Gains in life expectancy from medical interventions--standardizing data on outcomes

Prognostication--the lost skill of medicine

Making a prognosis is one of the primary functions of the medical profession. At the end of the nineteenth century prognostication took up approximately ten percent of medical textbooks, by 1970 this had fallen to nearly zero. Given medical technology's awesome ability to prolong the process and suffering of dying today's patients need to know their prognosis in order to make choices about their treatment options. Whilst precise predictions of the future are obviously not possible, relatively simple mathematical modelling techniques can make reasonable estimates of likely outcomes for individual patients. The life expectancy of a patient of any age with any illness can be estimated provided the disease-specific mortality of the illness is known. Decision analysis or logistic regression models can then be used to determine the risks and benefits of various treatment options. A patient's prognosis does not just depend on their age and primary diagnosis, but also on the severity of their illness, their functional capacity both prior to and during the illness and the number of co-morbidities also suffered from. Several predictive instruments have been developed to help simplify the prediction of the outcome of individual patients. There are conflicting reports on how these models compare with doctors' intuition--whatever their strengths and weaknesses it is unlikely that they worsen clinical judgement. Therefore, all doctors should become familiar with them and use them appropriately.

Individualizing the risks and benefits of postmenopausal hormone therapy

OBJECTIVE

The objective was to develop an individualized risk-benefit model quantifying the impact of combined use of estrogen and progestogen on chronic diseases.

DESIGN

The study population consisted of women, aged 40+, prescribed postmenopausal hormone therapy (HT) in the UK General Practice Research Database (N > 200,000). Individualized risks of fracture, colorectal cancer, diabetes mellitus, myocardial infarction, deep venous thrombosis/pulmonary embolism, breast cancer, and stroke were estimated using Cox regression. Relative rates from the Women's Health Initiative trial were used to estimate attributable risks (ie, excess risks) in a risk-benefit simulation model.

RESULTS

Risks and benefits increased with age and length of HT use. HT use for 5 years initiated at age 45 increased the absolute risk of myocardial infarction by 0.04% and breast cancer by 0.3% and reduced the risk of hip fracture by 0.03%. Comparably, 5-year HT use started at age 75 led to increases in the risks of myocardial infarction and breast cancer (+0.4% and +0.2%, respectively) and reduced that of hip fracture (-0.9%). There was considerable heterogeneity in the risks and benefits of HT. In most of the younger HT users, the frequency of risks exceeded that of the benefits, although the absolute excess risks were small. In HT users aged 70+, 62.4% experienced more benefits than risks, whereas 37.6% experienced more risks than benefits.

CONCLUSIONS

The frequency of beneficial and adverse effects of HT on chronic diseases was low in younger women, whereas the ratio of these risks and benefits varied substantially among the older users. However, the study could not asses the effects of HT on menopausal symptoms and quality of life, benefits more likely to be observed among younger women.

Sunitinib for advanced renal cell cancer

Renal cell cancer has been refractory to drug therapy in the large majority of patients. Targeted agents including sunitinib have been intensively evaluated in renal cell cancer over the past 5 years. Sunitinib is an oral small molecule inhibitor of several targets including multiple tyrosine kinase receptors of the angiogenesis pathway. This review surveys the rationale, development, validation, and clinical use of sunitinib that received conditional approval for use in North America and Europe in 2006. In patients with the clear-cell subtype of renal cell cancer and metastatic disease with good or moderate prognostic factors for survival, sunitinib 50 mg for 4 weeks of a 6-week cycle provides superior surrogate and patient-reported outcomes when compared with interferon-alfa, the previous commonly used first-line drug. Overall survival has not yet shown improvement over interferon and is problematic because of patient crossover from the control arm to sunitinib at disease progression. Toxicity is significant but manageable with experienced monitoring. Sunitinib therapy is an important step forward for this condition. High cost and limited efficacy support the ongoing search for further improved therapy.

Identifying the best treatment among common nonsurgical neck pain treatments: a decision analysis

STUDY DESIGN

Decision analysis.

OBJECTIVE

To identify the best treatment for nonspecific neck pain.

SUMMARY OF BACKGROUND DATA

In Canada and the United States, the most commonly prescribed neck pain treatments are nonsteroidal anti-inflammatory drugs (NSAIDs), exercise, and manual therapy. Deciding which treatment is best is difficult because of the trade-offs between beneficial and harmful effects, and because of the uncertainty of these effects.

METHODS

(Quality-adjusted) life expectancy associated with standard NSAIDs, Cox-2 NSAIDs, exercise, mobilization, and manipulation were compared in a decision-analytic model. Estimates of the course of neck pain, background risk of adverse events in the general population, treatment effectiveness and risk, and patient-preferences were input into the model. Assuming equal effectiveness, we conducted a baseline analysis using risk of harm only. We assessed the stability of the baseline results by conducting a second analysis that incorporated effectiveness data from a high-quality randomized trial.

RESULTS

There were no important differences across treatments. The difference between the highest and lowest ranked treatments predicted by the baseline model was 4.5 days of life expectancy and 3.4 quality-adjusted life-days. The difference between the highest and lowest ranked treatments predicted by the second model was 7.3 quality-adjusted life-days.

CONCLUSION

When the objective is to maximize life expectancy and quality-adjusted life expectancy, none of the treatments in our analysis were clearly superior.

What is the harm-benefit ratio of Cox-2 inhibitors?

BACKGROUND

Selective cyclooxygenase-2 (Cox-2) inhibitors, developed to reduce the risk of NSAID-related gastrointestinal (GI) complications, have been associated with an increased risk of cardiovascular events. Our objective was to determine the balance of potential harm and benefit related to Cox-2 inhibitors' exposure.

METHODS

The study population included patients aged 40+ years who received a prescription for Cox-2 inhibitors and were included in the General Practice Research Database. The incidence of upper GI events, myocardial infarction (MI) and stroke was estimated in this cohort. It was assumed that patients had experienced the upper GI and cardiovascular effects, as observed in clinical trials [relative rate (RR) of 0.49 for upper GI and 1.86 for MI]. Simulation methodology was used to estimate attributable risks, i.e. the difference between exposed and unexposed event probabilities.

RESULTS

The study population included 155,439 Cox-2 users. The number of upper GI events prevented by Cox-2 inhibitors was 179, while the number of excess MI cases was 83 per 10,000 patients treated for 4 years. A strong association was found between extent of GI benefit and cardiovascular harm. There was a large difference in the frequency of benefit over harm in only 6% of the patients (difference of 1% or more); 23% of the patients had more harm than benefit, including those with a history of ischaemic heart disease.

CONCLUSIONS

The benefit of Cox-2 inhibitors in reducing the frequency of upper GI events may be offset by their cardiovascular harm, particularly in patients with risk factors for cardiovascular disease.

Use of colonic stents in emergent malignant left colonic obstruction: a Markov chain Monte Carlo decision analysis

PURPOSE

This decision analysis examines the cost-effectiveness of colonic stenting as a bridge to surgery vs. surgery alone in the management of emergent, malignant left colonic obstruction.

METHODS

We used a Markov chain Monte Carlo decision analysis model to determine the effect on health-related quality of life of two strategies: emergency surgery vs. emergency colonic stenting as a bridge to definitive surgery. All relevant health states were modeled during a patient's expected lifespan. Outcome measures were mortality, the proportion of patients requiring a colostomy, quality-adjusted life expectancy, and costs. Deterministic and probabilistic sensitivity analyses were performed.

RESULTS

In our model, colonic stenting was more effective (9.2 quality-adjusted life months benefit) and less costly (CAD dollars 3,763; US dollars 3,135) than emergency surgery. Its benefits were secondary to reductions in acute mortality and in the likelihood of requiring a permanent colostomy. The results were only dependent on the rate of stenting complications (perforation, technical placement failure, and migration) and the patient's risk of surgical mortality, with the benefits being greatest among patients at high risk of operative mortality.

CONCLUSIONS

Colonic stenting as a bridge to surgery is more effective and less costly than surgery in the treatment of emergent, malignant left colonic obstruction. The benefits are most pronounced in high-risk patients and are diminished by increases in stent placement failure rates and perforation rates. In low-risk patients, the benefits are more modest and may not outweigh the risks.

Optimal management of high-risk T1G3 bladder cancer: a decision analysis

BACKGROUND

Controversy exists about the most appropriate treatment for high-risk superficial (stage T1; grade G3) bladder cancer. Immediate cystectomy offers the best chance for survival but may be associated with an impaired quality of life compared with conservative therapy. We estimated life expectancy (LE) and quality-adjusted life expectancy (QALE) for both of these treatments for men and women of different ages and comorbidity levels.

