod reliability in the detection and characterization of acute ischemic stroke with a reduction in scan time in comparison with conventional MRI.

Clinical course and treatment outcomes of toxocariasis-related eosinophilic disorder

Blood eosinophilia is a common clinical finding. Helminthic infections, including toxocariasis, are a common cause of eosinophilia; however, the clinical course of toxocariasis associated with eosinophilia is not fully understood. Thus, controversies exist regarding treatment indications.To evaluate the clinical features and natural course of various types of eosinophilia, with a particular focus on toxocariasis, we retrospectively reviewed the medical records of 1000 patients with peripheral blood eosinophilia who were referred to the allergy clinic at Asan Medical Center between 2007 and 2012. Clinical parameters and imaging study findings were evaluated. The treatment response to albendazole and resulting changes in eosinophilia and imaging studies were analyzed in patients diagnosed with toxocariasis.Among the 1000 subjects, toxocariasis was the most common cause of eosinophilia (n = 534; 53.4%), followed by allergic disease and adverse drug reactions. The majority of patients with toxocariasis were men, and they were mostly asymptomatic. More than one-third of patients (n = 215; 40.3%) with toxocariasis exhibited organ involvement, particularly hepatic involvement. In most cases of eosinophilia and organ involvement due to toxocariasis, the symptoms normalized regardless of treatment.Most cases of eosinophilia related to toxocariasis displayed a self-remitting course regardless of treatment. With the exception of several clinical situations, including ocular involvement, the clinical need for anti-helminthic therapy in toxocariasis is not that significant.

Neuronal Population Responses in the Human Ventral Temporal and Lateral Parietal Cortex during Arithmetic Processing with Digits and Number Words

Past research has identified anatomically specific sites within the posterior inferior temporal gyrus (PITG) and the intraparietal sulcus (IPS) areas that are engaged during arithmetic processing. Although a small region of the PITG (known as the number form area) is selectively engaged in the processing of numerals, its surrounding area is activated during both digit and number word processing. In eight participants with intracranial electrodes, we compared the timing and selectivity of electrophysiological responses in the number form area-surround and IPS regions during arithmetic processing with digits and number words. Our recordings revealed stronger electrophysiological responses in the high-frequency broadband range in both regions to digits than number words, with the difference that number words elicited delayed activity in the IPS but not PITG. Our findings of distinct profiles of responses in the PITG and the IPS to digits compared with number words provide novel information that is relevant to existing theoretical models of mathematical cognition.

Usefulness of argon plasma coagulation ablation subsequent to endoscopic snare papillectomy for ampullary adenoma

BACKGROUND AND AIM

Endoscopic snare papillectomy (ESP) is an effective treatment for ampullary adenoma. Argon plasma coagulation (APC) is widely used as an additional method to control bleeding or ablate the residual tumor. However, the efficacy of this procedure has not yet been fully evaluated. This study aimed to evaluate the usefulness of APC as an additional method to ESP.

METHODS

Patients who underwent ESP for ampullary adenoma between September 2005 and September 2015 were retrospectively reviewed. Using propensity score matching, we compared short- and long-term outcomes between the ESP-with-additional-APC group (ESP + APC group) and the ESP-only group. Primary outcome was early post-ESP adverse events (AE), and secondary outcomes were late AE and recurrence.

RESULTS

Among 109 patients, additional APC was carried out in 59 (54.1%) patients. After matching, 41 patients were included in both groups, respectively. Bleeding rate was significantly lower in the ESP + APC group than in the ESP-only group (7.3% vs 31.7%, odds ratio = 0.180, P < 0.01). However, there were no significant differences in other procedure-related early AE such as pancreatitis (12.2% vs 19.5%, P = 0.365), cholangitis (2.4% vs 9.8%, P = 0.198), and perforation (2.4% vs 2.4%, P = 1.000) between the ESP + APC group and the ESP-only group. During the follow-up period (mean 904 ± 868 days), papillary stricture (9.8% vs 4.9%, P = 0.405) and recurrence rates (24.4% vs 24.4%, P = 0.797) were not significantly different between the ESP + APC group and the ESP-only group.

CONCLUSION

Additional APC during ESP may have a beneficial effect by decreasing bleeding rate without harmful effects.

In vivo assessment of aortic root geometry in normal controls using 3D analysis of computed tomography

Aims

Understanding normal asymmetry in the aortic root could aid in the development of new surgical repair techniques or devices with improved haemodynamic performance. The purpose of this study was to assess geometric asymmetry and age-related changes in the normal aortic root using 3D computed tomography.

Methods and Results

The institutional review board approved this retrospective study of 130 normal subjects (mean age, 51.4 years; 58 men). Specialized 3D software measured individual cusp sinus volumes (CSVs), cusp surface areas (CSAs), and intercommissural distances (ICDs). Age-related aortic root changes were evaluated with simple correlation, ANOVA test among age groups, and multivariable linear regression analyses. The CSV and CSA of left coronary cusp (LCC) were significantly smaller than those of right coronary cusp (RCC) and non-coronary cusp (NCC) (both, P < 0.001) in all age groups. The mean ratios of RCC or NCC-to-LCC were 1.38 and 1.36 for CSV, 1.19 and 1.20 for CSA, and 1.21 and 1.06 for ICD, respectively. The CSV and ICD increased in older age with weak-to-moderate correlation coefficients in both men and women. By multivariable linear regression, CSVs and ICDs of all cusps showed a positive correlation with age (P < 0.05), and the female gender was associated with a smaller size of the CSV and CSA.

