Biomedical subjects

Kwan Hur

Publications and source records attributed to Kwan Hur.

10 recordsLinked to original sources

PubMed2006

Diabetes risk associated with use of olanzapine, quetiapine, and risperidone in veterans health administration patients with schizophrenia.

To evaluate risk of new-onset type 2 diabetes associated with use of selected antipsychotic agents, the authors conducted a new-user cohort study in a national sample of US Veterans Health Administration patients with schizophrenia (and no preexisting diabetes). The authors studied 15,767 patients who initiated use of olanzapine, risperidone, quetiapine, or haloperidol in 1999-2001 after at least 3 months with no antipsychotic prescriptions. Patients were followed for just over 1 year. New-onset diabetes was identified through diagnostic codes and prescriptions for diabetes medication. In Cox proportional hazards regression adjusting for potential confounders, with patients initiating haloperidol use designated the reference group, diabetes risk was increased equally with new use of olanzapine (hazard ratio (HR) = 1.64, 95% confidence interval (CI): 1.22, 2.19), risperidone (HR = 1.60, 95% CI: 1.19, 2.14), or quetiapine (HR = 1.67, 95% CI: 1.01, 2.76). Diabetes risks were higher in patients under age 50 years. When data were reanalyzed with prevalent-user cohorts and matched case-control designs, results were similar, with slightly less elevated risk estimates. Assuming that the observed associations are causal, approximately one third of new cases of diabetes may be attributed to use of olanzapine, risperidone, and quetiapine in patients taking these medications. Prescribers should be mindful of diabetes risks when treating patients with schizophrenia.

Antipsychotic Agents↗

PubMed2006

The relationship between antidepressant prescription rates and rate of early adolescent suicide.

OBJECTIVE: In 2002, 264 children and adolescents ages 5-14 died by suicide in the United States, the fifth leading cause of death. Of these suicides, 260 were in the 10-14 year age group, making suicide the third largest cause of death behind accidents and malignancy. Although 60% of suicides in the general population occur in the midst of a mood disorder, usually untreated, little is known about the relationship between treatment of mood disorders and youth suicide. The FDA recently linked adverse event reports of suicidal ideation among children and adolescents in randomized controlled trials to selective serotonin reuptake inhibitors (SSRIs) and consequently required a change in labeling that included a black box warning regarding SSRI use for all age groups. Given that the age-adjusted suicide rate is about six times higher in 15-19 year olds compared with 10-14 year olds, the risk-benefit ratio may be different in younger children. Therefore, this study examined the association between antidepressant medication prescription rate and suicide rate in children ages 5-14 prior to the FDA findings by analyzing associations at the county level across the United States. METHOD: National county-level suicide rate data among children ages 5-14 were broken down by sex, income, and race during the period 1996-1998. National county-level antidepressant prescription rate data were expressed as number of pills prescribed per person. The primary outcome measure was the suicide rate in each county expressed as number of suicides for a given population size. RESULTS: After adjustment for sex, race, income, access to mental health care, and county-to-county variability in suicide rates, higher SSRI prescription rates were associated with lower suicide rates in children and adolescents. CONCLUSIONS: The aggregate nature of these observational data precludes a direct causal interpretation of the results. More SSRI prescriptions are associated with lower suicide rates in children and may reflect antidepressant efficacy, treatment compliance, better quality mental health care, and low toxicity in the event of a suicide attempt by overdose.

Adolescent↗

PubMed2005

The relationship between antidepressant medication use and rate of suicide.

