[Disease burden of acute viral hepatitis in Guangdong Province, 1990-2019].

Objective: To examine the burden and trends of acute viral hepatitis in Guangdong Province from 1990 to 2019, and provide reference evidences for hepatitis prevention and control in the province. Methods: Data on acute viral hepatitis (hepatitis A, B, C, and E) in Guangdong from 1990 to 2019 were extracted from the Global Burden of Disease Study 2019 database. The incidence, prevalence, mortality, and disability-adjusted life years (DALY) data were analyzed by age and gender, and the estimated annual percentage change (EAPC) was calculated to describe the changing trends in disease burden. Results: From 1999 to 2019, the standardized incidence, prevalence, mortality, and DALY of acute viral hepatitis in Guangdong were higher than the national averages. In 2019, 51.43% (2 245 087/4 365 221) of acute viral hepatitis cases in Guangdong Province were mainly attributed to hepatitis B, and 77.18% (106/138) of deaths were due to acute hepatitis B. In different age groups, except for acute hepatitis B, which was more common in adults, the incidence rates of other types of viral hepatitis such as hepatitis A, B, and E showed an overall decreasing trend with age. The mortality rates of different types of acute viral hepatitis, except for the <5 age group, increased with age. The overall incidence and mortality rates of acute viral hepatitis were higher in men than in women. Conclusions: The overall burden of acute viral hepatitis in Guangdong declined in 2019, but remained higher than the national level. Further efforts are needed to strengthen hepatitis prevention and screening in different population in Guangdong Province, especially in children and the elderly.

Difficult Situation of Pancreas Transplantation in the Setting of Scarce Organ Donation.

BACKGROUND: Currently, pancreas transplantation has been a promising strategy to restore long-term normoglycemia as well as to improve life quality for patients with insulin-dependent diabetes mellitus (DM). However, the discrepancy between the number of organs needed and the number donated for transplantation is always enormous. Under a setting of scarce organ donations, we examined our limited experience of pancreas transplantation. METHODS: A retrospective review of pancreas transplantations was performed with the use of data from the Taiwan Organ Registry and Sharing Center and the Ministry of Health and Welfare. Pancreas transplantations in the Organ Transplantation Institute of Chang Gung Memorial Hospital also were reviewed. RESULTS: At present, there are 5 medical centers approved for pancreas transplantation in Taiwan. Overall, a total of 156 pancreas transplantations were performed from 2005 to the end of 2016; only 9 of them were performed in the Organ Transplantation Institute of Chang Gung Memorial Hospital. Although the number of organ donations is rising, pancreas transplantation numbers remain low. More than 20 pancreas transplantations were performed in 2016, yet there remained a total of 111 patients registered on the wait list for pancreas transplantation at the end of this study. Thus the gap between organ donation and transplantation is still vast. CONCLUSIONS: With continuing improvements in Taiwanese health policies and public education regarding organ transplantation, organ donation rates have risen steadily in recent years. Moreover, quality control and continuing evolution in organ transplantation is crucial to ameliorate the difficult situation of pancreas transplantation and other solid organ transplantation in the context of low levels of donation.

Effect modification by parental education on the associations of birth order and gender with learning achievement in adolescents.

BACKGROUND: A child's gender and ordinal position within a family have varied implications on his or her personality and cognitive development. However, little is known about whether or not parental educational level may moderate the effects of birth order and gender. METHODS: Basic Competence Test (BCT) scores of 290,588 young adolescents aged 15-16 years in Taiwan were analysed. Parental educational level was calculated as the highest educational attainment of the subjects' parents. The multiple linear regression model was used to assess the modification effects of parental educational levels on the associations of interest. RESULTS: After controlling for covariates, we noted a clear inverse relationship between birth order and BCT scores in Mandarin, Mathematics and Science. Additionally, boys had significantly lower mean scores in Mandarin, but had significantly higher mean scores in both Mathematics and Science. We also found the significant interactive effects of birth order, gender and parental educational attainment on BCT scores, in which the birth order and gender effects were more evident in higher-educated families than in lower-educated ones. CONCLUSIONS: This large cohort study confirmed that both birth order and gender may pose independent influences on BCT scores; moreover, such influences are significantly modified by parental educational attainment.

