Utility assessment and clinical trials of diagnostic interventions.
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Activities of Daily Living↗
Biomedical subjects
R F Nease
Publications and source records attributed to R F Nease.
Patient preferences for location of care: implications for regionalization.
BACKGROUND: Regionalization of high-risk surgical procedures to selected high-volume centers has been proposed as a way to reduce operative mortality. For patients, however, travel to regional centers may be undesirable despite the expected mortality benefit. OBJECTIVE: To determine the strength of patient preferences for local care. DESIGN: Using a scenario of potentially resectable pancreatic cancer and a modification of the standard gamble utility assessment technique, we determined the level of additional operative mortality risk patients would accept to undergo surgery at a local rather than at a distant regional hospital in which operative mortality was assumed to be 3%. We used multiple logistic regression to identify predictors of willingness to accept additional risk. SUBJECTS: One hundred consecutive patients (95% male, median age 65) awaiting elective surgery at the Veterans Affairs Medical Center in White River Jct., VT. MAIN OUTCOME MEASURE: Additional operative mortality risk patients would accept to keep care local. RESULTS: All patients preferred local surgery if the operative mortality risk at the local hospital were the same as the regional hospital (3%). If local operative mortality risk were 6%, which is twice the regional risk, 45 of 100 patients would still prefer local surgery. If local risk were 12%, 23 of 100 patients would prefer local surgery. If local risk were 18%, 18 of 100 patients would prefer local surgery. Further increases in local risk did not result in large changes in the proportion of patients preferring local care. CONCLUSIONS: Many patients prefer to undergo surgery locally even when travel to a regional center would result in lower operative mortality risk. Therefore, policy makers should consider patient preferences when assessing the expected value of regionalizing major surgery.
Aged↗
Who should be offered prenatal diagnosis? The 35-year-old question.
Prenatal diagnosis of chromosomal disorders is generally offered to women who will be 35 years or older at the time of delivery or who have been determined via serum screening to be at risk similar to that of a woman older than 35 years. This age threshold was based on 4 major rationales that reflect considerations of resources and effectiveness. In this paper, we explore the current screening recommendations and consider new information that calls the 35-years threshold into question. We conclude that guidelines regarding use of prenatal diagnosis account for the preferences of the individual patient as well as for individual risk.
Age Factors↗
Use of the polymerase chain reaction in the diagnosis of herpes simplex encephalitis: a decision analysis model.
PURPOSE: To evaluate the utility of an assay based on a polymerase chain reaction (PCR) of cerebrospinal fluid in the management of patients with suspected herpes simplex encephalitis. METHODS: A decision model was constructed and used to compare a PCR-based approach with empiric therapy. Inputs required by the model included the sensitivity (96%) and specificity (99%) of PCR (derived from review of the literature), the prevalence of herpes simplex encephalitis (5%, based on the actual prevalence at Barnes Hospital among patients treated empirically with acyclovir), the outcomes for patients with and without herpes simplex encephalitis (derived from clinical studies of the Collaborative Antiviral Study Group and the actual experience at Barnes Hospital), and the average duration of empiric acyclovir therapy for patients with possible herpes simplex encephalitis (5.3 days based on actual experience at Barnes Hospital). RESULTS: Using these input values, the decision model predicted better outcomes with empiric therapy. However, low rates of inappropriate discontinuation of empiric therapy in patients with herpes simplex encephalitis or improved diagnosis and outcome resulting from a negative PCR assay result in patients without herpes simplex encephalitis led to better outcomes with the PCR-based approach. The PCR-based approach was associated with 9.2 fewer doses of acyclovir per patient. CONCLUSION: Based on the decision model using conservative assumptions, a PCR-based approach can yield better outcomes and reduced acyclovir use compared with empiric therapy.
Acyclovir↗
Assessment of patient preferences among men with prostate cancer.
