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1.
Cancers (Basel) ; 16(4)2024 Feb 07.
Article in English | MEDLINE | ID: mdl-38398102

ABSTRACT

(1) Background: Accurate statistics on the causes of death in patients with chronic hepatitis B (CHB) are lacking. We investigated mortality rates and causes of death over time. (2) Methods: Data on patients newly diagnosed with CHB from 2007 to 2010 (cohort 1, n = 223,424) and 2012 to 2015 (cohort 2, n = 177,966) were retrieved from the Korean National Health Insurance Service. Mortality data were obtained from Statistics Korea. The causes of death were classified as liver-related (hepatic decompensation or hepatocellular carcinoma [HCC]) or extrahepatic (cardiovascular-related, cerebrovascular-related, or extrahepatic malignancy-related). (3) Results: Over a 10-year follow-up period of 223,424 patients (cohort 1) with CHB, the overall mortality was 1.54 per 100 person-years. The mortality associated with HCC was the highest (0.65 per 100 person-years), followed by mortality related to extrahepatic malignancies (0.26 per 100 person-years), and cardio/cerebrovascular diseases (0.18 per 100 person-years). In the non-cirrhotic CHB (87.4%), 70% (11,198/15,996) of patients died due to non-liver-related causes over ten years. The 10-year overall mortality was 0.86 per 100 person-years. Among these, mortality due to extrahepatic malignancies had the highest rate (0.23 per 100 person-years), followed by mortality related to HCC (0.20 per 100 person-years), and cardio/cerebrovascular diseases (0.16 per 100 person-years). The 5-year mortality associated with extrahepatic malignancies increased from 0.36 per 100 person-years (cohort 1) to 0.40 per 100 person-years (cohort 2). (4) Conclusions: Mortality related to HCC decreased, whereas mortality related to extrahepatic malignancies increased in the antiviral era. Extrahepatic malignancies were the leading cause of death among patients with CHB without cirrhosis.

2.
Stud Health Technol Inform ; 310: 1349-1351, 2024 Jan 25.
Article in English | MEDLINE | ID: mdl-38270038

ABSTRACT

To evaluate the feasibility of applying the Observational Medical Outcome Partnership (OMOP) Common Data Model (CDM) to databases of traditional East Asian medicine (TEAM), we composed a TEAM dataset and transformed it to the OMOP CDM. We found that some important TEAM information entities could not be transformed to the OMOP CDM (version 6.0) data fields. We suggest to develop data fields and guideline for transforming TEAM data to the OMOP CDM.


Subject(s)
Databases, Factual , Feasibility Studies
4.
J Clin Med ; 12(9)2023 May 08.
Article in English | MEDLINE | ID: mdl-37176776

ABSTRACT

The association of smoking with hepatocellular carcinoma (HCC) or cardiovascular disease (CVD) has been reported, but the study of its relationship with metabolic-associated fatty liver disease (MAFLD) is limited. We aimed to investigate the effect of smoking on the incidence of HCC or CVD in MAFLD patients. Using the Korean nationwide health screening database, we analyzed subjects between 2001 and 2015. A total of 283,088 subjects including 110,863 MAFLD patients and 172,225 controls were analyzed. Smoking status was divided by non-smoker, ex-smoker, or current smoker. In the follow-up period, a total of 2903 (1.0%) subjects developed HCC, and the MAFLD group (1723, 1.6%) had a significantly higher incidence than the control group (1180, 0.7%). In the MAFLD group, current smokers showed significantly higher risk of HCC compared to non-smokers (adjusted HR 1.24, 95% CI 1.08-1.41), whereas the control group did not (adjusted HR 1.07, 95% CI 0.89-1.30). A total of 18,984 (6.7%) patients developed CVD, and the incidence was significantly higher in the MAFLD group (8688, 7.8%) than in the control group (10,296, 6.0%), similar to HCC. The risk of CVD in current smokers increased by 22% compared to non-smokers in the MAFLD group (adjusted HR 1.22, 95% CI 1.15-1.30) and by 21% (adjusted HR 1.21, 95% CI 1.13-1.29) in the control group. Based on sex stratification, men showed increased incidence of both HCC and CVD by smoking, whereas women had only increased risk of CVD. Smoking significantly increases the incidence of HCC and CVD in MAFLD patients; thus, it is highly recommended to quit smoking completely in the population with MAFLD.