Long-term outcomes of living kidney donors over the past 28 years in a single center in Taiwan.

BACKGROUND: The chronic shortage of kidneys for transplantation has increased the number of living donations, but demand remains high, which has created a long waiting list of end-stage kidney disease patients. Donors with decreased renal mass may suffer a higher risk of developing proteinuria, hypertension (HTN), and chronic renal disease (CKD) during long-term follow-up. METHODS: We retrospectively retrieved medical data of living kidney donors at our hospital over the past 28 years. RESULTS: There were 45 male and 60 female donors with a mean donation age of 46.34 ± 12.47 years (range = 20-70y). The mean follow-up duration was 4.67 ± 4.78 years. The serum creatinine (Cr) at donation was 0.93 ± 0.22 mg/dL, while the latest Cr was 1.26 ± 0.45 mg/dL (P < .001). The mean age at follow-up was 50.95 ± 14.57 years. At last follow-up, eight subjects (7.6%) displayed HTN requiring treatment, 10 (9.5%), proteinuria and 55.4%, an estimated glomerular filtration rate (eGFR) of less than 60 mL/min, including one with diabetic nephropathy at 10 years after donation who required long-term hemodialysis. Although gender did not correlate with occurrence of HTN, proteinuria, and CKD, the occurrence of CKD was associated with age at donation (P < .001, odds ratio [OR] = 1.076), and age at follow-up (P < .001, OR = 1.071). HTN donors were older (P = .036, OR = 1.057) with longer follow-up durations (P = .007, OR = 1.166) and had higher Cr values at donation (P = .044, OR = 94.4). Donors with proteinuria were not related to gender, follow-up duration, initial Cr, warm ischemic time, or duration of admission. eGFR was indeed worse after donation (P = .002). CONCLUSIONS: Our results indicated a significant proportion of living donors may develop CKD upon long-term follow-up. The factors affecting donor risk of CKD were baseline renal function, older age, and duration after kidney donation.

SU-E-T-491: A FLUKA Monte Carlo Computational Model of a Scanning Proton Beam Therapy Nozzle at IU Proton Therapy Center.

PURPOSE: Charged particle therapy, especially proton therapy is a growing treatment modality worldwide. Monte Carlo (MC) simulation of the interactions of proton beam with equipment, devices and patient is a highly efficient tool that can substitute measurements for complex and unrealistic experiments. The purpose of this study is to design a MC model of a treatment nozzle to characterize the proton scanning beam and commissioning the model for the Indiana University Health Proton Therapy Center (IUHPTC. METHODS: The general purpose Monte Carlo code FLUKA was used for simulation of the proton beam passage through the elements of the treatment nozzle design. The geometry of the nozzle was extracted from the design blueprints. The initial parameters for beam simulation were determined from calculations of beam optics design to derive a semi-empirical model to describe the initial parameters of the beam entering the nozzle. The lateral fluence and energy distribution of the beam entering the nozzle is defined as a function of the requested range. The uniform scanning model at the IUHPTC is implemented. The results of simulation with the beam and nozzle model are compared and verified with measurements. RESULTS: The lateral particle distribution and energy spectra of the proton beam entering the nozzle were compared with measurements in the interval of energies from 70 MeV to 204.8 MeV. The accuracy of the description of the proton beam by MC simulation is better than 2% compared with measurements, providing confidence for complex simulation in phantom and patient dosimetry with the MC simulated nozzle and the uniform scanning proton beam. CONCLUSIONS: The treatment nozzle and beam model was accurately implemented in the FLUKA Monte Carlo code and suitable for the research purpose to simulate the scanning beam at IUHPTC.