PURPOSE: We developed a self-administered paper based instrument to assess patient preferences quantified as utilities for common outcomes associated with the management of prostate cancer. MATERIALS AND METHODS: A total of 50 patients was invited to test a self-administered paper based instrument designed to assess preferences for health outcomes associated with the management of localized prostate cancer. The 50 patients were selected from a group of 625 randomly identified men with prostate cancer who responded to a survey instrument designed to assess health related quality of life. The 50 patients selected for this pilot project were chosen because of the wide range of responses to the quality of life survey. Patient utilities were assessed for the 5 health states of overall quality of life, problems related to prostate cancer, and problems related to urinary, bowel and sexual dysfunction. RESULTS: Patients were able to complete the assigned tasks. The self-administered instrument had high test-retest reliability. In addition results obtained from this instrument showed a correlation with results obtained from assessments using other instruments, including an analog scale, a computer based system known as U-Titer, a quality of life survey and the Health Utility Index:3. CONCLUSIONS: A self-administered paper based instrument can be used to assess patient utilities for health states associated with prostate cancer management. Results from the instrument tested appear to be reliable and valid, and are comparable to those obtained from other assessment techniques. A self-administered paper based instrument has distinct advantages when conducting large survey studies because it can be incorporated at relatively low cost.
Aged↗
The importance of patient preferences for comorbidities in cost-effectiveness analyses.
When using cost-effectiveness analyses to prioritize the allocation of health care resources across patients, a standard definition of effectiveness must be used. In an informal review of cost-effectiveness analyses, we found a heterogeneity in the methods used to qualify adjust years of life. Many studies do not account for the morbid conditions that patients experience other than the index condition being studied. These studies systematically overstate health benefit relative to studies that do for comorbidities. We recommend that patient preferences for comorbid conditions be incorporated into analyses to allow a consistent and facile comparison of cost-utility ratios for societal decision making.
Comorbidity↗
Effect of locus of control and consideration of future consequences on time tradeoff utilities for current health.
Comments from subjects undergoing utility assessment suggest that personality traits may affect responses. We sought to describe the association between time-tradeoffs utility for current health and measures of two personality traits: (1) perceived control over one's life and (2) concern over immediate vs. future outcomes. One hundred subjects were recruited from the cafeteria of a large tertiary care hospital. Time-tradeoff utilities were assessed for current health relative to perfect health and death. Subjects also completed two previously validated scales, the Locus of Control (LOC), and Consideration of Future Consequences (CFC) instruments. The interview failure rate was less than 3%. The correlation between LOC score and utility for current health was modest (Spearman's rho = 0.196, p = 0.071), but increased substantially when subjects unwilling to trade were excluded (Spearman's rho = 0.33, p = 0.0043). The CFC scale was weakly correlated with utility for current health (Spearman's rho = 0.12, p = 0.2676). The Consideration of Future Consequences scale explains little of the variation in time-tradeoff utilities. In contrast, Locus of Control appears to partially explain the variation in time-tradeoff utilities for current health, even after controlling for health status.
Adult↗
Physicians' assessments of the utility of health states associated with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) infection.
An understanding of quality of life (QOL) with human immunodeficiency virus (HIV) is important because the merits of prevention and treatment alternatives may depend substantially on how these interventions affect QOL. Physicians' views about QOL are important, because they influence the therapeutic options that physicians consider or offer, the recommendations that physicians make, and because they are important for the analysis of certain policy questions. We assessed physicians' utilities of health states associated with HIV infection, and hepatitis B virus (HBV) infection; assessment of utilities for HBV was induced to provide a comparison with HIV utilities. We surveyed 200 housestaff and staff physicians in an academic medical centre by anonymous paper-based questionnaire and used the time-tradeoff method to assess physicians' utilities of the health states. On a scale in which 0 was equivalent to death, and 1 was equivalent to good health, the median utilities for asymptomatic HIV infection, symptomatic HIV infection, and AIDS were 0.833, 0.417, and 0.167, respectively (p < 0.01 or each two-way comparison). Median utilities for asymptomatic HBV infection, mildly symptomatic HBV infection, and severely symptomatic HBV infection were 0.917, 0.667, and 0.167, respectively (p < 0.01 for each two-way comparison). Although physicians varied substantially in the ratings of health states, they assessed the utility of life with HIV disease, including asymptomatic infection, as severely reduced. Studies of the effectiveness and cost-effectiveness of preventive and therapeutic interventions for HIV should evaluate the effect of the intervention on utility-based assessments of QOL. Studies that do not assess such effects may significantly underestimate or overestimate the value of these interventions, depending on the intervention's effect on QOL.
Acquired Immunodeficiency Syndrome↗
Estimating treatment benefits for the elderly: the effect of competing risks.
