39 results on '"Lawrence WF"'
Search Results
2. Economic evaluation alongside a clinical trial of psycho-educational interventions to improve adjustment to survivorship among patients with breast cancer.
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Mandelblatt JS, Cullen J, Lawrence WF, Stanton AL, Yi B, Kwan L, and Ganz PA
- Published
- 2008
3. Health limitations and quality of life associated with cancer and other chronic diseases by phase of care.
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Yabroff KR, McNeel TS, Waldron WR, Davis WW, Brown ML, Clauser S, and Lawrence WF
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- 2007
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4. Report of nationally representative values for the noninstitutionalized US adult population for 7 health-related quality-of-life scores.
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Hanmer J, Lawrence WF, Anderson JP, Kaplan RM, and Fryback DG
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BACKGROUND: Despite widespread use of generic health-related quality-of-life (HRQoL) scores, few have publicly published nationally representative US values. PURPOSE: To create current nationally representative values for 7 of the most common HRQoL scores, stratified by age and sex. METHODS: The authors used data from the 2001 Medical Expenditures Panel Survey (MEPS) and the 2001 National Health Interview Survey (NHIS), nationally representative surveys of the US noninstitutionalized civilian population: The MEPS was used to calculate 6 HRQoL scores: categorical self-rated health, EuroQoL-5D with US scoring, EuroQoL-5D with UK scoring, EuroQol Visual Analog Scale, mental and physical component summaries from the SF-12, and the SF-6D. The authors estimated Quality of Well-being scale scores from the NHIS. RESULTS: They included 22,523 subjects from MEPS 2001 and 32,472 subjects from NHIS 2001. Most age and sex categories had instrument completion rates above 85%. Females reported lower scores than males across all ages and instruments. In general, those in older age groups reported lower scores than younger age groups, with the exception of the mental component summary from the SF-12. CONCLUSION: This is one of the first sets of publicly available, nationally representative US values for any standardized HRQoL measure. These values are important for use in both generalized comparisons of health status and in cost-effectiveness analyses. [ABSTRACT FROM AUTHOR]
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- 2006
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5. Process utility in breast biopsy.
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Swan JS, Lawrence WF, and Roy J
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PURPOSE: To determine whether the waiting trade-off (WTO) is feasible for differentiating short-term biopsy preferences in an acute situation where anxiety is the symptomatic disease state. METHODS: 75 women with past experience of either breast core-needle biopsy (CNB), more invasive excisional surgical biopsy (EXB), or both, had telephone WTO assessments. Patients' baseline and test-related anxiety were valued by time trade-off (TTO) used to scale the WTO. Rating scales (RS) were obtained for convergent validity assessment with WTO and TTO. RESULTS: Data were obtained in 38 women who had both CNB and EXB ('paired') and 20 who had CNB only and 16 who had EXB only ('unpaired'). Patients rated only the procedure(s) they experienced. Median paired and mean unpaired WTO scores indicated patients were willing to wait significantly longer to avoid EXB (P = 0.0003, P = 0.0002, respectively). The waiting time difference between EXB and CNB was 2.1 weeks greater in unpaired data than paired data. RS scores comparing the procedures were significantly different only for paired data (P < 0.05). Median TTO preferences for baseline (1.00) and test anxiety (0.93) obtained in 74 patients were significantly different (P < 0.0001) and consistent with RS. Correlation was noted between WTO and RS (-0.307 to -0.453, P = 0.0205 to 0.0001). The median EXB quality-adjusted life years toll (1.5 quality-adjusted life days) calculated from pooled WTO data (paired and unpaired) from 54 patients is near a threshold in a published model. CONCLUSION: The WTO is feasible for discriminating preferences for short-term health states in an acute medical scenario where it might have been expected to be impracticable. [ABSTRACT FROM AUTHOR]
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- 2006
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6. Cost-effectiveness analysis based on the atypical squamous cells of undetermined significance/low-grade squamous intraepithelial lesion Triage Study (ALTS)
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Kulasingam SL, Kim JJ, Lawrence WF, Mandelblatt JS, Myers ER, Schiffman M, Solomon D, Goldie SJ, and ALTS Group
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- 2006
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7. Predicting EuroQoL EQ-5D preference scores from the SF-12 health survey in a nationally representative sample.
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Lawrence WF and Fleishman JA
- Abstract
PURPOSE: To predict the EuroQoL EQ-5D utility index from the SF-12 Health Survey for a US national sample of adults. METHODS: The authors used the 2000 Medical Expenditure Panel Survey to examine the relationship between instruments. Linear regression was used to predict EQ-5D scores from Physical Component Summary (PCS) and Mental Component Summary (MCS) scores of the SF-12. A prediction model was derived in one half of the sample and validated in the other half. RESULTS: Complete responses to both measures were available for 14,580 adults; 7313 (50.2%) surveys were used for the derivation set. The 2-variable model predicted 61% of the variance in EQ-5D scores and provided reasonable ability to predict mean EQ-5D scores from mean PCS and MCS scores. Confidence intervals are dependent on sample size and variance of PCS and MCS scores. CONCLUSIONS: EQ-5D scores can be reasonably predicted from the SF-12. This model allows researchers to estimate utility data for use in decision and cost-utility analyses. [ABSTRACT FROM AUTHOR]
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- 2004
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8. Development of an interactive decision aid for female BRCA1/BRCA2 carriers.
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Kaufman EM, Peshkin BN, Lawrence WF, Shelby R, Isaacs C, Brown K, Rispoli J, O'Neill S, Hurley K, DeMarco T, Brogan B, Grumet S, Jandorf L, McKenna K, Valdimarsdottir H, and Schwartz MD
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Shared decision making between patients and providers is becoming increasingly common, particularly when there is no clear preferred course of action. As a result, decision aids are being adopted with growing frequency and have been applied to many medical decision-making issues. One such issue where there is uncertainty is breast cancer risk management among BRCA1/BRCA2 carriers. We present the development of a CD-ROM decision aid to facilitate risk management decision making in this population. Our decision aid was developed with the intention of providing it through a randomized clinical trial. The CD-ROM is a multimedia, interactive intervention which provides information about breast cancer, risks associated with BRCA1 and BRCA2 mutations, risk management options for hereditary breast cancer, and a breast cancer risk management decision aid. The goal of this CD-ROM, offered as an adjunctive intervention, is to reduce decisional conflict and psychological distress and improve comprehension of risk information, decisional satisfaction, medical adherence, and quality of life for this population of women at increased risk for breast cancer. [ABSTRACT FROM AUTHOR]
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- 2003
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9. Effect of treatment on quality of life among men with clinically localized prostate cancer.
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Schapira MM, Lawrence WF, Katz DA, McAuliffe TL, Nattinger AB, Schapira, M M, Lawrence, W F, Katz, D A, McAuliffe, T L, and Nattinger, A B
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- 2001
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10. Inventory of data sources for estimating health care costs in the United States.