Assessment of the clinical outcomes and cost-effectiveness of the management of systolic heart failure in Chinese patients using a home-based intervention.

This study was designed to assess the clinical effect of a home-based telephone intervention in Chinese heart failure patients. A total of 550 Chinese heart failure patients were enrolled into either (i) a group that received the usual standard of care (UC group); or (ii) a group that received a home-based heart failure centre management programme using nursing specialist-led telephone consultations (HFC group). The impact of the home-based intervention on admission rate, admission length and medical costs over 6 months was measured. Although the mean left ventricular ejection fraction in HFC patients was 29.3% compared with 34.8% in UC patients, the home-based intervention resulted in a significantly lower all-cause admission rate per person (HFC 0.60 +/- 0.77 times/person; UC 0.96 +/- 0.85 times/person), a shorter all-cause hospital stay (reduced by 8 days per person) and lower total 6-month medical costs (reduced by US$2682 per patient). These results suggest that the home-based intervention with nursing specialist-led telephone consultations may improve the clinical outcome and provide cost-savings for Chinese patients with heart failure.

Factors associated with healthcare utilization costs for statin therapy--a pilot study in Hong Kong.

BACKGROUND: Socio-economic status, comorbidities and adherence to statin therapy might affect the cost-effectiveness of statin therapy in hyperlipidemia. OBJECTIVE: To examine the effects size of demographic factors, clinical factors and adherence to statin therapy on the direct medical costs for Chinese patients at high risk of coronary heart disease (CHD). METHODS: This was a prospective, observational cohort study conducted in the outpatient departments of a public teaching hospital in Hong Kong. Patients at high risk of CHD who had been on statin monotherapy for < 12 months were recruited. Baseline demographic and clinical data were obtained. Statin adherence was monitored prospectively over 6 months using the Medication Event Monitoring System. Total direct medical costs per member per month (cPMPM), including cost for clinic visits, statin medication, laboratory tests on lipids and management of CHD events if any, were calculated from the perspective of a public healthcare organization. RESULTS: 83 patients completed the study. Median cPMPM in 80 patients (96% of 83 patients) without a new CHD event (USD 42) and for 3 (4%) patients who experienced CHD events (USD 444) were significantly different (p = 0.003). History of congestive heart failure (beta = 1,957, 95% CI = 1,006 - 2,909), male gender (beta = 584, 95% CI = 215 - 952), coronary atherosclerosis (beta = 1,436, 95% CI = 538 - 2,334) and diabetes mellitus (beta = 604, 95% CI = 136 - 1,07 1) were positive predictors for cPMPM. CONCLUSION: In this pilot study male gender, diabetes mellitus, congestive heart failure and coronary atherosclerosis appear to be significantly associated with higher costs for Chinese patients at high risk of CHD.

Dose perturbations due to contrast medium and air in mammosite treatment: an experimental and Monte Carlo study.

In the management of early breast cancer, a partial breast irradiation technique called MammoSite (Proxima Therapeutic Inc., Alpharetta, GA) has been advocated in recent years. In MammoSite, a balloon implanted at the surgical cavity during tumor excision is filled with a radio-opaque solution, and radiation is delivered via a high dose rate brachytherapy source situated at the center of the balloon. Frequently air may be introduced during placement of the balloon and/or injection of the contrast solution into the balloon. The purpose of this work is to quantify as well as to understand dose perturbations due to the presence of a high-Z contrast medium and/or an air bubble with measurements and Monte Carlo calculations. In addition, the measured dose distribution is compared with that obtained from a commercial treatment planning system (Nucletron PLATO system). For a balloon diameter of 42 mm, the dose variation as a function of distance from the balloon surface is measured for various concentrations of a radio-opaque solution (in the range 5%-25% by volume) with a small volume parallel plate ion chamber and a micro-diode detector placed perpendicular to the balloon axis. Monte Carlo simulations are performed to provide a basic understanding of the interaction mechanism and the magnitude of dose perturbation at the interface near balloon surface. Our results show that the radio-opaque concentration produces dose perturbation up to 6%. The dose perturbation occurs mostly within the distances <1 mm from the balloon surface. The Plato system that does not include heterogeneity correction may be sufficient for dose planning at distances > or = 10 mm from the balloon surface for the iodine concentrations used in the MammoSite procedures. The dose enhancement effect near the balloon surface (<1 mm) due to the higher iodine concentration is not correctly predicted by the Plato system. The dose near the balloon surface may be increased by 0.5% per cm3 of air. Monte Carlo simulation suggests that the interface effect (enhanced dose near surface) is primarily due to Compton electrons of short range (<0.5 mm). For more accurate dosimetry in MammoSite delivery, the dose perturbation due to the presence of a radio-opaque contrast medium and air bubbles should be considered in a brachytherapy planning system.

