Assessing the cost-effectiveness of COX-2 specific inhibitors for arthritis in the Veterans Health Administration

Cost-effectiveness of generic celecoxib in knee osteoarthritis for average-risk patients: a model-based evaluation

OBJECTIVE

The cost-effectiveness of the recently-introduced generic celecoxib in knee OA has not been examined.

METHOD

We used the Osteoarthritis Policy (OAPol) Model, a validated computer simulation of knee OA, to evaluate long-term clinical outcomes, costs, and cost-effectiveness of generic celecoxib in persons with knee OA. We examined eight treatment strategies consisting of generic celecoxib, over-the-counter (OTC) naproxen, or prescription naproxen, with or without prescription or OTC proton-pump-inhibitors (PPIs) to reduce gastrointestinal (GI) toxicity. In the base case, we assumed that annual cost was $130 for OTC naproxen, $360 for prescription naproxen, and $880 for generic celecoxib. We considered a willingness-to-pay threshold of $100,000 per quality-adjusted life year (QALY) and discounted costs and benefits at 3% annually. In sensitivity analyses we varied celecoxib toxicity, discontinuation, cost, and pain level.

RESULTS

In the base case analysis of the high pain cohort (WOMAC 50), celecoxib had an incremental cost-effectiveness ratio (ICER) of $284,630/QALY compared with OTC naproxen. Only under highly favorable cost, toxicity, and discontinuation assumptions (e.g., annual cost below $360, combined with a reduction in the cardiovascular (CV) event rates below baseline values) was celecoxib likely to be cost-effective. Celecoxib might also be cost-effective at an annual cost of $600 if CV toxicity were eliminated completely. In subjects with moderate pain (WOMAC 30), at the base case CV event rate of 0.2%, generic celecoxib was only cost-effective at the lowest plausible cost ($190).

CONCLUSION

In knee OA patients with no comorbidities, generic celecoxib is not cost-effective at its current price.

Expression of PGDH correlates with cell growth in both esophageal squamous cell carcinoma and adenocarcinoma

Esophageal cancer represents the fourth most common gastrointestinal cancer and generally confers a poor prognosis. Prostaglandin-producing cyclo-oxygenase has been implicated in the pathogenesis of esophageal cancer growth. Here we report that prostaglandin dehydrogenase, the major enzyme responsible for prostaglandin degradation, is significantly reduced in expression in esophageal cancer in comparison to normal esophageal tissue. Reconstitution of PGDH expression in esophageal cancer cells suppresses cancer cell growth, at least in part through preventing cell proliferation and promoting cell apoptosis. The tumor suppressive role of PGDH applies equally to both squamous cell carcinoma and adenocarcinoma, which enriches our understanding of the pathogenesis of esophageal cancer and may provide an important therapeutic target.

Cost-effectiveness analyses of osteoarthritis oral therapies: a systematic review

BACKGROUND

Cost-effectiveness analyses (CEAs) have been performed for oral non-disease-altering osteoarthritis (OA) treatments for well over a decade. During that period the methods for performing these analyses have evolved as pharmacoeconomic methods have advanced, new treatments have been introduced, and the knowledge of associated adverse events (AEs) has improved.

OBJECTIVE

The objective of this systematic review was to trace the development of CEAs for oral non-disease-altering treatments in OA.

METHODS

A systematic search for CEAs of OA oral treatments was performed of the English-language medical literature using the following databases: PubMed, EMBASE, MEDLINE In-Process, EconLit, and Cochrane. Key requirements for inclusion were that the population described patients with OA or arthritis and that the analysis reported at least one incremental cost-effectiveness ratio. Each identified publication was assessed for inclusion. Thirteen characteristics and all AEs appearing in each included CEA were extracted and organized. Reference lists from these CEAs were also searched. A chronology of key CEAs in the field was compiled, noting the characteristics that advanced the state of the art in modeling oral OA treatments.