5.
Endocrine ; 79(1): 190-199, 2023 01.
Article in English | MEDLINE | ID: mdl-36220967

ABSTRACT

PURPOSE: Primary hyperparathyroidism (PHPT) is a common endocrine disorder with increasing incidence, while epidemiologic data in Asian population has been lacking. Therefore, we aimed to identify the incidence, prognosis, and prognostic factors of PHPT patients who underwent parathyroidectomy in Korea. METHODS: In this retrospective nationwide cohort, patients with PHPT were defined as those with diagnostic codes of PHPT and procedural codes for parathyroidectomy, excluding chronic renal failure or secondary hyperparathyroidism based on National Health Insurance Services database in Korea in 2002-2018. Main primary outcomes were all-cause mortality, cardiovascular, and cerebrovascular events. RESULTS: A total of 5561 patients were diagnosed with PHPT and had parathyroidectomy. The mean age was 54.5 years, and 71.8% were women. The age-standardized incidence was 10.1/100,000 person-year in 2018, rising from 1.7/100,000 person-year in 2002. During a mean of 5.9 years, history of cardiovascular disease, mood disorder, and genitourinary stone had increased risks of mortality with hazard ratios (HRs) of 1.59 (95% confidence interval [CI] 1.10-2.29), 1.43 (CI 1.14-1.80), and 1.40 (CI 1.09-1.80), respectively. History of hypertension, cerebrovascular disease, diabetes mellitus, and mood disorder were risk factors for cardiovascular events with HRs of 1.42 (CI 1.22-1.66), 1.29 (CI 1.05-1.58), 1.22 (CI 1.07-1.40), and 1.14 (CI 1.00-1.29), respectively. Mood disorder was a significant risk factor for cerebrovascular events (HR 1.30, CI 1.11-1.52). CONCLUSION: The incidence of PHPT patients who underwent parathyroidectomy has been rising in Korea as reported in other countries. Patients with complications, especially mood disorder, had increased cardiovascular and cerebrovascular events and mortality risks.


Subject(s)
Hyperparathyroidism, Primary , Hyperparathyroidism, Secondary , Humans , Female , Middle Aged , Male , Hyperparathyroidism, Primary/epidemiology , Hyperparathyroidism, Primary/surgery , Hyperparathyroidism, Primary/complications , Parathyroidectomy/adverse effects , Retrospective Studies , Hyperparathyroidism, Secondary/complications , Comorbidity
6.
Article in English | MEDLINE | ID: mdl-36091598

ABSTRACT

Background: Chronic rhinosinusitis (CRS) is a highly prevalent disease associated with poor quality of life. In this paper, we appraised the role of acupuncture in the treatment of CRS. Methods: Electronic databases were searched for randomized controlled clinical trials (RCTs) that examined the role of acupuncture in CRS. The primary outcome measures included posttreatment CRS severity, as measured by the Visual Analogue Scale (VAS) and Total Effective Rate (TER). The risk of bias and quality of evidence were evaluated according to the Cochrane Collaboration's risk-of-bias tool and GRADE tool, respectively. Results: Evidence from the RCTs (n = 10) suggested that acupuncture as a monotherapy or adjunctive therapy to conventional treatment was associated with significant improvements in VAS, TER, and quality of life when compared with conventional treatments for CRS. However, there was a similar incidence of adverse events. The risk of bias was unclear and the quality of evidence for each finding was generally moderate to low. Conclusions: Acupuncture as a stand-alone or adjunctive treatment for CRS was associated with clinical symptom improvement and better quality of life, without any risk for serious adverse events. However, the high clinical heterogeneity of the included RCTs and overall moderate-to-low quality of evidence necessitates rigorous, well-designed trials to confirm these findings. Trial Registrations. This trial is registered with PROSPERO (no. CRD42021292135).