METHODS AND FINDINGS

We evaluated two treatment strategies for high-risk, T1G3 bladder cancer using a decision-analytic Markov model: (1) Immediate cystectomy with neobladder creation versus (2) conservative management with intravesical bacillus Calmette-Guérin (BCG) and delayed cystectomy in individuals with resistant or progressive disease. Probabilities and utilities were derived from published literature where available, and otherwise from expert opinion. Extensive sensitivity analyses were conducted to identify variables most likely to influence the decision. Structural sensitivity analyses modifying the base case definition and the triggers for cystectomy in the conservative therapy arm were also explored. Probabilistic sensitivity analysis was used to assess the joint uncertainty of all variables simultaneously and the uncertainty in the base case results. External validation of model outputs was performed by comparing model-predicted survival rates with independent published literature. The mean LE of a 60-y-old male was 14.3 y for immediate cystectomy and 13.6 y with conservative management. With the addition of utilities, the immediate cystectomy strategy yielded a mean QALE of 12.32 y and remained preferred over conservative therapy by 0.35 y. Worsening patient comorbidity diminished the benefit of early cystectomy but altered the LE-based preferred treatment only for patients over age 70 y and the QALE-based preferred treatment for patients over age 65 y. Sensitivity analyses revealed that patients over the age of 70 y or those strongly averse to loss of sexual function, gastrointestinal dysfunction, or life without a bladder have a higher QALE with conservative therapy. The results of structural or probabilistic sensitivity analyses did not change the preferred treatment option. Model-predicted overall and disease-specific survival rates were similar to those reported in published studies, suggesting external validity.

CONCLUSIONS

Our model is, to our knowledge, the first of its kind in bladder cancer, and demonstrated that younger patients with high-risk T1G3 bladder had a higher LE and QALE with immediate cystectomy. The decision to pursue immediate cystectomy versus conservative therapy should be based on discussions that consider patient age, comorbid status, and an individual's preference for particular postcystectomy health states. Patients over the age of 70 y or those who place high value on sexual function, gastrointestinal function, or bladder preservation may benefit from a more conservative initial therapeutic approach.

Should Hemodialysis Patients With Atrial Fibrillation Undergo Systemic Anticoagulation? A Cost-Utility Analysis

BACKGROUND

Approximately 14% of hemodialysis patients have atrial fibrillation. Hemodialysis patients with atrial fibrillation appear to be at increased risk of both thromboembolic complications and bleeding. Furthermore, there is uncertainty regarding the efficacy of warfarin or acetylsalicylic acid (ASA) therapy for preventing strokes in this subgroup because they were excluded from relevant trials.

STUDY DESIGN

We performed a cost-utility analysis. Probabilistic sensitivity analysis was used to incorporate parameter uncertainty into the model. Expected value of perfect information and scenario analyses were performed to identify the important drivers of the decision and focus future research.

SETTING & POPULATION

Base case was a 60-year-old male hemodialysis patient in the United States.

MODEL, PERSPECTIVE, & TIME FRAME

A Markov Monte Carlo microsimulation model was constructed from the perspective of the health care payer, and patients were followed up during their lifetime.

INTERVENTION

We compared 3 alternative treatment strategies for permanent atrial fibrillation in hemodialysis patients: warfarin, ASA, or no treatment.

OUTCOMES

Quality-adjusted survival and cost.

RESULTS

ASA and warfarin both prolonged survival compared with no treatment (0.06 and 0.15 quality-adjusted life-years [QALYs], respectively). ASA was associated with an incremental cost-effectiveness ratio of $82,100/QALY. Warfarin provided additional benefits at a cost of $88,400 for each QALY gained relative to ASA. At a threshold of $100,000/QALY, the probabilities that no treatment, warfarin, and ASA were the most efficient therapy were 20%, 58%, and 23%, respectively.

LIMITATIONS

Parameterization data and costs were taken from US studies and may not be generalizable to other countries. Peritoneal dialysis patients were not included in the analysis.

CONCLUSIONS

The high future cost of hemodialysis constrains incremental cost-effectiveness ratios to values greater than commonly cited thresholds ($50,000/QALY). Based on available evidence, warfarin appears to be the optimal therapy to prevent thromboembolic stroke in hemodialysis patients with atrial fibrillation. Additional study is required to determine the efficacy of warfarin and risk of bleeding complications in this population so that patients can make a more informed choice.

Can postponement of an adverse outcome be used to present risk reductions to a lay audience? A population survey

BACKGROUND

For shared decision making doctors need to communicate the effectiveness of therapies such that patients can understand it and discriminate between small and large effects. Previous research indicates that patients have difficulties in understanding risk measures. This study aimed to test the hypothesis that lay people may be able to discriminate between therapies when their effectiveness is expressed in terms of postponement of an adverse disease event.

METHODS

In 2004 a random sample of 1,367 non-institutionalized Danes aged 40+ was interviewed in person. The participants were asked for demographic information and asked to consider a hypothetical preventive drug treatment. The respondents were randomized to the magnitude of treatment effectiveness (heart attack postponement of 1 month, 6 months, 12 months, 2 years, 4 years and 8 years) and subsequently asked whether they would take such a therapy. They were also asked whether they had hypercholesterolemia or had experienced a heart attack.

RESULTS

In total 58% of the respondents consented to the hypothetical treatment. The proportions accepting treatment were 39%, 52%, 56%, 64%, 67% and 73% when postponement was 1 month, 6 months, 12 months, 2 years, 4 years and 8 years respectively. Participants who thought that the effectiveness information was difficult to understand, were less likely to consent to therapy (p = 0.004).

CONCLUSION

Lay people can discriminate between levels of treatment effectiveness when they are presented in terms of postponement of an adverse event. The results indicate that such postponement is a comprehensible measure of effectiveness.

Treatment of high blood pressure and gain in event-free life expectancy

Objective

Consideration of absolute risk has been recommended for making decisions concerning preventive treatment in hypertension. We performed simulations to estimate the benefit of antihypertensive therapy over a life-time.

Methodology

The rate of nonfatal and fatal events of untreated hypertensives in the US population were estimated using data from Individual Data ANalysis of Antihypertensive drug intervention trials (INDANA; a meta-analysis on individual data in hypertension) and specific cause of death from national statistics. Disease-free survival curves until all patients have died were built using the “life-table” method. The treatment effect estimated from INDANA was applied to this curve to obtain the disease-free survival curve of the life-long treated population. Gains in event-free life expectancy (GLE) were estimated from survival curves. A sensitivity analysis was performed to assess the impact of possible death misclassifications.

Results

For a 40-year-old man, the gain in life expectancy without stroke and major cardiovascular events were 27 and 32 months, respectively, and were more substantial than those without coronary disease (19 months). The GLE decreased slowly with increasing age at the beginning of treatment, whereas short-term absolute risk reductions increase sharply with age.

Conclusions

Policies based on the selection of patients to treat according to absolute benefit do not maximize the GLE compared with strategies that treat low-risk patients.

Long-Term Survival in Men With High Grade Prostate Cancer: A Comparison Between Conservative Treatment, Radiation Therapy and Radical Prostatectomy—A Propensity Scoring Approach

PURPOSE

We performed a retrospective cohort study using propensity score analysis to calculate long-term survival in patients with prostate cancer with Gleason score 8 or greater who were treated with conservative therapy, radiation therapy and radical prostatectomy.

MATERIALS AND METHODS

Between January 1, 1980 and December 31, 1997, 3,159 patients in the Henry Ford Health System were diagnosed with clinically localized prostate cancer. Of these patients 453 had a Gleason score of 8 or greater in the biopsy specimen and they were the cohort. The end points were overall and prostate cancer specific survival. Propensity score analysis was used to more precisely compare the 3 treatments of observation, radiation and radical prostatectomy. Median patient followup was longer in the radical prostatectomy arm than in the conservative treatment and radiation therapy arms (68 months vs 52 and 54, respectively).

RESULTS

Of the 453 patients 197 (44%) were treated conservatively, 137 (30%) received radiation therapy and 119 (26%) underwent radical prostatectomy. Using propensity scoring analysis median overall survival for conservative therapy, radiation and radical prostatectomy was 5.2, 6.7 and 9.7 years, respectively. Median cancer specific survival was 7.8 years for conservative therapy and more than 14 years for radiation therapy and radical prostatectomy. The risk of cancer specific death following radical prostatectomy was 68% lower than for conservative treatment and 49% lower than for radiation therapy (p<0.001 and 0.053, respectively).

