Regression analysis on the variation in efficiency frontiers for prevention stage of HIV/AIDS

OBJECTIVES

To investigate how the cost effectiveness of preventing HIV/AIDS varies across possible efficiency frontiers (EFs) by taking into account potentially relevant external factors, such as prevention stage, and how the EFs can be characterized using regression analysis given uncertainty of the QALY-cost estimates.

METHODS

We reviewed cost-effectiveness estimates for the prevention and treatment of HIV/AIDS published from 2002-2007 and catalogued in the Tufts Medical Center Cost-Effectiveness Analysis (CEA) Registry. We constructed efficiency frontier (EF) curves by plotting QALYs against costs, using methods used by the Institute for Quality and Efficiency in Health Care (IQWiG) in Germany. We stratified the QALY-cost ratios by prevention stage, country of study, and payer perspective, and estimated EF equations using log and square-root models.

RESULTS

A total of 53 QALY-cost ratios were identified for HIV/AIDS in the Tufts CEA Registry. Plotted ratios stratified by prevention stage were visually grouped into a cluster consisting of primary/secondary prevention measures and a cluster consisting of tertiary measures. Correlation coefficients for each cluster were statistically significant. For each cluster, we derived two EF equations - one based on the log model, and one based on the square-root model.

DISCUSSION

Our findings indicate that stratification of HIV/AIDS interventions by prevention stage can yield distinct EFs, and that the correlation and regression analyses are useful for parametrically characterizing EF equations. Our study has certain limitations, such as the small number of included articles and the potential for study populations to be non-representative of countries of interest. Nonetheless, our approach could help develop a deeper appreciation of cost effectiveness beyond the deterministic approach developed by IQWiG.

Low-value services in value-based insurance design

OBJECTIVES

To identify potentially low-value services for inclusion in value-based insurance design (VBID) programs and to discuss challenges involved in incorporating such information.

METHODS

We searched the Tufts Medical Center Cost-Effectiveness Analysis Registry (www.cearegistry.org) to identify examples of low-value services, defined as interventions that make health worse without saving money or those that cost at least $100,000 per quality-adjusted life-year gained. We restricted our attention to papers published since 2000. We supplemented this literature review with a list of services recently rejected by the United Kingdom's National Institute for Health and Clinical Excellence for coverage by the UK's National Health Service.

RESULTS

The list of potentially low-value services includes several drugs to treat cancer, as well as other therapies such as left ventricular assist devices and lung volume reduction surgery. Building negative incentives into VBID programs to discourage use of low-value care will involve a number of challenges, including identification of appropriate candidates; the scope of services to be covered (ie, whether VBID should be expanded beyond drugs to address medical devices, procedures, and diagnostics); and whether VBID programs should target specific subgroups.

CONCLUSION

Identifying noncontroversial low-value services and designing VBID programs to discourage their use will not be easy. However, to fulfill their promise of improving value and moderating cost growth, VBID programs should target low-value as well as high-value care.

Much cheaper, almost as good: decrementally cost-effective medical innovation

Under conditions of constrained resources, cost-saving innovations may improve overall outcomes, even when they are slightly less effective than available options, by permitting more efficient reallocation of resources. The authors systematically reviewed all MEDLINE-cited cost-utility analyses written in English from 2002 to 2007 to identify and describe cost- and quality-decreasing medical innovations that might offer favorable "decrementally" cost-effective tradeoffs-defined as saving at least $100 000 per quality-adjusted life-year lost. Of 2128 cost-effectiveness ratios from 887 publications, only 9 comparisons (0.4% of total) described 8 innovations that were deemed to be decrementally cost-effective. Examples included percutaneous coronary intervention (instead of coronary artery bypass graft) for multivessel coronary disease, repetitive transcranial magnetic stimulation (instead of electroconvulsive therapy) for drug-resistant major depression, watchful waiting for inguinal hernias, and hemodialyzer sterilization and reuse. On a per-patient basis, these innovations yielded savings from $122 to almost $12 000 but losses of 0.001 to 0.021 quality-adjusted life-years (approximately 8 hours to 1 week). These findings demonstrate the rarity of decrementally cost-effective innovations in the medical literature.