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Lund JL, Yabroff KR, Ibuka Y, Russell LB, Barnett PG, Lipscomb J, Lawrence WF, Brown ML, Lund, Jennifer L, Yabroff, K Robin, Ibuka, Yoko, Russell, Louise B, Barnett, Paul G, Lipscomb, Joseph, Lawrence, William F, and Brown, Martin L
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- 2009
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11. Demographic variation in SF-12 scores: true differences or differential item functioning?
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Fleishman JA and Lawrence WF
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BACKGROUND: Demographic differences have been reported in summary measures of physical and mental health based on the SF-12 instrument. OBJECTIVES: This study examines the extent to which differential item functioning (DIF) contributes to observed subgroup differences in health status. DIF refers to situations in which the psychometric properties of items are not invariant across different groups. The presence of DIF confounds interpretation of subgroup differences. SUBJECTS: A national sample of 11,626 adult respondents in the 2000 Medical Expenditure Panel Survey who completed a self-administered questionnaire. MEASURES: In addition to the SF-12, we collected data on demographic characteristics (age, gender, education, and race/ethnicity) and whether the person had ever been diagnosed with six chronic medical conditions. RESULTS: Multiple-indicator multiple-cause latent variable models showed significant differences in physical health by gender, age, and education. Adjusting for DIF reduced but did not eliminate age and education differences. However, for mental health, adjusting for DIF resulted in Black-White differences becoming nonsignificant, and the effect for the oldest age group switched from positive to negative. Race/ethnicity was not associated with physical health status. CONCLUSIONS: Age group comparisons of mental health may be particularly affected by DIF. Differences in education, as well as age and gender, need to be controlled when making group comparisons. Additional work is needed to understand factors that give rise to demographic differences in reported health status. [ABSTRACT FROM AUTHOR]
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- 2003
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12. Federal sponsorship of cost-effectiveness and related research in health care: 1997-2001.
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Siegel JE, Byron SC, and Lawrence WF
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- 2005
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13. An overview and discussion of the Patient-Centered Outcomes Research Institute's decision aid portfolio.
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Gayer CC, Crowley MJ, Lawrence WF, Gierisch JM, Gaglio B, Williams JW Jr, Myers ER, Kendrick A, Slutsky J, and Sanders GD
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- Academies and Institutes, Financial Management, Humans, Decision Support Techniques, Delivery of Health Care, Patient Outcome Assessment
- Abstract
Decision aids (DAs) help patients make informed healthcare decisions in a manner consistent with their values and preferences. Despite their promise, DAs developed with public research dollars are not being implemented and adopted in real-world patient care settings at a rate consistent with which they are being developed. To appraise the sum of the parts of the portfolio and create a strategic imperative surrounding future funding, the Patient-Centered Outcomes Research Institute (PCORI) tasked the Duke Evidence Synthesis Group with evaluating its DA portfolio. This paper describes PCORI's portfolio of DAs according to the Duke Evidence Synthesis Group's analysis in the context of PCORI's mission and the field of decision science. The results revealed a diversity within PCORI's portfolio of funded DA projects. Findings support the movement toward more rigorous DA development, assessment and maintenance. PCORI's funding priorities related to DAs are clarified and comparative questions of interest are posed.
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- 2016
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14. Models in the development of clinical practice guidelines.
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Habbema JD, Wilt TJ, Etzioni R, Nelson HD, Schechter CB, Lawrence WF, Melnikow J, Kuntz KM, Owens DK, and Feuer EJ
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- Breast Neoplasms diagnosis, Colorectal Neoplasms diagnosis, Early Detection of Cancer, Humans, Mammography, Risk Assessment, Risk Factors, Evidence-Based Medicine, Models, Theoretical, Practice Guidelines as Topic
- Abstract
Clinical practice guidelines should be based on the best scientific evidence derived from systematic reviews of primary research. However, these studies often do not provide evidence needed by guideline development groups to evaluate the tradeoffs between benefits and harms. In this article, the authors identify 4 areas where models can bridge the gaps between published evidence and the information needed for guideline development applying new or updated information on disease risk, diagnostic test properties, and treatment efficacy; exploring a more complete array of alternative intervention strategies; assessing benefits and harms over a lifetime horizon; and projecting outcomes for the conditions for which the guideline is intended. The use of modeling as an approach to bridge these gaps (provided that the models are high-quality and adequately validated) is considered. Colorectal and breast cancer screening are used as examples to show the utility of models for these purposes. The authors propose that a modeling study is most useful when strong primary evidence is available to inform the model but critical gaps remain between the evidence and the questions that the guideline group must address. In these cases, model results have a place alongside the findings of systematic reviews to inform health care practice and policy.
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- 2014
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15. Comparative effectiveness research in clinical practice.
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Lawrence WF, Chang S, Kane RL, and Wilt TJ
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- Health Priorities legislation & jurisprudence, Health Priorities organization & administration, Health Services Research legislation & jurisprudence, Health Services Research organization & administration, Humans, Minnesota, Outcome and Process Assessment, Health Care legislation & jurisprudence, Outcome and Process Assessment, Health Care organization & administration, Patient Education as Topic legislation & jurisprudence, Patient Education as Topic organization & administration, Practice Guidelines as Topic, Comparative Effectiveness Research legislation & jurisprudence, Comparative Effectiveness Research organization & administration, Evidence-Based Medicine legislation & jurisprudence, Evidence-Based Medicine organization & administration
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The Agency for Healthcare Research and Quality (AHRQ) has funded systematic reviews of comparative effectiveness research in 17 areas over the last 10 years as part of a federal mandate. These reviews provide a reliable and unbiased source of comprehensive information about the effectiveness and risks of treatment alternatives for patients and clinicians. This article describes comparative effectiveness research, provides an overview of how physicians can use it in clinical practice, and references important contributions made by the Minnesota Evidence-based Practice Center.
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- 2014
16. Comparative effectiveness research in practice and policy for radiation oncology.
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Lawrence WF
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- Comparative Effectiveness Research legislation & jurisprudence, Decision Support Techniques, Humans, National Academies of Science, Engineering, and Medicine, U.S., Health and Medicine Division, United States, Comparative Effectiveness Research methods, Health Policy legislation & jurisprudence, Practice Guidelines as Topic, Radiation Oncology legislation & jurisprudence, Radiation Oncology methods
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Interest in comparative effectiveness research (CER) has increased dramatically over the past decade, yet perceptions about what comprises CER varies. CER has several attributes relevant to practice and policy: (1) The goal of CER is to inform decisions about health care. (2) Literature synthesis is used in addition to primary research. (3) CER evaluates not only overall outcomes for the population but also evaluates subgroups that may have heterogeneous outcomes. (4) Research places an emphasis on outcomes in the "real-world" settings. (5) Outcomes studied should be relevant to patients. In radiation oncology, where many of the traditional clinical trials are comparative in nature, the line between CER and "traditional" research may be blurred, but an increased emphasis on CER can help to bridge the research enterprise and clinical practice, helping to inform decision making at the patient, clinician, and policy levels., (© 2013 Published by Elsevier Inc.)