Conclusions

The LCC was significantly smaller than the other two cusps, and the aortic root size increased with age.

Comparison of the fixed ratio and the Z-score of FEV1/FVC in the elderly population: a long-term mortality analysis from the Third National Health and Nutritional Examination Survey

Background and objective

Despite the ongoing intense debate on the definition of airflow limitation by spirometry in the elderly population, there have only been few studies comparing the fixed ratio and the Z-score of forced expiratory volume in 1 second (FEV₁)/forced vital capacity (FVC) in terms of long-term mortalities. In this study, we aimed to identify the proper method for accurately defining the airflow limitation in terms of long-term mortality prediction in the elderly population.

Methods

Data were collected from the Third National Health and Nutrition Examination Survey in the US. Non-Hispanic Caucasians aged 65–80 years were included. The receiver operating characteristic (ROC) curves of both methods were plotted and compared for 10-year all-cause, respiratory, and COPD mortalities.

Results

Of 1,331 subjects, the mean age was 71.7 years and 805 (60.5%) were males. For the 10-year all-cause mortality, the area under the curve (AUC) of the fixed ratio was significantly greater than that of the Z-score of FEV₁/FVC, but both showed poor prediction performance (0.633 vs 0.616, p<0.001). For the 10-year respiratory and COPD mortalities, both the fixed ratio and the Z-score of FEV₁/FVC showed comparable prediction performance with greater AUCs (0.784 vs 0.778, p=0.160, and 0.896 vs 0.896, p=0.971, respectively). Interestingly, the conventional cutoff of 0.7 in the fixed ratio was consistently higher than the optimal for the 10-year all-cause, respiratory, and COPD mortalities (0.70 vs 0.69, 0.62, and 0.61, respectively), whereas that of −1.64 in the Z-score of FEV₁/FVC was consistently lower than the optimal cutoff (−1.64 vs −1.31, −1.47, and −1.41, respectively).

Conclusion

In the elderly population, both the fixed ratio and the Z-score of FEV₁/FVC showed comparable prediction performance for the 10-year respiratory and COPD mortalities. However, the conventional cutoff of neither 0.70 in the fixed ratio nor −1.64 in the Z-score of FEV₁/FVC was optimal for predicting the long-term mortalities.

A Dual Phosphodiesterase Inhibitor, Zardaverine (Type 3/4), Enhances Motility of Frozen-thawed Boar Sperm

BACKGROUND

Cryopreserved semen is useful for animal breeding via artificial insemination (AI); however, the use of frozen-thawed boar sperm is limited due to cryodamage.

OBJECTIVE

The goal of this study was to improve post-thaw motility of boar semen by supplementing the thawing medium with a phosphodiesterase inhibitor, Zardaverine.

MATERIALS AND METHODS

Thawed boar semen samples were treated with different concentrations of Zardaverine (0, 20, 50, 75, 100 µM) and the motility was evaluated using a computer-assisted sperm analyser. Toxic effects (sperm viability, DNA integrity, mitochondrial activity) were examined by eosin-nigrosin staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and MitoTracker.

RESULTS

Sperm motility values included curvilinear velocity, rectilinear speed, average value, linearity index, straightness index, and progressive motility. The kinetic values were significantly higher with the 50 uM Zardaverine supplementation compared to non-treated control. Furthermore, there were no toxic effects of the Zardaverine treatment.

CONCLUSION

The dual phosphodiesterase inhibitor (type 3/4) Zardaverine significantly enhanced the motility of thawed spermatozoa without adverse effects.

Generation of embryonic stem-like cells from in vivo-derived porcine blastocysts at a low concentration of basic fibroblast growth factor

Although basic fibroblast growth factor (bFGF) is an essential factor supporting the maintenance of porcine embryonic stem (ES) cell self-renewal and pluripotency, its high cost has limited previous studies, and the development of a low-cost culture system is required. For these systems, in vivo blastocysts were progressively cultured under various conditions consisting of different culture mediums and/or different feeder cell numbers at a low concentration of bFGF. As the results, the sequential culture of in vivo-derived porcine blastocysts on 5.0 × 10⁵ mouse embryonic fibroblast (MEF) feeder cells in alpha minimum essential medium-based medium for primary culture, on 2.5 × 10⁵ MEF feeder cells in Mixture medium for the 1st subpassage, and on 2.5 × 10⁵ MEF feeder cells in DMEM/Ham's F10-based medium for the post-2nd subpassage could support the establishment and maintenance of porcine ES-like cells at the low concentration of bFGF. The established porcine ES-like cells showed ES cell-specific characteristics such as self-renewal and pluripotency. We confirmed that porcine ES-like cells could be generated from in vivo-derived porcine blastocysts at a low concentration of bFGF.

Initial surgery versus conservative management of symptomatic severe mitral regurgitation in the elderly

OBJECTIVE

In elderly patients, the benefit of surgical correction of severe mitral regurgitation (MR) may not be greater than the operative risk. This study sought to compare the long-term clinical outcomes between initial surgery and conservative management in elderly patients (≥70 years of age) with severe MR.

METHODS

We prospectively evaluated 157 consecutive patients (75 men, 74±4 years of age) with severe degenerative MR and mild symptoms. Mitral valve surgery was performed on 79 (initial surgery group), whereas the conservative strategy was chosen for 78 patients (conservative management group). We compared the overall and cardiac mortality and cardiac event between strategies in the overall and propensity-matched cohort (46 pairs).