The Adoption of Cost-Effectiveness Acceptability Curves in Cost-Utility Analyses

Background. Cost-effectiveness acceptability curves (CEACs) plot the probability that one health intervention is more cost-effective than alternatives, as a function of societal willingness to pay for additional units of health (e.g., life-years or quality-adjusted life-years gained). Objectives. To quantify the adoption of CEACs in published cost-utility analyses (CUAs), and to identify factors associated with CEAC use. Methods. Data from the Tufts Medical Center Cost-Effectiveness Analysis Registry (www.cearegistry.org), a database with detailed information on approximately 1,400 CUAs published in the peer reviewed literature through 2006, was analyzed. The registry includes data on study origin, study methodology, reporting of results, whether CEACs were presented, and a subjective quality score. Univariate and multivariate logistic regression analyses were used to identify factors predicting CEAC use, from their introduction in 1994 through 2006. Results. Approximately 15% of CUAs published since 1994 present a CEAC. The use of CEACs has increased rapidly in recent years, from 2.1% of published CUAs in 2001 to 32.6% in 2006 (P < 0.0001). The most significant predictors of CEAC use were study quality (odds ratio [OR]: 2.26; 95% confidence interval [CI]: 1.80, 2.85), recent publication (OR: 1.99; 95% CI: 1.73, 2.29), and whether studies pertain to the UK (OR: 5.66; 95% CI: 3.67, 8.72) or Sweden (OR: 3.76; 95% CI: 1.67, 8.44). Conclusions. CEAC use is increasing in the published cost-effectiveness literature, especially in UK-based studies.

Cost savings and cost-effectiveness of clinical preventive care

It is well established that preventive care reduces the prevalence of disease and helps people live longer, healthier lives. Analysis of the cost-effectiveness of preventive care can guide policy-makers to allocate scarce resources. This synthesis reviews the evidence on the cost-effectiveness of clinical preventive care. Key findings include: although many preventive services are a good value (defined as costing less than $50,000 to $100,000 per Quality Adjusted Life Year), only a few, such as childhood immunizations and counseling adults on the use of low-dose aspirin are widely regarded as cost-saving. Costs to reduce risk factors, screening costs, and the cost of treatment when disease is found can offset any savings from preventive care. Prevention can reduce the incidence of disease, but savings may be partially offset by health care costs associated with increased longevity. Whether these additional competing risk costs outweigh the savings from avoiding the targeted disease depends on how healthy people are during the added life years. Given that so few preventive services save money and that these services are already in wide use, it is unlikely that prevention can reduce health care spending. The authors question whether the emphasis on savings is appropriate and suggest it is better to focus on high value preventive care, taking into account increased longevity and quality of life.

Transplantation risks and the real world: what does 'high risk' really mean?

Candidates for, and recipients of, transplants face numerous risks that receive varying degrees of attention from the media and transplant professionals. Characterizations such as 'high risk donor' are not necessarily accurate or informative unless they are discussed in context with the other risks patients face before and after transplantation. Moreover, such labels do not provide accurate information for informed consent discussions or decision making. Recent cases of donor-transmitted diseases from donors labeled as being at 'high risk' have engendered concern, new policy proposals and attempts to employ additional testing of donors. The publicity and policy reactions to these cases do not necessarily better inform transplant candidates and recipients about these risks. Using comparative risk analysis, we compare the various risks associated with waiting on the list, accepting donors with various risk characteristics, posttransplant survival and everyday risks we all face in modern life to provide some quantitative perspective on what 'high risk' really means for transplant patients. In our analysis, donor-transmitted disease risks are orders of magnitude less than other transplantation risks and similar to many everyday occupational and recreational risks people readily and willingly accept. These comparisons can be helpful for informing patients and guiding future policy development.