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- 2014
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17. Chapter 10: deciding whether to complement a systematic review of medical tests with decision modeling.
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Trikalinos TA, Kulasingam S, and Lawrence WF
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- Humans, Algorithms, Evidence-Based Medicine methods, Evidence-Based Medicine standards, Sensitivity and Specificity, Decision Support Techniques, Diagnostic Techniques and Procedures standards, Guidelines as Topic, Systematic Reviews as Topic
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Limited by what is reported in the literature, most systematic reviews of medical tests focus on "test accuracy" (or better, test performance), rather than on the impact of testing on patient outcomes. The link between testing, test results and patient outcomes is typically complex: even when testing has high accuracy, there is no guarantee that physicians will act according to test results, that patients will follow their orders, or that the intervention will yield a beneficial endpoint. Therefore, test performance is typically not sufficient for assessing the usefulness of medical tests. Modeling (in the form of decision or economic analysis) is a natural framework for linking test performance data to clinical outcomes. We propose that (some) modeling should be considered to facilitate the interpretation of summary test performance measures by connecting testing and patient outcomes. We discuss a simple algorithm for helping systematic reviewers think through this possibility, and illustrate it by means of an example.
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- 2012
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18. Patterns of care in early-stage breast cancer survivors in the first year after cessation of active treatment.
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Mandelblatt JS, Lawrence WF, Cullen J, Stanton AL, Krupnick JL, Kwan L, and Ganz PA
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- Adult, Aged, Aged, 80 and over, Female, Health Care Costs, Humans, Middle Aged, Survivors, Breast Neoplasms therapy, Health Services statistics & numerical data
- Abstract
Purpose: Patterns of health care use have not been well described for breast cancer survivors. The purpose of this study was to describe the health service use in a survivor cohort., Patients and Methods: Women with stage I or II breast cancer were recruited (n = 558) after primary treatment for a multicenter, randomized trial of psychoeducational interventions for facilitating transition to survivorship; 418 women completed the study. Participants completed calendar diaries detailing health care use for 1 year after treatment. Services were coded using Current Procedural Terminology-Fourth Edition codes; costs were estimated using year 2000 Medicare reimbursements., Results: Health care use diary data were available for 391 women (70% of the sample). On average, these survivors reported 30 episodes of health service use in the year after treatment. Total annual costs of care averaged more than 1,800 dollars per survivor; medical office visits were the major component of costs. Type of cancer treatment, depression, and physical function and comorbid illness were independent predictors of the costs of services. There were geographic variations in initial local treatment patterns and in post-treatment costs. Notably, all women should have received surveillance mammography in the time period, but only 61.9% did so; the odds of mammogram receipt were higher for women who had a lumpectomy (v mastectomy) and women who were white (v nonwhite)., Conclusion: Use of health services is frequent and intensive in the first year after treatment for breast cancer. Despite frequent contact with the health care system, there is room for improvement in providing guideline-suggested surveillance mammography for survivors.
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- 2006
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19. A national catalog of preference-based scores for chronic conditions in the United States.
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Sullivan PW, Lawrence WF, and Ghushchyan V
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- Adolescent, Adult, Female, Health Services Research, Health Status Indicators, Humans, Likelihood Functions, Male, Middle Aged, Quality of Life, Quality-Adjusted Life Years, Socioeconomic Factors, United States, Value of Life economics, Chronic Disease therapy, Consumer Behavior statistics & numerical data, Cost-Benefit Analysis
- Abstract
Background: The variability in preferences used in quality-adjusted life-years estimation jeopardizes the comparability of cost-effectiveness analyses and has led the Panel on Cost-Effectiveness in Health and Medicine (the PCEHM) to call for a catalog of "off-the-shelf" preference weights associated with conditions that can be used by health researchers without the burden of collecting primary data., Objective: The current research responds to the call by developing a nationally representative catalog of preference-based scores for chronic conditions and associated sociodemographic characteristics., Methods: The authors report the EQ-5Dindex scores of chronic conditions and associated sociodemographic characteristics in the nationally representative Medical Expenditure Panel Survey (MEPS). Chronic conditions were coded using "quality priority conditions" (QPC) and clinical classification categories (CCC). OLS, Tobit, and censored least absolute deviations (CLAD) regression models were used to provide condition estimates adjusted for age, comorbidity, gender, race, ethnicity, income, and education., Results: Unadjusted and adjusted EQ-5Dindex scores for each QPC and CCC code are presented. EQ-5Dindex scores for older age categories were lower than younger categories, female scores were lower than males, certain racial groups had lower scores than others, and EQ-5Dindex scores were higher for individuals with higher education and income levels., Conclusion: The preference-based chronic condition scores reported in this research are nationally representative and may be useful to researchers to calculate quality-adjusted life-years for cost-effectiveness analyses and population-based burden of illness studies without the difficulty of primary data collection. Further research is necessary to validate these scores in condition-specific studies.
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- 2005
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20. Geographic disparities in cervical cancer mortality: what are the roles of risk factor prevalence, screening, and use of recommended treatment?
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Yabroff KR, Lawrence WF, King JC, Mangan P, Washington KS, Yi B, Kerner JF, and Mandelblatt JS
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- Female, Health Services Accessibility, Humans, Papillomavirus Infections diagnosis, Papillomavirus Infections epidemiology, Patient Acceptance of Health Care, Risk Factors, Rural Health Services supply & distribution, United States epidemiology, Uterine Cervical Neoplasms diagnosis, Uterine Cervical Neoplasms therapy, Uterine Cervical Neoplasms virology, Vaginal Smears statistics & numerical data, Risk Assessment, Rural Health statistics & numerical data, Rural Health Services statistics & numerical data, Uterine Cervical Neoplasms mortality
- Abstract
Context: Despite advances in early detection and prevention of cervical cancer, women living in rural areas, and particularly in Appalachia, the rural South, the Texas/Mexico border, and the central valley of California, have had consistently higher rates of cervical cancer mortality than their counterparts in other areas during the past several decades., Methods: This paper reviews the published literature from 1966 to July 2002 to assess three potential pathways underlying this excess mortality--high human papilloma virus (HPV) prevalence, lack of or infrequent screening and advanced disease at diagnosis, and under-use of recommended treatment and shorter survival., Findings: Living in rural areas may impose barriers to cervical cancer control, including lack of transportation and medical care infrastructures. Population characteristics that place women at greater risk for developing and dying from cervical cancer, such as low income, lack of health insurance, and physician availability, are concentrated in rural areas. Published data, however, are insufficient to identify the key reasons for the observed mortality patterns., Conclusions: At this time, given the lack of definitive evidence in the published literature, decisions about priorities in areas with high rates of cervical cancer mortality will depend on knowledge of current levels of screening, incidence, and stage distribution; and service delivery infrastructures, resources, and acceptability of interventions to the target population.
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- 2005
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21. Burden of illness in cancer survivors: findings from a population-based national sample.
