On the use of survival analysis techniques to estimate medical care costs

Cost-Effectiveness of Reduced-Intensity Allogeneic Hematopoietic Cell Transplantation for Older Patients With High-Risk Myelodysplastic Syndrome: Analysis of BMT CTN 1102

PURPOSE

BMT CTN 1102 was a phase III trial comparing reduced-intensity allogeneic hematopoietic cell transplantation (RIC alloHCT) to standard of care for persons with intermediate- or high-risk myelodysplastic syndrome (MDS). We report results of a cost-effectiveness analysis conducted alongside the clinical trial.

METHODS

Three hundred eighty-four patients received HCT (n = 260) or standard of care (n = 124) according to availability of a human leukocyte antigen-matched donor. Cost-effectiveness was calculated from US commercial and Medicare perspectives over a 20-year time horizon. Health care utilization and costs were estimated using propensity score-matched cohorts of HCT recipients in the OptumLabs Data Warehouse (age 50-64 years) and Medicare (age 65 years and older). EuroQol 5 Dimension (EQ-5D) surveys of trial participants were used to derive health state utilities.

RESULTS

Extrapolated 20-year overall survival for those age 50-64 years was 29% for HCT (n = 105) versus 13% for usual care (n = 44) and 31% for HCT (n = 155) versus 12% for non-HCT (n = 80) for those age 65 years and older. HCT was more effective (+2.36 quality-adjusted life-years [QALYs] for age 50-64 years and +2.92 QALYs for age 65 years and older) and more costly (+$452,242 in US dollars (USD) for age 50-64 years and +$233,214 USD for age 65 years and older) than usual care, with incremental cost-effectiveness ratios of $191,487 (USD)/QALY and $79,834 (USD)/QALY, respectively. For persons age 50-64 years, there was a 29% chance that HCT was cost-effective using a willingness-to-pay (WTP) threshold of $150K (USD)/QALY and 51% at a $200K (USD)/QALY. For persons age 65 years and older, the probability was 100% at a WTP >$150K (USD)/QALY.

CONCLUSION

Among patients age 65 years and older with high-risk MDS, RIC HCT is a high-value strategy. For those age 50-64 years, HCT is a lower-value strategy but has similar cost-effectiveness to other therapies commonly used in oncology.

Cost-Effectiveness of Unrelated Umbilical Cord Blood vs. HLA Haploidentical Related Bone Marrow Transplant: Evidence from BMT CTN 1101

BACKGROUND

BMT CTN 1101 was a Phase III randomized controlled trial comparing reduced intensity conditioning followed by double unrelated umbilical cord blood (UCB) versus HLA-haploidentical related donor bone marrow (haplo-BM) transplantation for patients with high-risk hematologic malignancies.

OBJECTIVE

The objective of this study is to report the results of a parallel cost-effectiveness analysis.

STUDY DESIGN

Three hundred sixty-eight patients were randomized to unrelated UCB (n=186) or haplo-BM (n=182) transplant. We estimated healthcare utilization and costs using propensity score-matched BMT patients from the OptumLabs^Ⓡ Data Warehouse for trial participants <65 years and Medicare claims for participants ≥65 years. Weibull models were used to estimate 20-year survival. EQ-5D surveys by trial participants were used estimate Quality-Adjusted Life Years (QALYs).

RESULTS

At 5-year follow-up, survival was 42% for haplo-BM versus 36% for UCB (P=.06). Over a 20-year time horizon, haplo-BM is expected to be more effective (+0.63 QALY) and more costly +$118,953) for persons under 65. For those over 65, haplo-BM is expected to be more effective and less costly. In one-way uncertainty analyses, for persons <65, the cost per QALY result was most sensitive to life years and health state utilities. For persons ≥65, life years were more influential than costs and health state utilities.

CONCLUSION

Compared to UCB, haplo-BM was moderately cost-effective for patients aged <65 years, and less costly and more effective for persons ≥65 years. Haplo-BM is a fair value choice for commercially insured patients with high-risk leukemia and lymphoma who require HCT. For Medicare enrollees, haplo-BM is a preferred choice when considering costs and outcomes.

Cancer cost profiles: The Epicost estimation approach

Sustainability of cancer burden is becoming increasingly central in the policy makers' debate, and poses a challenge for the welfare systems, due to trends towards greater intensity of healthcare service use, which imply increasing costs of cancer care. Measuring and projecting the economic burden associated with cancer and identifying effective policies for minimising its impact are important issues for healthcare systems. Scope of this paper is to illustrate a novel comprehensive approach (called Epicost) to the estimation of the economic burden of cancer, based on micro-data collected from multiple data sources. It consists of a model of cost analysis to estimate the amount of reimbursement payed by the National Health Service to health service providers (hospitals, ambulatories, pharmacies) for the expenses incurred in the diagnoses and treatments of a cohort of cancer patients; these cancer costs are estimated in various phases of the disease reflecting patients' patterns of care: initial, monitoring and final phase. The main methodological features are illustrated using a cohort of colon cancer cases from a Cancer Registry in Italy. This approach has been successfully implemented in Italy and it has been adapted to other European countries, such as Belgium, Norway and Poland in the framework of the Innovative Partnership for Action Against Cancer (iPAAC) Joint Action, sponsored by the European Commission. It is replicable in countries/regions where population-based cancer registry data is available and linkable at individual level with administrative data on costs of care.

Health care costs in a randomized trial of antimicrobial duration among cystic fibrosis patients with pulmonary exacerbations

BACKGROUND

The purpose of these analyses was to determine whether overall costs were reduced in cystic fibrosis (CF) patients experiencing pulmonary exacerbation (PEx) who received shorter versus longer durations of treatment.

METHODS

Among people with CF experiencing PEx, we calculated 30-day inpatient, outpatient, emergency room, and medication costs and summed these to derive total costs in 2020 USD. Using the Kaplan-Meier sample average (KMSA) method, we calculated adjusted costs and differences in costs within two pairs of randomized groups: early robust responders (ERR) randomized to receive treatment for 10 days (ERR-10 days) or 14 days (ERR-14 days), and non-early robust responders (NERR) randomized to receive treatment for 14 days (NERR-14 days) or 21 days (NERR-21 days).

RESULTS

Patients in the shorter treatment duration groups had shorter lengths of stay per hospitalization (mean ± standard deviation (SD) for ERR-10 days: 7.9 ± 3.0 days per hospitalization compared to 10.1 ± 4.2 days in ERR-14 days; for NERR-14 days: 8.7 ± 4.9 days per hospitalization compared to 9.6 ± 6.5 days in NERR-21 days). We found statistically significantly lower adjusted mean costs (95% confidence interval) among those who were randomized to receive shorter treatment durations (ERR-10 days: $60,800 ($59,150 - $62,430) vs $74,420 ($72,610 - $76,450) in ERR-14 days; NERR-14 days: $66,690 ($65,960-$67,400) versus $74,830 ($73,980-$75,650) in NERR-21 days).

