Reading a cost-effectiveness or decision analysis study: Five things to consider

Cost-effectiveness studies and decision analyses of neurologic practices, treatments, and technologies are increasing in the literature and have an emerging role within both medicine and neurology. Knowledge about these research approaches, how to interpret the results of such studies, as well as an understanding of their limitations will be of growing importance for the practicing neurologist. We discuss 5 aspects of these analyses to increase awareness about the uses and limitations of cost-effectiveness articles in everyday practice.

Estimating and communicating prognosis in advanced neurologic disease

Prognosis can no longer be relegated behind diagnosis and therapy in high-quality neurologic care. High-stakes decisions that patients (or their surrogates) make often rest upon perceptions and beliefs about prognosis, many of which are poorly informed. The new science of prognostication--the estimating and communication "what to expect"--is in its infancy and the evidence base to support "best practices" is lacking. We propose a framework for formulating a prediction and communicating "what to expect" with patients, families, and surrogates in the context of common neurologic illnesses. Because neurologic disease affects function as much as survival, we specifically address 2 important prognostic questions: "How long?" and "How well?" We provide a summary of prognostic information and highlight key points when tailoring a prognosis for common neurologic diseases. We discuss the challenges of managing prognostic uncertainty, balancing hope and realism, and ways to effectively engage surrogate decision-makers. We also describe what is known about the nocebo effects and the self-fulfilling prophecy when communicating prognoses. There is an urgent need to establish research and educational priorities to build a credible evidence base to support best practices, improve communication skills, and optimize decision-making. Confronting the challenges of prognosis is necessary to fulfill the promise of delivering high-quality, patient-centered care.

Early stroke mortality, patient preferences, and the withdrawal of care bias

OBJECTIVE

Early mortality is a potential measure of the quality of care provided to hospitalized stroke patients. Whether in-hospital stroke mortality is reflective of deviations from evidence-based practices or patient/family preferences on life-sustaining measures is unclear.

METHODS

All ischemic stroke mortalities at an academic medical center were reviewed to better understand the causes of inpatient stroke mortality.

RESULTS

Among 37 deaths or discharges to hospice in 2009, 36 occurred after a patient/family decision to withdraw/withhold potentially life-sustaining interventions. An independent survey of 3 vascular neurologists revealed that some early deaths could have been delayed beyond 30 days if patients or families had agreed to more aggressive measures. From these data, we estimate the magnitude of a "withdrawal of care" bias to be approximately 40% of the observed short-term mortality.

CONCLUSIONS

Acute stroke mortality may be more reflective of patient/family preferences than the provision of evidence-based care.

Sham surgery controls in Parkinson's disease clinical trials: views of participants

BACKGROUND

Sham surgery controls are increasingly used in neurosurgical clinical trials in Parkinson's disease (PD) but remain controversial. We interviewed participants of such trials, specifically examining their understanding and attitudes regarding sham surgery.

METHODS

We conducted semistructured qualitative interviews with participants of 3 sham surgery-controlled trials for PD, focusing on their understanding of sham design, their reactions to it, its impact on decision making, and their understanding of posttrial availability of the experimental intervention and its impact on decisions to participate.

RESULTS

All subjects (n = 90) understood the 2-arm design; most (86%) described the procedural differences between the arms accurately. Ninety-two percent referred to scientific or regulatory reasons as rationales for the sham control, with 62% specifically referring to the placebo effect. Ninety-one percent said posttrial availability of the experimental intervention had a strong (48%) or some (43%) influence on their decision to participate, but only 68% understood the conditions for posttrial availability.

CONCLUSIONS

Most subjects in sham surgery-controlled PD trials comprehend the sham surgery design and its rationale. Although there is room for improvement, most subjects of sham surgery trials appear to be adequately informed.