7.
Front Pharmacol ; 13: 908941, 2022.
Article in English | MEDLINE | ID: mdl-35924061

ABSTRACT

Objectives: Chronic rhinosinusitis (CRS) is a disease with a high prevalence and a high socioeconomic burden. This study aimed to conduct a comprehensive systematic review to update the evidence on the use of herbal medicine (HM) for CRS treatment. Methods: A total of 14 electronic databases for randomized controlled trials (RCTs) evaluating the effects of HM on the treatment of CRS were searched for articles published before July 2021. The primary outcome was CRS severity post-treatment, measured with the Visual Analogue Scale (VAS) and Total Effective Rate (TER). The risk of bias of the included studies and the quality of evidence of the main findings were assessed using the Cochrane Collaboration's risk of bias tool and the Grading of Recommendations, Assessment, Development, and Evaluations tool. Results: A total of 80 RCTs were included. Compared to placebo, HM significantly improved CRS severity as measured by TER and VAS. When HM was compared with conventional treatment (CT) as monotherapy or adjuvant therapy, CRS severity measured by TER and VAS, quality of life, Lund-Kennedy endoscopy score, Lund-Mackay computed tomography score, and nasal mucociliary function were significantly improved in the HM group. No serious adverse events associated with HM were reported. The risk of bias was generally unclear, and the quality of evidence ranged from moderate to low. Conclusion: This review found some limited clinical evidence that HM or HM combined with CT may be more effective and safer than CT alone in treating CRS. However, the methodological quality of the included studies was generally low, and the quality of the evidence needs to be improved.

8.
J Cancer Res Clin Oncol ; 147(10): 3091-3097, 2021 Oct.
Article in English | MEDLINE | ID: mdl-33738545

ABSTRACT

PURPOSE: Parathyroid carcinoma (PC) is an exceedingly rare endocrine malignancy with a poor prognosis. Due to the rarity, the natural course and prognostic factors of the disease are yet unclear. Therefore, we aimed to identify the incidence, prognosis, and prognostic factors of PC in the nationwide cohort study. METHODS: The study is a nationwide study using the National Health Insurance Services database in Korea from 2002 to 2017. PC was defined as patients with ICD-10 code of PC and a procedural code for parathyroidectomy. RESULTS: From 2002 to 2017, 255 patients were diagnosed with PC whose mean age was 53.2 years, and 155 (60.2%) were women. The crude and age-standardized incidence were 10.2 and 6.6/10,000,000 person-year in 2016, rising from 4.1 and 3.8/10,000,000 person-year in 2003 (p < 0.001), respectively. The 5- and 10-year survival rates were 86.5 and 72.9%, respectively. In survival analysis, age over 50 years, thyroidectomy at the initial surgery, and reoperation had increased risk of mortality with HRs of 4.83 (95% CI 1.47-15.90), and 4.21 (95% CI 1.60-11.08), and 1.05 (95% CI 1.02-1.08) in multivariate analysis, respectively. CONCLUSION: Incidence of PC has been rising over time, similar to the trends in Western countries. The prognostic factors for mortality were old age, parathyroidectomy alone, and recurrence, emphasizing the importance of preoperative suspicion of the disease. The study is clinically meaningful in the first Asian nationwide study to reveal the natural course of PC.


Subject(s)
Parathyroid Neoplasms/epidemiology , Parathyroidectomy/mortality , Reoperation/mortality , Female , Follow-Up Studies , Humans , Incidence , Male , Middle Aged , Parathyroid Neoplasms/surgery , Prognosis , Republic of Korea/epidemiology , Retrospective Studies , Survival Rate
9.
J Clin Endocrinol Metab ; 106(3): e1362-e1372, 2021 03 08.
Article in English | MEDLINE | ID: mdl-33075802