CONCLUSIONS

Tied with earlier evidence that shorter treatment duration was not associated with worse clinical outcomes, our analyses indicate that treating with shorter antimicrobial durations can reduce costs without diminishing clinical outcomes.

The Economic Value of Improved Productivity from Treatment of Chronic Hepatitis C Virus Infection: A Retrospective Analysis of Earnings, Work Loss, and Health Insurance Data

Introduction

Patients with chronic hepatitis C virus infection (HCV) may incur significant indirect costs due to health-related work loss. However, the impact of curative HCV therapy on work productivity is not well characterized. We estimated the economic value of improved productivity following HCV treatment.

Methods

Adults diagnosed with HCV infection (Optum Healthcare Solutions data; Q1 1999 to Q1 2017) were stratified into two cohorts: (1) treated cohort, patients who received HCV therapy and (2) untreated cohort, therapy-naïve patients. For the treated cohort, the index date was set at the end of the post-treatment monitoring period, assumed to be 6 months after the end of treatment for patients with cirrhosis or for those treated with interferon-based therapy, and 3 months after the end of treatment for patients without cirrhosis who received interferon-free therapy. For the untreated cohort, an index date was randomly selected post-HCV diagnosis. Time from the index date to the first work-loss event was assessed using time to event analyses. An economic modeling approach was used to monetize the improved productivity from reduced risk of work-loss event in the 4 years post-index.

Results

Patients in the treated cohort had a lower risk of experiencing a work-loss event compared to untreated patients [unadjusted and adjusted hazard ratios and 95% CI 0.72 (0.61–0.86), and 0.68 (0.55–0.85), respectively; p < 0.001 for both]. The mean cumulative added productivity value associated with HCV treatment was US$4511 (CI $2778–$6278) at 1 year post-index and $21,429 (CI $12,733–$30,199) at 4 years post-index.

Conclusion

HCV treatment reduces the risk of work loss resulting in productivity gains for employers and employees. The monetary value associated with these productivity gains is substantial, and, after about 4 years, it is comparable to the wholesale acquisition cost of some direct-acting antiviral regimens in the United States. Employers may derive economic benefits from adopting HCV elimination strategies.

Electronic supplementary material

The online version of this article (10.1007/s12325-020-01492-x) contains supplementary material, which is available to authorized users.

Flexible parametric model for survival data subject to dependent censoring

When modeling survival data, it is common to assume that the (log-transformed) survival time (T) is conditionally independent of the (log-transformed) censoring time (C) given a set of covariates. There are numerous situations in which this assumption is not realistic, and a number of correction procedures have been developed for different models. However, in most cases, either some prior knowledge about the association between T and C is required, or some auxiliary information or data is/are supposed to be available. When this is not the case, the application of many existing methods turns out to be limited. The goal of this paper is to overcome this problem by developing a flexible parametric model, that is a type of transformed linear model. We show that the association between T and C is identifiable in this model. The performance of the proposed method is investigated both in an asymptotic way and through finite sample simulations. We also develop a formal goodness-of-fit test approach to assess the quality of the fitted model. Finally, the approach is applied to data coming from a study on liver transplants.

The cost-effectiveness of screening for ovarian cancer: results from the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS)

Background:

To assess the within-trial cost-effectiveness of an NHS ovarian cancer screening (OCS) programme using data from UKCTOCS and extrapolate results based on average life expectancy.

Methods:

Within-trial economic evaluation of no screening (C) vs either (1) an annual OCS programme using transvaginal ultrasound (USS) or (2) an annual ovarian cancer multimodal screening programme with serum CA125 interpreted using a risk algorithm (ROCA) and transvaginal ultrasound as a second-line test (MMS), plus comparison of lifetime extrapolation of the no screening arm and the MMS programme using both a predictive and a Markov model.

Results:

Using a CA125–ROCA cost of £20, the within-trial results show USS to be strictly dominated by MMS, with the MMS vs C comparison returning an incremental cost-effectiveness ratio (ICER) of £91 452 per life year gained (LYG). If the CA125–ROCA unit cost is reduced to £15, the ICER becomes £77 818 per LYG. Predictive extrapolation over the expected lifetime of the UKCTOCS women returns an ICER of £30 033 per LYG, while Markov modelling produces an ICER of £46 922 per QALY.

Conclusion:

Analysis suggests that, after accounting for the lead time required to establish full mortality benefits, a national OCS programme based on the MMS strategy quickly approaches the current NICE thresholds for cost-effectiveness when extrapolated out to lifetime as compared with the within-trial ICER estimates. Whether MMS could be recommended on economic grounds would depend on the confirmation and size of the mortality benefit at the end of an ongoing follow-up of the UKCTOCS cohort.

China's medical savings accounts: an analysis of the price elasticity of demand for health care

Although medical savings accounts (MSAs) have drawn intensive attention across the world for their potential in cost control, there is limited evidence of their impact on the demand for health care. This paper is intended to fill that gap. First, we built up a dynamic model of a consumer's problem of utility maximization in the presence of a nonlinear price schedule embedded in an MSA. Second, the model was implemented using data from a 2-year MSA pilot program in China. The estimated price elasticity under MSAs was between -0.42 and -0.58, i.e., higher than that reported in the literature. The relatively high price elasticity suggests that MSAs as an insurance feature may help control costs. However, the long-term effect of MSAs on health costs is subject to further analysis.

Accounting for Cured Patients in Cost-Effectiveness Analysis

BACKGROUND

Economic evaluations often measure an intervention effect with mean overall survival (OS). Emerging types of cancer treatments offer the possibility of being "cured" in that patients can become long-term survivors whose risk of death is the same as that of a disease-free person. Describing cured and noncured patients with one shared mean value may provide a biased assessment of a therapy with a cured proportion.

OBJECTIVE

The purpose of this article is to explain how to incorporate the heterogeneity from cured patients into health economic evaluation.

METHODS

We analyzed clinical trial data from patients with advanced melanoma treated with ipilimumab (Ipi; n = 137) versus glycoprotein 100 (gp100; n = 136) with statistical methodology for mixture cure models. Both cured and noncured patients were subject to background mortality not related to cancer.

RESULTS

When ignoring cured proportions, we found that patients treated with Ipi had an estimated mean OS that was 8 months longer than that of patients treated with gp100. Cure model analysis showed that the cured proportion drove this difference, with 21% cured on Ipi versus 6% cured on gp100. The mean OS among the noncured cohort patients was 10 and 9 months with Ipi and gp100, respectively. The mean OS among cured patients was 26 years on both arms. When ignoring cured proportions, we found that the incremental cost-effectiveness ratio (ICER) when comparing Ipi with gp100 was $324,000/quality-adjusted life-year (QALY) (95% confidence interval $254,000-$600,000). With a mixture cure model, the ICER when comparing Ipi with gp100 was $113,000/QALY (95% confidence interval $101,000-$154,000).