RESULTS

During the median follow-up of 5.4 years, overall death occurred less in the initial surgery group (16 vs 37 patients). This group showed reduced cardiac mortality (HR 0.31; 95% CI 0.13 to 0.73; p=0.007), overall mortality (HR 0.39; 95% CI 0.21 to 0.74; p=0.004) and cardiac event (HR 0.26; 95% CI 0.13 to 0.53; p<0.001). A significant reduction in cardiac mortality (HR 0.18; 95% CI 0.05 to 0.63; p=0.007), overall mortality (HR 0.36; 95% CI 0.15 to 0.86; p=0.022) and cardiac event (HR 0.20; 95% CI 0.07 to 0.52; p=0.001) in the initial surgery group was also observed in the propensity-matched cohort.

CONCLUSIONS

In elderly patients with severe degenerative MR and mild symptoms, initial surgical strategy was associated with significant long-term reductions in cardiac and overall mortality compared with conservative management.

Impact of left main coronary artery disease on long-term mortality in patients undergoing drug-eluting stent implantation

BACKGROUND

Limited data are available on long-term mortality according to the extent of coronary artery disease (CAD) in patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stent (DES). We assessed long-term mortality DES implantation according to the extent of CAD and the impact of left main CAD alone on mortality among patients undergoing PCI with DES.

METHODS AND RESULTS

A total of 18,716 patients were pooled from real-world PCI registries. The primary outcome was death from any cause. The median follow-up duration was 47.1 (interquartile range 32.8-57.9) months. The presence of left main CAD [adjusted hazard ratio (HR) 1.24, 95% confidence interval (CI) 1.05-1.46, p = 0.012] and the extent of diseased vessels (adjusted HR 1.17, 95% CI 1.08-1.27, p < 0.001) significantly increased the risk of all-cause mortality. Left main CAD alone was associated with a risk of all-cause mortality similar to one- and two-vessel CAD, whereas it was associated with a significantly lower risk of mortality compared with three-vessel CAD (adjusted HR 0.42, 95% CI 0.18-0.98, p = 0.044). Among patients with left main CAD, the risk of mortality tended to increase in proportion with the number of concomitant vessel CAD, but it did not achieve statistical significance.

CONCLUSIONS

Among patients undergoing DES implantation, the risk of mortality increased in a stepwise manner according to the extent of coronary CAD. Left main CAD alone was associated with a risk of long-term mortality similar to one- and two-vessel CAD.

Effect of a 4-Week Treatment with Cilostazol in Patients with Chronic Tinnitus: A Randomized, Prospective, Placebo-controlled, Double-blind, Pilot Study

OBJECTIVE

The aim of this prospective, double-blind, randomized, placebo-controlled study was to evaluate the efficacy of cilostazol, a selective phosphodiesterase 3 inhibitor, in patients with chronic tinnitus.

MATERIALS AND METHODS

Adult patients of chronic tinnitus lasting more than 3 months were included. Fifty eligible patients were randomly assigned to either cilostazol or control (placebo) group. The study medication of oral 100-mg cilostazol and a matching placebo were used twice a day for 4 weeks. Subjective tinnitus severity was evaluated using the visual analog scale (VAS), tinnitus handicap inventory (THI), and Short-Form 36 health survey (SF-36) at baseline and at 2 and 4 weeks after study initiation. Changes in tinnitus pitch and loudness matching values were also analyzed.

RESULTS

The improvement range in the VAS score was significantly greater in the cilostazol group than in the placebo group after 4 weeks' administration of cilostazol. The SF-36 subscales also showed improvement in quality of life in the physical component summary subscale, the aggregate subscale of the physical category. There were no significant improvements in the cilostazol group compared to the placebo group in the THI subscales and tinnitus characteristics of pitch and loudness matching values. Various degrees of headaches were experienced by 68% of patients in the cilostazol group.

CONCLUSION

A 4-week administration of oral cilostazol in patients with chronic tinnitus may mitigate the severity of subjective tinnitus.

The 100 Most-Cited Articles Focused on Ultrasound Imaging: A Bibliometric Analysis

Purpose The number of citations that an article has received reflects its impact on a particular research area. The aim of this study was to identify the 100 most-cited articles focused on ultrasound (US) imaging and to analyze the characteristics of these articles. Methods We determined the 100 most-cited articles on US imaging via the Web of Science database, using the search term. The following parameters were used to analyze the characteristics of the 100 most-cited articles: publication year, journal, journal impact factor, number of citations and annual citations, authors, department, institution, country, type of article, and topic. Results The number of citations for the 100 most-cited articles ranged from 1849 to 341 (median: 442.0) and the number of annual citations ranged from 108.0 to 8.1 (median: 22.1). The majority of articles were published in 1990 - 1999 (39 %), published in radiology journals (20 %), originated in the United States (45 %), were clinical observation studies (67 %), and dealt with the vessels (35 %). The Department of Internal Medicine at the University of California and the Research Institute of Public Health at the University of Kuopio (n = 4 each) were the leading institutions and Salonen JT and Salonen R (n = 4 each) were the most prolific authors. Conclusion Our study presents a detailed list and analysis of the 100 most-cited US articles, which provides a unique insight into the historical development in this field.

Lymph node standardized uptake values at pre-treatment 18F-fluorodeoxyglucose positron emission tomography as a valuable prognostic factor for distant metastasis in nasopharyngeal carcinoma

Objective:

The aim of the present study was to evaluate prognostic values of pre-treatment fluorine-18 fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) parameters for predicting the distant metastasis (DM) of nasopharyngeal cancer.