BACKGROUND: Approximately 30 000 people die annually by suicide in the United States. Although 60% of suicides occur during a mood disorder, mostly untreated, little is known about the relationship between antidepressant medication use and the rate of suicide in the United States. OBJECTIVE: To examine the association between antidepressant medication prescription and suicide rate by analyzing associations at the county level across the United States. DESIGN: Analysis of National Vital Statistics from the Centers for Disease Control and Prevention. SETTING: All US counties. PARTICIPANTS: All US individuals who committed suicide between 1996 and 1998. MAIN OUTCOME MEASURES: National county-level suicide rate data are broken down by age, sex, income, and race for the period of 1996 to 1998. National county-level antidepressant prescription data are expressed as number of pills prescribed. The primary outcome measure is the suicide rate in each county expressed as the number of suicides for a given population size. RESULTS: The overall relationship between antidepressant medication prescription and suicide rate was not significant. Within individual classes of antidepressants, prescriptions for selective serotonin reuptake inhibitors (SSRIs) and other new-generation non-SSRI antidepressants (eg, nefazodone hydrochloride, mirtazapine, bupropion hydrochloride, and venlafaxine hydrochloride) are associated with lower suicide rates (both within and between counties). A positive association between tricyclic antidepressant (TCA) prescription and suicide rate was observed. Results are adjusted for age, sex, race, income, and county-to-county variability in suicide rates. Higher suicide rates in rural areas are associated with fewer antidepressant prescriptions, lower income, and relatively more prescriptions for TCAs. CONCLUSIONS: The aggregate nature of these observational data preclude a direct causal interpretation of the results. A high number of TCA prescriptions may be a marker for those counties with more limited access to quality mental health care and inadequate treatment and detection of depression, which in turn lead to increased suicide rates. By contrast, increases in prescriptions for SSRIs and other new-generation non-SSRIs are associated with lower suicide rates both between and within counties over time and may reflect antidepressant efficacy, compliance, a better quality of mental health care, and low toxicity in the event of a suicide attempt by overdose.

Adolescent↗

PubMed2005

Surgical morbidity and mortality among American Indian and Alaska Native veterans: a comparative analysis.

BACKGROUND: Few studies have examined surgical risk factors and outcomes in American Indians and Alaska Natives (AI/ANs). My colleagues and I sought to determine if prevalence of preoperative risk factors for morbidity and mortality differed between male AI/AN and Caucasian surgical patients, and to determine if AI/ANs had an increased risk of surgical morbidity or mortality. STUDY DESIGN: We obtained data from the Veterans Affairs National Surgical Quality Improvement Program on major, noncardiac, surgical procedures performed between 1991 and 2002 for all AI/AN men (n = 2,155) and a random sample of Caucasian men (n = 2,264), matched by facility. Chi-square and t-test analyses were used to assess differences in preoperative risk factors between the two groups. Logistic regression was used to determine whether AI/AN race was independently associated with 30-day morbidity (defined as 1 or more of 21 postoperative complications) or 30-day all cause mortality after adjustment for major risk factors. RESULTS: Prevalence of major preoperative risk factors for morbidity and mortality often differed between the groups. Compared with Caucasians, AI/AN race did not predict morbidity (adjusted odds ratio, 0.92; 95% CI, 0.75-1.13), but AI/ANs were at higher risk for 30-day all cause postoperative mortality (adjusted odds ratio, 1.56; 95% CI, 1.04-2.35). CONCLUSIONS: Our results add postoperative mortality to health disparities experienced by AI/ANs. Future research should be conducted to identify other factors that contribute to this disparity.

Aged↗

PubMed2005

Deep brain stimulation in Parkinson disease: a metaanalysis of patient outcomes.

OBJECT: Deep brain stimulation (DBS) to treat advanced Parkinson disease (PD) has been focused on one of two anatomical targets: the subthalamic nucleus (STN) and the globus pallidus internus (GPI). Authors of more than 65 articles have reported on bilateral DBS outcomes. With one exception, these studies involved pre- and postintervention comparisons of a single target. Despite the paucity of data directly comparing STN and GPI DBS, many clinicians already consider the STN to be the preferred target site. In this study the authors conducted a metaanalysis of the existing literature on patient outcomes following DBS of the STN and the GPI. METHODS: This metaanalysis includes 31 STN and 14 GPI studies. Motor function improved significantly following stimulation (54% in patients whose STN was targeted and 40% in those whose GPI was stimulated), with effect sizes (ESs) of 2.59 and 2.04, respectively. After controlling for participant and study characteristics, patients who had undergone either STN or GPI DBS experienced comparable improved motor function following surgery (p = 0.094). The performance of activities of daily living improved significantly in patients with either target (40%). Medication requirements were significantly reduced following stimulation of the STN (ES = 1.51) but did not change when the GPI was stimulated (ES = -0.02). CONCLUSIONS: In this analysis the authors highlight the need for uniform, detailed reporting of comprehensive motor and nonmotor DBS outcomes at multiple time points and for a randomized trial of bilateral STN and GPI DBS.