RESULTS

Thirty publications of 28 CEAs were identified and evaluated. Developments in CEAs included an expanded set of comparators that broadened from non-steroidal anti-inflammatory drugs (NSAIDs) only to NSAIDs plus gastroprotective agents, cyclooxygenase-2 inhibitors, and opioids. In turn, AEs expanded from gastrointestinal (GI) events to also include cardiovascular (CV) and neurological events. Efficacy, which initially was presumed to be equivalent for all treatments, evolved to treatment-specific efficacies. Decision-tree analyses were generally replaced by Markov models or, occasionally, stochastic or discrete event simulation. Finally, outcomes have progressed from GI-centric measures to also include quality-adjusted life-years.

CONCLUSION

Methods used by CEAs of oral non-disease-altering OA treatments have evolved in response to changing treatments with different safety profiles and efficacies as well as technical advances in the application of decision science to health care.

Cost-utility analysis of duloxetine in osteoarthritis: a US private payer perspective

BACKGROUND

Duloxetine has recently been approved in the USA for chronic musculoskeletal pain, including osteoarthritis and chronic low back pain. The cost effectiveness of duloxetine in osteoarthritis has not previously been assessed. Duloxetine is targeted as post first-line (after acetaminophen) treatment of moderate to severe pain.

OBJECTIVE

The objective of this study was to estimate the cost effectiveness of duloxetine in the treatment of osteoarthritis from a US private payer perspective compared with other post first-line oral treatments, including nonsteroidal anti-inflammatory drugs (NSAIDs), and both strong and weak opioids.

METHODS

A cost-utility analysis was performed using a discrete-state, time-dependent semi-Markov model based on the National Institute for Health and Clinical Excellence (NICE) model documented in its 2008 osteoarthritis guidelines. The model was extended for opioids by adding titration, discontinuation and additional adverse events (AEs). A life-long time horizon was adopted to capture the full consequences of NSAID-induced AEs. Fourteen health states comprised the structure of the model: treatment without persistent AE, six during-AE states, six post-AE states and death. Treatment-specific utilities were calculated using the transfer-to-utility method and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total scores from a meta-analysis of osteoarthritis clinical trials of 12 weeks and longer. Costs for 2011 were estimated using Red Book, The Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project database, the literature and, sparingly, expert opinion. One-way and probabilistic sensitivity analyses were undertaken, as well as subgroup analyses of patients over 65 years old and a population at greater risk of NSAID-related AEs.

RESULTS

In the base case the model estimated naproxen to be the lowest total-cost treatment, tapentadol the highest cost, and duloxetine the most effective after considering AEs. Duloxetine accumulated 0.027 discounted quality-adjusted life-years (QALYs) more than naproxen and 0.013 more than oxycodone. Celecoxib was dominated by naproxen, tramadol was subject to extended dominance, and strong opioids were dominated by duloxetine. The model estimated an incremental cost-effectiveness ratio (ICER) of US$47,678 per QALY for duloxetine versus naproxen. One-way sensitivity analysis identified the probabilities of NSAID-related cardiovascular AEs as the inputs to which the ICER was most sensitive when duloxetine was compared with an NSAID. When compared with a strong opioid, duloxetine dominated the opioid under nearly all sensitivity analysis scenarios. When compared with tramadol, the ICER was most sensitive to the costs of duloxetine and tramadol. In subgroup analysis, the cost per QALY for duloxetine versus naproxen fell to US$24,125 for patients over 65 years and to US$18,472 for a population at high risk of cardiovascular and gastrointestinal AEs.

CONCLUSION

The model estimated that duloxetine was potentially cost effective in the base-case population and more cost effective for subgroups over 65 years or at high risk of NSAID-related AEs. In sensitivity analysis, duloxetine dominated all strong opioids in nearly all scenarios.

