Physicians' preference values for hepatitis C health states and antiviral therapy: a survey.

BACKGROUND: Physicians' perspectives regarding hepatitis C shape their approach to patient management. We used utility analysis to evaluate physicians' perceptions of hepatitis C-related health states (HS) and their threshold to recommend treatment. METHODS: A written questionnaire was administered to practicing physicians. They were asked to rate hepatitis C health states on a visual analog scale ranging from 0% (death) to 100% (health without hepatitis C). Physicians then judged quality of life associated with the side effects of antiviral therapy for hepatitis C and indicated the sustained virological response rate that they would require to recommend treatment. RESULTS: One hundred and thirteen physicians from five states were included. Median utility ratings for hepatitis C health states declined significantly with increasing severity of symptoms: HS1-No Symptoms, No Cirrhosis (88%; 12% reduction from good health), HS2-Mild Symptoms, No Cirrhosis (66%), HS3-Moderate Symptoms, No Cirrhosis (49%), HS4-Mild Symptoms, Cirrhosis (40%), HS5-Severe Symptoms, Cirrhosis (18%) [p < 0.001]. The median rating for life with side effects of antiviral therapy was 47%, suggesting a 53% reduction from good health. That was similar to the utility value for HS3-Moderate Symptoms, No Cirrhosis. The median threshold value for recommending treatment was a sustained response rate of 60%. CONCLUSIONS: 1) Physicians' utility ratings for hepatitis C health states were inversely related to the severity of disease manifestations described. 2) Physicians viewed side effects of therapy unfavorably and indicated that on average, they would require a 60% sustained response rate before recommending treatment, which far exceeds the efficacy of current antiviral therapy for hepatitis C in the majority of patients.

How did the acute ischemic heart disease predictive instrument reduce unnecessary coronary care unit admissions?

The use of the acute ischemic heart disease predictive instrument reduced coronary care unit (CCU) admissions for patients without acute ischemic heart disease by 30%. One hypothesis holds that it reinforced physicians' correctly low estimates of the probability of acute ischemia, supporting a decision against CCU admission, another that it lowered physicians' over-high probability estimates for acute ischemia so that CCU admission was felt to be unnecessary. The authors asked 86 physicians to estimate the probability of acute ischemia for each of three study cases and to decide on CCU admission. For the low-probability case, the mean of physicians' probability estimates for acute ischemia was 46%, vs. the predictive instrument's calculated probability of 19% (p less than 0.00001), a 142% over-estimation by the physicians. For the medium-probability case, the mean of physicians' estimates was 54%, vs. the calculated probability of 58% (not significant). For the high-probability case, the mean of physicians' estimates was 82%, vs. the calculated probability of 78% (not significant). All cases for which physicians considered not admitting to the CCU corresponded to their probability estimates of acute ischemia's being in a threshold range of approximately 10 to 30%. These results support the hypothesis that the mechanism by which the predictive instrument reduces unnecessary CCU admissions is by downward correction of physicians' overly-high suspicions of acute cardiac ischemia into a threshold range for which CCU admission is considered unnecessary.

Warfarin for dilated cardiomyopathy: a bloody tough pill to swallow?

Although current recommendations for the treatment of dilated cardiomyopathy include long-term anticoagulation to diminish the likelihood of systemic embolization, there have been no clinical trials examining the effectiveness of anticoagulation in preventing systemic embolization in these patients. Furthermore, those recommendations do not address the issue of the quality of life associated with long-term warfarin therapy. Using decision analysis, the authors examined the benefits and risks of long-term anticoagulation for patients 35 to 75 years of age who have dilated cardiomyopathy. The results show that anticoagulant therapy increases quality-adjusted life expectancy by 76 to 128 days, depending on the patient's age. Sensitivity analysis, however, demonstrates that the outcome is dependent on the disutility associated with long-term warfarin therapy. Interestingly, anticoagulation exerts most of its benefit by preventing pulmonary embolization, not systemic embolization. The authors conclude that the current recommendation to anticoagulate these patients, although probably correct for many patients, should take into consideration the change in lifestyle imposed by long-term anticoagulant therapy. For some patients, the benefit may not outweigh the sacrifice.