CONCLUSIONS

This analysis supports using cure modeling in health economic evaluation in advanced melanoma. When a proportion of patients may be long-term survivors, using cure models may reduce bias in OS estimates and provide more accurate estimates of health economic measures, including QALYs and ICERs.

Multiple chronic conditions and healthcare costs among adults

The prevalence of multiple chronic conditions (MCC) is increasing among individuals of all ages. MCC are associated with poor health outcomes. The presence of MCC has profound healthcare utilization and cost implications for public and private insurance payers, individuals, and families. Investigators have used a variety of definitions for MCC to evaluate costs associated with MCC. The objective of this article is to examine the current literature in estimating excess costs associated with MCC among adults. The discussion highlights some of the theoretical and technical merits of various MCC definitions and models used to estimate the excess costs associated with MCC.

Analyzing Health-Related Quality of Life in the EVOLVE Trial: The Joint Impact of Treatment and Clinical Events

BACKGROUND

The Evaluation of Cinacalcet HCl Therapy to Lower Cardiovascular Events (EVOLVE) clinical trial evaluated the effects of cinacalcet on clinical events in patients with secondary hyperparathyroidism (sHPT) who were on hemodialysis. Health-related quality of life (HRQoL) was assessed by a generic, preference-based health outcome measure (EQ-5D) at scheduled visits and after a study event. Here, we report the HRQoL analysis from EVOLVE.

METHODS

We assessed changes in HRQoL from baseline to scheduled visits, and estimated the acute (3 mo) and chronic (beyond 3 mo) effects of sHPT-related events on HRQoL using generalized estimating equation analysis controlling for baseline HRQoL and randomized assignment.

RESULTS

Data on HRQoL were available for 3547 of 3883 subjects, with 1650 events in the placebo and 1502 in the cinacalcet arm. At the study end, no difference in change from baseline HRQoL was observed in the direct comparison of EQ-5D by treatment arms. The regression analysis showed significant effects of events on HRQoL and a modest positive effect of cinacalcet. Estimated quality-adjusted life-year gains were of similar magnitude based on the observed data or the predictions from the model, with only a small gain in precision from the predicted analysis.

CONCLUSIONS

By contrast with a conventional comparison, a regression analysis demonstrated large decrements in HRQoL after events and a modest improvement in HRQoL with cinacalcet. As randomized controlled trials are rarely powered to detect differences in HRQoL, a prespecified regression analysis may be acceptable to improve precision of the effects and understand their origin.

Long-term costs of colorectal cancer treatment in Spain

BACKGROUND

Assessing the long-term cost of colorectal cancer (CRC) increases our understanding of the disease burden. The aim of this paper is to estimate the long-term costs of CRC care by stage at diagnosis and phase of care in the Spanish National Health Service.

METHODS

Retrospective study on resource use and direct medical cost of a cohort of 699 patients diagnosed and treated for CRC in 2000-2006, with follow-up until 30 June 2011, at Hospital del Mar (Barcelona). The Kaplan-Meier sample average estimator was used to calculate observed 11-year costs, which were then extrapolated to 16 years. Bootstrap percentile confidence intervals were calculated for the mean long-term cost per patient by stage. Phase-specific, long-term costs for the entire CRC cohort were also estimated.

RESULTS

With regard to stage at diagnosis, the mean long-term cost per patient ranged from €20,708 (in situ) to €47,681 (stage III). The estimated costs increased at more advanced stages up to stage III and then substantially decreased in stage IV. In terms of treatment phase, the mean cost of the initial period represented 24.8 % of the total mean long-term cost, whereas the cost of continuing and advanced care phases represented 16.9 and 58.3 %, respectively.

CONCLUSIONS

This study is the first to provide long-term cost estimates for CRC treatment, by stage at diagnosis and phase of care, based on data from clinical practice in Spain, and it will contribute useful information for future studies on cost-effectiveness and budget impact of different therapeutic innovations in Spain.

The Clinical and Economic Impacts of Skeletal-Related Events Among Medicare Enrollees With Prostate Cancer Metastatic to Bone

BACKGROUND

Approximately 40% of men diagnosed with metastatic prostate cancer experience one or more skeletal-related events (SREs), defined as a pathological fracture, spinal cord compression, or surgery or radiotherapy to the bone. Accurate assessment of their effect on survival, health care resource utilization (HCRU), and cost may elucidate the value of interventions to prevent SREs.

MATERIALS AND METHODS

Men older than age 65 years with prostate cancer and bone metastasis diagnosed between 2004 and 2009 were identified from linked Surveillance Epidemiology and End Results-Medicare records. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk for death associated with SREs were calculated by using Cox regression. HCRU and costs (in 2013 U.S. dollars) were evaluated in a propensity score-matched cohort by using Poisson regression and Kaplan-Meier sample average estimators, respectively.

RESULTS

Among 3,297 men with prostate cancer metastatic to bone, 40% experienced ≥1 SRE (median follow-up, 19 months). Compared with men who remained SRE-free, men with ≥1 SRE had a twofold higher risk for death (HR, 2.29; 95% CI, 2.09-2.51). Pathological fracture was associated with the highest risk for death (HR, 2.77; 95% CI, 2.38-3.23). Among men with ≥1 SRE, emergency department visits were twice as frequent (95% CI, 1.77-2.28) and hospitalizations were nearly four times as frequent (95% CI, 3.20-4.40). The attributable cost of ≥1 SRE was $21,191 (≥1 SRE: $72,454 [95% CI, $67,362-$76,958]; SRE-free: $51,263 [95% CI, $45,439-$56,100]).

CONCLUSION

Among men with prostate cancer metastatic to bone, experiencing ≥1 SRE is associated with poorer survival, increased HCRU, and increased costs. These negative effects emphasize the importance of SRE prevention in this population.

VenUS IV (Venous leg Ulcer Study IV) - compression hosiery compared with compression bandaging in the treatment of venous leg ulcers: a randomised controlled trial, mixed-treatment comparison and decision-analytic model

BACKGROUND

Compression is an effective and recommended treatment for venous leg ulcers. Although the four-layer bandage (4LB) is regarded as the gold standard compression system, it is recognised that the amount of compression delivered might be compromised by poor application technique. Also the bulky nature of the bandages might reduce ankle or leg mobility and make the wearing of shoes difficult. Two-layer compression hosiery systems are now available for the treatment of venous leg ulcers. Two-layer hosiery (HH) may be advantageous, as it has reduced bulk, which might enhance ankle or leg mobility and patient adherence. Some patients can also remove and reapply two-layer hosiery, which may encourage self-management and could reduce costs. However, little robust evidence exists about the effectiveness of two-layer hosiery for ulcer healing and no previous trials have compared two-layer hosiery delivering 'high' compression with the 4LB.