Economic outcomes for celecoxib: a systematic review of pharmacoeconomic studies

Osteoarthritis and rheumatoid arthritis are conditions that are associated with significant clinical burden, and impact on patients' functional status and quality of life. Medical costs related to treating these common and disabling conditions place an economic strain on healthcare systems. This systematic review was conducted to investigate the impact of celecoxib on healthcare costs for patients with rheumatoid arthritis and osteoarthritis. In total, 24 studies examined economic outcomes associated with celecoxib in patients with these conditions. Six of these studies evaluated economic outcomes in developing regions, including Mexico, Asia and Turkey. Across all geographies, most studies were cost-effectiveness analyses comparing celecoxib with nonselective NSAIDs alone or in combination with gastroprotective agents. Overall, based on local standards, economic models indicated favorable cost-effectiveness profiles for celecoxib compared with nonselective NSAIDs and other active-treatment options. Cost analyses indicated that the use of celecoxib resulted in lower direct medical costs.

Value of information in the osteoarthritis setting: cost effectiveness of COX-2 selective inhibitors, traditional NSAIDs and proton pump inhibitors

BACKGROUND

Recent National Institute for Health and Clinical Excellence (NICE) guidance recommended that when traditional NSAIDs or cyclo-oxygenase (COX)-2 selective inhibitors are used by people with osteoarthritis (OA), they should be prescribed along with a proton pump inhibitor (PPI). However, specific recommendations about the type of NSAID or COX-2 could not be made due to high levels of uncertainty in the economic evaluation.

OBJECTIVE

To investigate the value of obtaining further evidence to inform the economic evaluation of NSAIDs, COX-2s and PPIs for people with OA.

METHODS

An economic evaluation with an expected value of perfect information (EVPI) analysis was conducted, using a Markov model with data identified from a systematic review. The base-case model used adverse event data from the three largest randomized trials of COX-2 inhibitors, and we repeated the analysis using observational adverse event data. The model was run for a hypothetical population of people with OA, and subgroup analyses were conducted for people with raised gastrointestinal (GI) and cardiovascular (CV) risk. The EVPI was based upon the OA population in England - approximately 2.8 million people. Of these, 50% were assumed to use NSAIDs or COX-2 selective inhibitors for 3 months per year and 56% of these were assumed to be patients with raised GI and CV risk.

RESULTS

The value of further information for this decision problem was very high. Population-level EVPI was £85.1 million in the low-risk group and £179.5 million in the high-risk group (2007-8 values). Expected value of partial perfect information (EVPPI) analysis showed that the groups of parameters for which further evidence was likely to be of most value were CV adverse event risks and all adverse event rates associated with the specific drugs celecoxib and ibuprofen. The value of perfect information remained high even when observational adverse event data were used.

CONCLUSIONS

There is a very high value associated with obtaining further information on uncertain parameters for the economic evaluation of NSAIDs, COX-2 selective inhibitors and PPIs for people with OA. Obtaining further randomized or observational information on CV risks is likely to be particularly cost effective.

A comparison of cost effectiveness using data from randomized trials or actual clinical practice: selective cox-2 inhibitors as an example

BACKGROUND

Data on absolute risks of outcomes and patterns of drug use in cost-effectiveness analyses are often based on randomised clinical trials (RCTs). The objective of this study was to evaluate the external validity of published cost-effectiveness studies by comparing the data used in these studies (typically based on RCTs) to observational data from actual clinical practice. Selective Cox-2 inhibitors (coxibs) were used as an example.

METHODS AND FINDINGS

The UK General Practice Research Database (GPRD) was used to estimate the exposure characteristics and individual probabilities of upper gastrointestinal (GI) events during current exposure to nonsteroidal anti-inflammatory drugs (NSAIDs) or coxibs. A basic cost-effectiveness model was developed evaluating two alternative strategies: prescription of a conventional NSAID or coxib. Outcomes included upper GI events as recorded in GPRD and hospitalisation for upper GI events recorded in the national registry of hospitalisations (Hospital Episode Statistics) linked to GPRD. Prescription costs were based on the prescribed number of tables as recorded in GPRD and the 2006 cost data from the British National Formulary. The study population included over 1 million patients prescribed conventional NSAIDs or coxibs. Only a minority of patients used the drugs long-term and daily (34.5% of conventional NSAIDs and 44.2% of coxibs), whereas coxib RCTs required daily use for at least 6-9 months. The mean cost of preventing one upper GI event as recorded in GPRD was US$104k (ranging from US$64k with long-term daily use to US$182k with intermittent use) and US$298k for hospitalizations. The mean costs (for GPRD events) over calendar time were US$58k during 1990-1993 and US$174k during 2002-2005. Using RCT data rather than GPRD data for event probabilities, the mean cost was US$16k with the VIGOR RCT and US$20k with the CLASS RCT.