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Yabroff KR, Lawrence WF, Clauser S, Davis WW, and Brown ML
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- Activities of Daily Living, Adult, Age Distribution, Aged, Case-Control Studies, Educational Status, Efficiency, Female, Health Status, Health Status Indicators, Humans, Incidence, Male, Middle Aged, Prevalence, Quality of Life, Sex Distribution, Surveys and Questionnaires, Survivors statistics & numerical data, United States epidemiology, Cost of Illness, Neoplasms epidemiology
- Abstract
Background: Population trends in aging and improved cancer survival are likely to result in increased cancer prevalence in the United States, but few estimates of the burden of illness among cancer survivors are currently available. The purpose of this study was to estimate the burden of illness in cancer survivors in a national, population-based sample., Methods: A total of 1823 cancer survivors and 5469 age-, sex-, and educational attainment-matched control subjects were identified from the 2000 National Health Interview Survey. Multiple measures of burden, including utility, a summary measure of health, and days lost from work, were compared using two-sided tests of statistical significance for the two groups overall and for subgroups stratified by tumor site and time since diagnosis., Results: Compared with matched control subjects, cancer survivors had poorer outcomes across all burden measures (P<.01). Cancer survivors had lower utility values (0.74 versus 0.80; P<.001) and higher levels of lost productivity and were more likely to report their health as fair or poor (31.0% versus 17.9%; P<.001) than matched control subjects. Cancer survivors reported statistically significantly higher burden than did control subjects across tumor sites and across time since diagnosis (i.e., within the past year, 2-5 years, 6-10 years, and > or =11 years for the majority of measures., Conclusions: Cancer survivors have poorer health outcomes than do similar individuals without cancer across multiple burden measures. These decrements are consistent across tumor sites and are found in patients many years following reported diagnosis. Improved measurement of long-term burden of illness will be important for future prospective research.
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- 2004
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22. Short-term impact of cancer prevention and screening activities on quality of life.
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Cullen J, Schwartz MD, Lawrence WF, Selby JV, and Mandelblatt JS
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- Attitude to Health, Female, Genetic Testing standards, Genetic Testing trends, Humans, Male, Mass Screening trends, Neoplasms mortality, Prognosis, Quality-Adjusted Life Years, Sensitivity and Specificity, Sickness Impact Profile, Survival Rate, Time Factors, Mass Screening standards, Neoplasms prevention & control, Primary Prevention methods, Quality of Life
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Purpose: There are few data on the short-term effects of participating in cancer prevention activities, undergoing genetic risk assessment, or having routine screening. The objective of this article is to systematically review existing research on short-term effects of prevention, genetic counseling and testing, and screening activities on quality of life., Methods: We conducted a MEDLINE search for original research studies that were published between January 1, 1985, and December 31, 2002, and conducted in North America or Western Europe. Data were abstracted and summarized using a standardized format., Results: We reviewed 210 publications. Most studies focused on psychological states (anxiety, depression), symptoms, or general health status. One hundred thirty-one studies used 51 previously validated noncancer instruments. Many researchers (12.6%) also added cancer-specific measures, such as perceived cancer risk or symptom indices. Only one study measured satisfaction or quality of provider-client communication. While one report examined lost workdays, no other economic consequences of short-term outcomes were evaluated. Among seven studies that assessed short-term outcomes preferences, only four specifically used time trade-off or linear rating scale methods. No study used standard gamble or willingness-to-pay methods. The overwhelming majority of research indicated that short-term effects were transient. Only two studies linked short-term effects to long-term cancer-related health behaviors such as repeat screening., Conclusion: There is considerable heterogeneity in short-term outcome measurement. Clinicians need to be aware of potential for short-term, transient adverse effects. The impact of short-term experiences should to be linked to long-term health status and use of services.
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- 2004
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23. Acceptability of diagnostic tests for breast cancer.
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Liang W, Lawrence WF, Burnett CB, Hwang YT, Freedman M, Trock BJ, Mandelblatt JS, and Lippman ME
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- Adult, Aged, Biopsy psychology, Breast Neoplasms prevention & control, Breast Neoplasms psychology, Female, Humans, Magnetic Resonance Imaging psychology, Mass Screening psychology, Middle Aged, Prospective Studies, Radiographic Image Enhancement, Radionuclide Imaging, Triage methods, United States, Breast Neoplasms diagnostic imaging, Mammography psychology, Patient Acceptance of Health Care statistics & numerical data, Patient Satisfaction
- Abstract
Purpose: To assess the acceptability of new non-invasive breast cancer diagnostic tests intended to triage women in need of biopsy., Methods: Women who had abnormal screening tests and had been recommended to have a biopsy were invited to receive digital mammography, magnetic resonance imaging (MRI), and nuclear medicine evaluation (Tc-99m-sestamibi scanning) before biopsy. Participants completed a questionnaire about satisfaction and acceptability of the procedures. Satisfaction measured women's overall and test-specific satisfaction. Acceptability was measured by self-reported discomfort, embarrassment and women's preference in terms of willingness to pay to avoid a biopsy., Results: Women were satisfied with all of the potential diagnostic triage procedures. Most found the tests more comfortable than a routine mammogram (47, 50, and 66% undergoing MRI, digital mammography, and sestamibi scanning, respectively). Women who provided a response to willingness to pay questions (N = 43) were willing to pay an average of 611 dollars to have a test instead of a biopsy, if the test was as accurate as biopsy. The willingness to pay significantly decreased to 308 dollars if the test only had 95% accuracy. Those who had prior benign breast disease were less willing to pay for a test with 95% accuracy than those without this history., Conclusion: Instead of immediate biopsy after an abnormal screening, these results suggest that women would find non-invasive triage tests acceptable, or preferable to biopsy if they were equally accurate or nearly equally accurate as a biopsy. New technologies to diagnose breast cancer should focus on decreasing discomfort as well as increasing test accuracy.
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- 2003
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24. Process utility for imaging in cerebrovascular disease.
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Swan JS, Sainfort F, Lawrence WF, Kuruchittham V, Kongnakorn T, and Heisey DM
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- Adolescent, Adult, Aged, Angiography, Female, Humans, Male, Middle Aged, Statistics, Nonparametric, Time Factors, Cerebrovascular Disorders diagnostic imaging, Magnetic Resonance Angiography, Outcome and Process Assessment, Health Care, Patient Satisfaction
- Abstract
Rationale and Objectives: The morbidity associated with a diagnostic test can influence its cost-effectiveness, but the quantification of that morbidity is controversial. Accounting for pain and invasiveness requires the measurement of "process utility" in addition to the expected value of testing. An original time trade-off variant was applied to the imaging evaluation of cerebrovascular disease, for which differences in morbidity are important to patients., Materials and Methods: A "waiting trade-off" (WTO) was used to evaluate the preferences of 89 patients for magnetic resonance (MR) angiography and conventional x-ray angiography. Patients were experienced with both tests. A weighted difference was calculated between the period a patient was willing to wait for a test result and treatment after a hypothetical "ideal" test and the choice to undergo conventional angiography or MR angiography with immediate treatment. A rating scale was used to check the convergent validity of the WTO., Results: Paired data showed a highly significant difference (P = .0001) between the mean preference for conventional and MR angiography, favoring the latter and translating into a difference of 5 quality-adjusted life days. The more negatively patients judged their conventional angiographic experience, the longer they were willing to wait for the ideal test result., Conclusion: The WTO provides a reasonable estimate of the relative morbidity of more invasive conventional angiographic procedures and provides a quality-adjustment term for economic analysis. Such an approach may enable more complete evaluation of the effects of other processes on medical care.
