Decision analysis and economic modelling: a primer

Cost-effectiveness analysis of multigene expression profiling assays to guide adjuvant therapy decisions in women with invasive early-stage breast cancer

Gene expression profiling (GEP) testing using 12-gene recurrence score (RS) assay (EndoPredict®), 58-gene RS assay (Prosigna®), and 21-gene RS assay (Oncotype DX®) is available to aid in chemotherapy decision-making when traditional clinicopathological predictors are insufficient to accurately determine recurrence risk in women with axillary lymph node-negative, hormone receptor-positive, and human epidermal growth factor-receptor 2-negative early-stage breast cancer. We examined the cost-effectiveness of incorporating these assays into standard practice. A decision model was built to project lifetime clinical and economic consequences of different adjuvant treatment-guiding strategies. The model was parameterized using follow-up data from a secondary analysis of the Anastrozole or Tamoxifen Alone or Combined randomized trial, cost data (2017 Canadian dollars) from the London Regional Cancer Program (Canada) and secondary Canadian sources. The 12-gene, 58-gene, and 21-gene RS assays were associated with cost-effectiveness ratios of $36,274, $48,525, and $74,911/quality-adjusted life year (QALY) gained and resulted in total gains of 379, 284.3, and 189.5 QALYs/year and total budgets of $12.9, $14.2, and $16.6 million/year, respectively. The total expected-value of perfect information about GEP assays' utility was $10.4 million/year. GEP testing using any of these assays is likely clinically and economically attractive. The 12-gene and 58-gene RS assays may improve the cost-effectiveness of GEP testing and offer higher value for money, although prospective evidence is still needed. Comparative field evaluations of GEP assays in real-world practice are associated with a large societal benefit and warranted to determine the optimal and most cost-effective assay for routine use.

Economic Analysis of Anatomic Plating Versus Tubular Plating for the Treatment of Fibula Fractures

Ankle fractures are among the most common injuries requiring operative management. Implant choices include one-third tubular plates and anatomically precontoured plates. Although cadaveric studies have not revealed biomechanical differences between various plate constructs, there are substantial cost differences. This study sought to characterize the economic implications of implant choice. A retrospective review was undertaken of 201 consecutive patients with operatively treated OTA type 44B and 44C ankles. A Nationwide Inpatient Sample query was performed to estimate the incidence of ankle fractures requiring fibular plating, and a Monte Carlo simulation was conducted with the estimated at-risk US population for associated plate-specific costs. The authors estimated an annual incidence of operatively treated ankle fractures in the United States of 59,029. The average cost was $90.86 (95% confidence interval, $90.84-$90.87) for a one-third tubular plate vs $746.97 (95% confidence interval, $746.55-$747.39) for an anatomic plate. Across the United States, use of only one-third tubular plating over anatomic plating would result in statistically significant savings of $38,729,517 (95% confidence interval, $38,704,773-$38,754,261; P<.0001). General use of one-third tubular plating instead of anatomic plating whenever possible for fibula fractures could result in cost savings of up to nearly $40 million annually in the United States. Unless clinically justifiable on a per-case basis, or until the advent of studies showing substantial clinical benefit, there currently is no reason for the increased expense from widespread use of anatomic plating for fractures amenable to one-third tubular plating. [Orthopedics. 2018; 41(2):e252-e256.].

Economic Burden of Inpatient Admission of Ankle Fractures

BACKGROUND

Ankle fractures are among the most prevalent traumatic orthopaedic injuries. A large proportion of patients sustaining operative ankle fractures are admitted directly from the emergency department prior to operative management. In the authors' experience, however, many closed ankle injuries may be safely and effectively managed on an outpatient basis. The aim of this study was to characterize the economic impact of routine inpatient admission of ankle fractures.

METHODS

A retrospective review of all outpatient ankle fracture surgery performed by a single foot and ankle fellowship-trained surgeon at a tertiary level academic center in 2012 was conducted to identify any patients requiring postoperative inpatient admission. The National Inpatient Sample was queried for operative management of lateral malleolus, bimalleolar, and trimalleolar ankle fractures in 2012 with regard to national estimates of total volume and length of stay by age. The maximum allowable Medicare inpatient facility reimbursements for diagnosis related group 494 and Medicare outpatient facility reimbursements for Current Procedural Terminology codes 27792, 27814, and 27822 were obtained from the Medicare Acute Inpatient Prospective Pricer and the Medicare Outpatient Pricer Code, respectively. Private facility reimbursement rates were estimated at 139% of inpatient Medicare reimbursement and 280% of outpatient reimbursement, as described in the literature. Surgeon and anesthesiologist fees were considered similar between both inpatient and outpatient groups. A unique stochastic decision-tree model was derived from probabilities and associated costs and evaluated using modified Monte Carlo simulation.