Dose perturbations due to contrast medium and air in MammoSite® treatment: An experimental and Monte Carlo study.

In the management of early breast cancer, a partial breast irradiation technique called MammoSite® (Proxima Therapeutic Inc., Alpharetta, GA) has been advocated in recent years. In MammoSite, a balloon implanted at the surgical cavity during tumor excision is filled with a radio-opaque solution, and radiation is delivered via a high dose rate brachytherapy source situated at the center of the balloon. Frequently air may be introduced during placement of the balloon and/or injection of the contrast solution into the balloon. The purpose of this work is to quantify as well as to understand dose perturbations due to the presence of a high-Z contrast medium and/or an air bubble with measurements and Monte Carlo calculations. In addition, the measured dose distribution is compared with that obtained from a commercial treatment planning system (Nucletron PLATO system). For a balloon diameter of 42 mm, the dose variation as a function of distance from the balloon surface is measured for various concentrations of a radio-opaque solution (in the range 5%-25% by volume) with a small volume parallel plate ion chamber and a micro-diode detector placed perpendicular to the balloon axis. Monte Carlo simulations are performed to provide a basic understanding of the interaction mechanism and the magnitude of dose perturbation at the interface near balloon surface. Our results show that the radio-opaque concentration produces dose perturbation up to 6%. The dose perturbation occurs mostly within the distances <1mm from the balloon surface. The Plato system that does not include heterogeneity correction may be sufficient for dose planning at distances ⩾10mm from the balloon surface for the iodine concentrations used in the MammoSite procedures. The dose enhancement effect near the balloon surface (<1mm) due to the higher iodine concentration is not correctly predicted by the Plato system. The dose near the balloon surface may be increased by 0.5%percm3 of air. Monte Carlo simulation suggests that the interface effect (enhanced dose near surface) is primarily due to Compton electrons of short range (<0.5mm). For more accurate dosimetry in MammoSite delivery, the dose perturbation due to the presence of a radio-opaque contrast medium and air bubbles should be considered in a brachytherapy planning system.

The heterogeneity of schizophrenia in disease states.

PREVIOUS PRESENTATION: Some of the contents of this paper have been previously presented at the 16th Annual Meeting of the International Society for Technology Assessment in Health Care June 20, 2000 in the Hague, Netherlands and at the 21st Annual Meeting of the Society for Medical Decision Making as a poster on October 3, 1999 in Reno, NV. BACKGROUND: Studies of schizophrenia treatment often oversimplify the array of health outcomes among patients. Our objective was to derive a set of disease states for schizophrenia using the Positive and Negative Symptom Assessment Scale (PANSS) that captured the heterogeneity of symptom responses. METHODS: Using data from a 1-year clinical trial that collected PANSS scores and costs on schizophrenic patients (N=663), we conducted a k-means cluster analyses on PANSS scores for items in five factor domains. Results of the cluster analysis were compared with a conceptual framework of disease states developed by an expert panel. Final disease states were defined by combining our conceptual framework with the empirical results. We tested its utility by examining the influence of disease state on treatment costs and prognosis. RESULTS: Analyses led to an eight-state framework with varying levels of positive, negative, and cognitive impairment. The extent of hostile/aggressive symptoms and mood disorders correlated with severity of disease states. Direct treatment costs for schizophrenia vary significantly across disease states (F=27.47, df=7, p<0.0001), and disease state at baseline was among the most important predictors of treatment outcomes. CONCLUSION: The disease states we describe offer a useful paradigm for understanding the links between symptom profiles and outcomes.