Activities of Daily Living↗

PubMed2004

Inverse association between prostatic polyunsaturated fatty acid and risk of locally advanced prostate carcinoma.

BACKGROUND: An effect of fatty acids has been implicated in men with advanced-stage prostate carcinoma and in men who have died of the disease. To evaluate the influence of fatty acids in men with prostate carcinoma at earlier stages, the authors examined the relation between prostatic concentrations of fatty acids and locally advanced prostate carcinoma in men with clinically organ-confined disease. METHODS: Fatty acids were measured by capillary gas chromatography in fresh, nonmalignant prostate tissue specimens collected during surgery from 196 men undergoing radical prostatectomy for localized prostate carcinoma. Two-sided, two-sample Student t tests compared mean concentrations in men with extraprostatic disease (pT3-4N0-1M0) with control men with organ-confined disease. Logistic regression accounted for clinical stage, prostate-specific antigen level, Gleason sum, and other factors. RESULTS: Percent total prostatic polyunsaturated fatty acid (PUFA) was found to be inversely associated with risk of locally advanced prostate carcinoma (n=52) (odds ratio [OR]=0.93, 95% confidence interval [95% CI], 0.87-0.99; P=0.035). Risk of seminal vesicle involvement accounted for this association (OR=0.86, 95% CI, 0.78-0.95; P=0.003). Percent omega-3 fatty acid (eicosapentanoic + docosahexanoic acids) and percent arachidonic acid also were found to be inversely related to the risk of seminal vesicle involvement (OR=0.52, 95% CI, 0.30-0.90; P=0.02; and OR=0.84, 95% CI,; 0.75-0.95; P=0.005, respectively). CONCLUSIONS: Prostatic PUFA levels appear to influence the risk of locally advanced prostate carcinoma in men with clinically organ-confined disease. This association may be mediated through the immune system.

Aged↗

PubMed2004

Estimation and classification of fMRI hemodynamic response patterns.

In this paper, we propose an approach to modeling functional magnetic resonance imaging (fMRI) data that combines hierarchical polynomial models, Bayes estimation, and clustering. A cubic polynomial is used to fit the voxel time courses of event-related design experiments. The coefficients of the polynomials are estimated by Bayes estimation, in a two-level hierarchical model, which allows us to borrow strength from all voxels. The voxel-specific Bayes polynomial coefficients are then transformed to the times and magnitudes of the minimum and maximum points on the hemodynamic response curve, which are in turn used to classify the voxels as being activated or not. The procedure is demonstrated on real data from an event-related design experiment of visually guided saccades and shown to be an effective alternative to existing methods.

Bayes Theorem↗

PubMed2002

Identifying patient preoperative risk factors and postoperative adverse events in administrative databases: results from the Department of Veterans Affairs National Surgical Quality Improvement Program.

BACKGROUND: The Department of Veterans Affairs (DVA) National Surgical Quality Improvement Program (NSQIP) employs trained nurse data collectors to prospectively gather preoperative patient characteristics and 30-day postoperative outcomes for most major operations in 123 DVA hospitals to provide risk-adjusted outcomes to centers as quality indicators. It has been suggested that routine hospital discharge abstracts contain the same information and would provide accurate and complete data at much lower cost. STUDY DESIGN: With preoperative risks and 30-day outcomes recorded by trained data collectors as criteria standards, ICD-9-CM hospital discharge diagnosis codes in the Patient Treatment File (PTF) were tested for sensitivity and positive predictive value. ICD-9-CM codes for 61 preoperative patient characteristics and 21 postoperative adverse events were identified. RESULTS: Moderately good ICD-9-CM matches of descriptions were found for 37 NSQIP preoperative patient characteristics (61%); good data were available from other automated sources for another 15 (25%). ICD-9-CM coding was available for only 13 (45%) of the top 29 predictor variables. In only three (23%) was sensitivity and in only four (31%) was positive predictive value greater than 0.500. There were ICD-9-CM matches for all 21 NSQIP postoperative adverse events; multiple matches were appropriate for most. Postoperative occurrence was implied in only 41%; same breadth of clinical description in only 23%. In only four (7%) was sensitivity and only two (4%) was positive predictive value greater than 0.500. CONCLUSION: Sensitivity and positive predictive value of administrative data in comparison to NSQIP data were poor. We cannot recommend substitution of administrative data for NSQIP data methods.