RESULTS

Of 76 lateral malleolar, bimalleolar, and trimalleolar ankle fracture open reduction internal fixation cases performed in 2012 by the senior author, 9 patients required admission for polytrauma, medical comorbidities, or age. All 67 outpatients were discharged home the day of surgery. In the 2012 national cohort analyzed, 48,044 estimated inpatient admissions occurred postoperatively for closed ankle fractures. The median length of stay was 3 days for each admission and was associated with an estimated facility reimbursement ranging from $12,920 for Medicare reimbursement of lateral malleolus fractures to $18,613 for private reimbursement of trimalleolar fractures. Outpatient facility reimbursements per case were estimated at $4,125 for Medicare patients and $11,459 for private insurance patients. Nationally, annual inpatient admissions accounted for $796,033,050 in reimbursements, while outpatient surgery would have been associated with $419,327,612 for treatment of these same ankle fractures.

CONCLUSION

In the authors' experience, closed lateral malleolus, bimalleolar, and trimalleolar fractures were safely and effectively treated on an outpatient basis. Routine perioperative admission of patients sustaining ankle fractures likely results in more than $367 million of excess facility reimbursements annually in the United States. Even if a 25% necessary admission rate were assumed, routine inpatient admission of ankle fractures would result in a $282 million excess economic burden annually in the United States. Although in certain cases, inpatient admission may be necessary, with value-based decision making becoming increasingly the responsibility of the orthopaedic surgeon, understanding the implications of inpatient stays for ankle fracture surgery can ultimately result in cost savings to the US health care system and patients individually.

LEVEL OF EVIDENCE

Level III, comparative series.

Cost Analysis of Universal Screening vs. Risk Factor-Based Screening for Methicillin-Resistant Staphylococcus aureus (MRSA)

Background

The literature remains conflicted regarding the most effective way to screen for MRSA. This study was designed to assess costs associated with universal versus risk factor-based screening for the reduction of nosocomial MRSA transmission.

Methods

The study was conducted at The Ottawa Hospital, a large multi-centre tertiary care facility with approximately 47,000 admissions annually. From January 2006-December 2007, patients underwent risk factor-based screening for MRSA on admission. From January 2008 to August 2009 universal MRSA screening was implemented. A comparison of costs incurred during risk factor-based screening and universal screening was conducted. The model incorporated probabilities relating to the likelihood of being tested and the results of polymerase chain reaction (PCR) testing with associated effects in terms of MRSA bacteremia and true positive and negative test results. Inputted costs included laboratory testing, contact precautions and infection control, private room costs, housekeeping, and length of hospital stay. Deterministic sensitivity analyses were conducted.

Results

The risk factor-based MRSA screening program screened approximately 30% of admitted patients and cost the hospital over $780 000 annually. The universal screening program screened approximately 83% of admitted patients and cost over $1.94 million dollars, representing an excess cost of $1.16 million per year. The estimated additional cost per patient screened was $17.76.

Conclusion

This analysis demonstrated that a universal MRSA screening program was costly from a hospital perspective and was previously known to not be clinically effective at reducing MRSA transmission. These results may be useful to inform future model-based economic analyses of MRSA interventions.

Cost-effectiveness of using a gene expression profiling test to aid in identifying the primary tumour in patients with cancer of unknown primary

We aimed to investigate the cost-effectiveness of a 2000-gene-expression profiling (GEP) test to help identify the primary tumor site when clinicopathological diagnostic evaluation was inconclusive in patients with cancer of unknown primary (CUP). We built a decision-analytic-model to project the lifetime clinical and economic consequences of different clinical management strategies for CUP. The model was parameterized using follow-up data from the Manitoba Cancer Registry, cost data from Manitoba Health administrative databases and secondary sources. The 2000-GEP-based strategy compared to current clinical practice resulted in an incremental cost-effectiveness ratio (ICER) of $44,151 per quality-adjusted life years (QALY) gained. The total annual-budget impact was $36.2 million per year. A value-of-information analysis revealed that the expected value of perfect information about the test's clinical impact was $4.2 million per year. The 2000-GEP test should be considered for adoption in CUP. Field evaluations of the test are associated with a large societal benefit.

