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Biomedical subjects

T O Tengs

Publications and source records attributed to T O Tengs.

11 recordsLinked to original sources

The link between smoking and impotence: two decades of evidence.

BACKGROUND: Anti-tobacco advertisements now feature the risk of impotence as a reason to avoid or cease tobacco use. The scientific evidence, however, is mixed. To shed light on the controversy, we compiled 2 decades of published data on the link between smoking and impotence. METHODS: We searched MEDLINE from 1980 to the present for studies that reported smoking prevalence among impotent male subjects. For each study we recorded the age of subjects, their state of residence, the percentage that were current smokers, and the time period over which study data were collected. For comparison purposes, we estimated age-, state-, and year-specific smoking rates in the general male population using the Behavioral Risk Factors Surveillance System. We performed a meta-analysis using a random effects model. RESULTS: Among the 1008 journal articles examined, we identified 19 studies that reported the smoking habits of 3819 impotent men. Of these 19 studies, 16 indicated a smoking prevalence exceeding that of the general population. The 6 largest studies all revealed a higher prevalence of smoking among impotent men. Meta-analysis reveals that 40% of impotent men were current smokers compared with 28% of men in the general population. CONCLUSIONSBased on almost 2 decades of evidence, tobacco use is an important risk factor for impotence. Anti-tobacco advertisements featuring impotence as a reason to avoid or cease tobacco use are well grounded in scientific fact.

Adolescent↗

The cost-effectiveness of intensive national school-based anti-tobacco education: results from the tobacco policy model.

OBJECTIVES: School-based anti-tobacco education using the "social influences" model is known to reduce smoking among youth by 5-56%. Program effectiveness, however, dissipates in 1-4 years. Consequently, opinion leaders have questioned whether a more intensive national educational effort would be economically efficient. To address this question, we evaluated the cost-effectiveness of enhanced nationwide school-based anti-tobacco education relative to the status quo. METHODS: To estimate cost-effectiveness, we created the Tobacco Policy Model, a system dynamics computer simulation model. The model relies on secondary data and is designed to calculate the expected costs and public health gains of any tobacco policy or intervention over any time frame. RESULTS: Over 50 years, cost-effectiveness is estimated to lie between $4,900 and $340,000 per quality-adjusted life-year (QALY), depending on the degree and longevity of program effectiveness. Assuming a 30% effectiveness that dissipates in 4 years, cost-effectiveness is $20,000/QALY. Sensitivity analysis reveals that cost-effectiveness varies with cost, survival, and quality-of-life estimates but cost-effectiveness ratios generally remain favorable. CONCLUSIONS: Although not cost saving, a much more intensive school-based anti-tobacco educational effort would be an economically efficient investment for the nation.

Adolescent↗

Public health impact of changes in smoking behavior: results from the Tobacco Policy Model.

OBJECTIVES: The relative magnitude of the public health gains from preventing smoking initiation versus encouraging cessation or avoiding relapse in different ages and genders is estimated and compared. METHODS: Health gains are defined as the predicted increase in Quality-Adjusted Life-Years (QALYs) to the US population during a century. To estimate QALYs, we developed the Tobacco Policy Model. The model simulates a 10% reduction in the annual probability of initiation versus a 10% increase in cessation versus a 10% reduction in relapse in males and females in six age groups: 10 to 19, 20 to 29, 30 to 39, 40 to 49, 50 to 59 and 60 to 69. RESULTS: Among youth and young adults, reducing initiation yields far more QALYs than encouraging cessation or averting relapse. In middle-aged adults, cessation yields the most QALYs, followed by averting relapse and reducing initiation. In the oldest age group, averting relapse yields the most QALYs followed by cessation and reducing initiation. In general, increasing cessation and reducing relapse is more beneficial in males than in females whereas reducing initiation is more beneficial in females. CONCLUSIONS: The relative value of preventing initiation, encouraging cessation, and averting relapse differs by age and gender. Reducing initiation in youth is likely to offer the largest public health impact during the next century.

Adolescent↗

Health-related quality of life after stroke a comprehensive review.

BACKGROUND AND PURPOSE: We performed a comprehensive review of all quality-of-life (QOL) estimates for stroke appearing in the peer-reviewed literature between 1985 and 2000. We examine variation in QOL weights and the rigor of methods used to assess QOL and discuss the implications for cost-utility assessment and resource allocation decisions. METHODS: Through a systematic search, we identified 67 articles that met our inclusion criteria. A team of trained researchers read each article and followed detailed guidelines to extract QOL weights and other parameters. This effort yielded 161 QOL estimates for stroke-related health states. All estimates were measured on a 0 to 1 scale, with 0 representing the worst outcome and 1 representing the best. RESULTS: QOL estimates range from -0.02 to 0.71 (n=67) for major stroke, from 0.12 to 0.81 (n=14) for moderate stroke, from 0.45 to 0.92 (n=38) for minor stroke, and from 0.29 to 0.903 (n=42) for general stroke. Although QOL should decrease with severity, there were many instances in which the QOL for major stroke as reported by one study exceeded the QOL for moderate stroke as reported by another. The same reversal was found for moderate and minor stroke, and it occurred even when both authors used similar assessment methods and subject populations. Authors of cost-utility and decision analyses rarely base their choice of QOL weights on their own primary data (19%). When obtaining weights from secondary sources, some authors (23%) chose QOL weights for a severity of stroke that did not match the severity for which they sought data. CONCLUSIONS: QOL estimates for stroke vary greatly and are not always estimated in sound fashion. This impedes the comparability and quality of the cost-effectiveness studies that use these QOL weights and hampers good resource allocation decisions.