CONCLUSIONS

Survival of men with high grade prostate cancer can be improved by radical prostatectomy or radiation therapy.

Cost-effectiveness of genotypic antiretroviral resistance testing in HIV-infected patients with treatment failure

Background

Genotypic antiretroviral resistance testing (GRT) in HIV infection with drug resistant virus is recommended to optimize antiretroviral therapy, in particular in patients with virological failure. We estimated the clinical effect, cost and cost-effectiveness of using GRT as compared to expert opinion in patients with antiretroviral treatment failure.

Methods

We developed a mathematical model of HIV disease to describe disease progression in HIV-infected patients with treatment failure and compared the incremental impact of GRT versus expert opinion to guide antiretroviral therapy. The analysis was conducted from the health care (discount rate 4%) and societal (discount rate 2%) perspective. Outcome measures included life-expectancy, quality-adjusted life-expectancy, health care costs, productivity costs and cost-effectiveness in US Dollars per quality-adjusted life-year (QALY) gained. Clinical and economic data were extracted from the large Swiss HIV Cohort Study and clinical trials.

Results

Patients whose treatment was optimized with GRT versus expert opinion had an increase in discounted life-expectancy and quality-adjusted life-expectancy of three and two weeks, respectively. Health care costs with and without GRT were $US 421,000 and $US 419,000, leading to an incremental cost-effectiveness ratio of $US 35,000 per QALY gained. In the analysis from the societal perspective, GRT versus expert opinion led to an increase in discounted life-expectancy and quality-adjusted life-expectancy of three and four weeks, respectively. Health care costs with and without GRT were $US 551,000 and $US 549,000, respectively. When productivity changes were included in the analysis, GRT was cost-saving.

Conclusions

GRT for treatment optimization in HIV-infected patients with treatment failure is a cost-effective use of scarce health care resources and beneficial to the society at large.

Visual screening for malignant melanoma: a cost-effectiveness analysis

OBJECTIVE

To evaluate the cost-effectiveness of various melanoma screening strategies proposed in the United States.

DESIGN

We developed a computer simulation Markov model to evaluate alternative melanoma screening strategies.

PARTICIPANTS

Hypothetical cohort of the general population and siblings of patients with melanoma. Intervention We considered the following 4 strategies: background screening only, and screening 1 time, every 2 years, and annually, all beginning at age 50 years. Prevalence, incidence, and mortality data were taken from the Surveillance, Epidemiology, and End Results Program. Sibling risk, recurrence rates, and treatment costs were taken from the literature.

MAIN OUTCOME MEASURES

Outcomes included life expectancy, quality-adjusted life expectancy, and lifetime costs. Cost-effectiveness ratios were in dollars per quality-adjusted life year (US dollars/QALY) gained.

RESULTS

In the general population, screening 1 time, every 2 years, and annually saved 1.6, 4.4, and 5.2 QALYs per 1000 persons screened, with incremental cost-effectiveness ratios of US dollars 10,100/QALY, US dollars 80,700/QALY, and US dollars 586,800/QALY, respectively. In siblings of patients with melanoma (relative risk, 2.24 compared with the general population), 1-time, every-2-years, and annual screenings saved 3.6, 9.8, and 11.4 QALYs per 1000 persons screened, with incremental cost-effectiveness ratios of US dollars 4000/QALY, US dollars 35,500/QALY, and US dollars 257,800/QALY, respectively. In higher risk siblings of patients with melanoma (relative risk, 5.56), screening was more cost-effective. Results were most sensitive to screening cost, melanoma progression rate, and specificity of visual screening.

CONCLUSIONS

One-time melanoma screening of the general population older than 50 years is very cost-effective compared with other cancer screening programs in the United States. Screening every 2 years in siblings of patients with melanoma is also cost-effective.

Long-term survival probability in men with clinically localized prostate cancer treated either conservatively or with definitive treatment (radiotherapy or radical prostatectomy)

OBJECTIVES

To report the long-term survival probability in more than 3000 men with localized prostate cancer treated either conservatively or by definitive treatment (radiotherapy or radical prostatectomy).

METHODS

We studied 3159 men with biopsy-confirmed, clinically localized prostate cancer diagnosed from 1980 to 1997. We restricted our analysis to men 75 years of age or younger. The extent of comorbid disease was measured using the Charlson score. The Cox proportional hazards regression model was used to compare long-term survival in patients who were treated conservatively versus survival in patients treated with either radiotherapy or radical prostatectomy.

RESULTS

After adjusting for age, race, tumor grade, comorbid disease, income status, and year of diagnosis, the overall survival rate at 15 years was 35% for conservative management, 50% for radiotherapy, and 65% for radical prostatectomy. The corresponding prostate cancer-specific survival rates were 79%, 87%, and 92%. Patients undergoing radiotherapy or radical prostatectomy had lower overall mortality than patients undergoing conservative management (adjusted relative risk 0.67 for radiotherapy and 0.41 for prostatectomy; P <0.001). The increase in the survival duration was 4.6 years with radiotherapy and 8.6 years with radical prostatectomy.

CONCLUSIONS

The results of this study have shown that compared with conservative management, both radiotherapy and radical prostatectomy increase survival for men with localized prostate cancer.

Evaluation of intensive adjuvant chemotherapy in gastric cancer using life expectancy compared with log-rank test as a measure of survival benefit

BACKGROUND

The goal of radical cancer surgery with or without adjuvant therapy is to cure disease rather than to delay death. There is concern that the survival benefit of curative treatment may not be properly appreciated by the log-rank test (LRT), which is more sensitive to treatment that delays death than to treatment that achieves cure. To confirm this concern and to evaluate the survival benefit of adjuvant chemotherapy, the data from a previous randomized controlled trial are analyzed using both traditional and new methods.

METHODS

In this trial, 1410 gastric cancer patients with serosal or subserosal invasion had been classified by nodal and serosal status into four strata and randomized to receive high-dose or low-dose adjuvant regimens (mitomycin and tegafur-uracil) after gastrectomy. The two treatment groups were compared using the LRT as well as the life expectancy (LE) derived from the Boag model and the competing risk model.

RESULTS

The LRT showed no significant difference between the two groups, whereas the LE increased significantly with high-dose chemotherapy (1.4-year gain; 95% CI = 0.1-2.8). A greater gain of 4.4 years occurred exclusively in the serosa-negative node-positive stratum, associated with a 21% increase in cure rate. The gain in LE was particularly greater in younger patients.

CONCLUSIONS

Parametric LE analysis offers more relevant information about curative treatment than LRT. It suggests that high-dose chemotherapy may achieve cure in a subset of patients, eradicating residual malignancies left behind after gastrectomy and providing greater survival benefit than expected from LRT.

Cost-effectiveness of HIV treatment in resource-poor settings--the case of Côte d'Ivoire

BACKGROUND

As antiretroviral therapy is increasingly used in settings with limited resources, key questions about the timing of treatment and use of diagnostic tests to guide clinical decisions must be addressed.

METHODS

We assessed the cost-effectiveness of treatment strategies for a cohort of adults in Côte d'Ivoire who were infected with the human immunodeficiency virus (HIV) (mean age, 33 years; CD4 cell count, 331 per cubic millimeter; HIV RNA level, 5.3 log copies per milliliter). Using a computer-based simulation model that incorporates the CD4 cell count and HIV RNA level as predictors of disease progression, we compared the long-term clinical and economic outcomes associated with no treatment, trimethoprim-sulfamethoxazole prophylaxis alone, antiretroviral therapy alone, and prophylaxis with antiretroviral therapy.

RESULTS

Undiscounted gains in life expectancy ranged from 10.7 months with antiretroviral therapy and prophylaxis initiated on the basis of clinical criteria to 45.9 months with antiretroviral therapy and prophylaxis initiated on the basis of CD4 testing and clinical criteria, as compared with trimethoprim-sulfamethoxazole prophylaxis alone. The incremental cost per year of life gained was 240 dollars (in 2002 U.S. dollars) for prophylaxis alone, 620 dollars for antiretroviral therapy and prophylaxis without CD4 testing, and 1,180 dollars for antiretroviral therapy and prophylaxis with CD4 testing, each compared with the next least expensive strategy. None of the strategies that used antiretroviral therapy alone were as cost-effective as those that also used trimethoprim-sulfamethoxazole prophylaxis. Life expectancy was increased by 30% with use of a second line of antiretroviral therapy after failure of the first-line regimen.