Decision analytic modeling in spinal surgery: a methodologic overview with review of current published literature

BACKGROUND CONTEXT

In recent years, there has been an increase in the number of decision analysis studies in the spine literature. Although there are several published reviews on the different types of decision analysis (cost-effectiveness, cost-benefit, cost-utility), there is limited information in the spine literature regarding the mathematical models used in these studies (decision tree, Markov modeling, Monte Carlo simulation).

PURPOSE

The purpose of this review was to provide an overview of the types of decision analytic models used in spine surgery. A secondary aim was to provide a systematic overview of the most cited studies in the spine literature.

STUDY DESIGN/SETTING

This is a systematic review of the available information from all sources regarding decision analytics and economic modeling in spine surgery.

METHODS

A systematic search of PubMed, Embase, and Cochrane review was performed to identify the most relevant peer-reviewed literature of decision analysis/cost-effectiveness analysis (CEA) models including decisions trees, Markov models, and Monte Carlo simulations. Additionally, CEA models based on investigational drug exemption studies were reviewed in particular detail, as these studies are prime candidates for economic modeling.

RESULTS

The initial review of the literature resulted in 712 abstracts. After two reviewer-assessment of abstract relevance and methodologic quality, 19 studies were selected: 12 with decision tree constructs and 7 with Markov models. Each study was assessed for methodologic quality and a review of the overall results of the model. A generalized overview of the mathematical construction and methodology of each type of model was also performed. Limitations, strengths, and potential applications to spine research were further explored.

CONCLUSIONS

Decision analytic modeling represents a powerful tool both in the assessment of competing treatment options and potentially in the formulation of policy and reimbursement. Our review provides a generalized overview and a conceptual framework to help spine physicians with the construction of these models.

Margin re-excision and local recurrence in invasive breast cancer: A cost analysis using a decision tree model

BACKGROUND

SSO-ASTRO recently published guidelines defining adequate margins in breast conservation therapy (BCT) as no tumor on ink based on studies demonstrating little difference in local recurrence (LR) with wider margins. We hypothesize that not routinely re-excising close margins results in decreased costs without compromising care.

METHODS

A decision tree model was developed for the management of margins after BCT for invasive cancer. Patients were compared among three margin status groups: positive, close (≤2 mm) and negative (>2 mm). Ten publications provided re-excision rates (RER) and LR rates. The model assumed 140,000 BCT/year. Sensitivity analyses determined the most cost-effective strategy. Surgical costs were estimated using 2013 Medicare reimbursement rates.

RESULTS

Re-excising close margins was significantly more costly than the alternative, $233.1 million versus $214.3 million, per year in the United States. Total surgical cost was most sensitive to re-excision of close margins-increasing the RER from 0% to 100% resulted in an $18.8 million cost difference.

CONCLUSIONS

The strategy of re-excising close margins resulted in a predicted cost of $18.8 million per year. This does not include hospital costs, the cost of surgical complications after re-excision, and underestimates the potential savings by using Medicare reimbursement rates.

Is liver transplantation using organs donated after cardiac death cost-effective or does it decrease waitlist death by increasing recipient death?

OBJECTIVES

The aim of this study was to evaluate the cost-effectiveness in liver transplantation (LT) of utilizing organs donated after cardiac death (DCD) compared with organs donated after brain death (DBD).

METHODS

A Markov-based decision analytic model was created to compare two LT waitlist strategies distinguished by organ type: (i) DBD organs only, and (ii) DBD and DCD organs. The model simulated outcomes for patients over 10 years with annual cycles through one of four health states: survival; ischaemic cholangiopathy; retransplantation, and death. Baseline values and ranges were determined from an extensive literature review. Sensitivity analyses tested model strength and parameter variability.

RESULTS

Overall survival is decreased, and biliary complications and retransplantation are increased in recipients of DCD livers. Recipients of DBD livers gained 5.6 quality-adjusted life years (QALYs) at a cost of US$69 000/QALY, whereas recipients on the DBD + DCD LT waitlist gained 6.0 QALYs at a cost of US$61 000/QALY. The DBD + DCD organ strategy was superior to the DBD organ-only strategy.