ABSTRACT

CONTEXT: Adrenal Cushing syndrome (CS) is a major subtype of CS and has a high surgical cure rate. However, only a few studies have investigated the epidemiology and long-term outcomes of adrenal CS. OBJECTIVE: We aimed to investigate the nationwide epidemiology, long-term prognosis, and postoperative glucocorticoid replacement therapies of adrenal CS in Korea. DESIGN: Retrospective cohort study. SETTING: A nationwide claim database. PATIENTS: Adrenal CS patients who were defined as having undergone adrenalectomy, a diagnosis code of CS, and not having pituitary gland surgery. MAIN OUTCOME MEASURES: Crude incidence and age-standardized incidence rates, long-term mortality, comorbidities diagnosed preoperatively or developed postoperatively, and the pattern of postoperative glucocorticoid replacement therapy. RESULTS: From 2002 to 2017, there were a total of 1199 new adrenal CS patients, including 72 patients with adrenocortical carcinoma (malignant adrenal CS), in Korea. The crude and age-standardized incidence rates were 1.51 and 1.27 per million person-years, respectively. The overall standardized mortality ratio was 3.0 (95% confidence interval [CI], 2.4-3.7) for benign adrenal CS and 13.1 (95% CI, 7.6-18.6) for malignant adrenal CS. Adrenal CS patients had a high risk of having coronary artery disease, stroke, metabolic diseases, and depression. A similar proportion of patients were diagnosed with these comorbidities both preoperatively and postoperatively, suggesting a significant residual risk even after adrenalectomy. The median time of postoperative glucocorticoid replacement therapy was 10.1 months, and the major types of glucocorticoids used were prednisolone (66.6%) and hydrocortisone (22.4%). CONCLUSIONS: Adrenal CS is associated with multiple comorbidities even after treatment, which necessitates meticulous postoperative care.


Subject(s)
Adrenal Cortex Neoplasms/epidemiology , Adrenocortical Adenoma/epidemiology , Cushing Syndrome/epidemiology , Adrenal Cortex Neoplasms/complications , Adrenal Cortex Neoplasms/diagnosis , Adrenal Cortex Neoplasms/therapy , Adrenalectomy , Adrenocortical Adenoma/complications , Adrenocortical Adenoma/diagnosis , Adrenocortical Adenoma/therapy , Adult , Case-Control Studies , Cohort Studies , Comorbidity , Cushing Syndrome/diagnosis , Cushing Syndrome/etiology , Cushing Syndrome/therapy , Female , Glucocorticoids/therapeutic use , Hormone Replacement Therapy , Humans , Incidence , Male , Middle Aged , Mortality , Prognosis , Republic of Korea/epidemiology , Retrospective Studies , Young Adult
10.
J Psychosom Res ; 122: 1-5, 2019 07.
Article in English | MEDLINE | ID: mdl-31126405

ABSTRACT

OBJECTIVE: Because benzodiazepines (BZDs) can affect pupillae muscles, their use could be a risk factor for acute angle-closure glaucoma (AACG), which is an ophthalmic emergency. However, there is no research evidence for the association between BZDs and AACG, except two case reports. We aimed to investigate whether BZDs increase the risk of AACG in a geriatric population. METHODS: We performed a case-control study using a geriatric cohort from the National Health Insurance database (2002-2013) in Korea. Case subjects (n = 1117) were patients diagnosed with AACG. Controls, people who have not been diagnosed with AACG, were randomly matched with the case according to age, sex, and index year (n = 4468). To examine the risk of BZD use for AACG, we performed conditional logistic regression analyses with potential confounders including comorbidities and concomitant medication. RESULTS: The use of BZD within 30 days was not significantly associated with AACG risk (adjusted odds ratio [aOR] = 1.14, 95% confidence interval [CI] = 0.94-1.37). Further analyses showed that, compared with non-use of BZD, new BZD use had a significantly increased risk for the development of AACG (aOR = 1.62, 95% CI = 1.09-2.37). The risk was higher in the new BZD users exposed within 7 days (aOR = 3.09, 95% CI = 1.58-5.88). CONCLUSION: We found that BZDs increase the risk of AACG at the beginning of its use among the Korean elderly. Clinicians should monitor visual disturbance in the elderly during the early period after prescription of BZD.


