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Biomedical subjects

Jane Chang

Publications and source records attributed to Jane Chang.

10 recordsLinked to original sources
PubMed2006

Statistically designing microarrays and microarray experiments to enhance sensitivity and specificity.

Gene expression signatures from microarray experiments promise to provide important prognostic tools for predicting disease outcome or response to treatment. A number of microarray studies in various cancers have reported such gene signatures. However, the overlap of gene signatures in the same disease has been limited so far, and some reported signatures have not been reproduced in other populations. Clearly, the methods used for verifying novel gene signatures need improvement. In this article, we describe an experiment in which microarrays and sample hybridization are designed according to the statistical principles of randomization, replication and blocking. Our results show that such designs provide unbiased estimation of differential expression levels as well as powerful tests for them.

Breast Neoplasms↗
PubMed2006

Impact of chronic hand dermatitis on quality of life, work productivity, activity impairment, and medical costs.

BACKGROUND: The impact of chronic hand dermatitis (ChHD) on patient-reported outcomes and economic costs has not been assessed in a US population. OBJECTIVE: We sought to evaluate the quality of life, work productivity, activity impairment, and health care costs of patients with ChHD versus those without ChHD. METHODS: A 13-item self-assessment questionnaire to identify ChHD was developed and validated. Skindex-29 and Work Productivity and Activity Impairment questionnaires were used to assess quality of life and work productivity for ChHD. The survey was mailed to a random sample of 1380 members of a Massachusetts managed care organization (N = 507, response rate = 36.74%). Univariate and multivariate analyses were conducted to determine the incremental effect of ChHD on quality of life, work productivity, and activity impairment. Health insurance claims were used to assess medical costs. RESULTS: Quality of life, along with work productivity and activity impairment, were significantly worse for patients with CHD than for those without ChHD; however, there was no significant difference in work time missed. After adjusting for significant covariates, a 25% cost increase in total medical costs was found attributable to ChHD, which translates to an incremental cost of $70 per patient per month. LIMITATIONS: Survey response rate is not high; the survey respondents may not be completely representative of the nonrespondents. The cost burden of ChHD is underestimated because of the omission of over-the-counter drug and indirect costs. The multivariate models had a low goodness of fit indicated by the low R2 statistics. CONCLUSIONS: ChHD has a significant detrimental effect on quality of life, work productivity, activity impairment, and heath care costs. More awareness and treatment of this condition are needed to improve patient outcomes and decrease health care cost.

Chronic Disease↗
PubMed2006

Cost effectiveness of management of mild-to-moderate atopic dermatitis with 1% pimecrolimus cream in children and adolescents 2-17 years of age.

INTRODUCTION: Atopic dermatitis (AD) has the potential to cause a long-term economic impact on patients, their families, and the healthcare system. OBJECTIVE: To determine if 1% pimecrolimus cream is cost-effective in treating mild-to-moderate AD in patients 2-17 years of age. METHODS: Data on the efficacy of AD management with 1% pimecrolimus cream (Elidel, Novartis Pharma GmbH, Wehr, Germany) were obtained from a 12-month, randomized, double-blind, multinational, controlled clinical trial comparing pimecrolimus and conventional therapy. Markov modeling was used for the economic model, based on: (i) Investigator's Global Assessment scores assessed at each visit during the clinical trial; (ii) estimated costs for medication and physician visits for each level of disease severity; and (iii) utility values for each level of disease severity. The perspective was that of a third-party payer. RESULTS: In 2004 US dollars, the incremental cost-effectiveness of 1% pimecrolimus cream was 38,231 US dollars per quality-adjusted life year (QALY) gained compared with conventional therapy. Sensitivity analyses showed a range of 27,299 US dollarsto 63,457 US dollars per QALY gained. CONCLUSION: With an incremental cost-effectiveness ratio of <50,000 US dollars per QALY gained, 1% pimecrolimus cream offers a cost-effective therapeutic option in the management of AD.

Administration, Topical↗
PubMed2006

A survey-based assessment of the prevalence and severity of chronic hand dermatitis in a managed care organization.

Although studies conducted outside of the United States have found a 7% to 12% prevalence of chronic hand dermatitis, no US general population-based estimates have been reported. The objective of this study was to quantify the prevalence of chronic hand dermatitis in a US managed care organization population. A 13-item self-assessment questionnaire was developed and validated, with 85% sensitivity and 95% specificity. The questionnaire was mailed to 2 random member samples from a Massachusetts managed care organization: 502 general members and 878 members with dermatitis. The questionnaire had a 36.74% overall response rate, with a chronic hand dermatitis point prevalence of 17.49% and 33.33% in the general and dermatitis populations, respectively. Among the general population, the questionnaire results identified 16.94% members who had chronic hand dermatitis but had not sought dermatitis-related medical services. After direct standardization to the 2000 US Census population with respect to age, gender, and race distributions, the projected point prevalence was estimated at 16.36% in the US general population. In conclusion, we found a higher prevalence of chronic hand dermatitis than previously reported. Approximately 1 in 6 members did not seek medical attention, suggesting that chronic hand dermatitis may be underdetected and untreated and may require more awareness and effective management.

Adult↗
PubMed2005

Impact of disease severity and gastrointestinal side effects on the health state preferences of patients with osteoarthritis.