30 years of pharmaceutical cost-utility analyses: growth, diversity and methodological improvement

To review and critically evaluate published cost-utility analyses (CUAs) pertaining to pharmaceuticals for the past 3 decades. We examined data from the Tufts Medical Center Cost-Effectiveness Analysis Registry (www.cearegistry.org), which contains detailed information on English-language CUAs and their ratios (in $US, year 2008 values) published in peer-reviewed journals. We summarized study features using descriptive statistics for articles published from 1976 to 2006. Changes in study methodology over time were analysed by trend test. Analysis of ratios was restricted to those published from 2000 to 2006 from studies that correctly discounted future costs and benefits. Factors associated with having a favourable value (defined to be more than the median for all included ratios) were identified by logistic regression. Of 1393 CUAs published through 2006, 640 (45.9%) pertained to pharmaceuticals. The proportion of CUAs that focussed on pharmaceuticals increased from 34% for the period 1990-5 to 47% for the period 2001-5. Investigations with a US perspective accounted for 51% of all CUAs, although this proportion has decreased over time. The UK perspective investigations accounted for nearly 16% of all studies, and this portion has increased over time. About 24% of all CUAs were sponsored by industry, 48% were sponsored by non-industry sources, and 28% did not disclose their funding. Adherence to good methodological practices is roughly similar for studies with industry and non-industry sponsorship. Adherence to these practices has increased over time. Among the 1969 ratios meeting our inclusion criteria, the median value was $US22 000 per QALY. Logistic regression revealed that, while controlling for the intervention category (e.g. pharmaceutical, medical device, screening), ratios were more likely to be favourable if they were from studies sponsored by a pharmaceutical or device manufacturer (OR 1.53; 95% CI 1.07, 2.19). Ratios for pharmaceutical CUAs were less favourable than other ratios while controlling for sponsorship (OR 0.66; 95% CI 0.44, 0.98). The number of published pharmaceutical CUAs has grown steadily and accounts for almost half of all published CUAs. Adherence to good methodological practices does not appear to differ by study sponsor. Ratios from industry-sponsored studies are more favourable than other ratios. The results highlight that there are many opportunities for efficient healthcare investment, among pharmaceutical and non-pharmaceutical interventions, just as there are many investments that are inefficient.

Decision analytic models for Alzheimer's disease: state of the art and future directions

Decision analytic policy models for Alzheimer's disease (AD) enable researchers and policy makers to investigate questions about the costs and benefits of a wide range of existing and potential screening, testing, and treatment strategies. Such models permit analysts to compare existing alternatives, explore hypothetical scenarios, and test the strength of underlying assumptions in an explicit, quantitative, and systematic way. Decision analytic models can best be viewed as complementing clinical trials both by filling knowledge gaps not readily addressed by empirical research and by extrapolating beyond the surrogate markers recorded in a trial. We identified and critiqued 13 distinct AD decision analytic policy models published since 1997. Although existing models provide useful insights, they also have a variety of limitations. (1) They generally characterize disease progression in terms of cognitive function and do not account for other distinguishing features, such as behavioral symptoms, functional performance, and the emotional well-being of AD patients and caregivers. (2) Many describe disease progression in terms of a limited number of discrete states, thus constraining the level of detail that can be used to characterize both changes in patient status and the relationships between disease progression and other factors, such as residential status, that influence outcomes of interest. (3) They have focused almost exclusively on evaluating drug treatments, thus neglecting other disease management strategies and combinations of pharmacologic and nonpharmacologic interventions. Future AD models should facilitate more realistic and compelling evaluations of various interventions to address the disease. An improved model will allow decision makers to better characterize the disease, to better assess the costs and benefits of a wide range of potential interventions, and to better evaluate the incremental costs and benefits of specific interventions used in conjunction with other disease management strategies.

What’s More Dangerous, Your Aspirin Or Your Car? Thinking Rationally About Drug Risks (And Benefits)

We compare mortality risks of several common drugs with risks related to work, transportation, and recreation. Comparing risks can provide a more intuitive sense of the magnitude of drug risks than stand-alone estimates can, to help inform policy discussions. The drug risks we quantify generally exceed the magnitude of risks for other domains (although aspirin and cars are similarly "risky" under the definition of risk used here). Nonetheless, these comparisons underscore a crucial point: that risks should not be evaluated without considering attendant benefits. We discuss the need for the Food and Drug Administration to compare risks and benefits quantitatively, consistently, and explicitly.

