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

Cost Effectiveness of Pharmacological Management for Osteoarthritis: A Systematic Review

BACKGROUND AND OBJECTIVE

Osteoarthritis (OA) is a highly prevalent, disabling disease requiring chronic management that is associated with an enormous individual and societal burden. This systematic review provides a global cost-effectiveness evaluation of pharmacological therapy for the management of OA.

METHODS

Following Center for Reviews and Dissemination (CRD) guidance, a literature search strategy was undertaken using PubMed, EMBASE, Cochrane Library, Health Technology Assessment (HTA) database, and National Health Service Economic Evaluation database (NHS EED) to identify original articles containing cost-effectiveness evaluation of OA pharmacological treatment published before 4 November 2021. Risk of bias was assessed by two independent reviewers using the Joanna Briggs Institute (JBI) critical appraisal checklist for economic evaluations. The Quality of Health Economic Studies (QHES) instrument was used to assess the reporting quality of included articles.

RESULTS

Database searches identified 43 cost-effectiveness analysis studies (CEAs) on pharmacological management of OA that were conducted in 18 countries and four continents, with one study containing multiple continents. A total of four classes of drugs were assessed, including non-steroidal anti-inflammatory drugs (NSAIDs), opioid analgesics, symptomatic slow-acting drugs for osteoarthritis (SYSADOAs), and intra-articular (IA) injections. The methodological approaches of these studies showed substantial heterogeneity. The incremental cost-effectiveness ratios (ICERs) per quality-adjusted life-year (QALY) were (in 2021 US dollars) US$44.40 to US$307,013.56 for NSAIDS, US$11,984.84 to US$128,028.74 for opioids, US$10,930.17 to US$27,799.73 for SYSADOAs, and US$258.36 to US$58,447.97 for IA injections in different continents. The key drivers of cost effectiveness included medical resources, productivity, relative risks, and selected comparators.

CONCLUSION

This review showed substantial heterogeneity among studies, ranging from a finding of dominance to very high ICERs, but most studies found interventions to be cost effective based on specific ICER thresholds. Important challenges in the analysis were related to the standardization and methodological quality of studies, as well as the presentation of results.

Coxibs Refocus Attention on the Cardiovascular Risks of Non-Aspirin NSAIDs

Non-steroidal anti-inflammatory drugs (NSAIDs) were differentiated from steroidal anti-inflammatory medicines to help clinicians who needed to use anti-inflammatory agents that were safer than steroids. With market entry of rofecoxib in 1999, NSAIDs were then further classified into traditional NSAIDs and cyclooxygenase (COX)-2 inhibitors (coxibs), the latter posing potentially fewer gastrointestinal risks. In 2005, rofecoxib was withdrawn from the market because of concerns about the risk of heart attack and stroke with long-term use, and clinical practice began focusing more on the cardiovascular versus gastrointestinal safety of coxibs. Since then, many coxibs have remained unapproved by the US FDA or have been removed from the market. This article explains how coxibs refocused attention on the cardiovascular safety of NSAIDs and the general implications of that. COX-2 activity/specificity is one factor associated with increased cardiovascular risks; however, these risks cannot be attributed to coxibs alone. The traditional NSAIDs (i.e., meloxicam, etodolac, and nabumetone) have significant COX-2 specificity, but naproxen and ibuprofen have less specificity. All NSAIDs, whether traditional or a coxib, pose some cardiovascular risks. It is possible that clinicians continue to focus more on decreasing the immediate gastric risks than preventing the later cardiovascular risks. The cardiovascular risks posed by NSAIDs should not be disregarded for the sake of achieving gastrointestinal benefits. Current recommendations suggest NSAIDs should be considered a single class of non-aspirin NSAIDs. Preferred NSAIDs are ibuprofen and naproxen. Coxibs are preferred in patients with low cardiovascular risk and high gastrointestinal risk who are intolerant to anti-dyspepsia therapy.

