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Biomedical subjects

Dennis G Fryback

Publications and source records attributed to Dennis G Fryback.

12 recordsLinked to original sources
PubMed2006

Retrospective cost-effectiveness analysis of screening mammography.

BACKGROUND: Many guidelines recommend screening mammography every 1-2 years for women older than 40 years; more than 70% of women now participate in routine screening. No studies have examined the societal impact of screening practices over the past decade in the United States on costs and quality-adjusted life-years (QALYs). We performed a retrospective cost-effectiveness analysis comparing actual and alternative screening mammography scenarios. METHODS: We used a discrete-event simulation model of breast cancer epidemiology to estimate the costs and the number of QALYs that were associated with observed screening mammography patterns in the United States from 1990 to 2000 for women aged 40 years or older. We also estimated costs and QALYS for no screening and for 64 alternative screening scenarios. Incremental cost-effectiveness ratios were computed. Sensitivity analyses were performed on key parameters. RESULTS: Actual U.S. screening patterns from 1990 to 2000 accrued 947.5 million QALYs and cost $166 billion over the lifetimes of the screened women, resulting in a gain of 1.7 million QALYs for an additional cost of $62.5 billion compared with no screening. Among those polices that were not dominated--i.e., for which no alternative existed that produced more QALYs for lower costs--screening all women aged 40-80 years annually per some U.S. guidelines was the most expensive option, costing $58,000 per additional QALY gained compared with the next most costly alternative, screening all women aged 45-80 years annually. Many alternative screening scenarios generated more QALYs for less cost (with savings up to $6 billion) than actual screening patterns over the study period. Sensitivity analysis showed that conclusions about the cost-effectiveness of screening mammography policies were highly sensitive to small, short-term detrimental effects on quality of life from the screening test itself. CONCLUSIONS: Choosing among the efficient policies to guide current screening recommendations requires consideration of costs to promote participation in screening and measurement of acute quality-of-life effects of mammography.

Adult↗
PubMed2006

The Wisconsin Breast Cancer Epidemiology Simulation Model.

The Wisconsin Breast Cancer Epidemiology Simulation Model is a discrete-event, stochastic simulation model using a systems-science modeling approach to replicate breast cancer incidence and mortality in the U.S. population from 1975 to 2000. Four interacting processes are modeled over time: (1) natural history of breast cancer, (2) breast cancer detection, (3) breast cancer treatment, and (4) competing cause mortality. These components form a complex interacting system simulating the lives of 2.95 million women (approximately 1/50 the U.S. population) from 1950 to 2000 in 6-month cycles. After a "burn in" of 25 years to stabilize prevalent occult cancers, the model outputs age-specific incidence rates by stage and age-specific mortality rates from 1975 to 2000. The model simulates occult as well as detected disease at the individual level and can be used to address "What if?" questions about effectiveness of screening and treatment protocols, as well as to estimate benefits to women of specific ages and screening histories.

Adult↗
PubMed2006

Relative disutilities of 47 risk factors and conditions assessed with seven preference-based health status measures in a national U.S. sample: toward consistency in cost-effectiveness analyses.

BACKGROUND: Preference-based health measures yield summary scores that are compatible with cost-effectiveness analyses. There is limited comparative information, however, about how different measures weight health conditions in the U.S. population. METHODS: We examined data from 11,421 adults in the 2000 Medical Expenditure Panel Survey, a nationally representative sample of the U.S. general population, using information on sociodemographics (age, gender, race/ethnicity, income, and education), health status (EQ-5D, EQ-VAS, and SF-12), 4 risk factors (smoking, overweight, obesity, and lacking health insurance), and 43 conditions. From the EQ-5D, we derived summary scores using U.K. [EQ(UK)] and U.S. weights. From the SF-12 we derived SF-6D, and regression-predicted EQ-5D (U.S. and U.K. weights) and Health Utility Index scores. Each of the 7 preference measures was regressed on each of the 47 problems (risk factors and conditions) to determine the disutility associated with the problem, adjusting for socio-demographics. RESULTS: The adjusted disutilities averaged across the 47 problems for the 7 preference measures ranged from 0.059 for the SF-6D to 0.104 for the EQ(UK). Correlations between each of the measures of the adjusted disutilities ranged from 0.85-1.0. Standardization, using linear regression, attenuated between measure differences in disutilities. CONCLUSIONS: Absolute incremental cost-effectiveness analyses of a given problem would likely vary depending on the measure used, whereas the relative ordering of incremental cost-effectiveness analyses of a series of problems would likely be similar regardless of the measure chosen, as long as the same measure is used in each series of analyses. Absolute consistency across measures may be enhanced by standardization.

Adult↗
PubMed2005

Effect of screening and adjuvant therapy on mortality from breast cancer.

BACKGROUND: We used modeling techniques to assess the relative and absolute contributions of screening mammography and adjuvant treatment to the reduction in breast-cancer mortality in the United States from 1975 to 2000. METHODS: A consortium of investigators developed seven independent statistical models of breast-cancer incidence and mortality. All seven groups used the same sources to obtain data on the use of screening mammography, adjuvant treatment, and benefits of treatment with respect to the rate of death from breast cancer. RESULTS: The proportion of the total reduction in the rate of death from breast cancer attributed to screening varied in the seven models from 28 to 65 percent (median, 46 percent), with adjuvant treatment contributing the rest. The variability across models in the absolute contribution of screening was larger than it was for treatment, reflecting the greater uncertainty associated with estimating the benefit of screening. CONCLUSIONS: Seven statistical models showed that both screening mammography and treatment have helped reduce the rate of death from breast cancer in the United States.