[Fiberoptic endoscopic evaluation of swallowing--the Tel Aviv Voice and Swallowing Disorders Clinic]

Fiberoptic endoscopic evaluation of swallowing (FEES) involves passing a fiberoptic laryngoscope transnasally to visualize the hypopharynx, larynx, and proximal trachea in order to assess swallowing disorders. FEES has been compared with the modified barium swallow (MBS) (the presumed "gold standard"). To date, reports have demonstrated that FEES is as sensitive as, or even more sensitive, for use as a tool in swallowing assessment compared with the MBS. FEES provides the clinician with a safe, portable, effective, and valid means of evaluating individuals with swallowing disturbances. FEES allows the examiner to identify swallowing physiology, determine the safest and least restrictive level of oral intake, implement appropriate compensatory techniques, and identify a dysphagia rehabilitation plan. In this article we present the Tel-Aviv Voice and Swallowing Disorders Center experience. Out of 100 patients that were referred to our center for swallowing evaluation 97 patients underwent 102 FEES examinations. Three patients couldn't tolerate the examination. In 63% of the patients swallowing pathology was found. FEES were performed by teamwork involving a speech-language pathologist and otolaryngologist collaborating together thus optimally managing the individual with dysphagia safely and efficiently.

[The reflux symptom index--a clinical tool for the diagnosis of laryngopharyngeal reflux]

BACKGROUND

Laryngopharyngeal reflux (LPR) refers to the backflow of stomach contents into the throat. Patients with LPR suffer from hoarseness, throat discomfort, dysphonia, chronic cough, chronic throat clearing and dysphagia. In 2001 Koufman et al. published the self-administered nine-item reflux symptom index (RSI) to assist clinicians in detecting and documenting the presence of LPR. This instrument appears to be valid and highly reproducible.

OBJECTIVE

To develop the Hebrew version of the Reflux Symptom Index (RSI).

METHODS

Validation of the Hebrew questionnaire included translation of the original instrument from English to Hebrew by three independent translators and retranslation back from Hebrew to English by three other translators. In the United States, patients completed the original and back-translated questionnaires. Scores correlation of the two instruments was performed using correlation coefficient analysis. Validation of the questionnaire was performed by measuring the association between the mean RSI score and the reflux findings upon flexible endoscopy. A control group of 9 patients with no clinical signs of reflux was chosen for our outpatient clinic.

RESULTS

A total of '14 patients in the United States completed the original and the back-translated questionnaires. The correlation coefficient (r) was 0.92 (p < 0.001). In the second part of the study. 21 consistent Israeli patients that were referred to our voice center because of voice problems were requested to complete the questionnaire. History and endoscopic examinations did not reveal tumors, paralysis, functional voice problems or smoking. The mean age was 53 years (range 37-69 years). There were 14 women in the study group. Twenty patients had RSI higher then 10 (considered positive to the presence of reflux disease). Examination of the larynx demonstrated presence of reflux (e.g. edema of the vocal cords, posterior commissure hypertrophy, arythenoids edema, subglottic edema) in 19 cases (90.5% of patients). All the patients in the control group had a RSI lower then 10.

CONCLUSIONS

The Hebrew RSI is an easy self-administered and reliable instrument that can help the clinician detect patients suffering from LPR and monitor their treatment.