Subject(s)
Benzodiazepines/adverse effects , Glaucoma, Angle-Closure/chemically induced , Acute Disease , Aged , Case-Control Studies , Cohort Studies , Female , Humans , Male , Risk Factors
11.
Environ Health Insights ; 12: 1178630218812817, 2018.
Article in English | MEDLINE | ID: mdl-30546262

ABSTRACT

BACKGROUND AND PURPOSE: While providing medical services, hospitals generate many data about patients. Such medical data could contribute to better treatments once their associations or patterns have been identified. With properly analyzed medical data, traditional knowledge at an individual level could be further extended to broader populations. This comprehensive study was performed to demonstrate the effectiveness of light using medical data accumulated over 15 years. METHODS: Patients who were admitted to the window or door side of a six-bedded room were included. Patients admitted to the emergency room and elderly people aged >80 years were excluded. Patients' length of stay was compared per what bed they were in (excluding middle beds). A multiple regression analysis was performed with patients admitted to the window or door side to determine whether the window affected their hospital stay. In addition, a multiple regression analysis was performed after adjusting for confounders by 1:1 matching between the two groups (ie, age, sex, and admitting department). RESULTS: Participants were 38 788 patients with a bed near the window and 46 233 patients with a bed near the door. Results revealed that patients' length of stay was shorter for those near the window compared with those near the door, which was also true after group matching (33 921 participants in each group). CONCLUSIONS: Clinical trials that test evidence-based designs of physical environments in wards or hospital rooms are usually difficult to perform. As an alternative strategy, using accumulated electronic medical data, we assessed this key element of hospital design.

12.
PLoS One ; 12(4): e0176222, 2017.
Article in English | MEDLINE | ID: mdl-28437484

ABSTRACT

The Electrocardiogram Vigilance with Electronic data Warehouse II (ECG-ViEW II) is a large, single-center database comprising numeric parameter data of the surface electrocardiograms of all patients who underwent testing from 1 June 1994 to 31 July 2013. The electrocardiographic data include the test date, clinical department, RR interval, PR interval, QRS duration, QT interval, QTc interval, P axis, QRS axis, and T axis. These data are connected with patient age, sex, ethnicity, comorbidities, age-adjusted Charlson comorbidity index, prescribed drugs, and electrolyte levels. This longitudinal observational database contains 979,273 electrocardiograms from 461,178 patients over a 19-year study period. This database can provide an opportunity to study electrocardiographic changes caused by medications, disease, or other demographic variables. ECG-ViEW II is freely available at http://www.ecgview.org.


Subject(s)
Databases, Factual , Electrocardiography , Heart Conduction System/physiology , Heart Rate/physiology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Reference Values , Young Adult
13.
J Am Med Inform Assoc ; 24(4): 697-708, 2017 Jul 01.
Article in English | MEDLINE | ID: mdl-28087585

ABSTRACT

OBJECTIVE: We propose 2 Medical Dictionary for Regulatory Activities-enabled pharmacovigilance algorithms, MetaLAB and MetaNurse, powered by a per-year meta-analysis technique and improved subject sampling strategy. MATRIALS AND METHODS: This study developed 2 novel algorithms, MetaLAB for laboratory abnormalities and MetaNurse for standard nursing statements, as significantly improved versions of our previous electronic health record (EHR)-based pharmacovigilance method, called CLEAR. Adverse drug reaction (ADR) signals from 117 laboratory abnormalities and 1357 standard nursing statements for all precautionary drugs ( n = 101) were comprehensively detected and validated against SIDER (Side Effect Resource) by MetaLAB and MetaNurse against 11 817 and 76 457 drug-ADR pairs, respectively. RESULTS: We demonstrate that MetaLAB (area under the curve, AUC = 0.61 ± 0.18) outperformed CLEAR (AUC = 0.55 ± 0.06) when we applied the same 470 drug-event pairs as the gold standard, as in our previous research. Receiver operating characteristic curves for 101 precautionary terms in the Medical Dictionary for Regulatory Activities Preferred Terms were obtained for MetaLAB and MetaNurse (0.69 ± 0.11; 0.62 ± 0.07), which complemented each other in terms of ADR signal coverage. Novel ADR signals discovered by MetaLAB and MetaNurse were successfully validated against spontaneous reports in the US Food and Drug Administration Adverse Event Reporting System database. DISCUSSION: The present study demonstrates the symbiosis of laboratory test results and nursing statements for ADR signal detection in terms of their system organ class coverage and performance profiles. CONCLUSION: Systematic discovery and evaluation of the wide spectrum of ADR signals using standard-based observational electronic health record data across many institutions will affect drug development and use, as well as postmarketing surveillance and regulation.