Symptomatic and palliative care for stroke survivors

Stroke is the leading cause of disability and one of the most common causes of death worldwide. Outside the setting of acute management, secondary prevention and stroke rehabilitation, little has been written to address the ongoing symptomatic and palliative needs of these patients and their families. In this literature review, we look beyond secondary prevention with the aim of providing evidence-informed management guidelines for the myriad and often under-recognized symptomatic and palliative care needs of stroke survivors. Some of the most common and disabling post-stroke symptoms that are reviewed here include central post-stroke pain, hemiplegic shoulder pain, painful spasticity, fatigue, incontinence, post-stroke seizures, sexual dysfunction, sleep-disordered breathing, depression and emotionalism. We review the role of caregivers and explore ways to support them and, lastly, remind the reader to be perceptive to the patient's spiritual needs. The literature is most robust, including controlled trials, for central post-stroke pain and depression. Synthesis and discussion outside these areas are frequently limited to smaller studies, case reports and expert opinion. While some data exists to guide informed decision-making, there is an urgent need to document best practice and identify appropriate clinical standards for the full spectrum of symptoms experienced by stroke survivors. We present the current and established data to aid health care providers in symptomatic and palliative management of stroke survivors.

Challenges in assessing hospital-level stroke mortality as a quality measure: comparison of ischemic, intracerebral hemorrhage, and total stroke mortality rates

BACKGROUND AND PURPOSE

Public reporting efforts currently profile hospitals based on overall stroke mortality rates, yet the "mix" of hemorrhagic and ischemic stroke cases may impact this rate.

METHODS

Using the 2005 to 2006 New York state data, we examined the degree to which hospital stroke mortality rankings varied regarding ischemic versus hemorrhagic versus total stroke. Observed/expected ratio was calculated using the Agency for Healthcare Research and Quality Inpatient Quality Indicator software. The observed/expected ratio and outlier status based on stroke types across hospitals were examined using Pearson correlation coefficients (r) and weighted κ.

RESULTS

Overall 30-day stroke mortality rates were 15.2% and varied from 11.3% for ischemic stroke and 37.3% for intracerebral hemorrhage. Hospital risk-adjusted ischemic stroke observed/expected ratio was weakly correlated with its own intracerebral hemorrhage observed/expected ratio (r=0.38). When examining hospital performance group (mortality better, worse, or no different than average), disagreement was observed in 35 of 81 hospitals (κ=0.23). Total stroke mortality observed/expected ratio and rankings were correlated with intracerebral hemorrhage (r=0.61 and κ=0.36) and ischemic stroke (r=0.94 and κ=0.71), but many hospitals still switched classification depending on mortality metrics. However, hospitals treating a higher percent of hemorrhagic stroke did not have a statistically significant higher total stroke mortality rate relative to those treating fewer hemorrhagic strokes.

CONCLUSIONS

Hospital stroke mortality ratings varied considerably depending on whether ischemic, hemorrhagic, or total stroke mortality rates were used. Public reporting of stroke mortality measures should consider providing risk-adjusted outcome on separate stroke types.

Comparison of enrollees and decliners of Parkinson disease sham surgery trials

Concerns have been raised that persons with serious illnesses participating in high-risk research, such as PD patients in sham surgery trials, have unrealistic expectations and are vulnerable to exploitation. A comparison of enrollees and decliners of such research may provide insights about the adequacy of decision making by potential subjects. We compared 61 enrollees and 10 decliners of two phase II neurosurgical intervention (i.e., cellular and gene transfer) trials for PD regarding their demographic and clinical status, perceptions and attitudes regarding research risks, potential direct benefit, and societal benefit, and perspectives on the various potential reasons for and against participation. In addition to bivariate analyses, a logistic regression model examined variables regarding risks and benefits as predictors of participation status. Enrollees perceived lower risk of harm while tolerating higher risk of harm and were more action oriented, but did not have more advanced disease. Both groups rated hope for benefit as a strong reason to participate, whereas the fact that the study's purpose was not solely to benefit them was rated as "not a reason" against participation. Hope for benefit and altruism were rated higher than expectation of benefit as reasons in favor of participation for both groups. Enrollees and decliners are different in their views and attitudes toward risk. Although both are attracted to research because of hopes of personal benefit, this hope is clearly distinguishable from an expectation of benefit and does not imply a failure to understand the main purpose of research.