Methods:

73 patients diagnosed with nasopharyngeal cancer with regional lymph node (LN) involvement, who underwent pre-treatment ¹⁸F-FDG PET evaluation between January 2005 and December 2012, were retrospectively reviewed. We assessed the ¹⁸F-FDG PET parameters of the primary tumours (T–) and regional LNs (N–). For patients with bilateral retropharyngeal, bilateral neck and/or supraclavicular LN involvement, we also assessed the ¹⁸F-FDG PET parameters of the farthest LN station [N(f)–]. The following ¹⁸F-FDG PET parameters were evaluated: maximum standardized uptake value (SUV_max), mean standardized uptake value (SUV_mean), peak standardized uptake value (SUV_peak), metabolic tumour volumes (MTVs) (MTV₃₀–MTV₇₀, which were calculated as the tumour volume with 30%, 40%, 50%, 60% and 70% of the SUV_max as the threshold, respectively) and total lesion glycolysis (TLG) (TLG₃₀–TLG₇₀, which were determined by the product of each MTV and the corresponding SUV_mean within that MTV). Distant metastasis-free survival (DMFS) rates were estimated from the date of the start of radiotherapy to the date of DM or last follow-up by the Kaplan–Meier method. Univariate and multivariate analyses were performed to identify prognostic factors for DMFS. The median follow-up period was 53 months (range 12–110 months).

Results:

Most patients (95%) received concurrent chemoradiotherapy. The major failure pattern was DM (15 of all patients, 21%) and the 5-year DMFS was 79%. In univariate analysis, the T–SUV_max, T–SUV_mean, T–SUV_peak, N–SUV_max, N–SUV_peak, N(f)–SUV_max and N(f)–SUV_peak were significant prognostic factors for DMFS. In multivariate analysis, the T–SUV_max, T–SUV_peak, N(f)–SUV_max and N(f)–SUV_peak were significant prognostic factors for DMFS. Of these parameters, the N(f)–SUV_max (hazard ratio = 6.524; p = 0.001) and N(f)–SUV_peak (hazard ratio = 5.399; p = 0.001) were the strongest prognostic factors for DMFS.

Conclusion:

In patients with nasopharyngeal cancer with LN involvement, the standardized uptake value parameter of the farthest LN station seems to be an important ¹⁸F-FDG PET parameter for predicting DM. Further studies are needed to validate its clinical significance.

Advances in knowledge:

We found that pre-treatment ¹⁸F-FDG PET parameters of primary tumours and regional LNs (the SUV_max and SUV_peak of the primary tumour and the farthest LN station) were significant prognostic factors for DMFS in patients with nasopharyngeal carcinoma with LN involvement.

Tumor apparent diffusion coefficient as an imaging biomarker to predict tumor aggressiveness in patients with estrogen-receptor-positive breast cancer

The purpose of this retrospective study was to evaluate whether tumor apparent diffusion coefficient (ADC) was correlated with pathologic biomarkers such as tumor cellularity, Ki67, tumor-infiltrating lymphocytes (TILs), and peritumoral lymphocytic infiltrate (PLI) in patients with estrogen receptor (ER)-positive breast cancer. The study was approved by the institutional review board and informed consent was waived. From July 2014 to December 2014, we reviewed 140 ER-positive tumors in 138 consecutive patients (range, 28-77 years; mean, 52 years) who underwent preoperative breast MRI and definitive surgery. All patients underwent diffusion-weighted imaging with a 3T scanner. Two radiologists drew the region of interest of the entire tumor and obtained the mean and pixel-based histogram of ADC. On pathology, two pathologists reviewed tumor cellularity, Ki67, TILs, and PLI. Multiple linear regression analysis was used to determine pathologic variables independently associated with ADC. Tumors with high tumor cellularity and high Ki67 had significantly lower ADCs than those with low tumor cellularity and low Ki67 (P < 0.05 for all). Tumors without PLI had significantly higher standard deviation than those with PLI (0.23 ± 0.08 versus 0.18 ± 0.05; P < 0.001). Median ADC was negatively correlated with tumor cellularity (r = -0.441), and Ki67 (r = -0.382). The standard deviation of ADC was also negatively correlated with the degree of PLI (r = -0.319). On multivariate linear regression analysis, tumor cellularity and Ki67 were independently associated with tumor ADC. Tumor ADC would be an MRI biomarker for the prediction of tumor aggressiveness indicators such as Ki67, tumor cellularity, and PLI in ER-positive breast cancer. Copyright © 2016 John Wiley & Sons, Ltd.

Survival Outcome of Combined GnRH Agonist and Tamoxifen Is Comparable to That of Sequential Adriamycin and Cyclophosphamide Chemotherapy Plus Tamoxifen in Premenopausal Patients with Lymph-Node-Negative, Hormone-Responsive, HER2-Negative, T1-T2 Breast Cancer

Purpose

The purpose of this study was to compare treatment outcomes between combined gonadotropin-releasing hormone agonist and tamoxifen (GnRHa+T) and sequential adriamycin and cyclophosphamide chemotherapy and tamoxifen (AC->T) in premenopausal patients with hormone-responsive, lymph-node–negative breast cancer.