Cost-effectiveness of Low-dose Submicron Diclofenac Compared With Generic Diclofenac

PURPOSE

NSAIDs are commonly prescribed for the treatment of pain and inflammation. Despite the effectiveness of NSAIDs, concerns exist regarding their tolerability. Worldwide health authorities, including the European Medicines Agency, Health Canada, and the US Food and Drug Administration, have advised that NSAIDs be prescribed at the lowest effective dosage and for the shortest duration. Effective lowering of NSAID dosage without compromising pain relief has been demonstrated in randomized, controlled trials of the recently approved NSAID lower-dose submicron diclofenac. Building on previously published work from an independently published systematic review and meta-analysis, a linear dose-toxicity relationship between diclofenac dose and serious gastrointestinal (GI) events was recently demonstrated, indicating that reductions in adverse events (AEs) may be seen even with modest dose reductions in many patients. The objective of the present study was to estimate the potential reduction in risk for NSAID dose-related AEs, corresponding savings in health care costs, and the incremental cost-effectiveness of submicron diclofenac compared with generic diclofenac in the United States.

METHODS

Our decision-analytic cost-effectiveness model considered a subset of potential AEs that may be avoided by lowering NSAID dosage. To estimate the expected reductions in upper GI bleeding/perforation and major cardiovascular events with submicron diclofenac, our model used prediction equations estimated by meta-regressions using data from systematic literature reviews. Utilities, lifetime costs, and health outcomes associated with AEs were estimated using data from the literature. The face validity of the model structure and inputs was confirmed by clinical experts in the United States. Results were evaluated in 1-way and probabilistic sensitivity analyses.

FINDINGS

The model predicted that submicron diclofenac versus generic diclofenac could reduce the occurrence of modeled GI events (by 18.0%), cardiovascular events (by 6.9%), and acute renal failure (by 18.8%), leading to a 9.8% reduction in costs of treating AEs. Submicron diclofenac was predicted to be cost-saving, with results relatively insensitive to parameter uncertainty.

IMPLICATIONS

Submicron diclofenac has the potential to provide clinical and economic value to patients using NSAIDs in the United States. Further investigation regarding the potential effects of submicron diclofenac on the risks for additional NSAID dose-related toxicities should be explored.

[Cost-effectiveness analysis of celecoxib versus non-selective non-steroidal anti-inflammatory drug therapy for the treatment of osteoarthritis in Spain: A current perspective]

OBJECTIVE

To assess the cost-effectiveness of celecoxib and non-selective non-steroidal anti-inflammatory drugs for the treatment of osteoarthritis in clinical practice in Spain.

METHODS

A decision-tree model using distribution, doses, treatment duration and incidence of GI and CV events observed in the pragmatic PROBE-designed «GI-Reasons» trial was used for cost-effectiveness. Effectiveness was expressed in terms of event averted and quality-adjusted life-years (QALY) gained. QALY were calculated based on utility decrement in case of any adverse events reported in GI-Reasons trial. The National Health System perspective in Spain was applied; cost calculations included current prices of drugs plus cost of adverse events occurred. The analysis was expressed as an incremental cost-effectiveness ratio per QALY gained and per event averted. One-way and probabilistic analyses were performed.

RESULTS

Compared with non-selective non-steroidal anti-inflammatory drugs, at current prices, celecoxib treatment had higher overall treatment costs €201 and €157, respectively. However, celecoxib was associated with a slight increase in QALY gain and significantly lower incidence of gastrointestinal events (p<.001), with mean incremental cost-effectiveness ratio of €13,286 per QALY gained and €4,471 per event averted. Sensitivity analyses were robust, and confirmed the results of the base case.

CONCLUSION

Celecoxib at current price may be considered as a cost-effective alternative vs. non-selective non-steroidal anti-inflammatory drugs in the treatment of osteoarthritis in daily practice in the Spanish NHS.