CONCLUSIONS

The extension of life and quality of life provided by DCD LT to patients on the waiting list who might otherwise not receive a liver transplant makes the continued use of DCD livers cost-effective.

More donors or more delayed graft function? A cost-effectiveness analysis of DCD kidney transplantation

Expansion of the donor pool with expanded criteria donors and donation after cardiac death (DCD) donors is essential. DCD grafts result in increased rates of primary non-function (PNF) and delayed graft function (DGF). However, long-term patient and graft survival is similar between donation after brain death (DBD) donors and DCD donors. The aim of this study was to evaluate the cost-effectiveness of the use of DCD donors. A Markov-based decision analytic model was created to simulate outcomes for two wait list strategies: (i) wait list composed of only DBD organs and (ii) wait list combining DBD and DCD organs. Baseline values and ranges were determined from the Scientific Registry of Transplant Recipients (SRTR) database and literature review. Sensitivity analyses were conducted to test model strength and parameter variability. The wait list strategy consisting of DBD donors only provided recipients 5.4 Quality-adjusted life years (QALYs) at $65 000/QALY, whereas a wait list strategy combining DBD + DCD donors provided recipients 6.0 QALYs at a cost of $56 000/QALY. Wait lists with DCD donors provide adequate long-term survival despite more DGF. This equates to an improvement in quality of life and decreased cost when compared to remaining on dialysis for any period of time.

Cost-effectiveness analysis: stress ulcer bleeding prophylaxis with proton pump inhibitors, H2 receptor antagonists

OBJECTIVES

Proton pump inhibitors (PPIs) and H2-receptor antagonists (H2RAs) present varying pharmacological efficacy in preventing stress ulcer bleeding (SUB) in intensive care units. The literature also reports disparate rates of ventilator-assisted pneumonia (VAP) as side effects of these treatments. We compared the cost-effectiveness of these two prophylactic pharmacological options.

METHODS

We constructed a decision tree with a 60-day time horizon for patients at high risk for developing SUB, receiving either PPIs or H2RAs. For each treatment strategy, patients could be in one of three states of health: SUB, VAP, or no complication. Contemporary, clinically relevant probabilities were obtained from a broad literature search. Costs were estimated by using a representative US countrywide database. A third-party payer perspective was adopted. Cost-effectiveness and univariate and multivariate sensitivity analyses were performed.

RESULTS

Probabilities of SUB and VAP were 1.3% and 10.3% for PPIs versus 6.6% and 10.3% for H2RAs, respectively. Lengths of stay and per diem costs were 24 days and US $2764 for SUB, 42 days and US $3310 for VAP, and 14 days and US $2993 for patients without complications. Average costs per no complication were US $58,700 for PPIs and US $63,920 for H2RAs. The H2RA strategy was dominated by PPIs. Sensitivity analysis showed that these findings were sensitive to VAP rates but PPIs remain cost-effective. The acceptability curve shows the stability of the probabilistic results according to varying willingness-to-pay values.

CONCLUSION

PPI prophylaxis is the most efficient prophylactic strategy in patients at high risk of developing SUB when compared with using H2RAs.

Active surveillance for prostate cancer compared with immediate treatment: an economic analysis

BACKGROUND

The costs associated with a contemporary active surveillance strategy compared with immediate treatment for prostate cancer are not well characterized. The purpose of this study is to elucidate the health care costs of an active surveillance paradigm for prostate cancer.

METHODS

A theoretical cohort of 120,000 men selecting active surveillance for prostate cancer was created. The number of men remaining on active surveillance and those exiting to each of 5 treatments over 5 years were simulated in a Markov model. Estimated total costs after 5 years of active surveillance with subsequent delayed treatment were compared with immediate treatment. Sensitivity analyses were performed to test the effect of various surveillance strategies and attrition rates. Additional analyses to include 10 years of follow-up were performed.

RESULTS

The average simulated cost of treatment for 120,000 men initiating active surveillance with 5 years of follow-up and subsequent delayed treatment resulted in per patient cost savings of $16,042 (95% confidence interval [CI], $16,039-$16,046) relative to initial curative treatment. This represents a $1.9 billion dollar savings to the cohort. The strict costs of active surveillance exceeded those of brachytherapy in the ninth year of follow-up. A yearly biopsy within the active surveillance cohort increased costs by 22%, compared with every other year biopsy. At 10 years of follow-up, active surveillance still resulted in a cost benefit; however, the savings were reduced by 38% to $9944 (95% CI, $9941-$9948) per patient relative to initial treatment.