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- 2003
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25. Costs and benefits of different strategies to screen for cervical cancer in less-developed countries.
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Mandelblatt JS, Lawrence WF, Gaffikin L, Limpahayom KK, Lumbiganon P, Warakamin S, King J, Yi B, Ringers P, and Blumenthal PD
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- Acetic Acid, Adult, Age Factors, Aged, Biopsy, Cost-Benefit Analysis, Cryotherapy, DNA, Viral analysis, Developing Countries, Disease Progression, Female, Health Policy economics, Humans, Incidence, Life Expectancy, Middle Aged, Models, Theoretical, Papillomaviridae isolation & purification, Papillomavirus Infections diagnosis, Thailand epidemiology, Tumor Virus Infections diagnosis, Uterine Cervical Neoplasms epidemiology, Uterine Cervical Neoplasms virology, Uterine Cervical Dysplasia diagnosis, Uterine Cervical Dysplasia economics, Uterine Cervical Dysplasia epidemiology, Uterine Cervical Dysplasia virology, Mass Screening economics, Papanicolaou Test, Uterine Cervical Neoplasms diagnosis, Uterine Cervical Neoplasms economics, Vaginal Smears economics
- Abstract
Background: About 80% of cervical cancers occur in less-developed countries. This disproportionate burden of cervical cancer in such countries is due mainly to the lack of well-organized screening programs. Several cervical cancer screening strategies have been proposed as more cost-effective than cytology screening. We compared the costs and benefits of different strategies and their effectiveness in saving lives in a less-developed country., Methods: We used a population-based simulation model to evaluate the incremental societal costs and benefits in Thailand of seven screening techniques, including visual inspection of the cervix after applying acetic acid (VIA), human papillomavirus (HPV) testing, Pap smear, and combinations of screening tests, and examined the discounted costs per year of life saved (LYS)., Results: Compared with no (i.e., not well-organized) screening, all strategies saved lives, at costs ranging from 121 US dollars to 6720 US dollars per LYS, and reduced mortality, by up to 58%. Comparing each strategy with the next least expensive alternative, VIA performed at 5-year intervals in women of ages 35-55 with immediate treatment if abnormalities are found was the least expensive option and saved the greatest number of lives, with a cost of 517 US dollars per LYS. HPV screening resulted in similar costs and benefits, if the test cost is 5 US dollars and if 90% of women undergo follow-up after an abnormal screen. Cytology (Pap smear) was a reasonable alternative if sensitivity exceeds 80% and if 90% of women undergo follow-up. Compared with no screening, use of a combination of Pap smear and HPV testing at 5-year intervals in women of ages 20-70 could achieve greater than 90% reduction in cervical cancer mortality at a cost of 1683 US dollars per LYS, and VIA could achieve 83% reduction at 524 US dollars per LYS., Conclusions: Well-organized screening programs can reduce cervical cancer mortality in less-developed countries at low costs. These cost-effectiveness data can enhance decision-making about optimal policies for a given setting.
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- 2002
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26. Benefits and costs of using HPV testing to screen for cervical cancer.
- Author
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Mandelblatt JS, Lawrence WF, Womack SM, Jacobson D, Yi B, Hwang YT, Gold K, Barter J, and Shah K
- Subjects
- Adult, Aged, Cost-Benefit Analysis, DNA, Viral analysis, Female, Humans, Mass Screening methods, Middle Aged, Models, Theoretical, Polymerase Chain Reaction economics, Quality-Adjusted Life Years, United States, Uterine Cervical Neoplasms diagnosis, Uterine Cervical Neoplasms economics, Uterine Cervical Dysplasia diagnosis, Uterine Cervical Dysplasia economics, Uterine Cervical Dysplasia prevention & control, Uterine Cervical Dysplasia virology, Mass Screening economics, Papanicolaou Test, Papillomaviridae isolation & purification, Papillomavirus Infections diagnosis, Tumor Virus Infections diagnosis, Uterine Cervical Neoplasms prevention & control, Uterine Cervical Neoplasms virology, Vaginal Smears economics
- Abstract
Context: Despite quality assurance standards, Papanicolaou (Pap) test characteristics remain less than optimal., Objective: To compare the societal costs and benefits of human papillomavirus (HPV) testing, Pap testing, and their combination to screen for cervical cancer., Design, Setting, and Population: A simulation model of neoplasia natural history was used to estimate the societal costs and quality-adjusted life expectancy associated with 18 different general population screening strategies: Pap plus HPV testing, Pap testing alone, and HPV testing alone every 2 or 3 years among hypothetical longitudinal cohorts of US women beginning at age 20 years and continuing to 65 years, 75 years, or death., Main Outcome Measure: Discounted costs per quality-adjusted life-year (QALY) saved of each screening strategy., Results: Maximal savings in lives were achieved by screening every 2 years until death with combined HPV and Pap testing at an incremental cost of $76 183 per QALY compared with Pap testing alone every 2 years. Stopping biennial screening with HPV and Pap testing at age 75 years captures 97.8% of the benefits of lifetime screening at a cost of $70 347 per QALY. Combined biennial HPV and Pap testing to age 65 years captures 86.6% of the benefits achievable by continuing to screen until age 75 years. Human papillomavirus screening alone was equally effective as Pap testing alone at any given screening interval or age of screening cessation but was more costly and therefore was dominated. In sensitivity analyses, HPV testing would be more effective and less costly than Pap testing at a cost threshold of $5 for an HPV test., Conclusions: Screening with HPV plus Pap tests every 2 years appears to save additional years of life at reasonable costs compared with Pap testing alone. Applying age limits to screening is a viable option to maintain benefits while reducing costs.