Subject(s)
Adverse Drug Reaction Reporting Systems , Algorithms , Clinical Laboratory Information Systems , Nursing Records , Pharmacovigilance , Area Under Curve , Electronic Health Records , Humans , ROC Curve
14.
J Nanosci Nanotechnol ; 16(3): 2632-6, 2016 Mar.
Article in English | MEDLINE | ID: mdl-27455680

ABSTRACT

Low temperature, solution-processed metal oxide thin film transistors (MEOTFTs) have been widely investigated for application in low-cost, transparent, and flexible electronics. To enlarge the application area, solution-processed gate insulators (GI) have been investigated in recent years. We investigated the effects of the organic/inorganic bi-layer GI to ZnO thin film transistors (TFTs). PVP, YO(x) nanoparticle composite, and polysilazane bi-layer showed low leakage current (-10(-8) A/cm2 in 2 MV), which are applicable in low temperature processed MEOTFTs. Polysilazane was used as an interlayer between ZnO and PVP, YO(x) nanoparticle composite as a good charge transport interface with ZnO. By applying the PVP, YO(x), nanoparticle composite/polysilazane bi-layer structure to ZnO TFTs, we successfully suppressed the off current (I(off)) to -10(-11) and fabricated good MEOTFTs in 180 degrees C.


Subject(s)
Bismuth/chemistry , Nanoparticles , Silanes/chemistry , Yttrium/chemistry , Zinc Oxide/chemistry , Microscopy, Atomic Force , Microscopy, Electron, Transmission , Spectroscopy, Fourier Transform Infrared , Temperature , Thermogravimetry
15.
Healthc Inform Res ; 22(1): 39-45, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26893949

ABSTRACT

OBJECTIVES: This paper proposes new alert override reason codes that are improvements on existing Drug Utilization Review (DUR) codes based on an analysis of DUR alert override cases in a tertiary medical institution. METHODS: Data were obtained from a tertiary teaching hospital covering the period from April 1, 2012 to January 15, 2013. We analyzed cases in which doctors had used the 11 overlapping prescription codes provided by the Health Insurance Review and Assessment Service (HIRA) or had provided free-text reasons. RESULTS: We identified 27,955 alert override cases. Among these, 7,772 (27.8%) utilized the HIRA codes, and 20,183 (72.2%) utilized free-text reasons. According to the free-text content analysis, 8,646 cases (42.8%) could be classified using the 11 HIRA codes, and 11,537 (57.2%) could not. In the unclassifiable cases, we identified the need for codes for "prescription relating to operation" and "emergency situations." Two overlapping prescription codes required removal because they were not used. Codes A, C, F, H, I, and J (for drug non-administration cases) explained surrounding situations in too much detail, making differentiation between them difficult. These 6 codes were merged into code J4: "patient was not taking/will not take the medications involved in the DDI." Of the 11 HIRA codes, 6 were merged into a single code, 2 were removed, and 2 were added, yielding 6 alert override codes. We could codify 23,550 (84.2%) alert override cases using these codes. CONCLUSIONS: These new codes will facilitate the use of the drug-drug interactions alert override in the current DUR system. For further study, an appropriate evaluation should be conducted with prescribing clinicians.