OBJECTIVES

Part I To compare the clinical effectiveness and cost-effectiveness of HH and 4LB in terms of time to complete healing of venous leg ulcers. Part II To synthesise the relative effectiveness evidence (for ulcer healing) of high-compression treatments for venous leg ulcers using a mixed-treatment comparison (MTC). Part III To construct a decision-analytic model to assess the cost-effectiveness of high-compression treatments for venous leg ulcers.

DESIGN

Part I A multicentred, pragmatic, two-arm, parallel, open randomised controlled trial (RCT) with an economic evaluation. Part II MTC using all relevant RCT data - including Venous leg Ulcer Study IV (VenUS IV). Part III A decision-analytic Markov model.

SETTINGS

Part I Community nurse teams or services, general practitioner practices, leg ulcer clinics, tissue viability clinics or services and wound clinics within England and Northern Ireland.

PARTICIPANTS

Part I Patients aged ≥ 18 years with a venous leg ulcer, who were willing and able to tolerate high compression.

INTERVENTIONS

Part I Participants in the intervention group received HH. The control group received the 4LB, which was applied according to standard practice. Both treatments are designed to deliver 40 mmHg of compression at the ankle. Part II and III All relevant high-compression treatments including HH, the 4LB and the two-layer bandage (2LB).

MAIN OUTCOME MEASURES

Part I The primary outcome measure was time to healing of the reference ulcer (blinded assessment). Part II Time to ulcer healing. Part III Quality-adjusted life-years (QALYs) and costs.

RESULTS

Part I A total of 457 participants were recruited. There was no evidence of a difference in time to healing of the reference ulcer between groups in an adjusted analysis [hazard ratio (HR) 0.99, 95% confidence interval (CI) 0.79 to 1.25; p = 0.96]. Time to ulcer recurrence was significantly shorter in the 4LB group (HR = 0.56, 95% CI 0.33 to 0.94; p = 0.026). In terms of cost-effectiveness, using QALYs as the measure of benefit, HH had a > 95% probability of being the most cost-effective treatment based on the within-trial analysis. Part II The MTC suggests that the 2LB has the highest probability of ulcer healing compared with other high-compression treatments. However, this evidence is categorised as low to very low quality. Part III Results suggested that the 2LB had the highest probability of being the most cost-effective high-compression treatment for venous leg ulcers.

CONCLUSIONS

Trial data from VenUS IV found no evidence of a difference in venous ulcer healing between HH and the 4LB. HH may reduce ulcer recurrence rates compared with the 4LB and be a cost-effective treatment. When all available high-compression treatments were considered, the 2LB had the highest probability of being clinically effective and cost-effective. However, the underpinning evidence was sparse and more research is needed. Further research should thus focus on establishing, in a high-quality trial, the effectiveness of this compression system in particular.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN49373072.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 18, No. 57. See the NIHR Journals Library website for further project information.

Cost-effectiveness analysis alongside clinical trials II-An ISPOR Good Research Practices Task Force report

Clinical trials evaluating medicines, medical devices, and procedures now commonly assess the economic value of these interventions. The growing number of prospective clinical/economic trials reflects both widespread interest in economic information for new technologies and the regulatory and reimbursement requirements of many countries that now consider evidence of economic value along with clinical efficacy. As decision makers increasingly demand evidence of economic value for health care interventions, conducting high-quality economic analyses alongside clinical studies is desirable because they broaden the scope of information available on a particular intervention, and can efficiently provide timely information with high internal and, when designed and analyzed properly, reasonable external validity. In 2005, ISPOR published the Good Research Practices for Cost-Effectiveness Analysis Alongside Clinical Trials: The ISPOR RCT-CEA Task Force report. ISPOR initiated an update of the report in 2014 to include the methodological developments over the last 9 years. This report provides updated recommendations reflecting advances in several areas related to trial design, selecting data elements, database design and management, analysis, and reporting of results. Task force members note that trials should be designed to evaluate effectiveness (rather than efficacy) when possible, should include clinical outcome measures, and should obtain health resource use and health state utilities directly from study subjects. Collection of economic data should be fully integrated into the study. An incremental analysis should be conducted with an intention-to-treat approach, complemented by relevant subgroup analyses. Uncertainty should be characterized. Articles should adhere to established standards for reporting results of cost-effectiveness analyses. Economic studies alongside trials are complementary to other evaluations (e.g., modeling studies) as information for decision makers who consider evidence of economic value along with clinical efficacy when making resource allocation decisions.

ESTIMATING MEAN SURVIVAL TIME: WHEN IS IT POSSIBLE?

For right censored survival data, it is well known that the mean survival time can be consistently estimated when the support of the censoring time contains the support of the survival time. In practice, however, this condition can be easily violated because the follow-up of a study is usually within a finite window. In this article we show that the mean survival time is still estimable from a linear model when the support of some covariate(s) with nonzero coefficient(s) is unbounded regardless of the length of follow-up. This implies that the mean survival time can be well estimated when the support of linear predictor is wide in practice. The theoretical finding is further verified for finite samples by simulation studies. Simulations also show that, when both models are correctly specified, the linear model yields reasonable mean square prediction errors and outperforms the Cox model, particularly with heavy censoring and short follow-up time.

Understanding the value of emergency care: a framework incorporating stakeholder perspectives

BACKGROUND

In the face of escalating spending, measuring and maximizing the value of health services has become an important focus of health reform. Recent initiatives aim to incentivize high-value care through provider and hospital payment reform, but the role of the emergency department (ED) remains poorly defined.

OBJECTIVES

To achieve an improved understanding of the value of emergency care, we have developed a framework that incorporates the perspectives of stakeholders in the delivery of health services.

METHODS

A pragmatic review of the literature informed the design of this framework to standardize the definition of value in emergency care and discuss outcomes and costs from different stakeholder perspectives. The viewpoint of patient, provider, payer, health system, and society is each used to assess value for emergency medical conditions.

RESULTS

We found that the value attributed to emergency care differs substantially by stakeholder perspective. Potential targets to improve ED value may be aimed at improving outcomes or controlling costs, depending on the acuity of the clinical condition.

CONCLUSION

The value of emergency care varies by perspective, and a better understanding is achieved when specific outcomes and costs can be identified, quantified, and measured. Using this framework can help stakeholders find common ground to prioritize which costs and outcomes to target for research, quality improvement efforts, and future health policy impacting emergency care.