Measured versus estimated energy expenditure in mechanically ventilated critically ill patients.

Accurate determination of energy expenditure is essential in patients receiving nutritional support to meet metabolic needs. The purpose of this study was to assess and compare the energy expenditure as measured by indirect calorimetry (MEE) and estimated by 5 equations in the mechanically ventilated critically ill patients. Forty-six patients were divided into either enteral nutrition (EN) (n=l2), total parenteral nutrition (TPN) (n=16) or combined (EN plus TPN) (n=l8) groups. Patients' energy expenditure was measured by indirect calorimetry on two occasions. Anthropometric and biochemical measurements, energy expenditure and medical status (APACHE II score) were also assessed in the intensive care unit (ICU) of Taichung Veteran General hospital. No significant difference was found in the MEE among the 3 groups. The type of nutritional support did not affect MEE. Energy expenditure calculated by using Harris- Benedict, Kleiber and Liu equations times the estimated stress factor did not significantly different than the values of MEE in all groups. There were significant correlations (P<0.01) between MEE and patients' sex (r=-0.499), age (r=-0.402), height (r=0.533), knee height (r=0.431), current body weight (r=0.379), usual body weight (r=0.407), ideal body weight (r=0.466) and urinary urea nitrogen (r=0.383) in the pooled group. Results demonstrated that energy expenditure could be estimated in most critically ill patients by using Harris-Benedict, Kleiber and Liu equations if the estimated stress factor is in the reasonable value.

Sequential intravenous/oral antibiotic vs. continuous intravenous antibiotic in the treatment of pyogenic liver abscess.

AIM: Pyogenic liver abscesses result in substantial morbidity and mortality. Antimicrobial regimens using sequential intravenous/oral therapy may reduce the length of hospital stay. In this retrospective analysis, the efficacy of continuous intravenous antibiotic therapy (group I) vs. sequential intravenous/oral antibiotic therapy (group II) was studied in patients with pyogenic liver abscess. METHODS: One hundred and twelve consecutive patients (55 in group I and 57 in group II) with pyogenic liver abscess were analysed. Clinical response, length of hospital stay and relapse rates were examined. RESULTS: Group II had a significantly shorter duration of intravenous antibiotic treatment (3.2 weeks vs. 5.9 weeks, P < 0.01) and a shorter length of hospital stay (28 days vs. 42 days, P < 0.01) when compared to group I. Oral antibiotics were prescribed for a median duration of 2.9 weeks in group II after discharge. No relapse occurred within 6 weeks after the completion of treatment in both groups. The cost of therapy was significantly lower in group II than in group I by 33%. CONCLUSIONS: A sequential intravenous/oral antibiotic regime is a safe and effective treatment for pyogenic liver abscess. This reduces the cost of therapy and the length of hospital stay.

Vitamin B6 intakes and status assessment of elderly men and women in Taiwan.