16.
Healthc Inform Res ; 22(1): 54-8, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26893951

ABSTRACT

OBJECTIVES: A distributed research network (DRN) has the advantages of improved statistical power, and it can reveal more significant relationships by increasing sample size. However, differences in data structure constitute a major barrier to integrating data among DRN partners. We describe our experience converting Electronic Health Records (EHR) to the Observational Health Data Sciences and Informatics (OHDSI) Common Data Model (CDM). METHODS: We transformed the EHR of a hospital into Observational Medical Outcomes Partnership (OMOP) CDM ver. 4.0 used in OHDSI. All EHR codes were mapped and converted into the standard vocabulary of the CDM. All data required by the CDM were extracted, transformed, and loaded (ETL) into the CDM structure. To validate and improve the quality of the transformed dataset, the open-source data characterization program ACHILLES was run on the converted data. RESULTS: Patient, drug, condition, procedure, and visit data from 2.07 million patients who visited the subject hospital from July 1994 to November 2014 were transformed into the CDM. The transformed dataset was named the AUSOM. ACHILLES revealed 36 errors and 13 warnings in the AUSOM. We reviewed and corrected 28 errors. The summarized results of the AUSOM processed with ACHILLES are available at http://ami.ajou.ac.kr:8080/. CONCLUSIONS: We successfully converted our EHRs to a CDM and were able to participate as a data partner in an international DRN. Converting local records in this manner will provide various opportunities for researchers and data holders.

17.
ACS Appl Mater Interfaces ; 8(3): 2061-70, 2016 Jan 27.
Article in English | MEDLINE | ID: mdl-26704352

ABSTRACT

We report on the optimization of the plasma treatment conditions for a solution-processed silicon dioxide gate insulator for application in zinc oxide thin film transistors (TFTs). The SiO2 layer was formed by spin coating a perhydropolysilazane (PHPS) precursor. This thin film was subsequently thermally annealed, followed by exposure to an oxygen plasma, to form an insulating (leakage current density of ∼10(-7) A/cm(2)) SiO2 layer. Optimized ZnO TFTs (40 W plasma treatment of the gate insulator for 10 s) possessed a carrier mobility of 3.2 cm(2)/(V s), an on/off ratio of ∼10(7), a threshold voltage of -1.3 V, and a subthreshold swing of 0.2 V/decade. In addition, long-term exposure (150 min) of the pre-annealed PHPS to the oxygen plasma enabled the maximum processing temperature to be reduced from 180 to 150 °C. The resulting ZnO TFT exhibited a carrier mobility of 1.3 cm(2)/(V s) and on/off ratio of ∼10(7).

18.
Pharmacoepidemiol Drug Saf ; 25(3): 307-16, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26527579

ABSTRACT

PURPOSE: Distributed research networks (DRNs) afford statistical power by integrating observational data from multiple partners for retrospective studies. However, laboratory test results across care sites are derived using different assays from varying patient populations, making it difficult to simply combine data for analysis. Additionally, existing normalization methods are not suitable for retrospective studies. We normalized laboratory results from different data sources by adjusting for heterogeneous clinico-epidemiologic characteristics of the data and called this the subgroup-adjusted normalization (SAN) method. METHODS: Subgroup-adjusted normalization renders the means and standard deviations of distributions identical under population structure-adjusted conditions. To evaluate its performance, we compared SAN with existing methods for simulated and real datasets consisting of blood urea nitrogen, serum creatinine, hematocrit, hemoglobin, serum potassium, and total bilirubin. Various clinico-epidemiologic characteristics can be applied together in SAN. For simplicity of comparison, age and gender were used to adjust population heterogeneity in this study. RESULTS: In simulations, SAN had the lowest standardized difference in means (SDM) and Kolmogorov-Smirnov values for all tests (p < 0.05). In a real dataset, SAN had the lowest SDM and Kolmogorov-Smirnov values for blood urea nitrogen, hematocrit, hemoglobin, and serum potassium, and the lowest SDM for serum creatinine (p < 0.05). CONCLUSION: Subgroup-adjusted normalization performed better than normalization using other methods. The SAN method is applicable in a DRN environment and should facilitate analysis of data integrated across DRN partners for retrospective observational studies.