- Published
- 2002
- Full Text
- View/download PDF
27. Functional health outcomes as a measure of health care quality for Medicare beneficiaries.
- Author
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Bierman AS, Lawrence WF, Haffer SC, and Clancy CM
- Subjects
- Aged, Chronic Disease epidemiology, Comorbidity, Cost of Illness, Cross-Sectional Studies, Ethnicity statistics & numerical data, Female, Health Benefit Plans, Employee standards, Health Care Surveys, Humans, Male, Quality of Life, Socioeconomic Factors, United States epidemiology, Activities of Daily Living, Health Status Indicators, Managed Care Programs standards, Medicare Part C standards, Outcome Assessment, Health Care, Quality Indicators, Health Care
- Abstract
Objective: the Medicare Health Outcomes Survey (HOS), a new quality measure in the Health Plan Employer Data and Information Set, is designed to assess physical and mental functional health outcomes of Medicare beneficiaries enrolled in Medicare+Choice organizations. We discuss the rationale for the HOS measure together with methodologic challenges in its use and interpretation, using descriptive data from the baseline Medicare HOS to illustrate some of these challenges., Data Sources/study Design: The 1999 Cohort 2 Medicare HOS baseline data were used for a cross-sectional descriptive analysis. A random sample of 1,000 beneficiaries from each health plan with a Medicare+Choice contract was surveyed (N = 156,842; 282 organizations included in these analyses) ., Principal Findings: The HOS measure is designed to assess a previously unmeasured dimension of quality. Plan-level variation was seen across all baseline measures of sociodemographic characteristics and illness burden. At the individual level socioeconomic position as measured by educational attainment was strongly associated with functional status. The least educated beneficiaries had the highest burden of illness on all measures examined, and there was a consistent and significant gradient in health and functional status across all levels of education. In analyses stratified by race and ethnicity, socioeconomic gradients in f un ct ion persist ed. CONCLUSIONS Despite limitations, by focusing at t en t ion on the need to improve functional health out comes among elderly Medicare beneficiaries enrolled in Medicare+Choice, the HOS can serve as an important new tool to support efforts to improve health care quality. The HOS provides valuable information at the federal, state, and health plan levels that can be used to identify, prioritize, and evaluate quality improvement interventions and monitor progress for the program overall as well as for vulnerable subgroups. To interpret the HOS as a quality measure individual-and plan-level differences in functional status and illness burden, as well as methodologic issues in health status measurement, need to be recognized and addressed.
- Published
- 2001
28. Cost of genetic counseling and testing for BRCA1 and BRCA2 breast cancer susceptibility mutations.
- Author
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Lawrence WF, Peshkin BN, Liang W, Isaacs C, Lerman C, and Mandelblatt JS
- Subjects
- Adult, Breast Neoplasms diagnosis, Breast Neoplasms therapy, Cohort Studies, Costs and Cost Analysis, Data Collection, Female, Health Care Costs, Humans, Male, Middle Aged, Mutation, Prospective Studies, United States, Breast Neoplasms genetics, Genes, BRCA1 genetics, Genetic Counseling economics, Genetic Testing economics
- Abstract
Counseling and predictive testing are now available for the recently isolated BRCA1 and BRCA2 breast cancer susceptibility genes. We examined the societal costs of providing this counseling and testing to women at risk of having a breast cancer susceptibility mutation. Genetic counselors in a research program prospectively monitored the time necessary to provide counseling and results disclosure. A time-motion study was used to determine time spent on phone calls, preparation, and documentation for counseling. Study participants were surveyed to determine travel time and need for dependent care during counseling. The test cost was calculated using the charge for full BRCA1/2 gene sequencing (Myriad Genetics, Inc.) multiplied by a Medicare-based cost-to-charge ratio. Counselors spent an average of 4.2 h providing genetic counseling for women at risk of having a susceptibility mutation. Genetic counseling without testing cost on average $213, whereas counseling, testing, and disclosure of results totaled $2057. A brief physician-based counseling instead of genetic counselor-based counseling would produce only small reductions in total costs. Providing counseling and testing to the study population averaged $8034 per mutation found. The cost of testing and counseling exceeded $2000. The counseling portion of the cost comprised only 16% of the total cost, with the remainder representing costs associated with testing; thus, alternatives to full genetic counseling that shorten counseling time are unlikely to have a large impact on the overall cost of counseling and testing. The cost of detecting a mutation within a population of women is highly dependent on the prevalence of the mutation in the population.
- Published
- 2001
29. A time-tradeoff method for cost-effectiveness models applied to radiology.
- Author
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Swan JS, Fryback DG, Lawrence WF, Sainfort F, Hagenauer ME, and Heisey DM
- Subjects
- Adult, Aged, Aged, 80 and over, Angiography economics, Cost-Benefit Analysis, Female, Humans, Magnetic Resonance Angiography economics, Male, Middle Aged, Models, Econometric, Time Factors, Patient Satisfaction, Peripheral Vascular Diseases diagnosis, Peripheral Vascular Diseases diagnostic imaging, Quality-Adjusted Life Years, Waiting Lists
- Abstract
Purpose: The wait tradeoff (WTO) is a simple time-tradeoff method designed for temporary health states that uses a realistic and intuitive interface for the patient/subject. This method was tested by assessing patients' preferences for magnetic resonance angiography (MRA) versus x-ray angiography (XRA)., Materials and Methods: The WTO was tested by telephone interview in 38 patients with atherosclerotic peripheral vascular disease, all having previously undergone both MRA and XRA. At indifference point, patients were ambivalent about having MRA or XRA and immediate treatment, versus having a waiting period for test results and treatment after a hypothetical "ideal test" that entailed no pain or risk., Results: The patients were willing to wait a mean of 42.1 days after the ideal test for results and treatment, as opposed to XRA. They were willing to wait only 16.1 days as opposed to MRA. This difference in waiting times was significant (p = 0.0001) and indicates a clear preference for MRA, in agreement with known literature., Conclusion: The WTO method assesses preferences for these radiologic tests in an intuitive fashion that does not invoke artificial or irrelevant health states. This approach may also prove useful for other testing situations or short-term treatments being evaluated for cost-effectiveness.
- Published
- 2000
- Full Text
- View/download PDF
30. Computing population-based estimates of health-adjusted life expectancy.
- Author
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Rosenberg MA, Fryback DG, and Lawrence WF
- Subjects
- Actuarial Analysis, Aged, Bayes Theorem, Humans, Male, Population, Quality of Life, Health Status, Life Expectancy
- Abstract
Observed health-adjusted life expectancy (HALE) is an indicator of population health. There are a number of ways to compute HALE for a community. The authors surveyed several methods and demonstrate resulting variation in the estimates of HALE. Quality of well-being (QWB) measures from 1,430 participants in the Beaver Dam Health Outcomes Study are taken as weights. Actuarial life-table methods using community mortality data, State of Wisconsin census data from two time frames, and U.S. census data are used with the QWB to estimate HALE. Measurement of community population health using HALE computations can be completed with national, regional, or local data. Community-level estimates may not be well approximated using large-scale mortality experience. A Bayesian method is developed combining the local data with regional data. The Bayesian method creates a smooth set of rates, retains the local flavor of the community, and gives a measure of variability of the estimated HALE.