OBJECTIVE: To describe the health state preferences of patients with osteoarthritis (OA) according to the level of pain and disability and the extent of gastrointestinal side effects from nonsteroidal antiinflammatory drugs (NSAIDs). METHODS: Using combinations of 5 OA health states (4 specifying medication use) and 6 gastrointestinal side effect profiles, we developed 25 scenarios. In an Internet survey, adults with OA evaluated 5 randomly chosen health state-side effect scenarios (in addition to scenarios for congestive heart failure and wearing dentures, as benchmarks). They rated the scenarios on a 0-100 scale, in which 100 corresponds to best imaginable health. Unadjusted mean ratings were calculated using a difference-in-difference approach. A generalized linear model was used to estimate the effects of disease severity and side effect severity on the ratings, after controlling for patient characteristics. RESULTS: A total of 4,386 respondents whose mean age was 55.3 years, of whom 3,107 (70.8%) were women and 4,007 (91.4%) were white, completed the survey. Mean adjusted ratings for health state-side effect scenarios ranged from 94.9 for the mildest scenario to 25.3 for the most severe scenario. Severity of NSAID side effects had a greater negative influence on the ratings in milder OA states than in more severe OA states. Ratings were lower among men (P < 0.001) and among respondents with OA pain in the previous 24 hours (P < 0.001). Disease severity had a greater effect on ratings than did side effect severity. CONCLUSION: Patients consider pain and functional limitations associated with OA to be important determinants of well-being. Future research should attempt to determine whether patients prefer reductions in their OA-related pain and disability over improvements in treatment side effect profiles.

Aged↗
PubMed2003

The anthelmintic levamisole is an allosteric modulator of human neuronal nicotinic acetylcholine receptors.

L-[-]-2,3,5,6-Tetrahydro-6-phenylimidazo[2,1b]-thiazole hydrochloride (levamisole) is an anthelmintic that targets the nicotinic acetylcholine receptors of parasitic nematodes. We report here the effects of levamisole on human neuronal alpha 3 beta 2 and alpha 3 beta 4 nicotinic receptors, heterologously expressed in Xenopus oocytes and studied with the voltage clamp method. Applied alone, levamisole was a very weak partial agonist for the two subunit combinations. When co-applied with acetylcholine, micromolar concentrations of levamisole potentiated responses, while millimolar concentrations inhibited them; these effects were complex functions of both acetylcholine and levamisole concentrations. The differences in the levamisole effects on the two receptor combinations suggest that the effects are mediated by the beta subunit. Several combinations of agonist and anthelmintic gave the dual potentiation/inhibition behavior, suggesting that the modulatory effects are general. Levamisole inhibition showed macroscopic characteristics of open channel block. Several results led us to conclude that levamisole potentiation occurs through noncompetitive binding to the receptor. We propose pseudo-site binding for noncompetitive potentiation by levamisole.

Acetylcholine↗
PubMedDate not supplied

Common menstrual disorders in adolescence: nursing interventions.

Menstrual disorders such as amenorrhea, excessive uterine bleeding, dysmenorrhea, and premenstrual syndrome are common reasons for visits to healthcare providers by adolescent girls. Although menstrual irregularity can be normal during the first few years after menarche, other menstrual signs and symptoms may indicate a pathological condition that requires prompt attention and referral. This article discusses four common menstrual disorders seen in adolescent girls and focuses on specific nursing interventions aimed at eliciting an accurate menstrual history, providing confidentiality and communicating therapeutically, administering culturally sensitive care, and promoting independence and self-care.

Adolescent↗
PubMedDate not supplied

Health plan budget impact analysis for pimecrolimus.

OBJECTIVE: Budget impact models are useful tools for managed care organizations to make drug formulary decisions. The objective of this study was to estimate the incremental budgetary change in per-member-per-month (PMPM) medical and pharmacy costs for atopic dermatitis (AD) or eczema after the introduction of pimecrolimus cream 1%, a topical calcineurin inhibitor. METHODS: Estimates of the percentage of patients seeking care, treatment patterns, and quantities of medications dispensed for AD were measured using 2001 and 2002 medical and pharmacy records in a proprietary database for health plans distributed throughout the United States. Approximately 2.5 million health plan members had continuous health insurance coverage during the study period. Costs for medications were assigned using the 2003 wholesale acquisition cost, and costs for physician visits were based on average 2003 Medicare reimbursement rates. Efficacy data from clinical trials were used to model the impact of pimecrolimus on subsequent physician visits. Sensitivity analyses were performed to evaluate the impact of varying the percentage of patients seeking care, practice patterns, medication quantities, percentage of pimecrolimus users, and levels of patient cost sharing. RESULTS: The estimated percentage of health plan members seeking care for AD in 2001 was 3.2%. The estimated total cost PMPM for AD treatment prior to introduction of pimecrolimus was 0.362 dollars for all covered lives, assuming no patient cost sharing. In the year after its introduction, 5.2% of the AD population filled a prescription for pimecrolimus. The incremental increase in pharmacy benefit cost was 0.008 dollars PMPM in 2003 dollars, but the total incremental medical and pharmacy cost was 0.002 dollars PMPM after accounting for the projected reduction in physician visit costs, representing a 0.7% increase in all AD-related costs. Based on sensitivity analyses, the incremental total cost PMPM after the introduction of pimecrolimus ranged from -0.004 dollars to 0.026 dollars. CONCLUSION: Using claims data for the medical treatment of AD in 2001-2002 and the utilization of pimecrolimus, the addition of pimecrolimus as a treatment option for AD had a minimal impact on PMPM costs for AD-related care in 2003 dollars. As with all pharmacoeconomic models, health plans should perform their own budget forecasting using assumptions derived from their own pharmacy and medical claims data.

Budgets↗