Abstract 32: Variation in Discharge Practices and Use of Life-Sustaining Procedures: Potential Pitfalls for Adjusted Mortality Quality Measures

Introduction: The Center for Medicare and Medicaid Services (CMS) is developing a risk-standardized stroke mortality measure intended for public comparison of hospital-level quality of care. We sought to determine the impact of discharge practices and use of life sustaining procedures on risk-standardized mortality. We could then address questions such as, how much does mortality differ between hospitals that routinely discharge patients to hospice and those that don’t?

Methods: We estimated risk standardized stroke inpatient mortality for all hospitals in the Nationwide Inpatient Sample (NIS) from 2008-9, using hierarchical logistic regression following a similar approach used for existing CMS mortality measures. Hospital-level adjusted stoke mortality was then categorized as below average, average or above average using standardized Hospital Compare methodology. We then developed individual and hospital level variables to characterize hospital-level practices of interest: discharge to long term acute care (LTAC), discharge to hospice and a life-sustaining procedure index which combined the rates of gastrostomy, tracheostomy, hemicraniectomy and ventriculostomy. These variables were added to the base model in a second hierarchical logistic regression model. This model was used to compare differences in risk-standardized mortality from hospitals grouped in the highest and lowest practice quintiles and to estimate the effects of the hospital practices on grades.

Results: A total of 186,689 stroke patients were identified. Median age was 72 (IQR 60-82) and 52% were female. Seventy six percent of strokes were ischemic, 19% were ICH and 5% were SAH. Of the 1,366 hospitals in the sample 1,210 received average, 73 below average and 83 above average grades for stroke mortality using the base model. Hospitals that more commonly discharged patients to hospice or LTAC or used more life-sustaining procedures had lower mortality. Mean risk standardized mortality was higher in the lowest quintile of hospice utilizing hospitals compared to the highest (11.4% vs. 10.0%, p < 0.01) and in the lowest quintile of LTAC utilizing hospitals compared to the highest (11.4% vs. 10.3%, p = 0.02). Similarly, mean risk standardized mortality was higher in the lowest quintile of hospital use of life-sustaining procedures compared to the highest (11.3% vs. 10.7%, p < 0.01). Accounting for changes in hospital-level practices resulted in significant hospital grade reassignment. Of the 73 initial below average grades, 19 (26%)were reclassified to average and of the 83 initial above average grades, 35 (42%) were reclassified to average. Overall, 6% were reclassified.

Conclusions: Variation in discharge practices and use of life-sustaining procedures alters hospital mortality rankings and distorts perceptions of comparative hospital quality. ns of comparative hospital quality.

Abstract 5: Do Stroke Centers Reduce Mortality for Patients with Acute Ischemic Stroke? An Instrumental Variable Analysis

Background: Although the establishment of stroke centers based on the Brain Attack Coalition recommendations has great potential to improve quality of stroke care, little is known about whether stroke centers improve health outcomes such as mortality.

Methods: Using 2005-2006 New York State Statewide Planning and Research Cooperative System data, we identified 32,783 hospitalized patients age 18+ with a principal diagnosis of acute ischemic stroke (ICD-9 433.x1, 434.x1 and 436). We compared in-hospital mortality and up to one year all-cause mortality between New York State Designated Stroke Centers and non-stroke center hospitals. Because patients were not randomly assigned to hospitals, stroke centers might treat different types of patients than other hospitals (a selection effect). We used a “natural randomization” approach, instrumental variable analysis (differential distance was the instrument), to control for this selection effect. To determine whether the mortality difference was specific to stroke care, we repeated the analysis using a different group of patients with gastrointestinal (GI) hemorrhage (N=53,077).