CONCLUSIONS

These data demonstrate that active surveillance represents a considerable cost savings over immediate treatment for prostate cancer in a theoretical cohort after 5 and 10 years of follow-up.

Which is more cost-effective under the MELD system: primary liver transplantation, or salvage transplantation after hepatic resection or after loco-regional therapy for hepatocellular carcinoma within Milan criteria?

OBJECTIVE

The optimal strategy for treating hepatocellular carcinoma (HCC), a disease with increasing incidence, in patients with Child-Pugh class A cirrhosis has long been debated. This study evaluated the cost-effectiveness of hepatic resection (HR) or locoregional therapy (LRT) followed by salvage orthotopic liver transplantation (SOLT) vs. that of primary orthotopic liver transplantation (POLT) for HCC within the Milan Criteria.

METHODS

A Markov-based decision analytic model simulated outcomes, expressed in costs and quality-adjusted life years (QALYs), for the three treatment strategies. Baseline parameters were determined from a literature review. Sensitivity analyses tested model strength and parameter variability.

RESULTS

Both HR and LRT followed by SOLT were associated with earlier recurrence, decreased survival, increased costs and decreased quality of life (QoL), whereas POLT resulted in decreased recurrence, increased survival, decreased costs and increased QoL. Specifically, HR/SOLT yielded 3.1 QALYs (at US$96 000/QALY) and LRT/SOLT yielded 3.9 QALYs (at US$74 000/QALY), whereas POLT yielded 5.5 QALYs (at US$52 000/QALY). Sensitivity analyses supported these findings at clinically meaningful probabilities.

CONCLUSIONS

 Under the Model for End-stage Liver Disease (MELD) system, in patients with HCC within the Milan Criteria, POLT increases survival and QoL at decreased costs compared with HR or LRT followed by SOLT. Therefore, POLT is the most cost-effective strategy for the treatment of HCC.

[Health technology assessment: II. Cost effectiveness analysis]

New health technologies have made an impact in clinical and economic outcomes. Therefore, research methodologies that allow to evaluate the efficiency of these new technologies such as cost-effectiveness analysis are necessary. Cost-effectiveness analysis assess the value of health care interventions or drugs, the technology. Cost-effectiveness analysis is also deemed a determinant of modern health care practice, because the therapeutic options available at public (SUS) or private health care system must go through a formal health technology assessment in Brazil; thus, both the health care system and the health care professionals have to reevaluate the clinical consequences and costs of their actions to assure that the most efficient technologies are the one used in the practice. In this second article about health technology assessment we review the concepts of cost-effectiveness analysis, the steps involved in performing such analysis, and the criteria most frequently used to critically review the results.

Efficacy and cost-benefit analysis of risk-adaptive use of plerixafor for autologous hematopoietic progenitor cell mobilization

BACKGROUND

Plerixafor (P) reduces mobilization failure rates but it is very expensive. For better utilization of P, we employed a risk-adaptive strategy of using it only in patients who are at high risk of mobilization failure, defined by peripheral blood (PB) CD34+ cell count of fewer than 10×10(6)/L after 4 days of filgrastim (F) alone.

STUDY DESIGN AND METHODS

Herein, we present the results of efficacy and cost-benefit analysis of this risk-adaptive approach for hematopoietic progenitor cell (HPC) collection. All patients received daily F for 4 days, and P was added for those "at-risk" patients from Day 4 with apheresis commencing the following morning. F and P were continued daily for up to a maximum of 4 days or until more than 5×10(6) CD34+ cells/kg were collected. Forty-two transplant-eligible patients underwent HPC mobilization.

RESULTS

Eighteen patients mobilized with F alone and 24 patients required P with F. Two patients failed adequate HPC mobilization after F+P. Addition of P increased the PB CD34+ count by 6.8-fold with a mean yield of 4.9×10(6) CD34+ cells/kg. Decision-analysis model estimated cost-effectiveness for this risk-adaptive approach of using P with savings of $19,300/patient. Engraftment after HPC infusion was similar among the patients regardless of mobilization regimens.

CONCLUSION

These results suggest that addition of P to F based on a risk-adaptive strategy significantly reduces the frequency of mobilization failures and is also cost-effective.