CONCLUSIONS

A strategy of trimethoprim-sulfamethoxazole prophylaxis and antiretroviral therapy, with the use of clinical criteria alone or in combination with CD4 testing to guide the timing of treatment, is an economically attractive health investment in settings with limited resources.

Improving life expectancy and decreasing the incidence of complications associated with type 2 diabetes: a modelling study of HbA1c targets

To project the long-term clinical and cost outcomes that accompany predefined improvements in glycaemic control in patients with type 2 diabetes. A peer-reviewed, validated, non-product-specific Markov model of type 2 diabetes was used to project the long-term clinical and cost outcomes associated with three HbA1c reduction scenarios (vs. no reduction): (i) decreasing mean HbA1c from 9.5% to 8.0%; (ii) from 8.0% to 7.0%; and (iii) from 7.0% to 6.5%. A typical baseline US type 2 diabetes cohort derived from National Health and Nutrition Examination Survey data was simulated over a lifetime horizon (35 years). Incidence of diabetes-related complications and costs (2005 USD) were accounted based on published data. Discount rates (3% per annum) were applied to clinical benefits and costs. Sensitivity analyses were performed. Stepwise reductions in HbA1c as an independent variable correlated with delayed time to diabetes-related complications and a reduced cumulative incidence of complications, including cardiovascular, renal and neurologic comorbidities. Related costs also decreased. Reductions in both poorly- (9.5-8.0%) and better-controlled (7.0-6.5%) patients produced incremental gains in undiscounted life expectancy (LE) [1.06 (0.31) and 0.32 (0.34) years [mean (SD)], respectively]. Similar improvement patterns were observed in quality-adjusted life expectancy (QALE). Benefits from sequential reduction scenarios, when aggregated, exhibited the most dramatic effect. Improved glycaemic control was associated with reductions in complication rates and costs, as well as increased LE and QALE among type 2 patients. These data illustrate the long-term importance of reaching normoglycaemia and support intensified HbA1c control as a cornerstone of effective long-term type 2 diabetes management.

Number-needed-to-treat (NNT)--needs treatment with care

The "number-needed-to-treat" (NNT) was introduced about 15 years ago and has gained widespread use. It has been claimed to be "easy to understand" and gives "intuitive meaning". When used to measure the effectiveness of interventions targeting chronic disease processes e.g. atherosclerosis and osteoporosis, NNT (as well as relative and absolute risk reduction) does not capture the crucial time component, a fact that has important consequences: NNT varies over time, it may not mean that adverse events (fractures, myocardial infarctions etc.) are avoided, but simply that they are postponed. Finally, empirical studies indicate that lay people and doctors misunderstand NNT. We recommend that NNT be used with considerable care. There is probably no single effect measure that is able to convey all necessary information.

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.

Analyzing oncology clinical trial data using the Q-TWiST method: clinical importance and sources for health state preference data

PURPOSE

The Quality-adjusted Time Without Symptoms of disease and Toxicity (Q-TWiST) analysis method is frequently applied to evaluating outcomes in cancer clinical trials, but there is little information on what constitutes a clinically important difference (CID). We reviewed the Q-TWiST, health-related quality of life (HRQL) and utility measurement literature to develop recommendations for CID for the Q-TWiST. We also provide recommendations for measuring health utilities and for the design of Q-TWiST studies.

METHODS

The English language literature was searched between 1986 and 2003 for Q-TWiST studies in oncology. We estimated the percent differences between treatments based on median follow-up duration for overall, progression-free and quality-adjusted survival. We also reviewed the relevant HRQL and utility literature on clinical importance.

RESULTS

The overall differences between treatments for most (56%) of the observed, published values for Q-TWiST analyses ranged between 12% and 19%. Three-fourths of the Q-TWiST studies had gains in survival of 12%-17%, while differences in progression-free survival ranged from 12% to 26%. Studies that have evaluated the clinical importance of changes in HRQL scores suggest that changes of 5%-10% are clinically meaningful, and other research suggests that 0.5 standard deviation is a reasonable threshold for changes in HRQL for chronic diseases. Similarly, one guideline from the health state utility literature is that a 5%-10% difference in standard gamble utility scores is clinically important. Various sources are available for health utilities for Q-TWiST studies and the most valid are derived from patients or the general public, although most studies rely on sensitivity analyses with no collection of utilities.

CONCLUSIONS

We recommend that the CID for Q-TWiST is 10% of overall survival in a study, and differences of 15% are clearly clinically important. If less is known about a specific treatment and/or disease area, the CID should be greater than 5% but not more than 10% in planning sample size and statistical power. These CID estimates should be interpreted with caution, pending confirmation in future studies by direct patient assessment of the clinically relevant health states for Q-TWiST.

Human papillomavirus infection: An old disease, a new vaccine

Human papillomavirus (HPV) infection is common and causes a wide spectrum of disease. With recent advances in the development of prophylactic HPV vaccines, it is likely that these will be licensed for use in the near future. This review focuses on the science behind HPV vaccines, published clinical trial results for both prophylactic and therapeutic HPV vaccines, important issues relevant to implementation and cost-effectiveness models of HPV vaccination programs. It may be that an HPV vaccine that protects against the complications of HPV infection such as cervical cancer will be one of the most significant public health initiatives of this decade.

Counting the costs of overweight and obesity: modeling clinical and cost outcomes

OBJECTIVE

To quantify changes in clinical and cost outcomes associated with increasing levels of body mass index (BMI) in a US setting.

RESEARCH METHODS AND PROCEDURES

A semi-Markov model was developed to project and compare life expectancy (LE), quality-adjusted life expectancy (QALE) and direct medical costs associated with distinct levels of BMI in simulated adult cohorts over a lifetime horizon. Cohort definitions included age (20-65 years), gender, race, and BMI (24-45 kg m(-2)). Cohorts were exclusively male or female and either Caucasian or African-American. Mortality rates were adjusted according to these factors using published data. BMI progression over time was modeled. BMI-dependent US direct medical costs were derived from published sources and inflated to year 2004 values. A third party reimbursement perspective was taken. QALE and costs were discounted at 3% per annum.

RESULTS

In young Caucasian cohorts LE decreased as BMI increased. However, in older Caucasian cohorts the BMI associated with greatest longevity was higher than 25 kg m(-2). A similar pattern was observed in young adult African-American cohorts. A survival paradox was projected in older African-American cohorts, with some BMI levels in the obese category associated with greatest longevity. QALE in all four race/gender cohorts followed similar patterns to LE. Sensitivity analyses demonstrated that simulating BMI progression over time had an important impact on results. Direct costs in all four cohorts increased with BMI, with a few exceptions.

CONCLUSIONS

Optimal BMI, in terms of longevity, varied between race/gender cohorts and within these cohorts, according to age, contributing to the debate over what BMI level or distribution should be considered ideal in terms of mortality risk. Simulating BMI progression over time had a substantial impact on health outcomes and should be modeled in future health economic analyses of overweight and obesity.

Cost-effectiveness of enfuvirtide in HIV therapy for treatment-experienced patients in the United States

Enfuvirtide (ENF) is the first of a new class of antiretrovirals (ARVs) known as the HIV fusion inhibitors. Two phase III studies of ENF, TORO 1 and TORO 2, demonstrated that ENF given in combination with optimized background (OB) therapy significantly improved virological response, increased the time to virological failure, and increased CD4-cell count compared with OB alone among highly treatment-experienced patients. The present study investigated the long-term clinical outcomes, costs, and cost-effectiveness of ENF. Outcomes, costs, and cost-effectiveness were estimated using a Markov model. Viral suppression and immune reconstitution were determined from the outcomes of the clinical trials. Time to immunological failure, time to AIDS-defining event (ADE), and time to death were estimated based on published mathematical models of disease progression. Costs were based on published estimates of the use and costs of ARVs, cost of managing ADEs, and cost of laboratory and other outpatient services. Cost-effectiveness was calculated as the incremental cost per year of life gained, adjusted for quality of life. The combined effects of an increase in CD4 count and delayed time to virological and immunological failure with ENF + OB were predicted to produce a mean life expectancy of 7.4 years from initiation of therapy, which was 1.8 years (1.5 quality-adjusted lifeyears [QALYs]) greater than the life expectancy associated with OB alone. The incremental cost-effectiveness of ENF + OB was estimated to be Dollars 24,604 per QALY. ENF is projected to increase time to immunological failure, delay onset of new AIDS-defining events, and increase life expectancy by more than 1.5 years among treatment-experienced HIV-infected patients. The cost-effectiveness of ENF is comparable to many existing treatment and prevention management strategies for HIV.