- Published
- 1999
- Full Text
- View/download PDF
31. Serendipity in diagnostic imaging: magnetic resonance imaging of the breast.
- Author
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Lawrence WF, Liang W, Mandelblatt JS, Gold KF, Freedman M, Ascher SM, Trock BJ, and Chang P
- Subjects
- Adult, Age Distribution, Aged, Aged, 80 and over, Biopsy standards, Breast Neoplasms ethnology, Breast Neoplasms prevention & control, Diagnosis, Differential, Female, Humans, Mammography, Meta-Analysis as Topic, Middle Aged, Predictive Value of Tests, Prevalence, ROC Curve, Sensitivity and Specificity, United States epidemiology, Breast Neoplasms diagnosis, Breast Neoplasms epidemiology, Decision Support Techniques, Magnetic Resonance Imaging, Patient Selection
- Abstract
Background: Magnetic resonance imaging (MRI) of the breast has been proposed as a noninvasive diagnostic test for evaluation of suspicious ("index") lesions noted on mammography and/or clinical breast examination (CBE). However, women may have incidental ("serendipitous") lesions detected by MRI that are not found on mammography or CBE. To understand better whether or not biopsy procedures should be performed to evaluate serendipitous lesions, we estimated the breast cancer risk for women with this type of lesion., Methods: A decision analysis model was used to estimate the positive predictive value (i.e., the chance that a woman with a serendipitous lesion has cancer) of MRI for serendipitous lesions in women who had an abnormal mammogram and/or CBE suspicious for cancer (where a biopsy procedure is recommended). We restricted the analysis to data from women whose index lesions were noncancerous and used meta-analysis of published medical literature to determine the likelihood ratios (measures of how test results change the probability of having cancer) for MRI and the combination of CBE and mammography. The positive predictive value of MRI was calculated using the U.S. population prevalence of cancer (derived from registry data) and the likelihood ratios of the diagnostic tests., Results: Under a wide variety of assumptions, the positive predictive value of MRI was extremely low for serendipitous lesions. For instance, assuming sensitivity and specificity values for MRI of 95.6% and 68.6%, respectively, approximately four of 1000 55- to 59-year-old women with serendipitous lesions would be expected to have cancer (positive predictive value = 0.44%, 95% confidence interval = 0.24%-0.67%)., Conclusion: In women with a suspicious lesion discovered by mammography and/or CBE that is found to be benign, serendipitous breast lesions detected by MRI are extremely unlikely to represent invasive breast cancer. Immediate biopsy of such serendipitous lesions may, therefore, not be required.
- Published
- 1998
- Full Text
- View/download PDF
32. Does over-the-counter nicotine replacement therapy improve smokers' life expectancy?
- Author
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Lawrence WF, Smith SS, Baker TB, and Fiore MC
- Subjects
- Adult, Aged, Computer Simulation, Decision Trees, Female, Humans, Male, Markov Chains, Middle Aged, Smoking Cessation statistics & numerical data, United States, Drug and Narcotic Control, Life Expectancy, Nicotine therapeutic use, Nonprescription Drugs therapeutic use, Smoking epidemiology
- Abstract
Objective: To determine the public health benefits of making nicotine replacement therapy available without prescription, in terms of number of quitters and life expectancy., Design: A decision-analytic model was developed to compare the policy of over-the-counter (OTC) availability of nicotine replacement therapy with that of prescription ([symbol: see text]) availability for the adult smoking population in the United States., Main Outcome Measures: Long-term (six-month) quit rates, life expectancy, and smoking attributable mortality (SAM) rates., Results: OTC availability of nicotine replacement therapy would result in 91,151 additional successful quitters over a six-month period, and a cumulative total of approximately 1.7 million additional quitters over 25 years. All-cause SAM would decrease by 348 deaths per year and 2940 deaths per year at six months and five years, respectively. Relative to [symbol: see text] nicotine replacement therapy availability, OTC availability would result in an average gain in life expectancy across the entire adult smoking population of 0.196 years per smoker. In sensitivity analyses, the benefits of OTC availability were evident across a wide range of changes in baseline parameters., Conclusions: Compared with [symbol: see text] availability of nicotine replacement therapy, OTC availability would result in more successful quitters, fewer smoking-attributable deaths, and increased life expectancy for current smokers.
- Published
- 1998
- Full Text
- View/download PDF
33. Dollars may not buy as many QALYs as we think: a problem with defining quality-of-life adjustments.
- Author
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Fryback DG and Lawrence WF Jr
- Subjects
- Adult, Aged, Comorbidity, Cost-Benefit Analysis, Decision Support Techniques, Female, Humans, Male, Middle Aged, Survival Analysis, Decision Making, Computer-Assisted, Health Care Rationing economics, Quality Assurance, Health Care economics, Quality-Adjusted Life Years
- Abstract
The scale of health state quality that should be used to compute quality-adjusted life years (QALYs) ranges from 0 (death) to 1.0 (excellent health); this is called the "Q" scale. But many cost-utility analyses (CUAs) in the literature use the upper anchor of the scale to denote only the absence of the particular health condition under investigation, and weight the disease state proportional to this endpoint; these are called "q" scales. Computations using q-scale health-state weights ignore the fact that the average patient is still subject to chronic and acute conditions comorbid with the condition being analyzed; the absence of a particular condition is not in general the same as excellent health, i.e., the Q scale is longer than a q scale. CUAs based on q scales yield "qALYs." Incremental $/qALY ratios are generally lower than $/QALY ratios; in the example presented, $/qALY must be inflated by about 15% to yield $/QALY. Other CUAs correctly weight disease states using the Q scale, but erroneously assign a quality weight of 1.0 to absence of the disease in the CUA computations. The results of such analyses are called "NP-QALYs," as the correction factor to compute QALYs is not a simple proportional adjustment. The authors suggest that analysis doing cost-utility analyses without access to primary data from treated patients use average age-specific health-related quality-of-life weights from population-based studies to represent the state of not having a particular disease. Consumers of CUAs should closely examine the nature of the QALYs in any published analyses before making decisions based on their results.
- Published
- 1997
- Full Text
- View/download PDF
34. MR and conventional angiography: work in progress toward assessing utility in radiology.
- Author
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Swan JS, Fryback DG, Lawrence WF, Katz DA, Heisey DM, Hagenauer ME, Selzer PM, and Jacobson BK
- Subjects
- Angiography economics, Attitude to Health, Cost-Benefit Analysis, Female, Financing, Personal, Humans, Magnetic Resonance Angiography economics, Male, Middle Aged, Patient Satisfaction, Peripheral Vascular Diseases psychology, Time Factors, Angiography psychology, Magnetic Resonance Angiography psychology, Peripheral Vascular Diseases diagnosis, Quality of Life
- Abstract
Rationale and Objectives: The authors assessed health-related quality of life changes associated with peripheral x-ray angiography and magnetic resonance (MR) angiography., Materials and Methods: Utility (the desirability or preference that individuals exhibit for a particular health state) was assessed in 30 patients with peripheral vascular disease referred for angiography by using a rating scale, additional categoric scaling questions to separate preference from experience, a willingness-to-pay technique, functional and cognitive status questions, and a time trade-off technique. All patients underwent both MR angiography and x-ray angiography., Results: Patients reported significantly (P < .05) less anxiety after the test, less pain after the test, fewer new physical limitations, and less effect on performance of daily activities with MR angiography. Findings from the overall rating scale and categoric scaling questions also significantly (P < .05) favored MR angiography. Patients were willing to pay a mean of 2.12% of annual income to avoid MR angiography and a mean of 7.41% to avoid x-ray angiography. The median quality-adjusted life gain required by patients to undergo the procedures was 52.5-60 days for x-ray angiography and 10.5 days for MR angiography, without discounting., Conclusion: X-ray angiography has more profound short-term adverse effects on life than does MR angiography. Preference-based measures can be adapted to elicit patient values for short-term health states as seen in radiology.