Design of a cost-effectiveness analysis alongside a randomized trial of transplantation using umbilical cord blood versus HLA-haploidentical related bone marrow in advanced hematologic cancer

BACKGROUND

BMT CTN 1101 is a Phase III randomized controlled trial evaluating the comparative effectiveness of double unrelated umbilical cord blood (dUCB) versus HLA-haploidentical related donor bone marrow (haplo-BM) donor cell sources for blood or bone marrow transplantation (BMT) in patients with hematologic malignancies. Herein, we present the rationale, design and methods of the first cost-effectiveness analysis to be conducted alongside a BMT trial.

METHODS

Consenting patients will provide health insurance information to allow calculation of direct medical costs from reimbursement records, and will provide out-of-pocket costs, time costs and health-related quality of life measures through an online survey. These outcomes will inform a cost-effectiveness analysis comparing dUCB and haplo-BM donor cell sources from patient, payer and societal perspectives.

CONCLUSION

Novel approaches may significantly change the cost, outcomes or availability of BMT. The results of this analysis will be the first to provide a comprehensive evaluation of the comparative effectiveness of these approaches from multiple perspectives.

EVALUATING COSTS WITH UNMEASURED CONFOUNDING: A SENSITIVITY ANALYSIS FOR THE TREATMENT EFFECT

Estimates of the effects of treatment on cost from observational studies are subject to bias if there are unmeasured confounders. It is therefore advisable in practice to assess the potential magnitude of such biases. We derive a general adjustment formula for loglinear models of mean cost and explore special cases under plausible assumptions about the distribution of the unmeasured confounder. We assess the performance of the adjustment by simulation, in particular, examining robustness to a key assumption of conditional independence between the unmeasured and measured covariates given the treatment indicator. We apply our method to SEER-Medicare cost data for a stage II/III muscle-invasive bladder cancer cohort. We evaluate the costs for radical cystectomy vs. combined radiation/chemotherapy, and find that the significance of the treatment effect is sensitive to plausible unmeasured Bernoulli, Poisson and Gamma confounders.

Incremental Healthcare Costs and Outpatient Antifungal Treatment of Patients with Aspergillosis in the United States

Objectives: To evaluate the total and outpatient economic burden of aspergillosis, and to describe the outpatient antifungal treatment of aspergillosis within a large, commercially-insured population in the United States. Methods: Adults with at least one medical claim with an aspergillosis diagnosis (International Classification of Disease 9th Revision Clinical Modification [ICD-9-CM] code 117.3 or 484.6) between 07/01/04-03/01/11 were identified from the MarketScan Research Databases. Patients had ≥6 months of pre-index and ≥1 month of post-index continuous health plan and pharmacy benefit enrollment and no pre-index diagnosis of aspergillosis. Aspergillosis cases were propensity score-matched to a sample of controls without aspergillosis. Outpatient antifungal therapy and total and outpatient healthcare resource utilization were evaluated in the post-index period. General linear models were used to estimate costs, which were adjusted by the length of follow-up. Incremental costs were calculated between cohorts and a bootstrap procedure was used to produce corresponding variation and 95% confidence interval estimates. Results: Aspergillosis cases (N=5,499; mean age: 57.8 years; 48.6% female; 64.2% with cancer) were matched to 5,499 controls (mean age: 58.3 years; 48.4% female; 60.6% with cancer). Two-thirds of the aspergillosis cases had no outpatient prescription for an antifungal within 30 days of index; for those with outpatient antifungal therapy, voriconazole was the most commonly prescribed agent (60.9%). Average adjusted total and outpatient expenditures were greater for aspergillosis patients during follow-up than those of the matched controls ($26,680 and $9,248 greater, respectively). Conclusions: The economic burden of aspergillosis is substantial. Patients with aspergillosis utilize significantly more healthcare resources and thus incur greater healthcare costs than do similar patients without aspergillosis.

Estimating measurement error when annualizing health care costs

OBJECTIVE

Health insurers routinely annualize members' health care costs for reporting, predicting high cost cases and evaluating health management programmes. Annualization is the practice of extrapolating to a yearly cost from less than a year of data. In this paper, we systematically estimate the measurement error inherent in this approach.

STUDY DESIGN

The paper uses a retrospective observational study using longitudinal claims data from three types of insured populations: Medicare managed care, public employees and a self-insured employer.

METHODS

The unit of analysis was a block 'year' consisting of 12 consecutive months of cost data for any individual member. These blocks were constructed recursively allowing use of all available data that an individual could contribute. We tested the accuracy of the annualized costs by calculating the absolute error (AE) representing the difference, in dollars, between the actual annual costs and the predicted annual costs, and the absolute percentage error (APE) which is the absolute error divided by the actual 12-month costs.

RESULTS

Under the best case scenario (when 11 months of data were used to annualize costs), the mean AE ranged from approximately $2700 for the Medicare population to about $400 for the two working-aged populations; and the mean APE ranged from 9.6% to 11.0% in the three populations. Accuracy diminished systematically with fewer months of available data.

CONCLUSIONS

Due to the largely unpredictable nature of monthly costs, annualization can produce substantial measurement error. Given the importance of cost metrics for decision making, we offer several alternative approaches that insurers should consider to improve measurement accuracy.

Techniques for estimating health care costs with censored data: an overview for the health services researcher

Objective

The aim of this study was to review statistical techniques for estimating the mean population cost using health care cost data that, because of the inability to achieve complete follow-up until death, are right censored. The target audience is health service researchers without an advanced statistical background.

Methods

Data were sourced from longitudinal heart failure costs from Ontario, Canada, and administrative databases were used for estimating costs. The dataset consisted of 43,888 patients, with follow-up periods ranging from 1 to 1538 days (mean 576 days). The study was designed so that mean health care costs over 1080 days of follow-up were calculated using naïve estimators such as full-sample and uncensored case estimators. Reweighted estimators – specifically, the inverse probability weighted estimator – were calculated, as was phase-based costing. Costs were adjusted to 2008 Canadian dollars using the Bank of Canada consumer price index (http://www.bankofcanada.ca/en/cpi.html).

Results

Over the restricted follow-up of 1080 days, 32% of patients were censored. The full-sample estimator was found to underestimate mean cost ($30,420) compared with the reweighted estimators ($36,490). The phase-based costing estimate of $37,237 was similar to that of the simple reweighted estimator.

Conclusion

The authors recommend against the use of full-sample or uncensored case estimators when censored data are present. In the presence of heavy censoring, phase-based costing is an attractive alternative approach.