A quantitative analysis of prenatal methyl mercury exposure and cognitive development

Although a rich source of n-3 polyunsaturated fatty acids (PUFAs) that may confer multiple health benefits, some fish also contain methyl mercury (MeHg), which may harm the developing fetus. U.S. government recommendations for women of childbearing age are to modify consumption of high MeHg fish to reduce MeHg exposure, while recommendations encourage fish consumption among the general population because of the nutritional benefits. The Harvard Center for Risk Analysis convened an expert panel (see acknowledgements) to quantify the net impact of resulting hypothetical changes in fish consumption across the population. This paper quantifies the impact of prenatal MeHg exposure on cognitive development. Other papers quantify the beneficial impact of prenatal intake of n-3 PUFAs on cognitive function and the extent to which fish consumption protects against coronary heart disease mortality and stroke in adults. This analysis aggregates results from three major prospective epidemiology studies to quantify the association between prenatal MeHg exposure and cognitive development as measured by intelligence quotient (IQ). It finds that prenatal MeHg exposure sufficient to increase the concentration of mercury in maternal hair at parturition by 1 microg/g decreases IQ by 0.7 points. This paper identifies important sources of uncertainty influencing this estimate, concluding that the plausible range of values for this loss is 0 to 1.5 IQ points.

A quantitative risk-benefit analysis of changes in population fish consumption

Although a rich source of n-3 polyunsaturated fatty acids (PUFAs) that may confer multiple health benefits, some fish contain methyl mercury (MeHg), which may harm the developing fetus. U.S. government recommendations for women of childbearing age are to modify consumption of high-MeHg fish, while recommendations encourage fish consumption among the general population because of nutritional benefits. To investigate the aggregate impacts of hypothetical shifts in fish consumption, the Harvard Center for Risk Analysis convened an expert panel (see acknowledgements). Effects investigated include prenatal cognitive development, coronary heart disease mortality, and stroke. Substitution of fish with high MeHg concentrations with fish containing less MeHg among women of childbearing age yields substantial developmental benefits and few negative impacts. However, if women instead decrease fish consumption, countervailing risks substantially reduce net benefits. If other adults (mistakenly and inappropriately) also reduce their fish consumption, the net public health impact is negative. Although high compliance with recommended fish consumption patterns can improve public health, unintended shifts in consumption can lead to public health losses. Risk managers should investigate and carefully consider how populations will respond to interventions, how those responses will influence nutrient intake and contaminant exposure, and how these changes will affect aggregate public health.

A quantitative analysis of prenatal intake of n-3 polyunsaturated fatty acids and cognitive development

Although a rich source of n-3 polyunsaturated fatty acids (PUFAs) that may confer multiple health benefits, some fish also contain methyl mercury (MeHg), which may harm the developing fetus. U.S. government recommendations for women of childbearing age are to modify consumption of high-MeHg fish to reduce MeHg exposure, while recommendations encourage fish consumption among the general population because of the nutritional benefits. The Harvard Center for Risk Analysis convened an expert panel (see acknowledgements) to quantify the net impact of resulting hypothetical changes in fish consumption across the population. This paper estimates the impact of prenatal n-3 intake on cognitive development. Other papers quantify the negative impact of prenatal exposure to MeHg on cognitive development, and the extent to which fish consumption protects against coronary heart disease mortality and stroke in adults. This paper aggregates eight randomized controlled trials (RCTs) comparing cognitive development in controls and in children who had received n-3 PUFA supplementation (seven studies of formula supplementation and one study of maternal dietary supplementation). Our analysis assigns study weights accounting for statistical precision, relevance of three endpoint domains (general intelligence, verbal ability, and motor skills) to prediction of IQ, and age at evaluation. The study estimates that increasing maternal docosahexaenoic acid (DHA) intake by 100 mg/day increases child IQ by 0.13 points. The paper notes that findings were inconsistent across the RCTs evaluated (although our findings were relatively robust to changes in the weighting scheme used). Also, for seven of the eight studies reviewed, effects are extrapolated from formula supplementation to maternal dietary intake.