Results: Of the 32,783 stroke patients, nearly 50% (16,258) were admitted to stroke centers. Stroke centers had lower unadjusted in-hospital mortality and 30-, 90-, 180-, and 365-day all-cause mortality than non-stroke centers (7.0% vs. 7.8%, 10.0% vs. 12.6%, 14.6% vs. 17.5%, 18.0% vs. 21.0%, 22.4% vs. 26.2%, respectively). After adjusting for patient and hospital characteristics, comorbidities, and the patient selection effect, stroke centers were associated with significantly lower all-cause mortality. The adjusted differences were -2.6%, -2.7%, -1.8%, and -2.3% for 30-, 90-, 180- and 365-day mortality (all p<0.05). The adjusted difference in in-hospital mortality was -0.8% but was not statistically significant. In a specificity analysis of patients with GI hemorrhage, stroke centers had slightly higher mortality.

Conclusions: Hospitals that are Designated Stroke Centers had lower mortality for acute ischemic stroke than non-stroke center hospitals. The mortality benefit was specific to stroke and was not observed for GI hemorrhage. Providing stroke centers nationwide has the potential to reduce mortality.

Getting to value in neurological care: a roadmap for academic neurology

Academic neurology is undergoing transformational changes. The public investment in biomedical research and clinical care is enormous and there is a growing perception that the return on this huge investment is insufficient. Hospitals, departments, and individual neurologists should expect more scrutiny as information about their quality of care and financial relationships with industry are increasingly reported to the public. There are unprecedented changes occurring in the financing and delivery of health care and research that will have profound impact on the mission and operation of academic departments of neurology. With the passage of the Patient Protection and Affordable Care Act (PPACA) there will be increasing emphasis on research that demonstrates value and includes the patient's perspective. Here we review neurological investigations of our clinical and research enterprises that focus on quality of care and comparative effectiveness, including cost-effectiveness. By highlighting progress made and the challenges that lie ahead, we hope to create a clinical, educational, and research roadmap for academic departments of neurology to thrive in today's increasingly regulated environment.

Cost-effectiveness of disease-modifying therapy for multiple sclerosis: a population-based study

OBJECTIVE

To evaluate the cost-effectiveness of disease-modifying therapies (DMTs) in the United States compared to basic supportive therapy without DMT for patients with relapsing multiple sclerosis (MS).

METHODS

Using data from a longitudinal MS survey, we generated 10-year disease progression paths for an MS cohort. We used first-order annual Markov models to estimate transitional probabilities. Costs associated with losses of employment were obtained from the Bureau of Labor Statistics. Medical costs were estimated using the Centers for Medicare and Medicaid Services reimbursement rates and other sources. Outcomes were measured as gains in quality-adjusted life-years (QALY) and relapse-free years. Monte Carlo simulations, resampling methods, and sensitivity analyses were conducted to evaluate model uncertainty.

RESULTS

Using DMT for 10 years resulted in modest health gains for all DMTs compared to treatment without DMT (0.082 QALY or <1 quality-adjusted month gain for glatiramer acetate, and 0.126-0.192 QALY gain for interferons). The cost-effectiveness of all DMTs far exceeded $800,000/QALY. Reducing the cost of DMTs had by far the greatest impact on the cost-effectiveness of these treatments (e.g., cost reduction by 67% would improve the probability of Avonex being cost-effective at $164,000/QALY to 50%). Compared to treating patients with all levels of disease, starting DMT earlier was associated with a lower (more favorable) incremental cost-effectiveness ratio compared to initiating treatment at any disease state.

CONCLUSION

Use of DMT in MS results in health gains that come at a very high cost.

Racial differences in mortality among patients with acute ischemic stroke: an observational study

BACKGROUND

Black patients are commonly believed to have higher stroke mortality. However, several recent studies have reported better survival in black patients with stroke.

OBJECTIVE

To examine racial differences in stroke mortality and explore potential reasons for these differences.

DESIGN

Observational cohort study.

SETTING

164 hospitals in New York.