The cost-effectiveness of celecoxib versus non-steroidal anti-inflammatory drugs plus proton-pump inhibitors in the treatment of osteoarthritis in Saudi Arabia

BACKGROUND

Cyclooxygenase (COX)-2 inhibitors including celecoxib are as effective as non-selective non-steroidal anti-inflammatory drugs (ns-NSAIDs) in the treatment of osteoarthritis (OA) and have less gastrointestinal toxicity. Although they are associated with higher treatment costs, COX-2 inhibitors may simultaneously reduce costs associated with adverse events, hence, their overall economic benefit should be assessed.

OBJECTIVE

To evaluate the incremental cost effectiveness ratio (ICER) of celecoxib versus ns-NSAIDs, with/without proton-pump inhibitor (PPI) co-therapy, for managing OA in Saudi Arabian subjects aged ≥65 years.

METHODS

The National Institute for Health and Care Excellence health economic model from the UK, updated with relative risks of adverse events using CONDOR trial data, was adapted. Patients received celecoxib or ns-NSAIDs, with/without omeprazole. The effectiveness measure was quality-adjusted life years (QALYs) gained per patient. The analysis was conducted from the patient's perspective. Frequencies of resource use for adverse events were based on data collected in July 2012 from seven private hospitals in Jeddah, Saudi Arabia. Probabilistic sensitivity analysis was performed to construct cost-effectiveness acceptability curves (CEACs).

RESULTS

Over a 6-month treatment duration, QALYs gained per patient were higher with celecoxib (0.37) and celecoxib plus PPI (0.40) versus comparators. Ibuprofen plus PPI showed the lowest expected cost per patient (US$ 1,314.50 versus US$ 1,422.80 with celecoxib plus PPI and US$ 1,543.50 with celecoxib). Celecoxib plus PPI was the most cost-effective option with an ICER of US$ 1,805.00, followed by celecoxib (ICER, US$ 7,633.33) versus ibuprofen plus PPI. Over 2- and 5-year treatment durations, celecoxib plus PPI, and celecoxib, showed higher QALYs gained/patient and lower ICERs versus comparators. These ICERs are <1 gross domestic product/capita in Saudi Arabia in 2013 (US$ 25,961). CEACs over 6 months' treatment showed a significantly higher likelihood that celecoxib plus PPI and celecoxib alone would be more cost effective versus comparators once the willingness to pay is over US$ 2,000.00.

CONCLUSION

After considering new adverse event risks, celecoxib with/without PPI co-therapy was deemed very cost effective for medium- and long-term use in Saudi Arabian OA patients aged ≥65 years.

3,4-Dihydroxy-benzohydroxamic acid (Didox) suppresses pro-inflammatory profiles and oxidative stress in TLR4-activated RAW264.7 murine macrophages

Didox (3,4-dihydroxy-benzohydroxamic acid), is a synthetic ribonucleotide reductase (RR) inhibitor derived from polyhydroxy-substituted benzohydroxamic acid, and originally developed as an anti-cancer agent. Some studies indicate that didox may have anti-oxidative stress-like properties, while other studies hint that didox may have anti-inflammatory properties. Using nitric oxide production in response to LPS treatment as a sensitive screening assay for anti-inflammatory compounds, we show that didox is very potent at levels as low as 6.25 μM, with maximal inhibition at 100 μM. A qRT-PCR array was then employed to screen didox for other potential anti-inflammatory and anti-oxidative stress-related properties. Didox was very potent in suppressing the expression of these arrayed mRNA in response to LPS, and in some cases didox alone suppressed expression. Using qRT-PCR as a follow up to the array, we demonstrated that didox suppresses LPS-induced mRNA levels of iNOS, IL-6, IL-1, TNF-α, NF-κβ (p65), and p38-α, after 24h of treatment. Treatment with didox also suppresses the secretion of nitric oxide, IL-6, and IL-10. Furthermore, oxidative stress, as quantified by intracellular ROS levels in response to macrophage activators LPS and phorbol ester (PMA), and the glutathione depleting agent BSO, is reduced by treatment with didox. Moreover, we demonstrate that nuclear translocation of NF-κβ (p65) in response to LPS is inhibited by didox. These findings were supported by qRT-PCR for oxidative stress genes SOD1 and catalase. Overall, this study supports the conclusion that didox may have a future role in managing acute and chronic inflammatory diseases and oxidative stress due to high production of ROS.