Computed tomography screening for lung cancer in Hodgkin's lymphoma survivors: decision analysis and cost-effectiveness analysis

BACKGROUND

Hodgkin's lymphoma patients have an elevated risk of developing lung cancer and may be targeted for lung cancer screening. We used a decision-analytic model to estimate the potential clinical benefits and cost-effectiveness of computed tomography (CT) screening for lung cancer in Hodgkin's lymphoma survivors.

MATERIALS AND METHODS

We developed a Markov decision-analytic model to compare annual low-dose CT screening versus no screening in a hypothetical cohort of patients diagnosed with stage IA-IIB Hodgkin's lymphoma at age 25, with screening starting 5 years after initial diagnosis. We derived model parameters from published studies and the Surveillance, Epidemiology and End Results (SEER) Program, and assumed that stage-shift produces a survival benefit.

RESULTS

Annual CT screening increased survival by 0.64 years for smokers and 0.16 years for non-smokers. The corresponding benefits in quality-adjusted survival were 0.58 quality-adjusted life-years (QALYs) for smokers and 0.14 QALYs for non-smokers. The incremental cost-effectiveness ratios for annual CT screening compared with no screening were $34 100/QALY for smokers and $125 400/QALY for non-smokers.

CONCLUSIONS

Our analysis suggests that if early promising results for lung cancer screening hold, CT screening for lung cancer may increase survival and quality-adjusted survival among Hodgkin's lymphoma survivors, with a benefit and incremental cost-effectiveness ratio for smokers comparable to that of other recommended cancer screening strategies.

Life expectancy as an indicator of outcome in follow-up of population-based cancer registries: the example of childhood leukemia

BACKGROUND

Survival analysis is a standard methodology to assess progress in oncology disease treatment. However, survival analysis commonly only measures survival during the treatment period (and the period immediately afterwards), and does not provide an estimate of life expectancy, which is often of more interest to patients and to health policy makers. In this paper we propose a method to estimate childhood acute lymphoblastic leukemia (ALL) life expectancy through the integration of traditional survival analysis and life expectancy tables.

PATIENTS AND METHODS

The study included 305 incident cases registered by the Childhood Cancer Registry of Piedmont in 1979-1991. Vital status on 30 June 2004 was known for 304 cases. Survival analyses were carried out using the Kaplan-Meier method and the Gompertz model, according to the time period of diagnosis and gender.

RESULTS

Cumulative survival at 5 years increased from 58.6% (95% CI 48.9-68.3) for cases diagnosed in March 1979-July 1982 to 79.1% (95% CI 70.8-87.5) in March 1987-February 1991 (P = 0.002). Average life expectancy increased from 46.1 years for boys and 42.6 years for girls diagnosed in March 1979-July 1982 to 58.3 and 69.1, respectively, in March 1987-February 1991.

CONCLUSIONS

These analyses show an improvement over the time period of diagnosis of life expectancy for children with ALL.

Anévrismes intracrâniens non rompus : que proposer ?

Intracranial unruptured aneurysm (ICUA) has become a common condition for patient consultation. The mortality rate after fissuration is estimated to be between 52% and 85.7%. The final therapeutic decision results from a balance between the risk of rupture and risks related to the aneurysmal exclusion. Analysis of the risk of rupture risk enables a classification of risk factors. Depending on the circumstances of diagnosis, we considered the ICUA at high risk of rupture for incidental ICUA larger than 7 mm and in the event of associated aneurysms. Classifying by morphologic features, high-risk ICUA were located in the vertebrobasilar system (RR: 4.4; 95%CI: 2.7-6.8), those with a size between 7 and 12 mm (RR: 3.3; 95%CO: 1.3-8.2), larger than 12 mm (RR: 17; 95%CI: 8-36.1), those that were multilobular or a larger size and those ones with a index P/L superior to 3.4 (risk x20). Familial ICUA would expose to a major rupture risk (2 to 7 times sporadic ICUA). Some systemic factors were related to ICUA rupture: arterial hypertension (RR: 1.46; 95%CI: 1.01-2.11) and smoking addiction (RR: 3.04; 95%CI: 1.21-7.66). After microsurgical exclusion, the morbidity and mortality rates were 10% and 2% respectively. Some microsurgical morbidity factors were identified: age (32%>65 years), size (14%>15 mm), vertebrobasilar location and temporary occlusion. The rupture incidence after microsurgical exclusion was estimated 0.26%/year. After endovascular exclusion, the morbidity and mortality rates were 8% and 1% respectively. The complete exclusion rate varied between 47% and 67%. The rupture risk was estimated at 0.9%/year. Treatment recommendations were classified into 3 categories.

Cost-effectiveness of universal pneumococcal vaccination for infants in Italy

This study aimed at estimating the health and economic outcomes of universal infant vaccination with seven-valent pneumococcal conjugate vaccine (PCV-7) in Italy. A Markov model simulated lifetime evolution of a birth cohort (538,138 children): universal vaccination would avert 769 invasive infections, 18 deaths and 1323 life years. At base-case analysis, universal three-dose vaccination would cost euro 26,449 (95% CI: 1975-62,075) and euro 38,286 (95% CI: 22,164-70,801) per life year-saved in the societal and the NHS perspective, respectively. In the hypothesis of a 5-year long protection period, vaccination would cost euro 32,694 and euro 43,115 per life-year saved. Considering yearly incidence of invasive pneumococcal disease reported for Veneto and Sardinia regions, PCV-7 vaccination would result highly cost-effective determining a cost of euro 10,479 and euro 16,890 per life year-save in the NHS and the societal perspective, respectively.

Characterizing the Burden of Occupational Injury and Disease

OBJECTIVES

To review the literature on the burden of occupational disease and injury and to provide a comprehensive characterization of the burden.

METHODS

The scientific and governmental literature from 1990 to the present was searched and evaluated. Thirty-eight studies illustrative of the burden of occupational disease were reviewed for findings, methodology, strengths, and limitations.

RESULTS

Recent U.S. estimates of occupational mortality and morbidity include approximately 55,000 deaths (eighth leading cause) and 3.8 million disabling injuries per year, respectively. Comprehensive estimates of U.S. costs related to these burdens range between dollar 128 billion and dollar 155 billion per year. Despite these significant indicators, occupational morbidity, mortality, and risks are not well characterized in comparative burden assessments.

CONCLUSIONS

The magnitude of occupational disease and injury burden is significant but underestimated. There is a need for an integrated approach to address these underestimates.

Using competence network collaboration and decision-analytic modeling to assess the cost-effectiveness of interferon alpha-2b plus ribavirin as initial treatment of chronic hepatitis C in Germany

The objective of this study was to translate and apply a decision-analytic model for chronic hepatitis C (CHC) to the German health care context using competence network collaboration. The German Hepatitis C Model (GEHMO) competence network used a systematic multistep approach to identify and transfer a high quality Markov model for CHC to the German health care context. GEHMO was used to project lifetime clinical and economic outcomes and to determine the cost-effectiveness of initial antiviral therapy with interferon a-2b plus ribavirin from a societal perspective. In 40-year-old patients combination therapy for 24 and 48 weeks increased life expectancy by 1.6 and 2.3 years, respectively, compared with interferon alone for 48 weeks. The discounted incremental cost-utility ratios (ICUR) for combination therapy were euro 5,500 per quality-adjusted life-year gained (QALY) for 24 weeks and euro 6,800/QALY for 48 weeks of treatment. ICUR was euro 9,800/QALY for moving from 24 to 48 weeks of treatment. Combination therapy remained cost-effective in sensitivity analyses. In conclusion, combination therapy with interferon alpha-2b and ribavirin is effective and cost-effective compared with other well-accepted medical treatments. Competence network collaboration and decision modeling provide a useful and efficient approach to combine evidence from international studies with country-specific parameters.

Cost-effectiveness of irbesartan in diabetic nephropathy: a systematic review of published studies

BACKGROUND

To review published studies on the cost-effectiveness of the use of irbesartan for treatment of advance overt nephropathy in patients with type 2 diabetes and hypertension.

METHODS

Articles were identified based on a search of the PubMed databases using the keywords 'irbesartan', 'ESRD', 'cost-effectiveness', 'nephropathy' and 'costs', and by personal communication with the authors. Only studies published in the last 10 years were included. All costs data from the cost-effectiveness studies were inflated to 2003 Euros using published governmental conversion tables.

