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Biomedical subjects

Elizabeth C Hsia

Publications and source records attributed to Elizabeth C Hsia.

5 recordsLinked to original sources
PubMed2005

Management of aortic disease in Marfan Syndrome: a decision analysis.

BACKGROUND: Marfan syndrome is a relatively common heritable disorder of connective tissue that affects numerous organ systems, but the most severe complication is aortic aneurysm and dissection. A variety of medical and surgical approaches are available for managing the cardiovascular complications. Our objective was to compare elective composite graft surgery, elective valve-sparing surgery, and medical management for patients with both Marfan syndrome and thoracic aortic disease on the basis of life expectancy with differing diameters of the aortic root and rate of increase in the aortic root size. METHODS: A Markov decision analysis model was constructed to compare the 2 surgical options with watchful waiting with medical therapy. RESULTS: For our base-case analysis of a 20-year-old patient with Marfan syndrome and thoracic aortic aneurysm, the aortic valve-sparing option was preferred. It extended life expectancy to 73.8 years compared with the medical treatment option (71.4 years) and with the composite graft surgery (72.7 years). Our results show that there is a better outcome for a patient with an aortic root diameter between 3.0 and 3.5 cm with early prophylactic surgery than with deferred or emergency surgery. Medical treatment was preferred when the aortic root diameter was smaller than 3.0 cm. CONCLUSIONS: Although long-term follow-up data are not yet available, it appears that advances in the technique of valve-sparing surgery have made it the preferred option to composite graft, primarily to avoid the complications of anticoagulation. Our study indicates that patients who have an aortic root diameter of larger than 3.0 cm should be considered for prophylactic aortic surgery.

Adult↗
PubMed2005

Analysis of a cluster of cases of Wegener granulomatosis.

BACKGROUND: Wegener granulomatosis is a chronic inflammatory autoimmune disease of unknown etiology. The sporadic occurrence, lack of familial or genetic associations, and rising incidence suggest possible exposure to environmental agents as causative for this disease. OBJECTIVE: The objective of this study was to examine possible environmental triggers of Wegener granulomatosis. METHODS: While conducting an environmental survey of potential precipitants of Wegener granulomatosis on a cohort of patients seen at Doylestown Hospital and at the University of Pennsylvania, we identified a cluster of cases in the Dublin, Pennsylvania, region. Through hospital records and patient contacts, we located 7 cases diagnosed in a 3-year period within a 10-mile radius of an Environmental Protection Agency (EPA) Superfund toxic waste site. The radius of inclusion represents a population of approximately 50,000 individuals. Assuming complete ascertainment of cases--which is unlikely given the methods used to acquire patients--the prevalence is 2- to 4-fold greater than the expected rate of 3 per 100,000. We identified toxins at or above "action level" within the demarcated geographic region using published data from the EPA. Furthermore, we queried patients regarding their particular chemical exposures. RESULTS: These patients with Wegener granulomatosis were possibly exposed to high levels of trichloroethylene (TCE), vinyl chloride, methyl tertiary-butyl ether (MTBE), dichloroethene (DCE), and chromic acid from several industrial waste sites within the area. Additionally, these patients reported a total of greater than 30 possible exposures, including the aforesaid chemical contaminants. Three of 5 patients whose water source is known had well water that exposed them to industrial runoff and necessitated EPA intervention. CONCLUSION: This data, along with other epidemiologic studies, suggest possible toxic exposures as potentially correctable risk factors for Wegener granulomatosis. We encourage clinicians to seek data that suggests an unusual environmental exposure and to solicit information that might implicate an industrial source for these exposures.

Carcinogens, Environmental↗
PubMed2004

Predictive factors in early arthritis: long-term follow-up.

BACKGROUND: Because recent-onset inflammatory arthritis exhibits considerable clinical and prognostic variability, it is important to attempt to predict which patients are likely to have a poor prognosis as early as possible. Most prognostic studies have looked at patients who fulfilled proposed criteria for a definite diagnosis of rheumatoid arthritis (RA) or other well-defined conditions; less information exists concerning predictive factors for other types of early arthritis. OBJECTIVES: To examine prognosis in early arthritis, the authors assessed the long-term outcome in a cohort of patients who presented with inflammatory arthritis of short duration. Associations between outcome and patient clinical characteristics were analyzed to determine possible prognostic factors. METHODS: Since 1968, patients were selected to be followed up in 2 early-arthritis clinics if they had evidence of inflammatory joint disease and symptom duration was <1 year. Length of follow-up was variable, but was at least 1 year. At last follow-up, patients were classified as being in remission or as having persistent disease. Factors associated with a poor outcome were identified by using formal statistical methods. RESULTS: A total of 121 patients were included in this analysis. Mean disease duration to the first evaluation was 3 months, and median follow-up was 5 years (range, 1 to 30 months). Twenty-one patients (17%) had transient disease defined as total duration of <6 weeks. Sixty-three patients (52%) were in remission at final follow-up, with unclassified patients doing the best. Patients meeting criteria for RA or spondylarthropathies had more persistent disease. Polyarticular disease predicted more persistent disease (P <.05). In multivariable analyses, patients with initial hand involvement were much less likely to achieve remission of their disease (odds ratio, 0.18; 95% confidence interval, 0.05 to 0.66). Only 4 patients had either class 4 function or joint replacement. CONCLUSIONS: Our findings indicate that prognosis in early inflammatory arthritis is generally good, with more than half of all patients achieving remission in our cohort. Patients with unclassified arthritis fared better than those meeting criteria for RA or spondylarthropathy. Of the many clinical variables examined as possible prognostic factors, hand involvement was the strongest predictor of a poor outcome. RELEVANCE: The long follow-up of these patients with early arthritis provides clues for the clinician to the likely course and shows that many patients will do well.

Adult↗
PubMed2002

Cost-effectiveness analysis of the Lyme disease vaccine.

OBJECTIVE: A vaccine for Lyme disease was approved in 1998 for use in the US. Given the high cost of the vaccine, the low risk of Lyme disease in many areas, and the largely curable nature of the disease, the cost-effectiveness of the vaccine in various risk groups is uncertain. This study was undertaken to examine the cost-effectiveness of the Lyme disease vaccine and the factors that influence its cost-effectiveness. METHODS: We constructed a Markov decision-analysis model to evaluate the clinical effectiveness and cost-effectiveness of the Lyme disease vaccine in populations at various levels of risk for the disease. The probabilities of clinical events and costs were estimated from reports in the literature. Sensitivity analyses assessed the impact of potential variations of parameters on model results. RESULTS: At the average national incidence of Lyme disease (0.0067%), the incremental cost-effectiveness of vaccination was approximately $1,600,000 per case averted when a yearly booster was given for 10 years after the standard initial vaccination regimen of 3 inoculations at 0, 1, and 12 months. For populations with an annual Lyme disease incidence of 1% (the incidence in several well-defined geographical areas of the US), the incremental cost-effectiveness was approximately $9,900 per case averted. Disease incidence had to exceed 10% before vaccination with yearly boosters became both more effective and more cost saving than no vaccination. CONCLUSION: The Lyme disease vaccine is cost-effective only for individuals who live in areas where Lyme disease is endemic and who are frequently exposed to ticks.

Cost-Benefit Analysis↗