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.

A review of the efficacy, safety, and cost-effectiveness of COX-2 inhibitors for Africa and the Middle East region

Despite an increasingly sophisticated understanding of pain mechanisms, acute and chronic pain remain undertreated throughout the world. This situation reflects the large gap that exists between evidence and practice in pain management and is typified by inappropriate use of nonsteroidal anti-inflammatory drugs (NSAIDs). The scientific evidence around these drugs continues to expand at a high rate, yet physicians are often unaware of best practice. To address this gap among physicians in Africa and the Middle East, an Expert Panel meeting was convened with representatives from the region. The principal objective of the meeting was to review the latest guidelines on the management of acute and chronic pain and to review the efficacy, safety, and cost-effectiveness of cyclooxygenase-2 (COX-2) inhibitors in these settings. The main outcome of this review process was a number of consensus statements concerning the definitions of acute and chronic pain, and the efficacy, safety and cost-effectiveness of traditional nonselective NSAIDs (nsNSAIDs) and selective COX-2 inhibitors (coxibs). The panel agreed that nsNSAIDs and coxibs are effective analgesics with similar efficacy for acute pain; for chronic musculoskeletal pain, NSAIDs are significantly more effective than either placebo or paracetamol. Coxibs offer important safety advantages over nsNSAIDs, including gastrointestinal safety and preservation of platelet function; notably, the cardiovascular safety of coxibs has been the subject of much recent debate. Furthermore, the panel agreed there is substantial evidence to indicate that cost savings can be achieved by using celecoxib in patients at moderate to high risk of gastrointestinal adverse events, even in countries with moderate healthcare expenditures.

Celecoxib: a review of its use for symptomatic relief in the treatment of osteoarthritis, rheumatoid arthritis and ankylosing spondylitis

Celecoxib (Celebrex®) was the first cyclo-oxygenase (COX)-2 selective inhibitor (coxib) to be introduced into clinical practice. Coxibs were developed to provide anti-inflammatory/analgesic activity similar to that of nonselective NSAIDs, but without their upper gastrointestinal (GI) toxicity, which is thought to result largely from COX-1 inhibition. Celecoxib is indicated in the EU for the symptomatic treatment of osteoarthritis, rheumatoid arthritis and ankylosing spondylitis in adults. This article reviews the clinical efficacy and tolerability of celecoxib in these EU-approved indications, as well as overviewing its pharmacological properties. In randomized controlled trials, celecoxib, at the recommended dosages of 200 or 400 mg/day, was significantly more effective than placebo, at least as effective as or more effective than paracetamol (acetaminophen) and as effective as nonselective NSAIDs and the coxibs etoricoxib and lumiracoxib for the symptomatic treatment of patients with active osteoarthritis, rheumatoid arthritis or ankylosing spondylitis. Celecoxib was generally well tolerated, with mild to moderate upper GI complaints being the most common body system adverse events. In meta-analyses and large safety studies, the incidence of upper GI ulcer complications with recommended dosages of celecoxib was significantly lower than that with nonselective NSAIDs and similar to that with paracetamol and other coxibs. However, concomitant administration of celecoxib with low-dose cardioprotective aspirin often appeared to negate the GI-sparing advantages of celecoxib over NSAIDs. Although one polyp prevention trial noted a dose-related increase in cardiovascular risk with celecoxib 400 and 800 mg/day, other trials have not found any significant difference in cardiovascular risk between celecoxib and placebo or nonselective NSAIDs. Meta-analyses and database-derived analyses are inconsistent regarding cardiovascular risk. At recommended dosages, the risks of increased thrombotic cardiovascular events, or renovascular, hepatic or hypersensitivity reactions with celecoxib would appear to be small and similar to those with NSAIDs. Celecoxib would appear to be a useful option for therapy in patients at high risk for NSAID-induced GI toxicity, or in those responding suboptimally to or intolerant of NSAIDs. To minimize any risk, particularly the cardiovascular risk, celecoxib, like all coxibs and NSAIDs, should be used at the lowest effective dosage for the shortest possible duration after a careful evaluation of the GI, cardiovascular and renal risks of the individual patient.