RESULTS

Seven published studies were identified, spanning the following country settings: the US, Belgium and France, Germany, Hungary, Italy, Spain, and the UK. In each, the same pharmacoeconomic model was adapted using country-specific data to project and evaluate the clinical and cost outcomes of the treatment arms of the Irbesartan in Diabetic Nephropathy Trial (IDNT) (irbesartan, amlodipine or standard blood pressure control). Mean time to onset of ESRD was 8.23 years for irbesartan, 6.82 years for amlodipine and 6.88 years for the control (values were the same for Belgium, France, Germany, Hungary, Italy and Spain as transition probabilities for progression to ESRD were all derived from the IDNT). Mean cumulative incidence of ESRD was 36% with irbesartan, 49% with amlodipine and 45% with control treatment. Treatment with irbesartan was projected to improve life expectancy compared to both amlodipine and control in all seven published studies. Analysis of total lifetime costs showed that irbesartan treatment was cost saving compared to the other two treatment regimens, due to the associated reduction in ESRD cases. Cost savings with irbesartan became evident very early; after 2-3 years of treatment in most settings.

CONCLUSIONS

Modelling studies based on the IDNT published to date suggest that irbesartan treatment in patients with type 2 diabetes, hypertension and advanced nephropathy is both life- and cost-saving compared to amlodipine or control.

A randomized multicenter trial comparing resection and radiochemotherapy for resectable locally invasive pancreatic cancer

BACKGROUND

Though the outcome of resection for locally invasive pancreatic cancer is still poor, it has gradually improved in Japan, and the 5-year survival is now about 10%. However, the advantage of resection over radiochemotherapy has not yet been confirmed by a randomized trial. We conducted this study to compare surgical resection alone versus radiochemotherapy without resection for locally invasive pancreatic cancer using a multicenter randomized design.

METHODS

Patients with pancreatic cancer who met our preoperative criteria for inclusion (pancreatic cancer invading the pancreatic capsule without involvement of the superior mesenteric artery or the common hepatic artery, or without distant metastasis) underwent laparotomy. Patients with operative findings consistent with our criteria were randomized into a radical resection group and a radiochemotherapy group (200 mg/m(2)/day of intravenous 5-fluorouracil and 5040 cGy of radiotherapy) without resection. The 2 groups were compared for mean survival, hazard ratio, 1-year survival, quality of life scores, and hematologic and blood chemical data.

RESULTS

Twenty patients were assigned to the resection group and 22 to the radiochemotherapy group. There was 1 operative death. The surgical resection group had better results than the radiochemotherapy group as measured by 1-year survival (62% vs 32 %, P=.05), mean survival time (>17 vs 11 months, P < .03), and hazard ratio (0.46, P=.04). There were no differences in the quality of life score or laboratory data apart from increased diarrhea after surgical resection.

CONCLUSIONS

Locally invasive pancreatic cancer without distant metastases and major arterial invasion appears to be best treated by surgical resection.

Socioeconomic disparities in health: the impact of pharmacotherapy

Along with age and gender, socioeconomic status is a fundamental driver of health. This review discusses the meaning of socioeconomic status and how it influences health across a person's life. Particular attention is paid to the role of psychosocial stress and self-determination. Through various pathways, socioeconomic status may affect biologic aging. This review also discusses the implications of the socioeconomic status-health relationship for understanding international differences in population health such as differences in life expectancy. The review concludes with a discussion of the implications of these findings for national policies and the potential impact of pharmacotherapy.

Economic analysis of the Assessment of the Safety and Efficacy of a New Thrombolytic Regimen (ASSENT-3) study: costs of reperfusion strategies in acute myocardial infarction

BACKGROUND

The ASSENT-3 study examined the safety and efficacy of 3 alternative regimens for ST-elevation acute myocardial infarction: full-dose tenecteplase (TNK-tPA) plus enoxaparin; half-dose TNK-tPA plus unfractionated heparin plus abciximab; and full-dose TNK-tPA plus unfractionated heparin.

OBJECTIVE

The aim of the study was to examine the resource and economic effects of the 3 regimens in ASSENT-3 using empirically collected data from the trial.

METHODS

Cost estimates for each resource use component collected in ASSENT-3 were derived from Medicare reimbursement rates and from detailed billing data collected as part of a previous study. Costs of study drugs were estimated using average wholesale prices. All analyses were by intention to treat. Resource use and medical costs were examined first in the United States alone, and then in the entire cohort.

RESULTS

Differences in costs across treatment arms were primarily due to differences in cost of study medication. Irrespective of source of cost weights, the least expensive alternative among the 3 treatment regimens was TNK-tPA and enoxaparin. Although not statistically significant, in 80% of 1000 bootstrap replications, the TNK-tPA enoxaparin arm was associated with 30-day cost savings relative to the unfractionated heparin arm.

CONCLUSION

The favorable clinical outcomes demonstrated for enoxaparin arm relative to the unfractionated heparin arm in ASSENT-3 were accompanied by a favorable distribution of costs and support the designation of this regimen as economically attractive by conventional benchmarks.

Implications of the Prostate Cancer Prevention Trial: A Decision Analysis Model of Survival Outcomes

Purpose

To assess the estimated effect of finasteride prevention of prostate cancer on overall survival.

Methods

Data for our decision tree model came from men in the two arms (finasteride or placebo) of the Prostate Cancer Prevention Trial (PCPT) and from clinically localized prostate cancer patients studied for long-term survival outcomes. Our model compared survival outcomes for men treated with finasteride or placebo. Prostate cancer rates were based on the 7-year period prevalence of prostate cancer detected in the PCPT; survival probabilities were abstracted from the long-term outcome studies. We assessed variability in the PCPT and long-term survival studies to test the variability of our model.

Results

Survival advantages for a finasteride-treated (v those not treated with finasteride) population include gains of 1.7 months in 15-year cause-specific survival (assuming finasteride-altered Gleason scores and prostate cancer prevalence rates in the PCPT), of up to 3 months for cancers treated conservatively or surgically (assuming finasteride does not alter Gleason scores), and of 0.35 months (assuming the rate of cancers detected by for-cause biopsies in the PCPT), which increased to 1.7 months when assuming a 30% rate of biopsy-detected cancer in the PCPT placebo group. Model-variability analyses support several survival benefits associated with finasteride (eg, the uniform benefits assuming finasteride does not alter Gleason scores) but question certain others (eg, in 15-year recurrence-free survivals assuming finasteride does alter Gleason scores).

Conclusion

Finasteride can impart survival benefits according to our model, especially when we assume that finasteride does not alter Gleason scores.

Reducing the costs of phase III cardiovascular clinical trials

BACKGROUND

The pharmaceutical industry spends approximately 26.4 billion dollars annually for research and development (4.1 billion dollars in cardiovascular products). We compared pharmaceutical companies' planned resource use and costs in Phase III cardiovascular trials and identified cost-saving strategies.

METHODS AND RESULTS

We developed 2 case scenarios (a 17,000-patient, open-label acute coronary syndromes [ACS] trial and a 14,500-patient, double-blind congestive heart failure [CHF]) trial and surveyed 6 pharmaceutical experts about expected resources (e.g., number of sites, case report form [CRF] pages, and monitoring visits) needed for the trials. Using a validated model, we estimated costs under each expert's assumptions. ACS trial costs averaged 83 million dollars (median, 67 million dollars; range, 57 dollars to 158 million dollars) and 142 million dollars (median, 135 million dollars; range, 102 dollars to 207 million dollars) for the CHF trial. Site-related expenses (site management and payments) were >65% of total costs for both trials. In sensitivity analyses, total costs were reduced >40% by simultaneously reducing CRF pages, monitoring visits, and site-payment amounts but maintaining the numbers of patients and sites.

CONCLUSIONS

With a set number of sites and patients, the most efficient way to reduce trial costs and still meet the trial's scientific objectives is to reduce management complexity. Modest changes in management parameters release significant monies to answer more research questions.

Cost-effectiveness of hepatocellular carcinoma surveillance in patients with hepatitis C virus-related cirrhosis

BACKGROUND & AIMS

HCV-related cirrhosis is a leading risk factor for hepatocellular carcinoma (HCC). Surveillance might detect HCC at a treatable stage. We estimated the clinical and economic consequences of a common HCC surveillance strategy in patients with HCV-related cirrhosis in the context of alternative HCC treatment strategies.

METHODS

With a Markov model, we examined surveillance with serum alpha-fetoprotein and ultrasound every 6 months in patients with compensated HCV-related cirrhosis from age 45-70 years or death, and HCC treatment with resection, cadaveric liver transplantation (CLT), or living donor liver transplantation (LDLT).