Métodos de pesquisa em avaliação de tecnologia em saúde

Existe, atualmente, grande demanda para se aumentar a eficiência do ato médico e isto pode ser alcançado através de pesquisas de avaliação de tecnologia em saúde, a ATS. Esta visa, por um lado, determinar a melhor evidência de eficácia ou efetividade de um dado tratamento em saúde, por outro, determinar os custos associados com tal tratamento médico. Somente as alternativas com custo e efetividade comprovados, ou seja, que sejam eficientes, serão adotados doravante nos hospitais e sistemas de saúde público e privados. Exemplo são os custos crescentes de tratamentos com biológicos, por exemplo, em doença inflamatória intestinal ou hepatites virais, ou mesmo em oncologia. Há necessidade de se desenvolver pesquisas em ATS para a identificação não somente dos tratamentos que funcionam dos que não funcionam, mas também se os custos a eles associados compensam o seu uso. Este artigo introduz esta terminologia e os métodos para se desenvolver esses estudos.

Assessing technological change in cardiothoracic surgery

Technological innovation--broadly defined as the development and introduction of new drugs, devices, and procedures--has played a major role in advancing the field of cardiothoracic surgery. It has generated new forms of care for patients and improved treatment options. Innovation, however, comes at a price. Total national health care expenditures now exceed $2 trillion per year in the United States and all current estimates indicate that this number will continue to rise. As we continue to seek the most innovative medical treatments for cardiovascular disease, the spiraling cost of these technologies comes to the forefront. In this article, we address 3 challenges in managing the health and economic impact of new and emerging technologies in cardiothoracic surgery: (1) challenges associated with the dynamics of technological growth itself; (2) challenges associated with methods of analysis; and (3) the ways in which value judgments and political factors shape the translation of evidence into policy. We conclude by discussing changes in the analytical, financial, and institutional realms that can improve evidence-based decision-making in cardiac surgery.

The cost-effectiveness of hormone therapy in younger and older postmenopausal women

PURPOSE

To evaluate the health and economic outcomes of hormone therapy in younger and older postmenopausal women.

METHODS

We developed a cost-effectiveness model to evaluate outcomes associated with hormone therapy in younger and older postmenopausal women, using data sources from published literature through March 2008. The target population was 50-year-old and 65-year-old women given hormone therapy or no therapy, and then followed over their lifetime. Primary outcomes measured were quality-adjusted life-years (QALYs) and incremental cost per QALY gained.

RESULTS

For the base-case analysis, hormone therapy for 15 years in the younger cohort resulted in a gain of 1.49 QALYs with an incremental cost of $2438 per QALY gained, compared with no therapy. The results for younger women were robust to all sensitivity analyses, and treatment remained highly cost-effective (<$10,000 per QALY gained) within the range of individual assumptions used. Treatment durations of 5 years and 30 years also were highly cost-effective. In the older cohort, treatment for 15 years resulted in a net gain of 0.11 QALYs with a cost of $27,953 per QALY gained. However, a loss of QALYs was seen in the first 9 years. The results for older women were sensitive to many of the assumptions used.

CONCLUSIONS

Hormone therapy for 5 to 30 years in younger postmenopausal women increases quality-adjusted life-years and is cost-effective. Hormone therapy started in later years results in a loss of quality-adjusted life for several years before a net gain can be realized.

Users' guide to the orthopaedic literature: what is a cost-effectiveness analysis?

As the cost of healthcare continue to rise, orthopaedic surgeons are being pressured to practice cost-effective healthcare. Consequently, economic evaluation of treatment options are being reported more commonly in medical and surgical literature. As new orthopaedic procedures and treatments may improve patient outcome and function over traditional treatment options, the effect of the potentially higher costs of new treatments should be formally evaluated. Unfortunately, the resources available for healthcare spending are typically limited. Therefore, cost-effectiveness analyses have become an important and useful tool in informing which procedure or treatment to implement into practice. Cost-effectiveness analysis is a type of economic analysis that compares both the clinical outcomes and the costs of new treatment options to current treatment options or standards of care. For a clinician to be able to apply the results of a cost-effectiveness analysis to their practice, they must be able to critically review the available literature. Conducting an economic analysis is a challenging process, which has resulted in a number of published economic analyses that are of lower quality and may be fraught with bias. It is important that the reader of an economic analysis or cost-effectiveness analysis have the skills required to properly evaluate and critically appraise the methodology used before applying the recommendations to their practice. Using the principles of evidence-based medicine and the questions outlined in the Journal of the American Medical Association's Users' Guide to the Medical Literature, this article attempts to illustrate how to critically appraise a cost-effectiveness analysis in the orthopaedic surgery literature.