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.

Economic evaluation of nonsteroidal anti-inflammatory drug strategies in rheumatoid arthritis

Objectives:Although disease modifying antirheumatic drugs (DMARDs) are the first choice drugs in the treatment of rheumatoid arthritis, many patients still take nonsteroidal anti-inflammatory drugs (NSAIDs) as well. These drugs may cause serious gastric adverse events with continuous usage. Cyclooxygenase-2 (COX2) inhibitors were supposed to have a gastrointestinal (GI) friendly side effect profile. The aim of the study is to compare three therapeutic strategies: conventional NSAIDs, NSAID in combination with proton pump inhibitors (PPIs), and the selective COX2 inhibitor therapy (celecoxib).

Methods:A decision tree model was developed, for 1 year, to simulate cohorts within the three arms (NSAIDs, NSAID + PPI, celecoxib). The efficacy of the different active agents of NSAIDs in therapeutically relevant doses was assumed to be the same, consequently differences can be seen in the side effect profile of the drugs. Medical costs, the costs of the side effects (GI, cardiovascular [CV] events), and quality-adjusted life-years (QALYs) were calculated to gain an incremental cost-effectiveness ratio (ICER). Evaluations were made from a third party payer's perspective. We performed one-way deterministic sensitivity analyses; the results were displayed in tornado diagrams.

Results:Our model indicates that NSAID + PPI offers extra health gain for extra costs compared with conventional NSAIDs (ICER:14,287 euro/QALY), while it dominates celecoxib because of celecoxib's higher costs and lower effectiveness. According to the sensitivity analyses, QALYs had the highest influence on ICER.

Conclusions:Although COX2 inhibitors have elevated GI efficacy compared with NSAIDs, celecoxib seems to be an adequate choice only for a limited group of patients with specific conditions because of the significantly higher price and CV risk profile.

Impact of chondroitin sulphate on health utility in patients with knee osteoarthritis: towards economic analysis

OBJECTIVES

The first objective was to assess the effect of the chondroitin 4 and 6 sulphate (CS) on health-related quality of life using utility values in patients with knee osteoarthritis (OA) during a 24-month treatment course. The second objective was, using these data, to conduct economic analyses.

METHODS

Data from the STOPP study was used. This study was a randomised, double-blind, placebo (PL) -controlled trial of 2-year duration. In the STOPP study, authors assessed quality of life using the Western Ontario and McMaster Osteoarthritis Index (WOMAC). WOMAC scores were translated into Health Utility Index (HUI) scores using a specific formula. Incremental cost effectiveness ratio (ICER) was calculated taking into account the cost of CS and its effect on HUI scores, compared to PL.

RESULTS

At baseline, the mean (SD) HUI scores were 0.59 (0.17), and 0.59 (0.18) for the PL and CS groups, respectively (p=0.31 between the two groups). The mean (SD) HUI scores changes from baseline to 6 months were 0.02 (0.02), and 0.05 (0.01) for the PL and CS groups, respectively (p=0.03). After 24 months of follow-up, HUI score increases by 0.04 (0.02) in the PL group and by 0.05 (0.02) in the CS group (p=0.37). Using the price bracket of CS in Europe, ICER assessment always resulted in a cost below €30,000 per QALY gained, after 6, 12 and 24 months of treatment.

CONCLUSION

CS treatment increases health utilities in patients with knee OA compared to PL over the first 6 months of treatment. Economic evaluation based on these data suggests that CS treatment could be considered as cost-effective in patients with knee OA up to a period of 24 months. A limitation in this study is the absence of direct utility assessment as well as the absence of effective treatment as comparator.

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.