Materials and Methods

In total, 994 premenopausal women with T1-T2, lymph-node–negative, hormone-receptor-positive, HER2-negative breast cancer between January 2003 and December 2008 were included in this retrospective cohort study. GnRHa+T and AC->T were administered to 608 patients (61.2%) and 386 patients (38.8%), respectively. Propensity score matching and inverse probability weighting were applied to the original cohort, and 260 patients for each treatment arm were included in the final analysis. Recurrence-free, cancer-specific, and overall survival was compared between the two treatment groups.

Results

A total of 994 patients were followed up for a median of 7.4 years (range, 0.5 to 11.4 years). The 5-year follow-up rate was 98.7%, and 13 patients were lost to follow-up. In propensity-matched cohorts (n=520), there was no difference in recurrence-free, cancer-specific, and overall survival rates between the two treatment groups (p=0.306, p=0.212, and p=0.102, respectively), and this was maintained after applying inverse probability weighting.

Conclusion

GnRHa+T is a reasonable alternative to AC->T in patients with premenopausal, hormone-responsive, HER2-negative, lymph-node–negative, T1-T2 breast cancer.

Development of a spirometry T-score in the general population

BACKGROUND AND OBJECTIVE

Spirometry values may be expressed as T-scores in standard deviation units relative to a reference in a young, normal population as an analogy to the T-score for bone mineral density. This study was performed to develop the spirometry T-score.

METHODS

T-scores were calculated from lambda-mu-sigma-derived Z-scores using a young, normal age reference. Three outcomes of all-cause death, respiratory death, and COPD death were evaluated in 9,101 US subjects followed for 10 years; an outcome of COPD-related health care utilization (COPD utilization) was evaluated in 1,894 Korean subjects followed for 4 years.

RESULTS

The probability of all-cause death appeared to remain nearly zero until -1 of forced expiratory volume in 1 second (FEV1) T-score but increased steeply where FEV1 T-score reached below -2.5. Survival curves for all-cause death, respiratory death, COPD death, and COPD utilization differed significantly among the groups when stratified by FEV1 T-score (P<0.001). The adjusted hazard ratios of the FEV1 T-score for the four outcomes were 0.54 (95% confidence interval, 0.48-0.60), 0.43 (95% CI: 0.37-0.50), 0.30 (95% CI: 0.24-0.37), and 0.69 (95% CI: 0.59-0.81), respectively, adjusting for covariates (P<0.001).

CONCLUSION

The spirometry T-score could predict all-cause death, respiratory death, COPD death, and COPD utilization.

Young women with breast cancer in the United States and South Korea: comparison of demographics, pathology and management

BACKGROUND

Breast cancer diagnosed in young women may be more aggressive, with higher rates of local and distant recurrence compared to the disease in older women. Epidemiologic evidence suggests that Korean women have a lower incidence of breast cancer than women in the United States, but that they present at a younger age than their American counterparts. We sought to compare risk factors and management of young women with breast cancer in Boston, Massachusetts (US) with those in Seoul, South Korea (KR).

MATERIALS AND METHODS

A retrospective review was performed of consecutive patients less than 35 years old with a diagnosis of breast cancer at academic cancer centers in the US and KR from 2000-2005. Patient data were obtained by chart review. Demographic, tumor and treatment characteristics were compared utilizing Pearson's chi- square or Wilcoxon rank-sum tests where appropriate. All differences were assessed as significant at the 0.05 level.

RESULTS

205 patients from the US and 309 from KR were analyzed. Patients in US were more likely to have hormone receptor positive breast cancer, while patients in KR had a higher rate of triple negative lesions. Patients in US had a higher mean body mass index and more often reported use of birth control pills, while those in the KR were less likely to have a sentinel node procedure performed or to receive post mastectomy radiation.

CONCLUSIONS

Patients under 35 diagnosed with breast cancer in the US and KR differ with respect to demographics, tumor characteristics and management. Although rates of breast conservation and mastectomy were similar, US patients were more likely to receive post mastectomy radiation. The lower use of sentinel node biopsy is explained by the later adoption of the technique in KR. Further evaluation is necessary to evaluate recurrence rates and survival in the setting of differing disease subtypes in these patients.

Data-driven Analysis of TRP Channels in Cancer: Linking Variation in Gene Expression to Clinical Significance

BACKGROUND

Experimental evidence has suggested that transient receptor potential (TRP) channels play a crucial role in tumor biology. However, clinical relevance and significance of TRP channels in cancer remain largely unknown.

MATERIALS AND METHODS

We applied a data-driven approach to dissect the expression landscape of 27 TRP channel genes in 14 types of human cancer using International Cancer Genome Consortium data.

RESULTS

TRPM2 was found overexpressed in most tumors, whereas TRPM3 was broadly down-regulated. TRPV4 and TRPA1 were found up- and down-regulated respectively in a cancer type-specific manner. TRPC4 was found to be closely associated with incidence of head and neck cancer and poor survival of patients with kidney cancer. TRPM8 was identified as a new molecular marker for lung cancer diagnosis and TRPP1 for kidney cancer prognosis.

CONCLUSION

Our data-driven approach demonstrates that the variation in the expression of TRP channel genes is manifested across various human cancer types and genes, for certain TRP channels have strong predictive diagnostic and prognostic potential.

Outcome of Inhaler Withdrawal in Patients Receiving Triple Therapy for COPD

Background

The purpose of this study was to document outcomes following withdrawal of a single inhaler (step-down) in chronic obstructive pulmonary disease (COPD) patients on triple therapy (long-acting muscarinic antagonist and a combination of long-acting β2-agonists and inhaled corticosteroid), which a common treatment strategy in clinical practice.