RESULTS

Compared to natural history in the base case, surveillance with resection, listing for CLT, or LDLT increased life expectancy by 0.49, 2.58, and 3.81 quality-adjusted life-years (QALYs), respectively, all at costs less than 51,000 US dollars/QALY gained. The consequences of surveillance were most sensitive to the outcomes and costs of HCC treatments but not surveillance test performance characteristics or cost. Prioritizing CLT for patients with HCC over those with decompensated cirrhosis resulted in greater overall life expectancy with minimal increase in cost.

CONCLUSIONS

Surveillance for HCC in patients with compensated HCV-related cirrhosis might gain QALYs at acceptable costs. The impact of surveillance depends most on the outcomes and costs of HCC treatments, rather than surveillance test characteristics. By increasing organ availability for timely definitive treatment, LDLT might achieve the greatest gain in life expectancy at acceptable costs. Prioritizing CLT for HCC might increase the population-wide benefits of CLT.

Management for severe Crohn's disease: a lifetime cost-utility analysis

OBJECTIVES

Infliximab is a costly therapy for active Crohn's disease resistant to corticosteroids and immunosuppressive medication. The purpose of this study was to examine whether a treatment including infliximab (episodic re-infusions for relapse or maintenance therapy every 8 weeks) was relevant compared with conventional management (surgery and medical treatment without infliximab) for nonfistulizing resistant Crohn's disease.

METHODS

We performed a life-time cost-utility analysis with an analytic Markov decision model from the perspective of the third-party payer system. Utility measurement using Standard Gamble was used to adjust the survival time for each health state of the disease. Direct costs were estimated from standard management based on expert opinion. A sensitivity analysis was conducted to gauge the effects of uncertainty in the values assigned to variables.

RESULTS

The incremental effectiveness with infliximab therapy is .761 Quality-Adjusted Life Years (QALYs) for an added cost ranging from 48,478.79 euros to 596,990.35 euros, depending on treatment procedure. The incremental cost utility ratio expressed in euros per QALYs saved varied from 63,700.82 euros (episodic re-infusions) to over 762,245.09 euros (maintenance therapy).

CONCLUSIONS

Infliximab therapy could be cost-effective in the case of relapse treatment only, whereas the marginal cost-utility ratio exceeds conventional benchmarks for maintenance therapy. This analysis will be supplemented by conducting further randomized controlled trials and prospective observational study, focused on the costs of illness (direct and indirect), patient preferences, the disease's clinical course, and infliximab safety.

A model to estimate the lifetime health outcomes of patients with type 2 diabetes: the United Kingdom Prospective Diabetes Study (UKPDS) Outcomes Model (UKPDS no. 68)

AIMS/HYPOTHESIS

The aim of this study was to develop a simulation model for type 2 diabetes that can be used to estimate the likely occurrence of major diabetes-related complications over a lifetime, in order to calculate health economic outcomes such as quality-adjusted life expectancy.

METHODS

Equations for forecasting the occurrence of seven diabetes-related complications and death were estimated using data on 3642 patients from the United Kingdom Prospective Diabetes Study (UKPDS). After examining the internal validity, the UKPDS Outcomes Model was used to simulate the mean difference in expected quality-adjusted life years between the UKPDS regimens of intensive and conventional blood glucose control.

RESULTS

The model's forecasts fell within the 95% confidence interval for the occurrence of observed events during the UKPDS follow-up period. When the model was used to simulate event history over patients' lifetimes, those treated with a regimen of conventional glucose control could expect 16.35 undiscounted quality-adjusted life years, and those receiving treatment with intensive glucose control could expect 16.62 quality-adjusted life years, a difference of 0.27 (95% CI: -0.48 to 1.03).

CONCLUSIONS/INTERPRETATIONS

The UKPDS Outcomes Model is able to simulate event histories that closely match observed outcomes in the UKPDS and that can be extrapolated over patients' lifetimes. Its validity in estimating outcomes in other groups of patients, however, remains to be evaluated. The model allows simulation of a range of long-term outcomes, which should assist in informing future economic evaluations of interventions in type 2 diabetes.

Paradoxes of Non-Trivial Gene Networks: How Cancer-Causing Mutations Can Appear to Be Cancer-Protective

Abnormalities of gene structure or expression are commonly found in cancers, where they are used as prognostic markers, predicting the likely severity of disease or chances of response to therapy. An odds ratio (OR) of <1 indicates that a marker's presence is correlated with better outcome. An OR of <1 is also often taken to mean that the gene concerned has a protective effect in the mechanism of cancer. I show that this is not necessarily so. Modeling of the genes involved in the causation of cancer as a network of weak, failure-prone elements shows that "cancer-causing" genes (i.e., genes whose abnormality is causal in driving cancer) can nevertheless appear as "protective" markers in later stage cancers. This implies that results suggesting that well-known oncogenes have an OR of <1 are quite valid, and that predicting a "protective" role from an apparently protective prognostic value is not valid. I identify mdm-2 and bax as candidates for genes with an apparently protective role through this mechanism.

What impact would pancreatic beta-cell preservation have on life expectancy, quality-adjusted life expectancy and costs of complications in patients with type 2 diabetes? A projection using the CORE Diabetes Model

OBJECTIVE

Type 2 diabetes is characterised by progressive failure of pancreatic beta-cell function against a background of insulin resistance. Multifactorial interventions, including intensive glycaemic and blood pressure control, reduce the risk of onset and progression of complications. However, current management of type 2 diabetes focuses on treatment of signs and symptoms of disease instead of targeting underlying causes. A number of newer pharmacological interventions, including thiazolidinediones and glucagon-like peptides, have shown early promise in preserving pancreatic beta-cell function. The aim of this study was to investigate the impact of stabilising beta-cell function on long-term outcomes in patients with type 2 diabetes.

METHODS

The CORE Diabetes Model was used to project life expectancy (LE), quality-adjusted LE (QALE) and total lifetime complication costs (TC) for a cohort of newly-diagnosed patients with type 2 diabetes, either with a typical increase of HbA1c over time as observed in the UKPDS, or assuming stabilisation of HbA1c after diagnosis with a hypothetical new treatment, representing beta-cell function stabilisation. Costs due to diabetes-related complications (from a US third-party payer perspective), were discounted at 3% annually. Both non-discounted and discounted (at 3% annually) LE and QALE were calculated. Sensitivity analyses were performed to test the robustness of results.

RESULTS

Over a time period of 50 years, in a cohort with no increase of HbA1c over time, LE and QALE were improved by mean (SD) 1.02 (0.36) and 0.96 (0.25) years, and total costs of complications were reduced by 6,377 dollars (2,568) per patient compared to the cohort with a typical increase in HbA1c over time. Results were robust under a wide range of plausible assumptions.

CONCLUSIONS

New interventions that stabilise pancreatic betacell function may have an important impact on length and quality of life, and lead to reduced costs of complications in patients with type 2 diabetes.

The economics of the colony-stimulating factors in the prevention and treatment of febrile neutropenia

Healthcare costs continue to rise with hospitalization representing the single largest component of direct medical costs associated with cancer care. Neutropenia and its complications including febrile neutropenia remain the major dose-limiting toxicity associated with systemic cancer chemotherapy. Febrile neutropenia often occurs early in the course of chemotherapy and is associated with substantial morbidity, mortality and cost. The colony-stimulating factors (CSFs) have been used effectively in a variety of clinical settings to prevent or treat febrile neutropenia and to assist patients receiving dose-intensive chemotherapy. A meta-analysis of the available randomized controlled trials (RCTs) has confirmed the efficacy of prophylactic CSFs. Economic models based on measures of resource utilization derived from RCTs have provided estimates of expected treatment costs along with febrile neutropenia risk threshold estimates for the cost saving use of the CSFs. Recent studies have demonstrated the potential value of targeting the CSFs toward patients at greatest risk based on accurate and valid predictive models.

Effects of rofecoxib and naproxen on life expectancy among patients with rheumatoid arthritis: a decision analysis

BACKGROUND

The VIOXX Gastrointestinal Outcomes Research (VIGOR) trial showed a 53% decrease in the risk of upper gastrointestinal toxicity and a fivefold increase in the risk of myocardial infarction for rofecoxib (a selective cyclooxygenase-2 inhibitor) compared with naproxen. We examined the effects of these competing adverse events on life expectancy in patients with rheumatoid arthritis.

METHODS

We used decision analysis to compare the life expectancy of a cohort of rheumatoid arthritis patients taking naproxen versus a similar cohort taking rofecoxib, using data from the VIGOR trial. We incorporated the competing risks of upper gastrointestinal toxicity and myocardial infarction, as well as their long-term health consequences, on the basis of population-based studies.