Studies have indicated that vitamin B6 status decreases with age. However, little is known about vitamin B6 status of elderly people in Taiwan. The purpose of this study was to assess vitamin B6 status of elderly Taiwanese and to examine the effect of protein on various indices of vitamin B6 status in the elderly. Thirty-nine men (mean age = 69.9 +/- 4.2 years) and 55 women (mean age = 69.5 +/- 3.9 years) completed a 24-h diet recall. The mean total vitamin B6 intake (men: 1.7 +/- 0.9 g/day; women: 1.6 +/- 1.2 g/day) was higher than the 1998 US Dietary Reference Intakes (DRI) and the current Taiwan Recommended Daily Nutrient Allowance (RDNA). Dietary energy and protein intakes were not related to any vitamin B6 status parameters in any sex groups and the pooled group. Vitamin B6 intake correlated only with erythrocyte aspartate transaminase activity coefficient (EAST-AC) in the pooled (r = -0.214, p < 0.05) group. There were no significant differences in plasma pyridoxal 5'-phosphate (PLP), erythrocyte alanine transaminase activity coefficient (EALT-AC), and EAST-AC between sex groups. Although elderly subjects had adequate mean plasma PLP concentrations, 59% of men and 55% of women had plasma PLP concentrations lower than a cutoff of 20 nmol/L. The mean EALT-AC was < 1.25 in two groups with adequate vitamin B6 status. However, 23% of men and 18% of women had EALT-AC values > 1.25. The mean EAST-AC value of subjects was higher than the suggested value (< 1.8) for inadequate vitamin B6 status. The incidence of biochemical vitamin B6 deficiency in our elderly is probably more relevant from other causes than from dietary intake of protein and vitamin B6.

Prospective evaluation of patients refused admission to an intensive care unit: triage, futility and outcome.

OBJECTIVES: To evaluate factors associated with decisions to refuse ICU admission and to assess the outcome of refused patients. DESIGN AND SETTING: Prospective, descriptive evaluation in a multi-disciplinary intensive care unit, university referral hospital. PATIENTS AND PARTICIPANTS: All adult emergency referrals over a 7-month period. INTERVENTIONS: The number of beds available at the time of referral, the patient's age, gender, diagnosis, mortality probability model score and hospital survival were documented. The outcome of the referral and the reason for refusal were recorded. MEASUREMENTS AND RESULTS: Of 624 patients 388 were admitted and 236 (38%) refused. Reasons for refusal were triage (n=104), futility (n=82) and inappropriate referral (too well; n=50). The standardised mortality ratio (SMR) for refused and admitted groups was 1.24 (95% CI 1.05-1.46) and 0.93 (0.78-1.09) respectively. The SMR ratio (refused SMR/admitted SMR) was highest in the middle range of illness (1.95, 1.19-3.20). Inappropriate referrals had a better than expected outcome despite refusal, with a SMR ratio of 0.39 (0.11-0.99). Excluding inappropriate referrals, multivariate analysis demonstrated that refusal was associated with older age, diagnostic group and severity of illness. Triage decisions were associated with a diagnosis of sepsis, and futility decisions with greater severity of illness and recent cardiac arrest. CONCLUSIONS: Refusal of admission to our ICU is common. Excess mortality of patients refused is most marked in the middle range of severity of illness. Age, diagnostic group, and severity of illness are important in decision making. Strategies should be developed to create admission criteria that would identify patients in the middle range of severity of illness who should benefit most from ICU care.

Quantitative assessment of retinal thickness in diabetic patients with and without clinically significant macular edema using optical coherence tomography.

PURPOSE: To assess patients with diabetic macular edema quantitatively using optical coherence tomography (OCT). METHODS: OCT was performed in 14 eyes with diabetic retinopathy and ophthalmoscopic evidence of clinically significant macular edema (CSME) and in 19 diabetic eyes without CSME. Retinal thickness was computed from the tomograms at fovea and other 36 locations throughout the macula. RESULTS: The mean +/- standard deviation foveal thickness was 255.6 +/- 138.9 microm in eyes with CSME, and 174.6 +/- 38.2 microm in eyes without CSME (p = 0.051). Within 2000 microm of the center of the macula, eyes with CSME had significantly thicker retina in the inferior quadrant than those without CSME (p < 0.01). The foveal thickness was correlated with logMAR visual acuity (gamma = 0.68, p < 0.01). OCT identified sponge-like retinal swelling and/or cystoid macular edema in 11 (58%) eyes without CSME, and in 12 (86%) eyes with CSME. CONCLUSIONS: Criteria of CSME seem to be insufficient in really identifying macular edema. OCT may be more sensitive than a clinical examination in assessing diabetic macular edema and is a quantitative tool for documenting changes in macular thickening.