Acute severe low back pain. A population-based study of prevalence and care-seeking.

STUDY DESIGN: Telephone interviews were conducted with a random sample of adults in 4437 North Carolina households. The response rate was 79%. OBJECTIVE: The prevalence of low back pain and the correlates of care-seeking in a defined population were examined. SUMMARY OF BACKGROUND DATA: Previous research on low back pain has used varying definitions of the illness of low back pain, and has admixed patients with acute and chronic low back pain. Acute low back pain was examined in this study as a distinct phenomenon separate from chronic low back pain. METHODS: Respondents completed a detailed interview regarding the occurrence of and care sought for back pain in 1991. Acute back pain was defined as functionally limiting pain lasting less than 3 months. RESULTS: From this sample, 485 individuals had at least one occurrence of acute severe low back pain in 1991, representing 7.6% of the adult population. Symptoms were reported less commonly in individuals older than age 60 years (5% vs. 8.5%) and in nonwhites compared with whites (5% vs. 8.5%). Thirty-nine percent of those with back pain sought medical care; 24% sought care initially from an allopathic physician, 13% from a chiropractor, and 2% from other providers. More prolonged pain, more severe pain, and sciatica were associated with care-seeking. Gender, income, age, rural residence, and health insurance status did not correlate with the decision to seek medical care. Younger age, male gender, and nonjob-related pain did correlate with the decision to seek care from a chiropractor. CONCLUSIONS: Acute back pain is common. Care is often sought regardless of income and insurance status. Seeing a health care provider for acute back pain may not be discretionary from the perspective of the patient.

Measuring patient preferences for health outcomes: a decision analytic approach.

Decision analysis is a quantitative method used to assist difficult decisions. Its goal is to add insights when decision makers are faced with uncertainty. Decision analysis entails estimating the likelihood of clinical events, and, in addition, placing values on those events that are considered outcomes of interest. Placing values on clinical outcomes is called utility analysis. This paper introduces the utility analytic techniques used to quantify the worth of health outcomes for patients.

Expert testimony based on decision analysis: a malpractice case report.

OBJECTIVE: Expert testimony in malpractice cases is often subjective and biased. Decision-analytic techniques might provide an objective basis for such testimony. DESIGN: Case report. This article reports the case of a patient with chest pain that resulted in a malpractice suit alleging a delay in diagnosis of coronary artery disease. SETTING: The case occurred in a private practice; the expert witnesses and the decision analysis originated from a university teaching hospital. METHODS: A decision tree and threshold analysis were used to define the thresholds of disease probability at which either testing or treatment should be implemented. The expert testimony of two witnesses that exercise stress testing was the standard of care was compared with the results of the decision analysis. MAIN RESULTS: Decision analysis supported the view that cardiac catheterization would have been the more appropriate test. CONCLUSIONS: Techniques of decision analysis provide a structured and quantitative basis for empirical judgment and may help to minimize current problems with expert testimony.

Hypermedia in medical decision analysis: HyperDecision.

Early in the evolution of medical decision analysis, computers were employed to remove the tedium and insure the accuracy of repetitive calculations, a capacity they still serve today. However, user interfaces could be so complex as to be overwhelming, except for the capable few who designed them or used them often. HyperDecision is a hypercard-based decision analysis program with a simple user interface. A comprehensive tutorial and generic decision tree are integrated so that the fledgling user, whether medical student or seasoned clinician lacking evolved computer and/or decision analysis skills, can reap the benefits of computer support in their clinical practice. In the current political environment surrounding the practice of medicine, having easily accessible tools for both teaching and using medical decision analysis to evaluate and present the rational for medical decisions has taken on a new importance which the medical community must remain abreast of as we move toward the 21st century.

Management of infants at risk for occult bacteremia: a decision analysis.