Attributable Cost and Length of Stay for Patients with Enoxaparin-Associated Bleeding

OBJECTIVES

Patients receiving enoxaparin are at risk of bleeding. The study of the economic impact of enoxaparin-associated bleeding in Asian population, however, is limited. This study aimed to estimate the attributable costs and length of stay (LOS) of patients experiencing enoxaparin-associated bleeding compared with nonbleeding patients in the setting of acute coronary syndrome.

METHODS

We conducted a retrospective cohort study of hospitalized patients with acute coronary syndrome who received enoxaparin in a large university-affiliated hospital. Cost and LOS were compared among three groups of patients according to the status of bleeding event. The attributable cost and LOS were estimated by using multiple linear regressions with log-transformed model and adjusted by confounders. The adjusted means of cost and LOS estimates were retransformed to their natural values by using Duan's smearing estimator. The differences of costs and LOS were presented as mean with 95% confidence intervals (CIs).

RESULTS

Out of 346 patients, 134 experienced enoxaparin-associated bleeding (28 and 106 patients experienced major and minor bleeding, respectively). The average age and gender in both groups were similar. Compared to the nonbleeding group, the attributable cost and LOS were 108,226 Thai baht (95% CI: 87,068-129,386) and 8 days (95% CI: 7.1-9.0) for major bleeding and 72,997 Thai baht (95% CI: 57,822-88,172) and 3.1 days (95% CI: 2.5-3.7) for minor bleeding, respectively.

CONCLUSIONS

Bleeding is significantly associated with increased cost and LOS among enoxaparin users. These findings suggest that strategies aiming to reduce bleeding events may potentially help reduce the cost of care among patients with acute coronary syndrome receiving enoxaparin therapy.

Current Methods for Recurrent Events Data with Dependent Termination: A Bayesian Perspective

There has been a recent surge of interest in modeling and methods for analyzing recurrent events data with risk of termination dependent on the history of the recurrent events. To aid the future users in understanding the implications of modeling assumptions and modeling properties, we review the state of the art statistical methods and present novel theoretical properties, identifiability results and practical consequences of key modeling assumptions of several fully specified stochastic models. After introducing stochastic models with noninformative termination process, we focus on a class of models which allows both negative and positive association between the risk of termination and the rate of recurrent events via a frailty variable. We also discuss the relationship as well as the major differences between these models in terms of their motivations and physical interpretations. We discuss associated Bayesian methods based on Markov chain Monte Carlo tools, and novel model diagnostic tools to perform inference based on fully specified models. We demonstrate the usefulness of current methodology through an analysis of a data set from a clinical trial. In conclusion, we explore possible future extensions and limitations of the methodology.

Regression models for analyzing costs and their determinants in health care: an introductory review

OBJECTIVE

This article aims to describe the various approaches in multivariable modelling of healthcare costs data and to synthesize the respective criticisms as proposed in the literature.

METHODS

We present regression methods suitable for the analysis of healthcare costs and then apply them to an experimental setting in cardiovascular treatment (COSTAMI study) and an observational setting in diabetes hospital care.

RESULTS

We show how methods can produce different results depending on the degree of matching between the underlying assumptions of each method and the specific characteristics of the healthcare problem.

CONCLUSIONS

The matching of healthcare cost models to the analytic objectives and characteristics of the data available to a study requires caution. The study results and interpretation can be heavily dependent on the choice of model with a real risk of spurious results and conclusions.

Cost of illness in patients with metastatic colorectal cancer

OBJECTIVES

To estimate total costs and metastatic colorectal cancer (mCRC)-related costs and assess primary cost drivers of treating newly diagnosed mCRC patients after the introduction of biologic therapies.

METHODS

Using a large national claims database, costs of mCRC patients were estimated in 2004-2009 by examining (1) the cost difference between mCRC patient and their matched non-cancer cohorts, and (2) mCRC-related costs. Costs were further assessed by phase of disease (diagnostic, treatment, and death). The survival analysis technique was used to estimate cost of handling variable length of follow-up and data censoring.

RESULTS

A total of 6,746 mCRC patients met all eligibility criteria, 6,675 of them were matched to patients without cancer. Among the three phases of disease, the treatment phase was the longest (16.4 months). Compared with matched patients with no cancer, total monthly costs were $14,585 higher for mCRC patients, which was driven by higher inpatient ($7,546) and outpatient ($6,749) care (p < 0.001 for all comparisons). During the study period, cost share of biologics increased from 4.8% among patients diagnosed in 2004 to 9.4% for those diagnosed in 2008.

CONCLUSIONS

The costs associated with treating mCRC are substantial. Inpatient and outpatient care remain key cost drivers in the medical management of mCRC. Cost chare of biologics was low, but increased between 2004 and 2009. The study sample only included patients with commercial and Medicare supplemental insurance in the US thus may not be generalizable to patients with other insurance or in other countries. Indirect costs associated with mCRC were not examined.

The Alberta population-based prospective evaluation of the quality of life outcomes and economic impact of bariatric surgery (APPLES) study: background, design and rationale

Background

Extreme obesity affects nearly 8% of Canadians, and is debilitating, costly and ultimately lethal. Bariatric surgery is currently the most effective treatment available; is associated with reductions in morbidity/mortality, improvements in quality of life; and appears cost-effective. However, current demand for surgery in Canada outstrips capacity by at least 1000-fold, causing exponential increases in already protracted, multi-year wait-times. The objectives and hypotheses of this study were as follows: 1. To serially assess the clinical, economic and humanistic outcomes in patients wait-listed for bariatric care over a 2-year period. We hypothesize deterioration in these outcomes over time; 2. To determine the clinical effectiveness and changes in quality of life associated with modern bariatric procedures compared with medically treated and wait-listed controls over 2 years. We hypothesize that surgery will markedly reduce weight, decrease the need for unplanned medical care, and increase quality of life; 3. To conduct a 3-year (1 year retrospective and 2 year prospective) economic assessment of bariatric surgery compared to medical and wait-listed controls from the societal, public payor, and health-care payor perspectives. We hypothesize that lower indirect, out of pocket and productivity costs will offset increased direct health-care costs resulting in lower total costs for bariatric surgery.

Methods/design

Population-based prospective cohort study of 500 consecutive, consenting adults, including 150 surgically treated patients, 200 medically treated patients and 150 wait-listed patients. Subjects will be enrolled from the Edmonton Weight Wise Regional Obesity Program (Edmonton, Alberta, Canada), with prospective bi-annual follow-up for 2 years. Mixed methods data collection, linking primary data to provincial administrative databases will be employed. Major outcomes include generic, obesity-specific and preference-based quality of life assessment, patient satisfaction, patient utilities, anthropometric indices, cardiovascular risk factors, health care utilization and direct and indirect costs.