Subject(s)
Clinical Laboratory Information Systems/standards , Comparative Effectiveness Research/methods , Computer Simulation , Databases, Factual/standards , Electronic Health Records/standards , Pharmacoepidemiology/methods , Clinical Laboratory Information Systems/trends , Databases, Factual/trends , Electronic Health Records/trends , Laboratories, Hospital/standards , Republic of Korea , Retrospective Studies , Software
19.
ACS Appl Mater Interfaces ; 6(21): 18693-703, 2014 Nov 12.
Article in English | MEDLINE | ID: mdl-25285585

ABSTRACT

Although solution-processable high-k inorganic dielectrics have been implemented as a gate insulator for high-performance, low-cost transition metal oxide field-effect transistors (FETs), the high-temperature annealing (>300 °C) required to achieve acceptable insulating properties still limits the facile realization of flexible electronics. This study reports that the addition of a 2-dimetylamino-1-propanol (DMAPO) catalyst to a perhydropolysilazane (PHPS) solution enables a significant reduction of the curing temperature for the resulting SiO2 dielectrics to as low as 180 °C. The hydrolysis and condensation of the as-spun PHPS film under humidity conditions were enhanced greatly by the presence of DMAPO, even at extremely low curing temperatures, which allowed a smooth surface (roughness of 0.31 nm) and acceptable leakage characteristics (1.8 × 10(-6) A/cm(2) at an electric field of 1MV/cm) of the resulting SiO2 dielectric films. Although the resulting indium zinc oxide (IZO) FETs exhibited an apparent high mobility of 261.6 cm(2)/(V s), they suffered from a low on/off current (ION/OFF) ratio and large hysteresis due to the hygroscopic property of silazane-derived SiO2 film. The ION/OFF value and hysteresis instability of IZO FETs was improved by capping the high-k LaZrOx dielectric on a solution-processed SiO2 film via sol-gel processing at a low temperature of 180 °C while maintaining a high mobility of 24.8 cm(2)/(V s). This superior performance of the IZO FETs with a spin-coated LaZrOx/SiO2 bilayer gate insulator can be attributed to the efficient intercalation of the 5s orbital of In(3+) ion in the IZO channel, the good interface matching of IZO/LaZrOx and the carrier blocking ability of PHPS-derived SiO2 dielectric film. Therefore, the solution-processable LaZrOx/SiO2 stack can be a promising candidate as a gate dielectric for low-temperature, high-performance, and low-cost flexible metal oxide FETs.

20.
PLoS One ; 8(10): e75214, 2013.
Article in English | MEDLINE | ID: mdl-24130689

ABSTRACT

BACKGROUND: Most available quality indicators for hospitals are represented by simple ratios or proportions, and are limited to specific events. A generalized method that can be applied to diverse clinical events has not been developed. The aim of this study was to develop a simple method of evaluating physicians' prescription patterns for diverse events and their level of awareness of clinical practice guidelines. METHODS AND FINDINGS: We developed a quantitative method called Prescription pattern Around Clinical Event (PACE), which is applicable to electronic health records (EHRs). Three discrete prescription patterns (intervention, maintenance, and discontinuation) were determined based on the prescription change index (PCI), which was calculated by means of the increase or decrease in the prescription rate after a clinical event. Hyperkalemia and Clostridium difficile-associated diarrhea (CDAD) were used as example cases. We calculated the PCIs of 10 drugs related to hyperkalemia, categorized them into prescription patterns, and then compared the resulting prescription patterns with the known standards for hyperkalemia treatment. The hyperkalemia knowledge of physicians was estimated using a questionnaire and compared to the prescription pattern. Prescriptions for CDAD were also determined and compared to clinical knowledge. Clinical data of 1698, 348, and 1288 patients were collected from EHR data. The physicians prescribing behaviors for hyperkalemia and CDAD were concordant with the standard knowledge. Prescription patterns were well correlated with individual physicians' knowledge of hyperkalemia (κ = 0.714). Prescribing behaviors according to event severity or clinical condition were plotted as a simple summary graph. CONCLUSION: The algorithm successfully assessed the prescribing patterns from the EHR data. The prescription patterns were well correlated with physicians' knowledge. We expect that this algorithm will enable quantification of prescribers' adherence to clinical guidelines and be used to facilitate improved prescribing practices.


Subject(s)
Electronic Health Records , Practice Patterns, Physicians' , Adult , Aged , Algorithms , Female , Humans , Male , Middle Aged , Young Adult
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