Methods

Through a retrospective observational study, COPD patients receiving triple therapy over 2 years (triple group; n=109) were compared with those who had undergone triple therapy for at least 1 year and subsequently, over 9 months, initiated inhaler withdrawal (step-down group, n=39). The index time was defined as the time of withdrawal in the stepdown group and as 1 year after the start of triple therapy in the triple group.

Results

Lung function at the index time was superior and the previous exacerbation frequency was lower in the stepdown group than in the triple group. Step-down resulted in aggravating disease symptoms, a reduced overall quality of life, decreasing exercise performance, and accelerated forced expiratory volume in 1 second (FEV₁) decline (54.7±15.7 mL/yr vs. 10.7±7.1 mL/yr, p=0.007), but there was no observed increase in the frequency of exacerbations.

Conclusion

Withdrawal of a single inhaler during triple therapy in COPD patients should be conducted with caution as it may impair the exercise capacity and quality of life while accelerating FEV₁ decline.

Comparison of survival outcome of concurrent GnRH agonist plus tamoxifen to that of sequential adriamycin and cyclophosphamide chemotherapy plus tamoxifen in premenopausal, lymph node-negative, hormone-responsive, HER2-negative, T1-2 breast cancer patients

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Background: The purpose of this study was to compare treatment outcomes between gonadotropin-releasing hormone (GnRH) agonist plus tamoxifen and adriamycin and cyclophosphamide (AC)-containing chemotherapy plus tamoxifen in hormone-responsive, premenopausal, node-negative, breast cancer patients. Methods: Among 7278 breast cancer patients who were diagnosed as breast cancer at Asan medical center, Seoul, Korea, 994 premenopausal women with node-negative, hormone receptor-positive, HER2-negative, T1-2 breast cancers were included in this retrospective cohort study: A median follow-up was 7.4 years (range, 0.5-11.4 years). 608 patients (61.2%) were treated with GnRH agonist together with tamoxifen, and 386 patients (38.8%) were treated with AC-containing chemotherapy with tamoxifen. The propensity score matching and inverse probability weighting was applied to original cohort based on patients’ age, operation method, nuclear and histologic grade, estrogen receptor and progesterone receptor positivity, T stage, Her2 positivity, and p53 positivity. In final analysis, 260 patients for each treatment arm were included. Results: In propensity matched cohorts (n = 520), a total of 34 patients had recurrence. There were 5 cancer-specific deaths and 12 overall deaths among total 520 patients. There were no survival differences for recurrence-free survival (p= 0.306), cancer-specific survival (p= 0.212), and overall survival (p= 0.102) between the two treatment groups. After applying inverse probability weighting, there were no survival differences for recurrence-free survival (p = 0.522), cancer-specific survival (p= 0.154). However, GnRH agonist with tamoxifen arm showed better overall survival than AC chemotherapy with tamoxifen arm (p= 0.021). Conclusions: Adding GnRH agonist to tamoxifen is a reasonable alternative to adding AC chemotherapy to tamoxifen in premenopausal, hormone-responsive, HER2-negative, lymph node-negative, T1-2, breast cancer patients.

MR Enterography for the Evaluation of Small-Bowel Inflammation in Crohn Disease by Using Diffusion-weighted Imaging without Intravenous Contrast Material: A Prospective Noninferiority Study

PURPOSE

To determine whether magnetic resonance (MR) enterography performed with diffusion-weighted imaging (DWI) without intravenous contrast material is noninferior to contrast material-enhanced (CE) MR enterography for the evaluation of small-bowel inflammation in Crohn disease.

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained for this prospective noninferiority study. Fifty consecutive adults suspected of having Crohn disease underwent clinical assessment, MR enterography, and ileocolonoscopy within 1 week. MR enterography included conventional imaging and DWI (b = 900 sec/mm(2)). In 44 patients with Crohn disease, 171 small-bowel segments that were generally well distended and showed a wide range of findings, from normalcy to severe inflammation (34 men, 10 women; mean age ± standard deviation, 26.9 years ± 6.1), were selected for analysis. Image sets consisting of (a) T2-weighted sequences with DWI and (b) T2-weighted sequences with CE T1-weighted sequences were reviewed by using a crossover design with blinding and randomization. Statistical analyses included noninferiority testing regarding proportional agreement between DWI and CE MR enterography for the identification of bowel inflammation with a noninferiority margin of 80%, correlation between DWI and CE MR enterography scores of bowel inflammation severity, and comparison of accuracy between DWI and CE MR enterography for the diagnosis of terminal ileal inflammation by using endoscopic findings as the reference standard.

RESULTS

The agreement between DWI and CE MR enterography for the identification of bowel inflammation was 91.8% (157 of 171 segments; one-sided 95% confidence interval: ≥88.4%). The correlation coefficient between DWI and CE MR enterography scores was 0.937 (P < .001). DWI and CE MR enterography did not differ significantly regarding the sensitivity and specificity for the diagnosis of terminal ileal inflammation (P > .999). DWI and CE MR enterography concurred in the diagnosis of penetrating complications in five of eight segments.

CONCLUSION

DWI MR enterography was noninferior to CE MR enterography for the evaluation of inflammation in Crohn disease in generally well-distended small bowel, except for the diagnosis of penetration.

Endoscopic and Oncologic Outcomes of Endoscopic Resection for Superficial Esophageal Neoplasm

BACKGROUND/AIMS

Endoscopic resection (ER) of superficial esophageal neoplasm (SEN) is a technically difficult procedure. We investigated the clinical outcomes of ER for SEN to determine its feasibility and effectiveness.