PARTICIPANTS

5319 black and 18 340 white patients aged 18 years or older who were hospitalized with acute ischemic stroke between January 2005 and December 2006.

MEASUREMENTS

Influence of race on mortality, examined by using propensity score analysis. Secondary outcomes were selected aspects of end-of-life treatment, use of tissue plasminogen activator, hospital spending, and length of stay. Patients were followed for mortality for 1 year after admission.

RESULTS

Overall in-hospital mortality was lower for black patients than for white patients (5.0% vs. 7.4%; P < 0.001), as was all-cause mortality at 30 days (6.1% vs. 11.4%; P < 0.001) and 1 year (16.5% vs. 24.4%; P < 0.001). After propensity score adjustment, black race was independently associated with lower in-hospital mortality (odds ratio [OR], 0.77 [95% CI, 0.61 to 0.98]) and all-cause mortality up to 1 year (OR, 0.86 [CI, 0.77 to 0.96]). The adjusted hazard ratio was 0.87 (CI, 0.79 to 0.96). After adjustment for the probability of dying in the hospital, black patients with stroke were more likely to receive life-sustaining interventions (OR, 1.22 [CI, 1.09 to 1.38]) but less likely to be discharged to hospice (OR, 0.25 [CI, 0.14 to 0.46]).

LIMITATIONS

The study used hospital administrative data that lacked a stroke severity measure. The study design precluded determination of causality.

CONCLUSION

Among patients with acute ischemic stroke, black patients had lower mortality than white patients. This could be the result of differences in receipt of life-sustaining interventions and end-of-life care.

Association between stroke center hospitalization for acute ischemic stroke and mortality

CONTEXT

Although stroke centers are widely accepted and supported, little is known about their effect on patient outcomes.

OBJECTIVE

To examine the association between admission to stroke centers for acute ischemic stroke and mortality.

DESIGN, SETTING, AND PARTICIPANTS

Observational study using data from the New York Statewide Planning and Research Cooperative System. We compared mortality for patients admitted with acute ischemic stroke (n = 30,947) between 2005 and 2006 at designated stroke centers and nondesignated hospitals using differential distance to hospitals as an instrumental variable to adjust for potential prehospital selection bias. Patients were followed up for mortality for 1 year after the index hospitalization through 2007. To assess whether our findings were specific to stroke, we also compared mortality for patients admitted with gastrointestinal hemorrhage (n = 39,409) or acute myocardial infarction (n = 40,024) at designated stroke centers and nondesignated hospitals.

MAIN OUTCOME MEASURE

Thirty-day all-cause mortality.

RESULTS

Among 30,947 patients with acute ischemic stroke, 15,297 (49.4%) were admitted to designated stroke centers. Using the instrumental variable analysis, admission to designated stroke centers was associated with lower 30-day all-cause mortality (10.1% vs 12.5%; adjusted mortality difference, -2.5%; 95% confidence interval [CI], -3.6% to -1.4%; P < .001) and greater use of thrombolytic therapy (4.8% vs 1.7%; adjusted difference, 2.2%; 95% CI, 1.6% to 2.8%; P < .001). Differences in mortality also were observed at 1-day, 7-day, and 1-year follow-up. The outcome differences were specific for stroke, as stroke centers and nondesignated hospitals had similar 30-day all-cause mortality rates among those with gastrointestinal hemorrhage (5.0% vs 5.8%; adjusted mortality difference, +0.3%; 95% CI, -0.5% to 1.0%; P = .50) or acute myocardial infarction (10.5% vs 12.7%; adjusted mortality difference, +0.1%; 95% CI, -0.9% to 1.1%; P = .83).

CONCLUSION

Among patients with acute ischemic stroke, admission to a designated stroke center was associated with modestly lower mortality and more frequent use of thrombolytic therapy.