Discussion

The results will identify the spectrum of potential risks associated with protracted wait times for bariatric care and will quantify the economic, humanistic and clinical impact of surgery from the Canadian perspective. Such information is urgently needed by health-service providers and policy makers to better allocate use of finite resources. Furthermore, our findings should be widely-applicable to other publically-funded jurisdictions providing similar care to the extremely obese.

Trial Registration

Clinicaltrials.gov NCT00850356

Risk-adjusted capitation rates for children: how useful are the survey-based measures?

OBJECTIVE

Despite the recognition by some experts that survey measures have the potential to improve capitation rates for those with chronic conditions, few studies have examined risk-adjustment models for children, and fewer still have focused on survey measures. This study evaluates the performance of risk-adjustment models for children and examines the potential of survey-based measures for improving capitation rates for children.

DATA SOURCES

The study sample includes 8,352 Medicaid children who were followed up for 2 years by the Medical Expenditure Panel Survey in 2000-2005.

STUDY METHODS

Children's information in 1 year was used to predict their expenditures in the next year. Five models were estimated, including one each that used demographic characteristics, subjectively rated health status, survey measures about children with special health care needs (CSHCN), prior year expenditures, and Hierarchical Condition Category (HCC), which is a diagnosis-based model. The models were tested at the individual level using multiple regression methods and at the group level using split-half validation to evaluate their impact on expenditure predictions for CSHCN.

PRINCIPAL FINDINGS

The CSHCN information explained higher proportion of the variance in annual expenditures than the subjectively rated health status, but less than HCC measures and prior expenditures. Adding the CSHCN information into demographic factors as adjusters would remarkably increase capitation rates for CSHCN.

CONCLUSIONS

Survey measures, such as the CSHCN information, can improve risk-adjustment models, and their inclusion into capitation adjustment may help provide appropriate payments to managed-care plans serving this vulnerable group of children.

Survival models for cost data: the forgotten additive approach

The usage of the Aalen additive approach is proposed to model cost data. Using a Monte Carlo simulation, in a wide set of scenarios, we showed that the Aalen model is performing well and can be a reasonable alternative to the standard Gamma regression models. In addition, with reference to the COSTAMI trial data, we highlighted the ability of the Aalen model to offer additional information about the relationships between costs and specific covariates, as compared with standard regression techniques.

Costs of an early intervention versus a conservative strategy in acute coronary syndrome

BACKGROUND

The Randomised Intervention Treatment of unstable Angina (RITA-3) found that non-ST-elevation myocardial infarction and unstable angina patients randomised to routine early arteriography experienced a lower rate of death or myocardial infarction than patients randomised to conservative therapy over a five year period of follow up. This paper uses data from the RITA-3 trial to compare the health service costs of the two strategies.

METHODS

The resource use data included initial arteriography and revascularisation procedures in the early intervention group and subsequently in both groups; in-patient days in hospital for any reason in the first year of follow-up; incidence of myocardial infarction; and cardiac medication.

RESULTS

After five years, the early intervention arm accrued a total mean cost of pound sterling 11,340 (euro 15,592) and the conservative arm a mean of pound sterling 9749(euro 13,405), an additional mean cost in the intervention arm of pound sterling 1591 (95% CI pound sterling 851 to pound sterling 2276) (euro 2188; 95%CI euro 1160 to euro 3228). On average, costs increased with age and were higher in male patients and in patients with severe angina. However, the incremental cost of the intervention strategy was consistent across different patient sub-groups.

CONCLUSION

Over a period of 5 years, the initial additional cost of a strategy of early intervention is only partially offset by subsequent interventions in patients managed conservatively.

Assessing the impact of censoring of costs and effects on health-care decision-making: an example using the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study

OBJECTIVES

Losses to follow-up and administrative censoring can cloud the interpretation of trial-based economic evaluations. A number of investigators have examined the impact of different levels of adjustment for censoring, including nonadjustment, adjustment of effects only, and adjustment for both costs and effects. Nevertheless, there is a lack of research on the impact of censoring on decision-making. The objective of this study was to estimate the impact of adjustment for censoring on the interpretation of cost-effectiveness results and expected value of perfect information (EVPI), using a trial-based analysis that compared rate- and rhythm-control treatments for persons with atrial fibrillation.

METHODS

Three different levels of adjustment for censoring were examined: no censoring of cost and effects, censoring of effects only, and censoring of both costs and effects. In each case, bootstrapping was used to estimate the uncertainty incosts and effects, and the EVPI was calculated to determine the potential worth of further research.

RESULTS

Censoring did not impact the adoption decision. Nevertheless, this was not the case for the decision uncertainty or the EVPI. For a threshold of $50,000 per life-year, the EVPI varied between $626,000 (partial censoring) to $117 million (full censoring) for the eligible US population.

CONCLUSIONS

The level of adjustment for censoring in trial-based cost-effectiveness analyses can impact on the decisions to fund a new technology and to devote resources for further research. Only when censoring is taken into account for both costs and effects are these decisions appropriately addressed.

Ten-year survival and cost following breast cancer recurrence: estimates from SEER-medicare data

OBJECTIVE

A variety of pharmacologic therapies are available or in development for the prevention of breast cancer recurrence. Assessing the value of these treatments is compromised by a paucity of data on the impact of recurrence on economic costs and survival. The purpose of this study was to shed light on these issues.

METHODS

We conducted a retrospective analysis of linked SEER-Medicare data. All patients in the National Cancer Institute's Surveillance Epidemiology and End Results (SEER) registry who were diagnosed with nonmetastatic breast cancer during 1991-1993 were identified, and their subsequent Medicare claims were scanned for evidence of further breast cancer events (local or distant recurrence, contralateral breast cancer). Medicare claims were then scanned from the time of the event through 2002 to assess patterns of survival and costs.

RESULTS

We identified 10,798 patients in SEER who were diagnosed with nonmetastatic breast cancer during 1991-1993, including 1833 who subsequently had another breast cancer event (local recurrence, 958; distant recurrence, 622; contralateral breast cancer, 253). Median survival was 37 months and 8 months among patients with local and distant recurrence, respectively; 53% of patients with contralateral breast cancer remained alive after all the data were censored at 97 months. Expected 10-year costs (2004 US$, discounted 3%) attributable to distant recurrence, local recurrence, and contralateral breast cancer were $11,450 (SE 2056), $19,596 (SE 1754), and $19,183 (SE 4131), respectively.

CONCLUSION

Breast cancer recurrence and contralateral breast cancer lead to substantial increases in costs, amounting to approximately $11,000-19,000 over 10 years depending on type. The impact of these events on survival also varies considerably by type.

Proper modeling strategies selection for the assessment of post-infarction costs

BACKGROUND

The evaluation of the economic impact of ischemic disease has gained increasing interest. Such field of investigation is suffering however of the heterogeneity of methods used in evaluating costs, limiting the comparison of study results.