METHODS

Subjects who underwent ER for SEN at Asan Medical Center between December 1996 and December 2010 were eligible. The clinical features of patients and tumors, histopathological characteristics, adverse events, ER results and survival were investigated.

RESULTS

A total of 129 patients underwent ER for 147 SENs. En bloc resection (EnR) was performed in 118 lesions (80.3%). Complete resection (CR) was accomplished in 128 lesions (86.5%), and curative resection (CuR) was performed in 118 lesions (79.7%). The EnR, CR, and CuR rates were significantly greater in the endoscopic submucosal dissection group when compared to those in the endoscopic resection group. Adverse events occurred in 22 patients (17.1%), including bleeding (n=2, 1.6%), perforation (n=12, 9.3%), and stricture (n=8, 6.2%). Local tumor recurrence occurred in 2.0% of patients during a median follow-up of 34.8 months. The 5-year overall and disease-specific survival rates were 94.0% and 97.5%, respectively.

CONCLUSIONS

ER is a feasible and effective method for the treatment of SEN as indicated by favorable clinical outcomes.

Effect of pregnancy in asthma on health care use and perinatal outcomes

BACKGROUND

It is generally known that pregnancy in asthmatic patients increases the risk of asthma exacerbations and poor perinatal outcomes. However, the effect of pregnancy in asthmatic patients on health care use is not known well. In addition, its effect on perinatal outcomes is still controversial because of study limitations caused by ethical issues. National Health Insurance claim data are an ideal resource for studying real-world health care use patterns of asthma.

OBJECTIVE

We sought to evaluate the effect of pregnancy on asthma in terms of asthma-related health care use and prescription patterns in concert with the effect of asthma exacerbations on adverse pregnancy outcomes.

METHODS

Among all asthmatic patients in the Korean National Health Insurance claim database from January 2009 to December 2013, pregnant women who delivered in 2011 with pre-existing asthma were enrolled. Analyses included asthma-related health care use and prescription patterns compared between pregnant asthmatic women and nonpregnant female asthmatic control subjects, as well as within the pregnant subjects from before pregnancy throughout postpartum periods. In addition, the association between asthma exacerbation during pregnancy and adverse pregnancy outcomes was assessed.

RESULTS

A total of 3,357 pregnant asthmatic patients were compared with 50,355 nonpregnant asthmatic patients, and 10,311 pregnant patients were included to determine the effect of asthma exacerbations on adverse pregnancy outcome in the study. Pregnant asthmatic patients underwent more asthma-related hospitalizations (1.3% vs 0.8%, P = .005) but had significantly fewer outpatient visits and prescriptions for most asthma medications than nonpregnant asthmatic patients. The proportion of patients ever hospitalized gradually increased throughout pregnancy (first trimester, 0.2%; second trimester, 0.5%; and third trimester, 0.7%; P = .018). The prevalence of asthma exacerbation during pregnancy was 5.3%, and the patients who had acute exacerbation during pregnancy had significantly higher asthma-related health care use in terms of hospitalization, intensive care unit admission, and emergency department and outpatient visits within 1 year before delivery than those who had not. However, asthma exacerbation during pregnancy was not significantly related to adverse perinatal outcomes, except for cesarean section (27.1% vs 18.9%, P < .001). All exacerbations were managed with systemic corticosteroids, and the patients who ever experienced acute exacerbations maintained asthma medications, including inhaled corticosteroid-based inhalers, throughout the pregnancy period.

CONCLUSION

Pregnancy profoundly affects asthma-related health care use but to a different degree depending on whether the patient experienced an exacerbation. Asthma exacerbation during pregnancy is not associated with adverse pregnancy outcomes while managed appropriately with systemic corticosteroids. However, further studies are needed to clarify the effect of asthma control on perinatal outcome and delivery method.

On growth measurements of abdominal aortic aneurysms using maximally inscribed spheres

The maximum diameter, total volume of the abdominal aorta, and its growth rate are usually regarded as key factors for making a decision on the therapeutic operation time for an abdominal aortic aneurysm (AAA) patient. There is, however, a debate on what is the best standard method to measure the diameter. Currently, two dominant methods for measuring the maximum diameter are used. One is measured on the planes perpendicular to the aneurism's central line (orthogonal diameter) and the other one is measured on the axial planes (axial diameter). In this paper, another method called 'inscribed-spherical diameter' is proposed to measure the diameter. The main idea is to find the diameter of the largest sphere that fits within the aorta. An algorithm is employed to establish a centerline for the AAA geometries obtained from a set of longitudinal scans obtained from South Korea. This centerline, besides being the base of the inscribed spherical method, is used for the determination of orthogonal and axial diameter. The growth rate parameters are calculated in different diameters and the total volume and the correlations between them are studied. Furthermore, an exponential growth pattern is sought for the maximum diameters over time to examine a nonlinear growth pattern of AAA expansion both globally and locally. The results present the similarities and discrepancies of these three methods. We report the shortcomings and the advantages of each method and its performance in the quantification of expansion rates. While the orthogonal diameter measurement has an ability of capturing a realistic diameter, it fluctuated. On the other hand, the inscribed sphere diameter method tends to underestimate the diameter measurement but the growth rate can be bounded in a narrow region for aiding prediction capability. Moreover, expansion rate parameters derived from this measurement exhibit good correlation with each other and with growth rate of volume. In conclusion, although the orthogonal method remains the main method of measuring the diameter of an abdominal aorta, employing the idea of maximally inscribed spheres provides both a tool for generation of the centerline, and an additional parameter for quantification of aneurysmal growth rates.