CONCLUSIONS

The published cost-effectiveness analyses of coxibs lacked external validity, did not represent patients in actual clinical practice, and should not have been used to inform prescribing policies. External validity should be an explicit requirement for cost-effectiveness analyses.

Evidence for endoscopic ulcers as meaningful surrogate endpoint for clinically significant upper gastrointestinal harm

BACKGROUND & AIMS

Surrogate endpoints are biomarkers intended to substitute for a clinical endpoint. Are endoscopic ulcers a useful surrogate endpoint for a biological progression to clinical endpoints of ulcer complications (perforation, ulcers, and bleeds), hospital admission, or death?

METHODS

Review of randomized trials, meta-analyses, clinical outcomes trials, and observational studies.

RESULTS

No large study examined both endoscopic and clinical endpoints. Endoscopic ulcers and clinically significant ulcer complications were affected in the same direction and to about the same extent in 4 distinct circumstances: (1) by risk factors-age, previous history of symptomatic ulcer or bleeding, Helicobacter pylori, aspirin; (2) in studies of antiulcer treatments with differing modes of action, especially in relation to nonsteroidal anti-inflammatory drug toxicity, and Helicobacter pylori infection; (3) in studies evaluating ulcer complications with Cox-2 selective drugs and nonsteroidal anti-inflammatory drugs; and (4) in studies of interventions in patients with high risk of recurrent ulcer bleed needing nonsteroidal anti-inflammatory drug therapy. All study designs showed consistent and reproducible effects on gastrointestinal ulcer complications paralleling endoscopy.

CONCLUSIONS

Consistent and plausible findings from disparate populations and designs make endoscopic ulcers a strong candidate for surrogacy, though direct progression from endoscopic ulcers to ulcer complications cannot be demonstrated. Large outcome studies are needed to establish the power of the surrogacy, absolute risk of clinical outcomes, and to identify the totality of risks and benefits of new pharmacologic therapies.

Impact of patient sample on costs of events in pharmacoeconomic models

Pharmacoeconomic guidelines have focused on improving the measurement of effectiveness, but have largely ignored the assessment of cost inputs. We explored differences in adverse event cost estimates derived from three different sources in a case study of selective COX2 NSAIDs. We found substantial differences in costs of adverse events across data sources. We also determined that treatment costs associated with adverse events differed substantially based upon inclusion/exclusion criteria. Health services researchers should be deliberate in the choice of adverse event treatment costs that are used in decision analytic models. Future guidelines should seek to delineate best practices for cost calculations.

An economic model of long-term use of celecoxib in patients with osteoarthritis

Background

Previous evaluations of the cost-effectiveness of the cyclooxygenase-2 selective inhibitor celecoxib (Celebrex, Pfizer Inc, USA) have produced conflicting results. The recent controversy over the cardiovascular (CV) risks of rofecoxib and other coxibs has renewed interest in the economic profile of celecoxib, the only coxib now available in the United States. The objective of our study was to evaluate the long-term cost-effectiveness of celecoxib compared with nonselective nonsteroidal anti-inflammatory drugs (nsNSAIDs) in a population of 60-year-old osteoarthritis (OA) patients with average risks of upper gastrointestinal (UGI) complications who require chronic daily NSAID therapy.

Methods

We used decision analysis based on data from the literature to evaluate cost-effectiveness from a modified societal perspective over patients' lifetimes, with outcomes expressed as incremental costs per quality-adjusted life-year (QALY) gained. Sensitivity tests were performed to evaluate the impacts of advancing age, CV thromboembolic event risk, different analytic horizons and alternate treatment strategies after UGI adverse events.