To fully involve patients in treatment decisions, physicians need to communicate future health prospects that patients will have both with and without newly diagnosed disease. These prospects depend not only on the risks patients face from the new disease but also on the risks they face from other causes. Nowhere is an understanding of these competing risks more relevant than in the care of the elderly. In this study, we use the declining exponential approximation for life expectancy (DEALE) to provide a framework to help clinicians gauge the effect of competing risks as a function of age. Because older patients have many competing risks for death, the absolute effect of a new diagnosis on life expectancy is often relatively small. Consequently, the potential gain in survival even from perfect therapy may also be small. Moreover, no therapy is perfect, and the risks of therapy often increase with age. In the elderly, the combination of a high burden of competing risks and high rates of treatment-related complications conspires to reduce the net benefit of numerous interventions. We conclude that, compared with younger patients, the elderly should request only the more clearly effective treatments and should be willing to tolerate fewer associated complications before they agree to initiate therapy.
Aged↗
Cost-effectiveness of HIV screening in acute care settings.
BACKGROUND: Although screening inpatients for human immunodeficiency virus (HIV) in acute care hospital settings has been recommended, the cost-effectiveness of screening is not known. OBJECTIVE: To estimate the cost-effectiveness of a voluntary screening program in acute care hospitals and associated clinics. RESULTS: During the first year, an HIV screening program implemented in acute care hospital settings in which the seroprevalence of HIV infection is 1% or more would result in the identification of approximately 110,000 undetected cases of HIV infection. The program would result in expenditures of approximately $171 million for testing and counseling, and expenditures of approximately $2 billion for incremental medical care for the patients identified as having HIV infection during the first year of screening. When the seroprevalence of HIV is 1%, the cost-effectiveness of screening is $47,200 per year of life saved. When the effect of early identification of HIV infection on the patient's quality of life also is considered, screening is less cost-effective. Screening-induced reductions in risk behavior improve the cost-effectiveness of screening by preventing the transmission of HIV.
Acute Disease↗
Automated utility assessment of global health.
The objective of this study was to characterize the performance of an automated utility assessment instrument for measuring preferences for overall health. The study population consisted of 83 subjects recruited from the cafeteria of a large tertiary care hospital. We assessed utilities for current health relative to perfect health and death using the rating scale, time tradeoff and standard gamble metrics. To validate the instrument, we compared utilities with the General Health subscale of the SF-36 Health Survey instrument, satisfaction with current health, and degree of bother due to current health. We evaluated interview failure rate based on irrational orderings of two practice assessments (monocular and binocular blindness) or inability to complete the interview. As expected, utility for overall health was statistically significantly associated with the General Health subscale score and measures of satisfaction with current health and degree of bother. There is substantial variation in utilities among patients with similarly severe overall health, and substantial overlap in utilities among subjects with different levels of overall health. The failure rate in the study was acceptable (9.6%). Automated assessment of utility for overall health provides a feasible means for estimating individual preferences.
Adult↗
The effect of an educational intervention on the perceived risk of breast cancer.
OBJECTIVE: To appraise women's perceived risk of developing breast cancer and the effects of a physician's educational intervention on this perception. DESIGN: Longitudinal before-and-after study involving four measures of participants risk of developing breast cancer. Eligible women provided the data needed to calculate an objective estimate of their individual risk of developing breast cancer before age 80 using the Gail formula. They also provided a subjective estimate of their individual perceived risk. Then, each participant met with a general internal medicine physician who provided personalized information and education. Immediately after education, and again several months later, we reassessed each woman's perceived risk. SETTING: Physicians office. PARTICIPANTS: A convenience sample of 59 women participating in the Tamoxifen Breast Cancer Prevention Trial. Twenty-nine women returned for the follow-up risk assessment. MEASUREMENTS AND MAIN RESULTS: The median calculated risk of breast cancer before age 80 (by the Gail formula) was 15%, but the median perceived risk before educational intervention was 50%. The perceived risk after educational intervention fell to 25%. At late follow-up, the median perceived risk remained at 25%. The difference between the preeducational perceptions and the calculated estimates was significant (1) < .0001). After educational intervention, perceived risk measures shifted closer to the calculated value, but still remained significantly higher (p <.0001). CONCLUSIONS: Women often substantially overestimate their chances of getting breast cancer. Educational intervention by a physician, including explanation of an individual's calculated risk, can reduce this error. The effect of education appears to persist at least for several months.