The impact of smoking on airflow limitation in subjects with history of asthma and inactive tuberculosis

BACKGROUND

Although smoking is the most important and modifiable cause of chronic obstructive pulmonary disease (COPD), other risk factors including asthma and tuberculosis (TB) are also associated. It is common for COPD patients to have more than one of these risk factors. The aims of this study were to determine the prevalence of airflow limitation (FEV1/FVC<0.7) according to the risk factors and to investigate their impact and interaction in airflow limitation.

METHODS

From the Korean National Health and Nutrition Examination Survey between 2008 and 2012, we analyzed participants over 40 years of age by spirometry, chest radiograph and questionnaire about asthma and smoking history.

RESULTS

Of 12,631 participants, 1,548 (12.3%) had airflow limitation. The prevalence of airflow limitation in smokers (≥10 pack-year), asthmatics, and those with inactive TB was 23.9%, 32.1%, and 33.6%. The prevalence increased with the number of risk factors: 86.1% had airflow limitation if they had all three risk factors. Impacts of inactive TB and asthma on airflow limitation were equivalent to 47 and 69 pack-years of smoking, respectively. Airflow limitation resulted from lower levels of smoking in those with inactive TB and asthma. A potential interaction between smoking and inactive tuberculosis in the development of airflow limitation was identified (p = 0.054).

CONCLUSIONS

Asthma and inactive TB lesions increase susceptibility to smoking in the development of airflow limitation. People with these risk factors should be seen as a major target population for anti-smoking campaigns to prevent COPD.

Higher serum carcinoembryonic antigen levels associate with more frequent development of incident fractures in Korean women: a longitudinal study using the national health insurance claim data

BACKGROUND

Pro-inflammatory cytokines play important roles in bone metabolism and several studies have shown that carcinoembryonic antigen (CEA) may promote inflammation. We investigated the association of serum CEA levels with the risk of osteoporosis and incident fracture.

METHODS

We performed a small cross-sectional study with 302 Korean women and a large, longitudinal study with 7192 Korean women in an average 3-year follow-up period. For the cross-sectional study, bone mineral density (BMD) and bone turnover markers (BTMs) were measured. For the longitudinal study, incident fractures in the follow-up period were identified by using the selected International Classification of Diseases, 10th revision (ICD-10) codes and the nationwide claims database of the Health Insurance Review and Assessment Service of Korea.

RESULTS

In the cross-sectional study, serum CEA levels correlated negatively with BMD at the lumbar spine (γ=-0.023; P=0.029) and positively with BTMs (γ=0.122 to 0.138, P=0.002 to P<0.001) after adjustment for confounding variables. In the longitudinal study, 254 (3.5%) women developed incident fractures in the follow-up period (2.8±1.3 years). After adjustment for potential confounders, the hazard ratio (HR) per 1 ng/mL increment of the baseline CEA level for the development of incident fracture was 1.22 [95% confidence interval (CI): 1.05-1.42]. The HR was markedly higher in subjects in the highest CEA quartile category compared with those in the lowest CEA quartile category (HR=1.54, 95% CI: 1.04-2.28).

CONCLUSION

Therefore, serum CEA may be a biomarker of the risk of incident fracture in postmenopausal Korean women.

New scoring system for the differentiation of chronic obstructive pulmonary disease and asthma

BACKGROUND AND OBJECTIVE

It remains difficult to differentiate between chronic obstructive pulmonary disease (COPD) and asthma in clinical practice, especially in a primary care setting. The purpose of this study was to develop a new scoring system for differentiating between COPD and asthma, and to evaluate its effectiveness.

METHODS

First, to identify important variables differentiating COPD from asthma, the data of 197 patients with COPD and 138 patients with asthma were assessed retrospectively. Secondly, a scoring system that was based on these variables was then developed, and its performance was internally validated using a bootstrapping-based method. Thirdly, the scoring system was externally validated using prospectively collected data from patients with COPD (n = 104) or asthma (n = 96).

RESULTS

The final scoring system was composed of the four variables: age of onset of breathlessness (<40 years, 0 points; 40-60 years, 2 points; >60 years, 4 points), continuous breathlessness (no, 0 points; yes, 1 point), diurnal variation of breathlessness (yes, 0 points; no, 1 point) and emphysematous change in chest X-ray (no, 0 points; yes, 1 point). The patients were classified by their total score into three categories: 0-2 points, probable asthma; 3-4 points, difficult-to-differentiate; 5-7 points, probable COPD. The new scoring system performed well in the external validation dataset (area under the curve, 0.86; 95% confidence interval: 0.813-0.911; P < 0.001).

CONCLUSIONS

The new scoring system that was developed in this study may be a useful tool for differentiating between COPD and asthma in primary care.

Propensity score matching: a conceptual review for radiology researchers

The propensity score is defined as the probability of each individual study subject being assigned to a group of interest for comparison purposes. Propensity score adjustment is a method of ensuring an even distribution of confounders between groups, thereby increasing between group comparability. Propensity score analysis is therefore an increasingly applied statistical method in observational studies. The purpose of this article was to provide a step-by-step nonmathematical conceptual guide to propensity score analysis with particular emphasis on propensity score matching. A software program code used for propensity score matching was also presented.