Biomedical subjects

W Hwang

Publications and source records attributed to W Hwang.

25 records · Page 2Linked to original sources

PubMed1999

For-profit versus not-for-profit dialysis care for children with end stage renal disease.

OBJECTIVE: Over the last 2 decades, for-profit dialysis units have become the most common providers of renal replacement therapy for adults with end stage renal disease (ESRD) and have had an increasing role in the dialysis of children. We undertook a study to determine whether dialysis facility profit status influences the choice of dialysis therapy in the pediatric population. DESIGN: Cross-sectional study of national data from the Health Care Financing Administration. SETTING: Free-standing and hospital-based outpatient dialysis facilities in the United States. PATIENTS: A total of 1568 children and adolescents (</=19 years of age) eligible for US Medicare ESRD benefits in 1994. OUTCOME MEASURES: The association between dialysis modality choice and the profit status of the facility. Crude associations were estimated by the OR of a patient being treated with peritoneal dialysis (PD) versus hemodialysis at nonprofit versus for-profit facilities. Adjusted associations were estimated using logistic regression analysis. RESULTS: In bivariate analysis, children with ESRD dialyzed at nonprofit facilities were nearly three times as likely as those at for-profit facilities to be on PD (OR: 2.9; 95% CI: 2.3,3.6). In multivariate analysis, after controlling for patient age, sex, race, cause and duration of ESRD, free-standing versus hospital-based facility, and the pediatric expertise of the facility, patients at nonprofit facilities were more than twice as likely as those dialyzed at for-profit facilities to be on PD (OR: 2.3; 95% CI: 1.6, 3.4). After taking into account the clustering of patients within facilities, the association between nonprofit status and the use of PD persisted (OR: 2.2; 95% CI: 1.5,3.2). CONCLUSIONS: Children with ESRD treated at nonprofit facilities are more likely to receive PD than are those treated at for-profit facilities even after controlling for other patient and facility characteristics. This finding suggests that clinical decision making for pediatrics may be influenced by the ownership of the health care facility in which the patient is treated.

Adolescent↗

PubMed1997

Does greater pediatric experience influence treatment choices in chronic disease management? Dialysis modality choice for children with end-stage renal disease.

OBJECTIVE: To determine whether treatment choice for children with end-stage renal disease varies with greater pediatric experience at the dialysis facility. DESIGN: National cross-sectional study. SETTING: Outpatient dialysis facilities throughout the United States. PATIENTS: All children (age, < or = 19 years) undergoing dialysis in 1990, identified using the Medicare End-stage Renal Disease registry (1990 facility survey and quarterly dialysis records). OUTCOME MEASURES: The odds of receiving peritoneal dialysis vs hemodialysis according to the pediatric experience of the facility. "Pediatric experience" for dialysis facilities was defined as the number of patients 19 years old or younger divided by the total number of patients treated at that facility. Adjustment, using multiple logistic regression, was made for differences in age, sex, cause and duration of end-stage renal disease, income, education, and facility characteristics. RESULTS: In 1990, there were 1256 patients 19 years old or younger who underwent a single-treatment modality at a single facility for most of the year. Sixty-three percent (790/ 1256) were treated at facilities with fewer than 5% of patients younger than 19 years. Thirty-six percent were treated at centers with less than 1% of pediatric patients. In a multivariate analysis, pediatric experience in a facility was independently associated with the use of peritoneal dialysis in children. Children treated at facilities with more than 10% pediatric patients were 60% more likely to be treated with peritoneal dialysis rather than hemodialysis compared with children treated at facilities with fewer than 1% of pediatric patients, even after controlling for patient age, race, income, education, cause and duration of end-stage renal disease, and facility characteristics such as hospital-based vs independent unit and for-profit vs not-for-profit status (odds ratio, 1.6; 95% confidence interval, 1.1-2.3). CONCLUSIONS: Children receiving care at dialysis facilities that have greater experience with pediatric patients are more likely to receive peritoneal dialysis than hemodialysis, a therapy with recognized clinical benefits for children that is inherently less resource intensive than is hemodialysis.

Adolescent↗

PubMed1997

Racial differences in choice of dialysis modality for children with end-stage renal disease.