Agreement of decision analyses and subsequent clinical studies in infectious diseases

PURPOSE

Decision analysis techniques can compare management strategies when there are insufficient data from clinical studies to guide decision making. We compared the outcomes of decision analyses and subsequent clinical studies in the infectious disease literature to assess the validity of the conclusions of the decision analyses.

METHODS

A search strategy to identify decision analyses in infectious disease topics published from 1990 to 2005 was developed and performed using PubMed. Abstracts of all identified articles were reviewed, and infectious disease-related decision analyses were retained. Subsequent clinical trials and observational studies that corresponded to these decision analyses were identified using prespecified search strategies. Clinical studies were considered a match for the decision analysis if they assessed the same patient population, intervention, and outcome. Agreement or disagreement between the conclusions of the decision analysis and clinical study were determined by author review.

RESULTS

The initial PubMed search yielded 318 references. Forty decision analyses pertaining to 29 infectious disease topics were identified. Of the 40, 16 (40%) from 13 infectious disease topics had matching clinical studies. In 12 of 16 (75%), conclusions of at least 1 clinical study agreed with those of the decision analysis. Three of the 4 decision analyses in which conclusions disagreed were from the same topic (management of febrile children).

CONCLUSIONS

There was substantial agreement between the conclusions of decision analyses and clinical studies in infectious diseases, supporting the validity of decision analysis and its utility in guiding management decisions.

Timing of Antiretroviral Therapy Initiation in Tuberculosis Patients With AIDS

In HIV-infected tuberculosis patients with <200 CD4 lymphocytes/mm, highly active antiretroviral therapy (HAART) improves survival but can be complicated by immune reconstitution inflammatory syndrome (IRIS) and drug toxicity. We conducted a decision analysis in hypothetical cohorts of 1000 patients in which HAART was initiated during the first 2 months of tuberculosis therapy (early) or during months 2 through 6 of tuberculosis therapy (deferred) or was withheld until after tuberculosis therapy (no HAART). Outcomes assessed were 1-year mortality and the combined outcome of 1-year mortality, new AIDS-defining illness, severe IRIS, and severe drug toxicity. There were 33, 48, and 147 deaths and 497, 501, and 501 combined outcome events in the early HAART, deferred HAART, and no-HAART groups, respectively; most events were drug toxicity in the early and deferred groups and HIV-related mortality or AIDS-defining illness in the no-HAART group. In a 2-way sensitivity analysis of mortality, early HAART was favored, even with the highest reported rates of IRIS (70%) and severe drug toxicity (56%). Deferred HAART was favored over early HAART only if the IRIS-related mortality rate in the early group exceeded 4.6%. These results support early initiation of HAART in patients with AIDS, except when IRIS-related mortality rates are high.

Evidence-based practice in clinical psychology: What it is, why it matters; what you need to know

The history and meaning of evidence-based practice (EBP) in the health disciplines was described to the Council of University Directors of Clinical Psychology (CUDCP) training programs. Evidence-based practice designates a process of clinical decision-making that integrates research evidence, clinical expertise, and patient preferences and characteristics. Evidence-based practice is a transdisciplinary, idiographic approach that promotes lifelong learning. Empirically supported treatments (ESTs) are an important component of EBP, but EBP cannot be reduced to ESTs. Psychologists need additional skills to act as creators, synthesizers, and consumers of research evidence, who act within their scope of clinical expertise and engage patients in shared decision-making. Training needs are identified in the areas of clinical trial methodology and reporting, systematic reviews, search strategies, measuring patient preferences, and acquisition of clinical skills to perform ESTs.

Neonatal mortality and morbidity after elective cesarean delivery versus routine expectant management: a decision analysis

A number of competing risks and benefits influence the rates of neonatal morbidity and mortality in elective cesarean delivery versus expectant management. To compare these rates, we developed complex decision trees to model the expected outcomes among hypothetical cohorts of 1,000,000 uncomplicated pregnancies undergoing elective cesarean delivery versus 1,000,000 comparable pregnancies undergoing routine pregnancy management. A separate tree was created for each complication, including neonatal death, respiratory morbidity, intracranial hemorrhage, and brachial plexus injury. We found that neonatal mortality was increased among elective cesarean deliveries, but perinatal mortality was higher with routine expectant management due to fetal deaths. Respiratory morbidity was substantially more common among infants delivered by elective cesarean delivery, whereas intracranial hemorrhage and brachial plexus injury were less common. We conclude that the fetal/neonatal impact of elective cesarean is mixed, but any improvement in perinatal health is likely to be small.