Cost-Benefit Analysis↗

One thousand health-related quality-of-life estimates.

OBJECTIVE: Analysts performing cost-effectiveness analyses often do not have the resources to gather original quality-of-life (QOL) weights. Furthermore, variability in QOL for the same health state hampers the comparability of cost-effectiveness analyses. For these reasons, opinion leaders such as the Panel on Cost-Effectiveness in Health and Medicine have called for a national repository of QOL weights. Some authors have responded to the call by performing large primary studies of QOL. We take a different approach, amassing existing data with the hope that it will be combined responsibly in meta-analytic fashion. Toward the goal of developing a national repository of QOL weights to aid cost-effectiveness analysts, 1,000 health-related QOL estimates were gathered from publicly available source documents. METHODS: To identify documents, we searched databases and reviewed the bibliographies of articles, books, and government reports. From each document, we extracted information on the health state, QOL weight, assessment method, respondents, and upper and lower bounds of the QOL scale. Detailed guidelines were followed to ensure consistency in data extraction. RESULTS: We identified 154 documents yielding 1,000 original QOL weights. There was considerable variation in the weights assessed by different authors for the same health state. Methods also varied: 51% of authors used direct elicitation (standard gamble, time tradeoff, or rating scale), 32% estimated QOL based on their own expertise or that of others, and 17% used health status instruments. CONCLUSIONS: This comprehensive review of QOL data should lead to more consistent use of QOL weights and thus more comparable cost-effectiveness analyses.

Attitude to Health↗

Five-hundred life-saving interventions and their cost-effectiveness.

We gathered information on the cost-effectiveness of life-saving interventions in the United States from publicly available economic analyses. "Life-saving interventions" were defined as any behavioral and/or technological strategy that reduces the probability of premature death among a specified target population. We defined cost-effectiveness as the net resource costs of an intervention per year of life saved. To improve the comparability of cost-effectiveness ratios arrived at with diverse methods, we established fixed definitional goals and revised published estimates, when necessary and feasible, to meet these goals. The 587 interventions identified ranged from those that save more resources than they cost, to those costing more than 10 billion dollars per year of life saved. Overall, the median intervention costs $42,000 per life-year saved. The median medical intervention cost $19,000/life-year; injury reduction $48,000/life-year; and toxin control $2,800,000/life-year. Cost/life-year ratios and bibliographic references for more than 500 life-saving interventions are provided.

Cost-Benefit Analysis↗

Minimizing the time to search visual displays: the role of highlighting.

Office computer users frequently need to search long lists of options for a particular target. Highlighting a subset of the options can shorten the average display search time. The goal of the current research was to identify the subset of options to highlight that minimizes users' average search time for any given display. To begin, a mathematical model of the visual search process was constructed which could be used to predict the average search time for a target in a display with or without highlighted options. The predictions of this model were then compared with the results of a visual search experiment that varied the type of highlighting (blocked, random, or no highlighting), the number of highlighted options, and the probability that a target was highlighted. Overall the predictions of the model were consistent with the results from the experiment. Finally, procedures based on the model were developed which could be used to find the optimal subset of options to highlight for a given display--that is, the subset of highlighted options that minimizes users' search times.

Computers↗

Oregon's Medicaid ranking and cost-effectiveness: is there any relationship?

The authors examine whether Oregon's 1990, 1991, 1992, and 1993 prioritized lists were ranked in a manner consistent with cost-effectiveness. Two sets of cost-effectiveness data are used: data from economic analyses and Oregon's own cost-effectiveness data. Comparing the ranks of Oregon's lists with the ranks of cost-effectiveness estimates from the literature reveals Spearman correlations of -0.08 for the 1990 list, +0.39 for the 1991 list, +0.25 for the 1992 list, and +0.24 for the 1993 list. Comparing Oregon's lists with Oregon's own cost-effectiveness data reveals rank correlations of +0.99 for the 1990 list, +0.06 for the 1991 list, -0.05 for the 1992 list, and -0.03 for the 1993 list. Thus, there appear to be essentially no relationship between the 1990 list and cost-effectiveness estimates from the economic literature and modest positive relationships between the 1991-93 lists and the literature. In addition, there is virtually no relationship between the 1991-93 lists and Oregon's own cost-effectiveness data. Further, the correlations are very different from +1.0, suggesting that other factors are at play. For example, the 1993 list that is currently being implemented was ranked primarily by improvement in five-year survival and human judgment, not cost-effectiveness.

Cost-Benefit Analysis↗

Testing for the BRCA1 and BRCA2 breast-ovarian cancer susceptibility genes: a decision analysis.

OBJECTIVE: The authors developed a Markov decision model to evaluate the health implications of testing for mutations in the BRCA1 and BRCA2 breast-ovarian cancer susceptibility genes. Prophylactic measures considered included various combinations of immediate and delayed bilateral mastectomy and oophorectomy or taking no action. METHODS: The model incorporated the likelihood of developing breast and/or ovarian cancer, survival, and quality of life. Parameter values were taken from public databases, the published literature, and a survey of cancer experts. Outcomes considered were additional life expectancy and quality-adjusted life years (QALYs). Results are reported for 30-year-old cancer-free women at various levels of hereditary risk. RESULTS AND CONCLUSIONS: The vast majority of women will not benefit from testing because their pre-test risks are low and surgical prophylaxis is undesirable. However, women who have family histories of early breast and/or ovarian cancer may gain up to 2 QALYs by allowing genetic testing to inform their decisions.

Adult↗