RESULTS

For 58-year-old women with rheumatoid arthritis (i.e., typical of participants in the VIGOR trial), naproxen was associated with a longer life expectancy than was rofecoxib (difference = 4.4 months). This difference was larger among 58-year-old men (7.8 months). The probability that naproxen is associated with a longer life expectancy than rofecoxib among 58-year-old patients was 92% for women and 98% for men. Life expectancy became the same between the two treatments when the risk of upper gastrointestinal toxicity was 70% higher or the risk of myocardial infarction was 40% lower than that of the base case among women, and when the risk of upper gastrointestinal toxicity was 4.4-fold higher or the risk of myocardial infarction was 70% lower among men.

CONCLUSION

Our analysis suggests that the competing risks of upper gastrointestinal toxicity and myocardial infarction shown in the VIGOR trial would project a longer life expectancy with naproxen than rofecoxib among patients with rheumatoid arthritis, except in those at low risk of myocardial infarction or at high risk of upper gastrointestinal toxicity.

Death rates of medical school class presidents

Medical professionals often face many competing demands to contribute both to the clinical care of patients and to the public health of society. We studied the long-term survival of doctors graduating from one medical school over one century (n = 1521), comparing those who were presidents of their class to those who appeared alphabetically before or alphabetically after the president in the graduating class photograph. Statistics on long-term mortality were obtained from licensing authorities, medical obituaries, professional associations, alumni records, and national physician directories (follow-up 94% complete, median follow-up duration = 38 years, total deaths = 220). We found that most graduates were male (88%), white (93%), and younger than 30 years at time of graduation (93%). Presidents more frequently made contributions to society than their classmates, as recognized by professional alumni notices (21.9% vs. 13.3%, P < 0.001) and Who's Who directory listings (7% vs. 0.5%, P < 0.001). Nonetheless, survival after medical school was 2.4 years shorter for presidents than their classmates (49.0 vs. 51.4, P = 0.036). The decrease in life-expectancy was unrelated to medical school marks or early career mortality and was accentuated after adjustments for birth year, gender, race, and specialization (P = 0.001 ). We suggest that the type of medical professional who sacrifices themselves for this type of professional prestige may also be the type who fails to look after their health or is otherwise prone to early mortality.

Cost-effectiveness of recombinant human activated protein C and the influence of severity of illness in the treatment of patients with severe sepsis

PURPOSE

To evaluate the cost-effectiveness of recombinant human activated protein C (rhAPC) compared with usual therapy for patients with severe sepsis, and also to determine the influence that severity of illness exerts on cost-effectiveness.

MATERIALS AND METHODS

We use a Markov model-based cost-effectiveness analysis of treatment strategies for patients with severe sepsis. Therapy includes treatment with either rhAPC and usual therapy, or usual therapy alone. Probabilities for clinical outcomes were obtained from a large randomized clinical trial comparing the use of rhAPC with placebo (PROWESS study) and from outcomes literature for patients with severe sepsis and its complications. Cost estimates were based on Medicare reimbursement rates, Health Care Financing Administration information and the literature. Outcome measures include life-years, quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness.

RESULTS

Compared with usual therapy alone, rhAPC treatment for patients with very severe sepsis (APACHE II score > or = 25) was associated with an incremental cost-effectiveness ratio of $13 493/QALY. Treatment of patients with less severe sepsis with rhAPC (APACHE II score < 25) had an incremental cost-effectiveness ratio of $403,000/QALY. For patients with very severe sepsis the incremental cost-effectiveness ratio for treatment with rhAPC remained under $30,000/QALY, over a broad range of variables, including costs of rhAPC, costs of acute care and costs and probabilities of complications of treatment. For patients with less severe sepsis, drug costs would need to fall well below current market price before achieving cost-effectiveness. A probabilistic sensitivity analysis comparing rhAPC treatment with usual therapy for patients with very severe sepsis showed that < 1% of Monte Carlo simulations had incremental cost-effectiveness ratios > $50,000/QALY.

CONCLUSIONS

The use of rhAPC for the treatment of patients with very severe sepsis, as determined by APACHE II score > or = 25, appears cost-effective, while treatment of patients with APACHE II score < 25 is not cost-effective.

Is it influenza or anthrax? A decision analytic approach to the treatment of patients with influenza-like illnesses

STUDY OBJECTIVE

We analyze the risks and benefits of alternative treatment strategies for non-septic-appearing febrile patients with influenza-like illnesses and possible exposure to anthrax.

METHODS

We used a decision analytic model to evaluate 6 testing and treatment strategies in an emergency department. Patients were non-septic-appearing and had influenza-like illnesses but low likelihood of exposure to anthrax. The following interventions were used: (1) no empiric antibiotics; (2) blood culture and treatment only if the result was positive; (3) rapid testing for influenza and, for those who tested negative, treatment with 60 days of ciprofloxacin; (4) a two-test strategy in which all patients were first tested for influenza; those who tested negative had a blood culture test and were treated empirically with ciprofloxacin for 3 days while waiting for blood culture results; (5) culture test for all patients and treatment with ciprofloxacin for up to 3 days while waiting for blood culture results; and (6) treatment of all patients with ciprofloxacin empirically for 60 days. Main outcome measures were deaths, complications from anthrax, adverse events from ciprofloxacin, and ciprofloxacin patient-days.

RESULTS

For nonzero probabilities of anthrax, patient mortality was always lowest in the strategies in which all patients were treated empirically for anthrax either for 60 days or for 3 days pending blood culture results. These strategies, however, were associated with more morbidity (more ciprofloxacin patient-days and more antibiotic adverse events) than were strategies without empiric treatment. The numbers of adverse events and antibiotic patient-days were reduced substantially with the two-test strategy, in which patients with influenza were identified early and not treated. In general, for probabilities of anthrax equaling or exceeding 2%, treating all patients empirically for 60 days was best, but for probabilities between 0.1% and 2%, the sensitivity of blood culture for anthrax determined the optimal strategy: when the sensitivity exceeded 95%, a short course of empiric ciprofloxacin until blood culture results became available was best, but for sensitivities below 95%, more aggressive empiric antibiotics use was warranted. The proportion of patients with influenza in the community affected the choice of strategy, so that seasonal variation exists.

CONCLUSION

During influenza season, our findings support rapid testing for influenza, followed by empiric treatment for anthrax pending blood culture results for those who test negative for influenza. Our results help to highlight the importance of developing rapid and sensitive tests for anthrax and of developing improved surveillance and methods to calculate the previous probability of attacks.

Intensive lifestyle changes or metformin in patients with impaired glucose tolerance: Modeling the long-term health economic implications of the diabetes prevention program in Australia, France, Germany, Switzerland, and the United Kingdom

BACKGROUND

In the Diabetes Prevention Program (DPP), interventions with metformin (plus standard lifestyle advice) or intensive lifestyle changes (ILC) reduced the risk of developing type 2 diabetes mellitus (DM) by 31% and 58%, respectively, versus control (standard lifestyle advice only) in patients with impaired glucose tolerance (IGT).

OBJECTIVE

The goal of this study was to establish whether implementing the active treatments used in the DPP would be cost-effective in Australia, France, Germany, Switzerland, and the United Kingdom.

METHODS

A Markov model simulated 3 states-IGT, type 2 DM, and deceased-using probabilities from the DPP and published data. Country-specific direct costs were used throughout.

RESULTS

Assuming only within-trial effects and costs of interventions, both metformin and ILC improved life expectancy versus control. Mean improvements in nondiscounted life expectancy were 0.11 and 0.22 years for metformin and ILC, respectively. Both interventions were associated with cost savings versus control in all countries except the United Kingdom, where a small increase in costs was observed in both intervention arms. When a lifetime effect of interventions was assumed, incremental improvements in life expectancy were 0.35 and 0.90 years for metformin and ILC, respectively. Results were sensitive to probabilities of developing type 2 DM, the projected long-term duration of effect of interventions after the 3-year trial period, the relative risk of mortality for type 2 DM compared with IGT, and the costs of implementing the interventions.

CONCLUSIONS

Based on probabilities from the DPP and published data, in this model analysis, incorporation of the DPP interventions into clinical practice in 5 developed countries was projected to lead to an increase in DM-free years of life, improvements in life expectancy, and either cost savings or minor increases in costs compared with standard lifestyle advice in a population with IGT. Thus, financial constraints should not prevent the implementation of DM prevention programs.