Cost-effectiveness of growth factors during hepatitis C anti-viral therapy

BACKGROUND

Although the current standard of care for controlling anaemia and neutropenia during anti-viral therapy for hepatitis C is to use dose reduction of ribavirin and pegylated interferon, respectively, erythropoietin and granulocyte colony-stimulating factor are now being advocated as alternatives to dose reduction.

AIM

To determine the cost-effectiveness of erythropoietin and granulocyte colony-stimulating factor as an alternative to anti-viral dose reduction during antihepatitis C therapy.

METHODS

Decision analysis was used to assess cost-effectiveness by estimating the cost of using a growth factor per quality-adjusted life-year gained.

RESULTS

Under baseline assumptions, the cost per quality-adjusted life-year of using growth factors ranged from 16,247 US dollars for genotype 1 with neutropenia to 145,468 US dollars for genotype 2/3 patients with anaemia. These findings are sensitive to the relationship between dose reduction and sustained virological response.

CONCLUSIONS

Based upon our findings and the varying strength of the evidence for a relationship between dose reduction and sustained virological response: granulocyte colony-stimulating factor may be cost-effective for genotype 1 patients; erythropoietin is probably not cost-effective for genotype 2/3 patients; no conclusion can be reached regarding the cost-effectiveness of erythropoietin for genotype 1 patients or granulocyte colony-stimulating factor for genotype 2/3 patients. Randomized trials are needed to firmly establish the relationship between dose reduction and sustained virological response.

Do the benefits of finasteride outweigh the risks in the prostate cancer prevention trial?

PURPOSE

The Prostate Cancer Prevention Trial demonstrated that finasteride could reduce the incidence of prostate cancer by 25%. However, its use was also associated with an increased risk of high grade cancer resulting in uncertainty surrounding the net benefits of therapy.

MATERIALS AND METHODS

We used the Montreal Prostate Cancer Model, a validated Markov model of prostate cancer progression, to compare the forecasted survival in treated and untreated men. The conditions of the model were varied to reflect different assumptions about whether the cancer grade difference observed in the PCPT was real or a treatment associated artifact, and whether cancers detected on end of study biopsies were clinically significant.

RESULTS

For a hypothetical cohort of 1,000, 62-year-old men treated with finasteride, an increased survival of 140 life-years (0.14 years per individual) is forecasted if all diagnosed cancers are considered. If tumor grade differences are held to be artifactual, the forecasted benefits increase to 200 life-years. However, if the tumor grade difference is real and only clinically detected cancers are considered, estimated increased survival is only 20 life-years (0.02 years per individual).

CONCLUSIONS

The primary prevention of prostate cancer with finasteride looks promising. However, at the present time it should only be considered with caution until we have answered critical questions surrounding the difference in cancer grade observed in the PCPT and the clinical significance of cancers detected on protocol directed end of study biopsies.

Personal view: passing the buck and taking a free ride -- a game-theoretical approach to evasive management strategies in gastroenterology

BACKGROUND

'Free-riding' physicians enjoy the status, prestige and income of their profession without fully contributing to its overall mission. By shifting the costs of potential medical complications and difficult patient encounters to other physicians, they reap the benefits of their profession without carrying its full weight.

AIM

To describe this phenomenon in terms of decision analysis and characterize the parameters affecting its occurrence.

METHODS

The interaction between two physicians is modeled as a non-zero-sum game. Two strategies of either contributing to patient management or taking a free ride are available to both physicians. The four possible outcomes are arranged in a two-by-two game matrix.

RESULTS

Physicians practice medicine because their personal benefit exceeds their cost. High cost to the physician results in a high probability of taking a free ride and copping out from potentially risky management. Increasing the benefit decreases the probability of free riding. As the number of possible encounters with other physicians increases, the probability of free riding increases and the probability for effective management by each individual physician decreases.

CONCLUSION

If individual gastroenterologists felt less threatened by administrative repercussions and medico-legal consequences of untoward events, each one of them would contribute more to effective patient management.