Benchmarking↗

PubMed2002

The National Surgical Quality Improvement Program in non-veterans administration hospitals: initial demonstration of feasibility.

OBJECTIVE: To assess the feasibility of implementing the National Surgical Quality Improvement Program (NSQIP) methodology in non-VA hospitals. SUMMARY BACKGROUND DATA: Using data adjusted for patient preoperative risk, the NSQIP compares the performance of all VA hospitals performing major surgery and anonymously compares these hospitals using the ratio of observed to expected adverse events. These results are provided to each hospital and used to identify areas for improvement. Since the NSQIP's inception in 1994, the VA has reported consistent improvements in all surgery performance measures. Given the success of the NSQIP within the VA, as well as the lack of a comparable system in non-VA hospitals, this pilot study was undertaken to test the applicability of the NSQIP models and methodology in the nonfederal sector. METHODS: Beginning in 1999, three academic medical centers (Emory University, Atlanta, GA; University of Michigan, Ann Arbor, MI; University of Kentucky, Lexington, KY) volunteered the time of a dedicated surgical nurse reviewer who was trained in NSQIP methodology. At each academic center, these nurse reviewers used NSQIP protocols to abstract clinical data from general surgery and vascular surgery patients. Data were manually collected and then transmitted via the Internet to a secure web site developed by the NSQIP. These data were compared to the data for general and vascular surgery patients collected during a concurrent time period (10/99 to 9/00) within the VA by the NSQIP. Logistic regression models were developed for both non-VA and VA hospital data. To assess the models' predictive values, C-indices (0.5 = no prediction; 1.0 = perfect prediction) were calculated after applying the models to the non-VA as well as the VA databases. RESULTS: Data from 2,747 (general surgery 2,251; vascular surgery 496) non-VA hospital cases were compared to data from 41,360 (general surgery 31,393; vascular surgery 9,967) VA cases. The bivariate relationships between individual risk factors and 30-day mortality or morbidity were similar in the non-VA and VA patient populations for over 66% of the risk variables. C-indices of 0.942 (general surgery), 0.915 (vascular surgery), and 0.934 (general plus vascular surgery) were obtained following application of the VA NSQIP mortality model to the non-VA patient data. Lower C-indices (0.778, general surgery; 0.638, vascular surgery; 0.760, general plus vascular surgery) were obtained following application of the VA NSQIP morbidity model to the non-VA patient data. Although the non-VA sample size was smaller than the VA, preliminary analysis suggested no differences in risk-adjusted mortality between the non-VA and VA cohorts. CONCLUSIONS With some adjustments, the NSQIP methodology can be implemented and generates reasonable predictive models within non-VA hospitals.

Feasibility Studies↗

PubMedDate not supplied

Outcome after pancreaticoduodenectomy for periampullary cancer: an analysis from the Veterans Affairs National Surgical Quality Improvement Program.

The aim of this study is to define the risk factors that predict adverse outcomes for patients undergoing pancreaticoduodenectomy for periampullary cancer in the Department of Veterans Affairs Healthcare System (VA). The VA National Surgical Quality Improvement Program prospectively collected data on 462 patients undergoing pancreaticoduodenectomy in 123 VA medical centers from 1990 to 2000. Independent variables included 68 preoperative and 12 intraoperative variables. The main outcome measures were 30-day postoperative mortality and morbidity, as measured by a set of 20 pre-defined complications. Predictive models for 30-day morbidity and mortality were constructed using logistic regression analysis. The 30-day morbidity rate was 45.9% (212/462). The 30-day postoperative mortality rate was 9.3% (43/462). Significant predictors of mortality included: preoperative serum albumin, American Society of Anesthesiologists classification, preoperative bilirubin >20mg/dl, and operative time. The use of preoperative biliary tract instrumentation did not predict postoperative death or septic complications. This study provides a set of preoperative risk factors that are predictive of adverse outcome following pancreaticoduodenectomy. These factors may assist in patient selection for this procedure and are likely to facilitate risk-adjusted comparison of pancreaticoduodenectomy outcomes between different health care systems.

Adult↗