Adult↗
PubMed2005

American College of Radiology Imaging Network digital mammographic imaging screening trial: objectives and methodology.

This study was approved by the Institutional Review Board (IRB) of the American College of Radiology Imaging Network (ACRIN) and each participating site and by the IRB and the Cancer Therapy Evaluation Program at the National Cancer Institute. The study was monitored by an independent Data Safety and Monitoring Board, which received interim analyses of data to ensure that the study would be terminated early if indicated by trends in the outcomes. The ACRIN, which is funded by the National Cancer Institute, conducted the Digital Mammographic Imaging Screening Trial (DMIST) primarily to compare the diagnostic accuracy of digital and screen-film mammography in asymptomatic women presenting for screening for breast cancer. Over the 25.5 months of enrollment, a total of 49 528 women were included at the 33 participating sites, which used five different types of digital mammography equipment. All participants underwent both screen-film and digital mammography. The digital and screen-film mammograms of each subject were independently interpreted by two radiologists. If findings of either examination were interpreted as abnormal, subsequent work-up occurred according to the recommendations of the interpreting radiologist. Breast cancer status was determined at biopsy or follow-up mammography 11-15 months after study entry. In addition to the measurement of diagnostic accuracy by using the interpretations of mammograms at the study sites, DMIST included evaluations of the relative cost-effectiveness and quality-of-life effects of digital versus screen-film mammography. Six separate reader studies using the de-identified archived DMIST mammograms will also assess the diagnostic accuracy of each of the individual digital mammography machines versus screen-film mammography machines, the effect of breast density on diagnostic accuracy of digital and screen-film mammography, and the effect of different rates of breast cancer on the diagnostic accuracy in a reader study.

Breast Neoplasms↗
PubMed2004

Measuring economic outcomes of cancer.

Economic outcomes are increasingly important in cancer research. This article provides an introduction to the nature and measurement of economic outcomes in cancer and gives the reader entry points to a considerable literature on measuring economic endpoints in health and medicine. Economic outcomes data are defined here as measures of resources consumed in prevention, detection, and treatment of cancer and its sequellae. Part I of this essay discusses the questions addressed by economic outcomes. Part II presents a typology of and introduction to measurement of economic outcomes. Part III discusses important measurement issues and calls for development and validation of standardized protocols and questionnaires to measure economic outcomes, especially at the patient level.

Health Care Costs↗
PubMed2003

Understanding differences between self-ratings and population ratings for health in the EuroQOL.

OBJECTIVE: To examine the source and magnitude of differences between self-ratings for health and ratings of corresponding health state profiles by the general population in the EuroQOL. DATA AND METHODS: EuroQOL data were analysed from the 1993 measurement and valuation of health study (MVH), a sample of 2997 members of the UK adult population, nationally representative by age, gender and social class. Multivariate regression analyses were used to examine the source of differences in visual analogue scores (VAS) between self-ratings and general population ratings. The source of observed differences were investigated with respect to four hypothesized factors: (1) Socio-demographics (age, gender, education, social class); (2) The level of respondent difficulty in completing the rating task; (3) Values for particular EQ-5D health profile attributes; and (4) Differences in the scope of health attributes and levels considered in the rating task (e.g., self-ratings may reflect preferences for attributes not captured by EQ-5D profiles). RESULTS: Overall, mildly ill individuals provided lower self-ratings (3-4 points), and moderately ill individuals higher self-ratings (7 points), than ratings for these states provided by the general population. Socio-demographic characteristics and difficulties in rating task completion did not explain differences between self and general population VAS ratings, contributing differences of 1 point or less in all 15 rating comparisons examined. Rating differences related more closely to a lack of correspondence between health state descriptions and self-raters' actual health experiences (differences in scope) than differences in values for health profile attributes between self-raters and the general population. CONCLUSIONS: EQ-5D health state descriptions may be too sparse to comprehensively describe certain health states. Adding new health state levels or dimensions, or changing the nature and tone of health state descriptions, may be useful steps for improvement.

Attitude to Health↗
PubMed2001

HALYS and QALYS and DALYS, Oh My: similarities and differences in summary measures of population Health.

Health-adjusted life years (HALYs) are population health measures permitting morbidity and mortality to be simultaneously described within a single number. They are useful for overall estimates of burden of disease, comparisons of the relative impact of specific illnesses and conditions on communities, and in economic analyses. Quality-adjusted life years (QALYs) and disability-adjusted life years (DALYs) are types of HALYs whose original purposes were at variance. Their growing importance and the varied uptake of the methodology by different U.S. and international entities makes it useful to understand their differences as well as their similarities. A brief history of both measures is presented and methods for calculating them are reviewed. Methodological and ethical issues that have been raised in association with HALYs more generally are presented. Finally, we raise concerns about the practice of using different types of HALYs within different decision-making contexts and urge action that builds and clarifies this useful measurement field.

Cost of Illness↗
PubMedDate not supplied

Report of nationally representative values for the noninstitutionalized US adult population for 7 health-related quality-of-life scores.

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.

Adult↗