Use of a decision-analytic model to support the use of a new oral US contrast agent in patients with abdominal pain

RATIONALE AND OBJECTIVES

The authors performed this study to compare the cost and diagnostic abilities of ultrasound (US) performed with and without the use of an oral contrast material recently approved by the U.S. Food and Drug Administration.

MATERIALS AND METHODS

An interactive decision-analytic model was constructed to compare US performed with and without contrast material (SonoRx; Bracco Diagnostics) for the evaluation of patients with abdominal pain who were suspected of having pancreatic disease. The model considered all resources that might be used to evaluate a patient suspected of having pancreatic disease (eg, US, computed tomography [CT], endoscopic retrograde cholangiopancreatography, fine-needle aspiration biopsy, and open biopsy). The literature and an expert panel were the clinical data sources. Cost estimates were based on Medicare and non-Medicare reimbursements. The primary cost-effectiveness measure was the cost to achieve a diagnosis.

RESULTS

SonoRx-enhanced US was less expensive than unenhanced US ($714 vs $808, respectively, with Medicare costs; $1,612 vs $1,878, respectively, with non-Medicare costs) and as effective (0.785 vs 0.782, respectively). SonoRx-enhanced US was more cost-effective than unenhanced US ($909 vs $1,034, respectively, with Medicare costs; $2,052 vs $2,401, respectively, with non-Medicare costs). This relationship was maintained throughout extensive sensitivity analyses.

CONCLUSION

SonoRx-enhanced US is more cost-effective than unenhanced US, primarily because it avoids the need for CT. CT may be avoided owing to the higher probability of obtaining optimal US scans with oral contrast material.

Cost of treating an episode of variceal bleeding in a VA setting

OBJECTIVES

The specific aims of this study were to develop a demographic description of a sample of patients presenting with bleeding esophageal varices and determine the direct health care costs of variceal bleeding.

METHODS

This was a retrospective evaluation of patients who underwent esophagogastroduodenoscopy at the Portland VA Medical Center between January 1993 and May 1997. Data sources included both electronic databases and patient medical charts. The primary unit of analysis was an episode of care, defined as an index bleed plus 6 months of follow-up or death, whichever came first.

RESULTS

The total inpatient direct cost was $1,566,904 and outpatient direct cost was $104,611, for a total of $1,671,515 for 100 bleeding episodes in 79 patients. Episodes of care for patients receiving < or =2 units of packed red blood cells were approximately a third as costly as those receiving >2 units of packed red blood cells (n = 17, $6,470 and n = 83, $17,553). The difference in costs was statistically significant (p < 0.05), and primarily attributable to hospital bed costs.

CONCLUSIONS

There is a substantial financial burden associated with this illness, primarily attributable to inpatient costs. In addition to severity of bleeding, Child's class, endoscopic findings, and the timing of pharmacological therapy seem to influence the overall cost of managing esophageal varices.

Review of the development, validation, and application of predictive instruments in interventional cardiology

Within the last few years, risk assessment has become an integral part of clinical practice, particularly for thoracic surgery and interventional procedures. Risk assessment statistical models are being used in medical decision making, quality improvement tools, and as aids to patient counseling. This literature review was conducted to evaluate the types of predictive models and outcomes measures that have been examined, and methods used in development, validation, and application of these models. A Medline search performed to identify articles (limited to human studies) published in English from 1980 to 1999 resulted in 89 articles, of which 71 were evaluable. Populations studied for model development included patients undergoing coronary artery bypass graft (CABG), percutaneous transluminal coronary revascularization (PTCR), cardiac catheterization, or stenting procedures and patients with angina or stroke. The models were equally developed from a single center versus multicenter and from retrospective databases versus prospective studies. In terms of model perspectives, only three of the models measured cost or cost-effectiveness as the outcome; the remainder considered only clinical outcomes. The most commonly reported types of predictive models were developed using logistic regression and Bayesian techniques, followed by neural networks, rule-based artificial intelligence, simultaneous equation system, and multiple linear regression. Factors to consider when developing or evaluating a predictive model include uniformity of definitions of outcomes, uniformity of definitions of variables, completeness of data, number and frequency of variables, timeliness and source of data, development population characteristics, development and testing (validation) cohorts, and calibration and discrimination. Application of these models to an individual patient can spur quality improvement efforts that can lead to dramatic, system-wide improvements in outcomes.

Pharmacoeconomic analysis of selected antibiotics in lower respiratory tract infection

An interactive pharmacoeconomic model was designed to evaluate the effects of clinical response and adverse drug events on the comparative cost and cost-effectiveness of a relatively new antibiotic, clarithromycin, compared with those of six other antibiotics used to treat community-acquired lower respiratory tract infection. The cost and cost-effectiveness analyses were based don 12 randomized, double-blind, controlled clinical trials conducted between 1987 and 1992 in regionally distributed outpatient clinics in the United States. The trials enrolled a total of 2377 patients. Of the 2377, 1102 patients were treated for acute exacerbation of chronic bronchitis, 591 for pneumonia, and 201 for either of the two conditions. Safety data for one of the antibiotics was obtained from a trial of patients with sinusitis (N = 483). The antibiotics included in the analysis were amoxicillin/clavulanate, ampicillin, cefaclor, cefixime, cefuroxime, clarithromycin, and erythromycin. The main outcome measures were the costs of resources to achieve a clinical response, costs related to managing adverse drug events, and costs of antibiotic treatment from the perspective of managed care. The mean total cost per episode ranged from approximately $137 to $267. The drug acquisition cost typically contributed a small amount to the overall cost. For the cost-effectiveness analysis, in which complication-free cure was used as a proxy for patient satisfaction, the range of mean cost per complication-free cure varied from approximately $307 for clarithromycin to $612 for cefaclor. When ranked from most to least cost-effective, the order was as follows: clarithromycin, cefixime, amoxicillin/clavulanate, erythromycin, cefuroxime, ampicillin, and cefaclor. The costs associated with clinical management (including treatment failure) and managing adverse drug events significantly contribute to the total cost and cost-effectiveness of antibiotics in the outpatient setting. Cost-effectiveness analyses are valuable in analyzing the various costs associated with the treatment of lower respiratory tract infection (acute exacerbation of chronic bronchitis or pneumonia) and may be useful tools for physicians managing patients, members of pharmacy and therapeutics committees developing formularies, and medical staff implementing practice guidelines.