A cost-effectiveness analysis of carotid artery stenting compared with endarterectomy

Endarterectomy and angioplasty with stenting have emerged as 2 alternative treatments for carotid artery stenosis. This study's objective was to determine the cost-effectiveness of carotid artery stenting (CAS) compared with carotid endarterectomy (CEA) in symptomatic subjects who are suitable for either intervention. A Markov analysis of these 2 revascularization procedures was conducted using direct Medicare costs (2007 US$) and characteristics of a symptomatic 70-year-old cohort over a lifetime. In the base case analysis, CAS produced 8.97 quality-adjusted life-years, compared with 9.64 quality-adjusted life-years for CEA. The incremental cost of stenting was $17,700, and thus CAS was dominated by CEA. Sensitivity analyses show that the long-term probabilities of major stroke or mortality influenced the results. In the base case analysis, CEA for patients with symptomatic stenosis has a greater benefit than CAS, with lower direct costs. With 59% probability, CEA will be the optimal intervention when all of the model assumptions are varied simultaneously.

Palliative care consultations in hospitalized stroke patients

OBJECTIVE

To determine the pattern and characteristics of palliative care (PC) consultations in patients with stroke and compare them with the characteristics of nonstroke consultations.

METHODS

The palliative care program at Strong Memorial Hospital (SMH) was established in October 2001. SMH is a 765-bed academic medical center with approximately 38,000 discharges. For each consult from 2005 to 2007, we collected demographic, clinical, and service-related information. We explored similarities and differences in patients with different types of stroke, including patients with ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage, and subdural hematoma. In addition, we compared these data to the nonstroke patients who had a palliative care consultation during the same time period.

RESULTS

Over the 3-year period from 2005 to 2007, there were a total of 101 consultations in patients with stroke (6.3% of all PC consultations). Of the 101 consultations, 31 were in patients with ischemic stroke, 26 in patients with intracerebral hemorrhage, 30 in patients with subarachnoid hemorrhage, and 14 in patients with subdural hematoma. Patients with stroke who had a PC consult were more functionally impaired, less likely to have capacity, more likely to die in the hospital, and to have fewer traditional symptom burdens than other common diagnoses seen on the PC consultation service. The most common trajectory to death was withdrawal of mechanical ventilation, but varied by type of stroke. Common treatments negotiated in these consultations included mechanical ventilation, artificial nutrition, tracheostomy, and less likely antibiobics, intravenous fluids, and various neurosurgical procedures.

CONCLUSIONS

Patients with stroke are a common diagnosis seen on an inpatient palliative care consult service. Each stroke type represents patients with potentially distinct palliative care needs.

Health state preferences and decision-making after malignant middle cerebral artery infarctions

OBJECTIVES

Despite recent trials demonstrating improved functional outcomes in patients with malignant middle cerebral artery ischemic strokes treated with hemicraniectomy, survivors still experience significant stroke-related disability. The value assigned to health states with significant disability varies widely and may influence decisions regarding hemicraniectomy.

METHODS

A medical decision analysis was used to evaluate the results of recent hemicraniectomy trials in terms of quality-adjusted life-years. Survival data and probability of various functional outcome states (modified Rankin score 2-3 or 4-5) at 1 year were abstracted from clinical trial data. Utility scores for modified Rankin states were abstracted from literature sources. Sensitivity analyses were performed to study results over a wide range of utility values. All modeling was performed on TreeAge Pro software.

RESULTS

The hemicraniectomy treatment pathway was associated with more quality-adjusted life-years over the first year than the medical management pathway (0.414 vs 0.145). Hemicraniectomy remained the preferred option except when the utility associated with the possible outcome states dropped considerably (0.72 to 0.40 for Rankin 2-3, and 0.41 to 0.04 for Rankin 4-5), or when 1-week surgical mortality increased considerably (5% to 67%).

CONCLUSIONS

Over a 1-year time horizon, treating patients with malignant middle cerebral artery strokes with hemicraniectomy is associated with more quality-adjusted life-years than medical management alone, except under conditions where patients value possible resultant health states very poorly or surgical mortality is excessively high.