Medicare physician payment changes: impact on physicians and beneficiaries.

The Balanced Budget Act (BBA) of 1997 generally reduced Medicare payments for surgical services while increasing them for other services. Concern about implications of these fee reductions prompted the Medicare Payment Advisory Commission to sponsor a national survey of physicians to learn their views on Medicare payment and whether access to care has changed for Medicare beneficiaries. Results suggest that beneficiaries' access to care has not declined. While physicians are concerned about Medicare reimbursement, they are more concerned about reimbursement from managed care plans and Medicaid. Continued monitoring will be important to detect any emerging access problems accompanying upcoming payment reductions.

[Analysis of tendency of false and inferior species from Chinese medicinal materials markets].

OBJECTIVE: To offer information on the supervision by analysing the change of origin of false and inferior species from Chinese medicinal materials (CMM) markets. METHOD: 750 cases false and inferior species from Hubei province were compared classifiedly. RESULTS: In recent ten years, distributive characteristics of false and inferior species from CMM markets is as follows. First, false and inferior species from prepared medicinal herb increase, so do with man-made adulteration and poisonous species. Second, false and inferior species increase in rural area, country fairs, individual clinics and medicine booths. Last, extracted products are sold and used as certified products. CONCLUSION: CMM country fairs, outlying rural area, individual clinics and private medicine booths are the center of further supervision hereafter.

Cost-effectiveness of radiofrequency ablation for supraventricular tachycardia.

BACKGROUND: Radiofrequency ablation is an established but expensive treatment option for many forms of supraventricular tachycardia. Most cases of supraventricular tachycardia are not life-threatening; the goal of therapy is therefore to improve the patient's quality of life. OBJECTIVE: To compare the cost-effectiveness of radiofrequency ablation with that of medical management of supraventricular tachycardia. DESIGN: Markov model. DATA SOURCES: Costs were estimated from a major academic hospital and the literature, and treatment efficacy was estimated from reports from clinical studies at major medical centers. Probabilities of clinical outcomes were estimated from the literature. To account for the effect of radiofrequency ablation on quality of life, assessments by patients who had undergone the procedure were used. TARGET POPULATION: Cohort of symptomatic patients who experienced 4.6 unscheduled visits per year to an emergency department or a physician's office while receiving long-term drug therapy for supraventricular tachycardia. TIME HORIZON: Patient lifetime. PERSPECTIVE: Societal. INTERVENTIONS: Initial radiofrequency ablation, long-term antiarrhythmic drug therapy, and treatment of acute episodes of arrhythmia with antiarrhythmic drugs. OUTCOME MEASURES: Costs, quality-adjusted life-years, life-years, and marginal cost-effectiveness ratios. RESULTS OF BASE-CASE ANALYSIS: Among patients who have monthly episodes of supraventricular tachycardia, radiofrequency ablation was the most effective and least expensive therapy and therefore dominated the drug therapy options. Radiofrequency ablation improved quality-adjusted life expectancy by 3.10 quality-adjusted life-years and reduced lifetime medical expenditures by $27 900 compared with long-term drug therapy. Long-term drug therapy was more effective and had lower costs than episodic drug therapy. RESULTS OF SENSITIVITY ANALYSIS: The findings were highly robust over substantial variations in assumptions about the efficacy and complication rate of radiofrequency ablation, including analyses in which the complication rate was tripled and efficacy was decreased substantially. CONCLUSIONS: Radiofrequency ablation substantially improves quality of life and reduces costs when it is used to treat highly symptomatic patients. Although the benefit of radiofrequency ablation has not been studied in less symptomatic patients, a small improvement in quality of life is sufficient to give preference to radiofrequency ablation over drug therapy.