Because febrile infants with no obvious source of bacterial infection may have bacteremia, and because bacteremia is difficult to diagnose on clinical grounds, we used decision analysis to evaluate whether such infants should be treated with antibiotics, tested further, or sent home. Using a simple decision tree, we found that the decision to give empiric antibiotic treatment is the decision of choice. The difference in quality-adjusted life expectancy between the "best" and "worst" decisions was only 11 days. However, this difference translated to prevention of death or permanent disability in 60 cases per 100,000 febrile children. Further, empiric treatment remained the best management alternative unless the probability of bacteremia was less than 1.4% (less than any published prevalence), or the efficacy of treatment was less than 21%. Our analysis demonstrated that a test with far greater sensitivity than leukocyte count or other tests currently in use is needed to justify testing rather than treating empirically. Further, an enormous patient population would be needed to find a difference of both clinical and statistical significance between treated and untreated patients in a controlled trial. In the absence of such trials, we recommend blood culture and empiric antibiotic treatment of all infants at risk for occult bacteremia.

Effectiveness and cost benefit of a proposed live cytomegalovirus vaccine in the prevention of congenital disease.

Congenital infection by human cytomegalovirus (CMV) is presently the leading infectious cause of mental retardation and congenital deafness in the United States. Live CMV vaccines in healthy adults have been shown to be safe and to induce immune responses similar to those that occur with natural CMV infection. Yet, only recently has a live CMV vaccine been tested for its protective ability. To evaluate the cost benefit and effectiveness of the proposed live CMV vaccine, we compared the following strategies: routine immunization, selective immunization of those women screened and found to be seronegative, and no immunization. Our results show that, when direct costs alone are considered, routine immunization of healthy women aged 15-25 years is cost beneficial even in populations with CMV seroprevalence as high as 87%. In populations with lower seroprevalence (55%-70%), for every 100,000 women immunized, more than 24 cases of symptomatic congenital CMV infection at birth and a similar number of cases with late sequelae (mainly deafness) would be prevented yearly. Such immunization would result in a net annual saving of $2.5 million.

The effects of blinding on the quality of peer review. A randomized trial.

Peer reviewers are blinded sometimes to authors' and institutions' names, but the effects of blinding on review quality are not known. We, therefore, conducted a randomized trial of blinded peer review. Each of 127 consecutive manuscripts of original research that were submitted to the Journal of General Internal Medicine were sent to two external reviewers, one of whom was randomly selected to receive a manuscript with the authors' and institutions' names removed. Reviewers were asked, but not required, to sign their reviews. Blinding was successful for 73% of reviewers. Quality of reviews was higher for the blinded manuscripts (3.5 vs 3.1 on a 5-point scale). Forty-three percent of reviewers signed their reviews, and blinding did not affect the proportion who signed. There was no association between signing and quality. Our study shows that, in our setting, blinding improves the quality of reviews and that research on the effects of peer review is possible.

Finding cancer in primary care outpatients with low back pain: a comparison of diagnostic strategies.

OBJECTIVE: To compare strategies for diagnosing cancer in primary care patients with low back pain. Strategies differed in their use of clinical findings, erythrocyte sedimentation rate (ESR), and plain x-rays prior to imaging and biopsy. DESIGN: Decision analysis and cost effectiveness analysis with sensitivity analyses. Strategies were compared in terms of sensitivity, specificity, and diagnostic cost effectiveness ratios. SETTING: Hypothetical MEASUREMENTS: Estimates of disease prevalence and test characteristics were taken from the literature. Costs were represented by the Medicare reimbursement for the tests and procedures employed. MAIN RESULTS: In the baseline analysis, using magnetic resonance imaging (MRI) as the imaging procedure prior to a single biopsy, strategies ranged in sensitivity from 0.40 to 0.73, with corresponding diagnostic costs of $14 to $241 per patient and average cost effectiveness ratios of $5,283 to $49,814 per case of cancer found. Incremental cost effectiveness ratios varied from $8,397 to $624,781; 5 strategies were dominant in the baseline analysis. Use of a higher ESR cutoff point (50 mm/hr) improved specificity and cost effectiveness for certain strategies. Imaging with MRI, or bone scan followed in series by MRI, resulted in a fewer unnecessary biopsies than imaging with bone scan alone. Cancer prevalence was an important determinant of cost effectiveness. CONCLUSIONS: We recommend a strategy of imaging patients who have a clinical finding (history of cancer, age > or = 50 years, weight loss, or failure to improve with conservative therapy) in combination with either an elevated ESR (> 50 mm/hr) or a positive x-ray, or using the same approach but imaging directly those patients with a history of cancer.