Adult↗
The importance of patient preference in the decision to screen for prostate cancer. Prostate Patient Outcomes Research Team.
OBJECTIVE: Routine screening for prostate cancer is controversial because of frequent false-positive results, the potential for slow, non-life-threatening growth of untreated cancer, the uncertainty regarding whether treatment can extend life, and the potential for treatment complications. This study examines how information about prostate-specific antigen (PSA) testing and the uncertain benefits of treating prostate cancer affects patients' desire for PSA testing. DESIGN: An educational videotape designed to inform men about the uncertainty surrounding PSA screening and the treatment of early-stage prostate cancer was presented to two groups of male patients 50 years of age or older. SETTING: Dartmouth-Hitchcock Medical Center. PATIENTS/PARTICIPANTS: For study 1, men seeking a free prostate cancer screening were preassigned to view the educational videotape (N = 184) or another videotape (N = 185). For study 2, men scheduled to visit a general internal medicine clinic viewed either the educational videotape (N = 103) or no videotape (N = 93). MEASUREMENTS AND MAIN RESULTS: The men's information and preferences about prostate cancer screening and treatment and actual choice of PSA test at the next test opportunity were measured. Men who viewed the educational videotape were: better informed about PSA tests, prostate cancer, and its treatment; preferred no active treatment if cancer were found; and preferred not to be screened (all significant at p < or = .002 in both studies). Men viewing the educational video were less likely to have a PSA test (p = .041, study 2). This tendency was not significant at the free-PSA clinic (p = .079). CONCLUSIONS: Preference regarding cancer screening and treatment is greatly affected by information about medical uncertainties. Because informed patient choices vary. PSA screening decisions should incorporate individual preferences.
Case-Control Studies↗
Perceptions of breast cancer risk and screening effectiveness in women younger than 50 years of age.
BACKGROUND: The National Cancer Institute has recently changed its approach and has substituted summary-of-evidence statements for specific recommendations for breast cancer screening in women 40-50 years of age, leaving these women with a greater share of decision-making responsibility. To make an informed decision about breast cancer screening, women need accurate information about their breast cancer risk and the benefit of screening. Although it has been suggested that women younger than 50 years of age overestimate this risk and benefit, their estimates have not been quantified. PURPOSE: The purpose of this study was to determine how women 40-50 years of age perceive their risk of breast cancer and the effectiveness of screening and how these perceptions compare with estimates derived from epidemiologic studies of breast cancer incidence and randomized clinical trials of screening. METHODS: We mailed a questionnaire to 200 women, identified through the computerized medical records of Dartmouth-Hitchock Medical Center, who were between 40 and 50 years of age and had no history of breast cancer. Each woman was asked about her risk factors for breast cancer and asked to estimate her probabilities of developing breast cancer and dying of it within 10 years, with and without screening. The women's answers were compared with individual probabilities derived from the Gail et al. model, age-specific probabilities of developing and dying of breast cancer in the United States, and the results of randomized clinical trials of screening. RESULTS: The mailed questionnaire was completed and returned by 145 (73%) of the 200 women. Respondents over-estimated their probability of dying of breast cancer within 10 years by more than 20-fold (median, 22.3; interquartile range, 11.1-74.2). Assuming a 10% relative risk reduction from screening, respondents overestimated the relative risk reduction by sixfold (median, 6.0; interquartile range, 5.0-7.5) and the absolute risk reduction more than 100-fold (median, 127.5; interquartile range, 47.1-399.6). The median perceived estimate of absolute risk reduction was 6.0 breast cancer deaths per 100 women; the median calculated estimate was only 0.04 per 100 women. CONCLUSION: These findings suggest that many women younger than 50 years of age substantially overestimate their breast cancer risk and the effectiveness of screening. IMPLICATIONS: A balanced presentation of information about breast cancer risk and screening effectiveness may improve decision making for women younger than 50 years of age and reduce their anxiety about breast cancer, regardless of whether they choose to be screened.
Adult↗
Screening surgeons for HIV infection. A cost-effectiveness analysis.