A quantitative analysis of fish consumption and coronary heart disease mortality

Although a rich source of n-3 polyunsaturated fatty acids (PUFAs) that may confer multiple health benefits, some fish contain methyl mercury (MeHg), which may harm the developing fetus. U.S. government recommendations for women of childbearing age are to modify consumption of high-MeHg fish to reduce MeHg exposure, while recommendations encourage fish consumption among the general population because of the nutritional benefits. The Harvard Center for Risk Analysis convened an expert panel (see acknowledgements) to quantify the net impact of resulting hypothetical changes in fish consumption across the population. This paper estimates the impact of fish consumption on coronary heart disease (CHD) mortality and nonfatal myocardial infarction (MI). Other papers quantify stroke risk and the impacts of both prenatal MeHg exposure and maternal intake of n-3 PUFAs on cognitive development. This analysis identified articles in a recent qualitative review appropriate for the development of a dose-response relationship. Studies had to satisfy quality criteria, quantify fish intake, and report the precision of the relative risk estimates. Relative risk results were averaged, weighted proportionately by precision. CHD risks associated with MeHg exposure were reviewed qualitatively because the available literature was judged inadequate for quantitative analysis. Eight studies were identified (29 exposure groups). Our analysis estimated that consuming small quantities of fish is associated with a 17% reduction in CHD mortality risk, with each additional serving per week associated with a further reduction in this risk of 3.9%. Small quantities of fish consumption were associated with risk reductions in nonfatal MI risk by 27%, but additional fish consumption conferred no incremental benefits.

A quantitative analysis of fish consumption and stroke risk

Although a rich source of n-3 polyunsaturated fatty acids (PUFAs) that may confer multiple health benefits, some fish contain methyl mercury (MeHg), which may harm the developing fetus. U.S. government recommendations for women of childbearing age are to modify consumption of high-MeHg fish to reduce MeHg exposure, while recommendations encourage fish consumption among the general population because of the nutritional benefits. The Harvard Center for Risk Analysis convened an expert panel (see acknowledgements) to quantify the net impact of resulting hypothetical changes in fish consumption across the population. This paper estimates the impact of fish consumption on stroke risk. Other papers quantify coronary heart disease mortality risk and the impacts of both prenatal MeHg exposure and maternal intake of n-3 PUFAs on cognitive development. This analysis identified articles in a recent qualitative literature review that are appropriate for the development of a dose-response relationship between fish consumption and stroke risk. Studies had to satisfy quality criteria, quantify fish intake, and report the precision of the relative risk estimates. The analysis combined the relative risk results, weighting each proportionately to its precision. Six studies were identified as appropriate for inclusion in this analysis, including five prospective cohort studies and one case-control study (total of 24 exposure groups). Our analysis indicates that any fish consumption confers substantial relative risk reduction compared to no fish consumption (12% for the linear model), with the possibility that additional consumption confers incremental benefits (central estimate of 2.0% per serving per week).

When Is Evidence Sufficient?

Traditional conceptualizations of evidence-based medicine rely heavily on randomized controlled trials. Although initiatives to broaden definitions of evidence have been advanced, they generally have not tied evidentiary criteria formally and quantitatively to the benefits and costs involved in a decision to adopt or reject an intervention. Decision analysis provides a framework for combining information to inform the adoption decision in this manner. Value-of-information analysis, a related methodology, helps to determine whether it is worthwhile to collect additional information as well as the type of research that would be most helpful.

Fuels for urban transit buses: a cost-effectiveness analysis

Public transit agencies have begun to adopt alternative propulsion technologies to reduce urban transit bus emissions associated with conventional diesel (CD) engines. Among the most popular alternatives are emission controlled diesel buses (ECD), defined here to be buses with continuously regenerating diesel particle filters burning low-sulfur diesel fuel, and buses burning compressed natural gas (CNG). This study uses a series of simplifying assumptions to arrive at first-order estimates for the incremental cost-effectiveness (CE) of ECD and CNG relative to CD. The CE ratio numerator reflects acquisition and operating costs. The denominator reflects health losses (mortality and morbidity) due to primary particulate matter (PM), secondary PM, and ozone exposure, measured as quality adjusted life years (QALYs). We find that CNG provides larger health benefits than does ECD (nine vs six QALYs annually per 1000 buses) but that ECD is more cost-effective than CNG (dollar 270 000 per QALY for ECD vs dollar 1.7 million to dollar 2.4 million for CNG). These estimates are subject to much uncertainty. We identify assumptions that contribute most to this uncertainty and propose potential research directions to refine our estimates.