OBJECTIVE

The aim of the study is to show how estimates of 1-year costs of treatment of patients with uncomplicated acute myocardial infarction can vary significantly in relation to the statistical method adopted in the analysis.

RESEARCH DESIGN AND METHODS

The study analyses post-IMA costs as a function of demographic and clinical covariates, by applying the following statistical survival models: the parametric survival model assuming Weibull distribution, the Cox proportional hazard (PH) model and the Aalen additive regression for modelling costs. The Aalen approach is robust both for the non-proportionality in hazard and for departures from normality. In addition it is able to easily model the effect of covariates on the extreme costs. This cost analysis is based on data collected in the two COSTAMI trials (N=487).

RESULTS

There is agreement in all models with the effects of the considered covariates (age, sex, duration of disease and presence of other pathologies). There is a clear tendency of both the Aalen and the Cox model to provide a lower mean cost estimate than the other model, but with the additional feature for the Aalen model to be able to cope with all the other models in furnishing unbiased estimates with the advantage of a greater flexibility in representing the covariates' effect on the cost process.

CONCLUSIONS

An appropriate choice of the model is crucial in avoiding mis-interpretation of cost determinants of IMA patients. For our data set the Aalen model proved itself to be a realistic and informative way to characterize the effect of covariates on costs.

Estimating the costs for a group of geriatric patients using the Coxian phase-type distribution

The length of stay in hospital of geriatric patients may be modelled using the Coxian phase-type distribution. This paper examines previous methods which have been used to model health-care costs and presents a new methodology to estimate the costs for a cohort of patients for their duration of stay in hospital, assuming there are no further admissions. The model, applied to 1392 patients admitted into the geriatric ward of a local hospital in Northern Ireland, between 2002 and 2003, should be beneficial to hospital managers, as future decisions and policy changes could be tested on the model to investigate their influence on costs before the decisions were carried out on a real ward.

Evaluating hospital costs in type 2 diabetes care: does the choice of the model matter?

BACKGROUND

Awareness of the economic burden of diabetes has led to a number of studies on economic issues. However, comparison among cost-of-illness studies is problematic because different methods are used to arrive at a final cost estimate.

OBJECTIVE

The aim of the study is to show how estimates of hospitalisation costs for diabetic patients can vary significantly in relation to the statistical method adopted in the analysis.

RESEARCH DESIGN AND METHODS

The study analyses diabetic patients' costs as a function of demographic and clinical covariates, by applying the following statistical survival models: the parametric survival model assuming Weibull distribution, the Cox proportional hazard (PH) model and the Aalen additive regression for modelling costs. The Aalen approach is robust both for the non proportionality in hazard and for departures from normality. In addition it is able to easily model the effect of covariates on the extreme costs. This cost analysis is based on data collected for a retrospective observational study analysing repeated hospitalisations (N = 4816) in a cohort of 3892 diabetic patients.

RESULTS

There is agreement in all models with the effects of the considered covariates (age, sex, duration of disease and presence of other pathologies). An effect of over- or under-estimation, according to the chosen model due to arguably inappropriate model fitting, was observed, being more evident for some specific profiles of the patients, and overall accounting for as much as 20% of the estimated effect. The Aalen model was able to cope with all the other models in furnishing unbiased estimates with the advantage of a greater flexibility in representing the covariates' effect on the cost process.

CONCLUSIONS

An appropriate choice of the model is crucial in avoiding misinterpretation of cost determinants of type 2 diabetes care. For our data set the Aalen model proved itself to be a realistic and informative way to characterise the effect of covariates on costs.

Cost-minimization analysis of a phase III trial comparing concurrent versus sequential radiochemotherapy for locally advanced non-small-cell lung cancer (GFPC-GLOT 95–01)

BACKGROUND

We conducted an economic analysis of a phase III clinical trial comparing sequential radiochemotherapy (RT-CT) with concurrent RT-CT in patients with locally advanced non-small-cell lung cancer.

PATIENTS AND METHODS

The trial was a randomized multicenter study comparing three cycles of chemotherapy (arm A) followed by radiotherapy against an RT-CT combination (two cycles of platinum etoposide) followed by two cycles of platinum-vinorelbine (arm B). The economic analysis adopted the payer's perspective and only included direct costs. Costs (euro, 1996-2003) were recorded until the cut-off date. A cost minimization analysis and a sensitivity analysis were carried out.

RESULTS

Data from 173 patients were used in the economic study. Protocol costs tended to be higher in arm B, while relapse costs were significantly higher in arm A. The total number of hospital days was higher in arm B. The average total cost per patient was euro16,074 in arm A and euro15,245 in arm B (P=0.15). The cost minimization analysis favored arm B. This advantage persisted in the sensitivity analysis.

CONCLUSIONS

Concurrent RT-CT was not the more costly strategy in this phase III trial, despite lengthier hospitalization for toxicity. Other studies of similar design are needed to confirm these results in future randomized trials.

Medical cost analysis: application to colorectal cancer data from the SEER Medicare database

Incompleteness is a key feature of most survival data. Numerous well established statistical methodologies and algorithms exist for analyzing life or failure time data. However, induced censorship invalidates the use of those standard analytic tools for some survival-type data such as medical costs. In this paper, some valid methods currently available for analyzing censored medical cost data are reviewed. Some cautionary findings under different assumptions are envisioned through application to medical costs from colorectal cancer patients. Cost analysis should be suitably planned and carefully interpreted under various meaningful scenarios even with judiciously selected statistical methods. This approach would be greatly helpful to policy makers who seek to prioritize health care expenditures and to assess the elements of resource use.

A dynamic model for estimating changes in health status and costs

We develop an innovative method to assess total treatment costs over a finite period of time while incorporating the dynamics of change in the health status of patients. Costs are incurred through medical care use while patients sojourn in health states. Because complete ascertainment of costs and observation of events are not always feasible, some patient utilization will be incomplete and events will also be censored. A Markov model is used to estimate the transition probabilities between health states and the impact of patient variables on transition intensities. A mixed-effects model is used for sojourn costs with transition times as random effects and patient variables as fixed effects. The models are combined to estimate net present values (NPVs) of expenditures over a finite time interval as a function of patient characteristics. The method is applied to a data set of 624 incident cases of cancer. Physical functioning after cancer diagnosis was assessed periodically through structured interviews. The outcomes of interest are normal physical function, impaired physical function, or the terminal state, dead. Charges were obtained from Medicare claim files for 2 years following cancer diagnosis. For demonstration purposes, we estimate NPVs for charges incurred over 2 years by cancer site and cancer stage. Our method, a joint regression model, provides a flexible approach to assessing the influence of patient characteristics on both cost and health outcomes while accommodating heteroscedasticity, skewness and censoring in the data.