UNLABELLED: OBJECTIVE. To determine the cost-effectiveness of a policy to screen surgeons for human immunodeficiency virus (HIV) infection to prevent transmission of HIV to patients having invasive procedures. DESIGN: Cost-effectiveness analysis. RESULTS: A one-time national screening program would identify approximately 137 surgeons with HIV infection (range, 28 to 423 surgeons) and would prevent approximately 4.3 infections (range, 1.9 to 21.3 infections) in patients treated by infected surgeons and 0.9 infections (range, 0 to 12.9 infections) in sexual partners of infected surgeons at a direct cost of $8.1 million and an induced cost of approximately $44 million. It would result in expenditures of $458,000 per year of life saved (range, $147,000 to $687,000 per year of life saved), whereas an annual screening program would result in expenditures of approximately $1.1 million per year of life saved (range, $338,000 to $1,886,000 per year of life saved). If the prevalence of HIV infection in surgeons is estimated to be three times our base-case estimate (an increase from 0.1% to 0.3%), annual screening would result in expenditures of approximately $741,000 per year of life saved. If the probability of seroconversion after a patient is exposed to a contaminated instrument is increased to 5.0% from our base-case estimate of 0.29%, an annual screening program would still cost more than $228,000 per year of life saved. CONCLUSION: Screening surgeons for HIV to prevent transmission of HIV to patients having invasive procedures requires expenditures per year of life saved that are considerably in excess of those of most accepted health interventions. Surveillance studies of patients treated by surgeons infected with HIV should be continued to confirm that transmission of HIV to patients having invasive procedures is rare.
Cost-Benefit Analysis↗
Variation in patient utilities for outcomes of the management of chronic stable angina. Implications for clinical practice guidelines. Ischemic Heart Disease Patient Outcomes Research Team.
OBJECTIVE: Although practice guidelines sometimes make recommendations based on symptom severity, they rarely account for how patients feel about their symptoms. To investigate the possible importance of patient preferences in treatment of ischemic heart disease, we assessed attitudes toward symptoms in patients with angina pectoris. DESIGN: Case series. SETTING: Ambulatory cardiology clinics at two tertiary care medical centers. PATIENTS: A total of 220 subjects were selected from 589 patients with chronic stable angina referred from cardiologists to achieve patients samples balanced for sex, race, and angina severity. MAIN OUTCOME MEASURES: We measured patients' attitudes toward their angina using the rating scale, time trade-off, and standard gamble utility metrics. Reliability of measurements was evaluated by repeating the assessments 2 weeks later on 50 willing patients. RESULTS: While the mean responses followed the expected patterns (those with more severe Canadian Cardiovascular Society scores chose lower utilities), attitudes toward symptoms varied substantially among patients with similarly severe angina. For example, there was a 33% chance that a patient with class II angina had a time trade-off utility that was lower (ie, more bothered by symptoms) than a patient with more severe angina (class III/IV). This variation in utilities was not due to random error in the assessments. CONCLUSIONS: Angina patients with similar functional limitation vary considerably in their tolerance for their symptoms, as measured by utilities. Our findings suggest that guidelines for the management of ischemic heart disease should be based on the preferences of the individual patient rather than on symptom severity alone.
Adult↗
Patient desire for information and decision making in health care decisions: the Autonomy Preference Index and the Health Opinion Survey.
OBJECTIVES: To compare results on the Autonomy Preference Index (API) and the Health Opinion Survey (HOS), two instruments that measure patient desire for information and involvement in decision making. DESIGN: Cross-sectional survey. SETTING: University-based primary care outpatient longitudinal and acute care clinic. PATIENTS: 167 patients with benign prostatic hyperplasia, back pain, or mild hypertension seen from October 1991 to December 1992. MEASUREMENTS AND MAIN RESULTS: On the API and the HOS (both scaled from 0 to 1), the patients had intermediate desire for involvement in decision making (median API: 0.42; HOS: 0.36) and higher desire for information (median API: 0.97; HOS: 0.57). With either instrument, the desire for information exceeded that for involvement in decision making (p < 0.0001). The API information scores were higher than the HOS information scores (p < 0.0001), probably because the HOS focuses on patient behavior rather than desire. Variation in desire for information and involvement in decision making was substantial and largely unexplained. CONCLUSIONS: Most patients have a high desire for information, the desire for information and involvement in decision making varies substantially among patients, and the API is preferable to the HOS for researchers interested in focusing solely on patient desire for information.
Adult↗
Economic heartburn: average cost-effectiveness and gastroesophageal reflux disease.
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Clinical Trials as Topic↗