- Published
- 1997
- Full Text
- View/download PDF
35. Predicting Quality of Well-being scores from the SF-36: results from the Beaver Dam Health Outcomes Study.
- Author
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Fryback DG, Lawrence WF, Martin PA, Klein R, and Klein BE
- Subjects
- Activities of Daily Living classification, Aged, Aged, 80 and over, Cohort Studies, Female, Humans, Male, Middle Aged, Models, Statistical, Regression Analysis, Renal Dialysis, Wisconsin epidemiology, Health Status Indicators, Health Surveys, Quality of Life
- Abstract
Background: The SF-36 and the Quality of Well-being index (QWB) both quantify health status, yet have very different methodologic etiologies. The authors sought to develop an empirical equation allowing prediction of the QWB from the SF-36., Data: They used empirical observations of SF-36 profiles and QWB scores collected in interviews of 1,430 persons during the Beaver Dam Health Outcomes Study, a community-based population study of health status, and 57 persons from a renal dialysis clinic., Method: The eight scales of the SF-36, their squares, and all pairwise cross-products, were used as candidate variables in stepwise and best-subsets regressions to predict QWB scores using 1,356 interviews reported in a previous paper. The resulting equation was cross-validated on the remaining 74 cases and using the renal dialysis patients., Results: A six-variable regression equation drawing on five of the SF-36 components predicted 56.9% of the observed QWB variance. The equation achieved an R2 of 49.5% on cross-validation using Beaver Dam participants and an R2 of 58.7% with the renal dialysis patients. An approximation for computing confidence intervals for predicted QWB mean scores is given., Conclusion: SF-36 data may be used to predict mean QWB scores for groups of patients, and thus may be useful to modelers who are secondary users of health status profile data. The equation may also be used to provide an overall health utility summary score to represent SF-36 profile data so long as the profiles are not severely limited by floor or ceiling effects of the SF-36 scales. The results of this study provide a quantitative link between two important measures of health status.
- Published
- 1997
- Full Text
- View/download PDF
36. Health status and hypertension: a population-based study.
- Author
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Lawrence WF, Fryback DG, Martin PA, Klein R, and Klein BE
- Subjects
- Aged, Aged, 80 and over, Comorbidity, Cross-Sectional Studies, Female, Humans, Hypertension drug therapy, Male, Middle Aged, Surveys and Questionnaires, Wisconsin, Antihypertensive Agents therapeutic use, Health Status, Hypertension psychology, Quality of Life
- Abstract
We describe the relation between self-reported hypertension and measures of health-related quality of life (HRQOL) in a community-dwelling population. In a cross-sectional study, 1430 randomly selected adults, aged 45 to 89 years, were interviewed to obtain a medical history and health status measures, including the SF-36 questionnaire, the Quality of Well Being (QWB) index, and time trade-off (TTO) assessments. A total of 519 participants reported being affected by hypertension (HTN group). The HTN group, compared to the No HTN group, had significantly lower age-adjusted health status scores measured by the General Health scale of the SF-36 and by TTO, with differences between groups for each measure comprising approximately 5% of the total scale. HTNs also had a significant decline in general health status measures associated with increasing numbers of antihypertensive medications but not with specific classes of medications. We conclude that hypertension and hypertension drug therapy are associated with clinically meaningful decreases in reported health status.
- Published
- 1996
- Full Text
- View/download PDF
37. Magnetic resonance angiography in progressive renal failure: a technology assessment.
- Author
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Lawrence WF, Grist TM, Brazy PC, and Fryback DG
- Subjects
- Cost-Benefit Analysis, Humans, Middle Aged, Models, Biological, Models, Economic, ROC Curve, Renal Artery Obstruction complications, Sensitivity and Specificity, Kidney Failure, Chronic etiology, Magnetic Resonance Angiography economics, Renal Artery Obstruction diagnosis
- Abstract
The objective of this study was to assess the cost-effectiveness of magnetic resonance angiography (MRA) imaging for renal artery stenosis (RAS) in people with progressive renal failure (PRF). We created a simulation model to determine the incremental cost-effectiveness of MRA screening in PRF compared with the fallback strategy of not screening. Costs, probabilities, and utilities were estimated from the literature and from institutional data. A three-state Markov model was used to simulate the progression from PRF to end-stage renal disease and death. In our baseline analysis, assuming a sensitivity of 0.85 and a specificity of 0.8 of MRA for RAS, we obtained an incremental cost-effectiveness of MRA screening compared with no screening of $2,214 per quality-adjusted life year saved, which is less than many commonly performed procedures. Under our baseline assumptions, if the receiver-operating characteristic curve of MRA for RAS is better than the chance curve, then MRA screening would be cost-effective. The analysis was most sensitive to assumptions about renal function after correction of RAS and prevalence of RAS, although the results show that MRA remains cost-effective for reasonable ranges of these assumptions. The use of MRA in PRF would be a worthwhile investment of resources in comparison with many currently funded procedures. The expense and morbidity associated with end-stage renal disease make any reasonable way of delaying or preventing the disease worth examining in detail.
- Published
- 1995
- Full Text
- View/download PDF
38. Decibel notation with correlated and uncorrelated signals.
- Author
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Punch JL and Lawrence WF
- Subjects
- Noise, Sound, Weights and Measures
- Abstract
Audiologists perform sound level measurements in a variety of settings. These measurements typically involve clinical audiometric calibration, specification of sound field levels in industrial environments, psychoacoustic experimentation, or specification of sound levels in hearing and test boxes or anechoic chambers. Any of these circumstances can present problem situations in which some form of signal combination is involved. Solutions of such problems require use of the concepts of average power and signal correlation, as they are related to decibel notation. These concepts are discussed in the present paper, and several examples that apply these concepts to specific measurement situations are presented.
- Published
- 1977
39. Measurement of attack-release times in compression hearing aids.
- Author
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Punch JL, Lawrence WF, and Causey GD
- Subjects
- Acoustics, Hearing Aids standards, Reference Standards, Time Factors, Hearing Aids instrumentation
- Abstract
A system for measurement of attack-release times in hearing aids with automatic-gain-control circuitry is described, with a view toward implementing that portion of the ANSI S3.22-1976 Standard in which parameters for these measurements are specified. Signal generation is accomplished by using a phased-array loudspeaker arrangement designed to produce transient-free pulsed acoustic sinusoids. Output waveforms are captured by a commercial transient recorder, and are displayed in either an oscilloscopic or graphic mode. A specific means of calculating attack and release times is recommended whereby variously shaped output waveforms are amenable to the basic protocol outlined in the ANSI Standard.
- Published
- 1978
- Full Text
- View/download PDF
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