OBJECTIVE: Black-white disparities in the use of specific medical and surgical services have been reported in adult populations. Such disparities are not well documented in children. We sought to determine whether racial disparities in the use of medical services exist among children with chronic illness who have similar health insurance, specifically the choice of dialysis modality for individuals with end-stage renal disease. DESIGN: National cross-sectional study. SETTING: Outpatient dialysis facilities throughout the United States. PATIENTS AND PARTICIPANTS: All Medicare-eligible children (age, </=19 years) undergoing renal replacement therapy in 1990 in the United States, using data from the Medicare ESRD registry. OUTCOME MEASURES: The odds of receiving hemodialysis versus peritoneal dialysis according to race. Adjustment was made for differences in age, gender, cause, and duration of end-stage renal disease, income, education, and facility characteristics using multiple logistic regression. RESULTS: In 1990, 870 white and 368 black children received chronic (>1 year) renal replacement therapy in the United States. In bivariate analysis, blacks were two times (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.7, 2.8) more likely than whites to receive hemodialysis versus peritoneal dialysis. After controlling for other patient and facility characteristics in multivariate analysis, black children were still significantly more likely than white children to receive hemodialysis (OR, 2.4; 95% CI, 1.7, 3.5). CONCLUSIONS: Black race is strongly associated with the use of hemodialysis in children. Family, patient, or provider preferences could account for the difference in choice of therapy by race.

Adolescent↗

PubMed1994

Cyclic AMP-dependent expression of the Escherichia coli serC-aroA operon.

The Escherichia coli serC-aroA operon encodes biosynthetic enzymes for unrelated amino acid biosynthetic pathways leading to the synthesis of serine and the aromatic amino acids. A serC-aroA-lac translational fusion was constructed in the vector pMC1403. Synthesis of beta-galactosidase from the serC-aroA-lac fusion was found to be enhanced in the presence of lactose as the sole carbon source. This enhancement was not observed in strains containing a cya or crp mutant. However, the exogenous addition of cAMP greatly increased the beta-galactosidase synthesis in the cya mutant strain. The serC-aroA mRNA content, analyzed by a dot blot assay, also appeared to increase in the serC+ aroA+ cells after the exogenous addition of cAMP. These findings unambiguously indicate that the expression of the serC-aroA operon is positively controlled by cAMP.

Base Sequence↗

PubMed1988

A relationship between the activities of hepatic lanosterol 14 alpha-demethylase and 3-hydroxy-3-methylglutaryl-CoA reductase.

At 1-2 h after intragastric administration of ketoconazole, a cytochrome P-450 inhibitor, to rats, there was a 50-60% decrease in the activity of hepatic 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase. Inhibition reached a maximum at 6-12 h after the drug was given, but after 24 h enzyme activity was stimulated by 60%. The rates of synthesis of hepatic non-saponifiable lipids in vivo showed a similar time-dependent pattern of change. During the first few hours after drug administration, the hepatic cytochrome P-450-dependent metabolism of lanosterol was suppressed in vivo. However, 24 h after treatment, this activity was stimulated, an effect which was also observed by pre-treatment of the rats with the drug for several days. Suppression of hepatic HMG-CoA reductase and lanosterol 14 alpha-demethylase activities was accompanied by a relative increase in the accumulation of labelled polar sterols in the liver in vivo. In the intestine, ketoconazole also resulted in a rapid decline in the rate of synthesis of non-saponifiable lipids and an inhibition of lanosterol 14 alpha-demethylation in vivo. However, in contrast with the liver, there was no stimulation of non-saponifiable lipid synthesis after 24 h.

Animals↗

PubMedDate not supplied

Comparison of risk adjusters for medicaid-enrolled children with and without chronic health conditions.

OBJECTIVE: Several capitation payment systems have been developed and implemented recently by public and private insurers as well as by individual managed care organizations. Many pediatricians have expressed concern that methods for establishing capitation rates may not adequately account for the higher expected expenditures for children with chronic health conditions. In this study, we evaluate a demographic- and 4 diagnosis-based models, paying particular attention to their performance for children with chronic health conditions. METHODS: We selected children 18 years of age and under who were enrolled in the Maryland Medicaid Program in 1995 and 1996. We defined the population of children with chronic health conditions using ICD-9 codes. Individual and group-level analyses were utilized to measure the ability of the different risk adjustment models to predict expenditures in 1996 based upon information available in 1995. RESULTS: All 4 diagnosis-based models significantly outperformed the demographic model for children overall and for children with chronic health conditions. Differences between diagnosis-based models were small, especially as the size of test populations increased. CONCLUSIONS: Risk adjustment methods that account directly for health status promise to reduce incentives to exclude children with chronic illnesses from managed care plans and to provide a foundation for more appropriate payments to pediatricians who care for these children.

Adolescent↗

PubMedDate not supplied

Out-of-pocket medical spending for care of chronic conditions.

We examined out-of-pocket medical spending by persons with and without chronic conditions using data from the 1996 Medical Expenditure Panel Survey (MEPS). Our results show that mean out-of-pocket spending increased with the number of chronic conditions. The level of this spending also varied by age and insurance coverage, among other characteristics. Out-of-pocket spending for prescription drugs was substantial for both elderly and nonelderly persons with chronic conditions. As policymakers continue to use cost sharing and design of benefit packages to contain health spending, it is important to consider the impact of these policies on persons with chronic conditions and their families.

Chronic Disease↗