Results

Our main findings were: 1) the base model incremental cost-effectiveness ratio (ICER) for celecoxib versus nsNSAIDs was $31,097 per QALY; 2) the ICER per QALY was $19,309 for a model in which UGI ulcer and ulcer complication event risks increased with advancing age; 3) the ICER per QALY was $17,120 in sensitivity analyses combining serious CV thromboembolic event (myocardial infarction, stroke, CV death) risks with base model assumptions.

Conclusion

Our model suggests that chronic celecoxib is cost-effective versus nsNSAIDs in a population of 60-year-old OA patients with average risks of UGI events.

Effect of guided imagery with relaxation on health-related quality of life in older women with osteoarthritis

Osteoarthritis (OA) is the most common cause of disability in older adults, which, in turn, leads to poor quality of life (QOL). Disability is caused primarily by the joint degeneration and pain associated with OA. A randomized pilot study was conducted to test the effectiveness of guided imagery with relaxation (GIR) to improve health-related QOL (HRQOL) in women with OA. A two-group (intervention versus control) longitudinal design was used to determine whether GIR leads to better HRQOL in these individuals and whether improvement in HRQOL could be attributed to intervention-associated improvements in pain and mobility. Twenty-eight women were randomized to either the GIR intervention or the control intervention group. Using GIR for 12 weeks significantly increased women's HRQOL in comparison to the women who used the control intervention, even after statistically adjusting for changes in pain and mobility. These findings suggest that the effects of GIR on HRQOL are not limited to improvements in pain and mobility. GIR may be an easy-to-use self-management intervention to improve the QOL of older adults with OA.

Economic Evaluation of Tramadol/Paracetamol Combination Tablets for??Osteoarthritis Pain in The Netherlands

OBJECTIVE

To compare the costs of treating osteoarthritis (OA) pain using combination tramadol/paracetamol tablets, NSAIDs alone, NSAIDs plus proton pump inhibitors (PPIs), or NSAIDs plus histamine H(2)-receptor antagonists (H(2)RAs) from the perspective of the Dutch healthcare system.

DESIGN AND METHODS

A decision-analytical model was constructed to model the cost outcomes of the four treatment strategies over 6 months. A cost-minimisation approach was used, which considered data related to resource utilisation, medication costs and costs for the treatment of adverse events. Data, derived mainly from the clinical literature, were supplemented by inputs from a Delphi panel as well as official price and tariff lists. The base-case analysis considered direct medical costs, including those for treating all adverse events with tramadol/paracetamol and gastrointestinal (GI) adverse events with NSAIDs. Separate scenario analyses explored costs of NSAID-based regimens: (i) according to 21 levels of risk for GI adverse events, and (ii) when renal events attributable to NSAIDs were considered. Robustness of the model was tested using univariate sensitivity analysis.

RESULTS

In the base-case analysis, costs for 6 months' treatment of OA pain using tramadol/paracetamol were euro244.45, compared with euro317.32 for NSAIDs + PPIs, euro200.67 for NSAIDs + H(2)RAs, and euro125.86 for NSAIDs alone. This provided a cost saving of euro72.87 per patient over 6 months for tramadol/paracetamol compared with NSAIDs + PPIs. Tramadol/paracetamol became cost saving compared with NSAIDs alone and NSAIDs + H(2)RAs for GI risk levels >13 and >10, respectively. When renal adverse events of NSAIDs were con- sidered, tramadol/paracetamol was cost saving compared with all NSAID-based regimens (saving euro228.40 vs NSAIDs, euro418.42 vs NSAIDs + PPIs, and euro302.69 vs NSAIDs + H(2)RAs [year of costing 2005]). Sensitivity analysis confirmed the model was robust to wide-ranging changes in the value of input parameters.

CONCLUSION

Tramadol/paracetamol is cost saving compared with NSAIDs + PPIs for the treatment of OA pain over a period of 6 months regardless of the risk of GI or renal complications. Tramadol/paracetamol is also cost saving compared with treatment with NSAIDs alone and NSAIDs + H(2)RAs for patients at medium and high risk of GI adverse events and in all cases if considering renal adverse events. Despite not being quantified in monetary terms, the lower incidence of adverse events with tramadol/paracetamol is a clinical benefit.