RESUMO
OBJECTIVES: To review the clinical effectiveness and cost-effectiveness of cyclooxygenase-2 (COX-2) selective non-steroidal anti-inflammatory drugs (NSAIDs) (etodolac, meloxicam, celecoxib, rofecoxib, etoricoxib, valdecoxib and lumiracoxib) for osteoarthritis (OA) and rheumatoid arthritis (RA). DATA SOURCES: Electronic databases were searched up to November 2003. Industry submissions to the National Institute for Health and Clinical Excellence (NICE) in 2003 were also reviewed. REVIEW METHODS: Systematic reviews of randomised controlled trials (RCTs) and a model-based economic evaluation were undertaken. Meta-analyses were undertaken for each COX-2 selective NSAID compared with placebo and non-selective NSAIDs. The model was designed to run in two forms: the 'full Assessment Group Model (AGM)', which includes an initial drug switching cycle, and the 'simpler AGM', where there is no initial cycle and no opportunity for the patient to switch NSAID. RESULTS: Compared with non-selective NSAIDs, the COX-2 selective NSAIDs were found to be equally as efficacious as the non-selective NSAIDs (although meloxicam was found to be of inferior or equivalent efficacy) and also to be associated with significantly fewer clinical upper gastrointestinal (UGI) events (although relatively small numbers of clinical gastrointestinal (GI) and myocardial infarction (MI) events were reported across trials). Subgroup analyses of clinical and complicated UGI events and MI events in relation to aspirin use, steroid use, prior GI history and Helicobacter pylori status were based on relatively small numbers and were inconclusive. In the RCTs that included direct COX-2 comparisons, the drugs were equally tolerated and of equal efficacy. Trials were of insufficient size and duration to allow comparison of risk of clinical UGI events, complicated UGI events and MIs. One RCT compared COX-2 (celecoxib) with a non-selective NSAID combined with a gastroprotective agent (diclofenac combined with omeprazole); this included arthritis patients who had recently suffered a GI haemorrhage. Although no significant difference in clinical GI events was reported, the number of events was small and more such studies, where patients genuinely need NSAIDs, are required to confirm these data. A second trial showed that rofecoxib was associated with fewer diarrhoea events than a combination of diclofenac and misoprostol (Arthrotec). Previously published cost-effectiveness analyses indicated a wide of range of possible incremental cost per quality-adjusted life-year (QALY) gained estimates. Using the simpler AGM, with ibuprofen or diclofenac alone as the comparator, all of the COX-2 products are associated with higher costs (i.e. positive incremental costs) and small increases in effectiveness (i.e. positive incremental effectiveness), measured in terms of QALYs. The magnitude of the incremental costs and the incremental effects, and therefore the incremental cost-effectiveness ratios, vary considerably across all COX-2 selective NSAIDs. The base-case incremental cost per QALY results for COX-2 selective NSAIDs compared with diclofenac for the simpler model are: celecoxib (low dose) 68,400 pounds; celecoxib (high dose) 151,000 pounds; etodolac (branded) 42,400 pounds; etodolac (generic) 17,700 pounds; etoricoxib 31,300 pounds; lumiracoxib 70,400 pounds; meloxicam (low dose) 10,300 pounds; meloxicam (high dose) 17,800 pounds; rofecoxib 97,400 pounds; and valdecoxib 35,500 pounds. When the simpler AGM was run using ibuprofen or diclofenac combined with proton pump inhibitor (PPI) as the comparator, the results change substantially, with the COX-2 selective NSAIDs looking generally unattractive from a cost-effectiveness point of view (COX-2 selective NSAIDs were dominated by ibuprofen or diclofenac combined with PPI in most cases). This applies both to 'standard' and 'high-risk' arthritis patients defined in terms of previous GI ulcers. The full AGM produced results broadly in line with the simpler model. CONCLUSIONS: The COX-2 selective NSAIDs examined were found to be similar to non-selective NSAIDs for the symptomatic relief of RA and OA and to provide superior GI tolerability (the majority of evidence is in patients with OA). Although COX-2 selective NSAIDs offer protection against serious GI events, the amount of evidence for this protective effect varied considerably across individual drugs. The volume of trial evidence with regard to cardiovascular safety also varied substantially between COX-2 selective NSAIDs. Increased risk of MI compared to non-selective NSAIDs was observed among those drugs with greater volume of evidence in terms of exposure in patient-years. Economic modelling shows a wide range of possible costs per QALY gained in patients with OA and RA. Costs per QALY also varied if individual drugs were used in 'standard' or 'high'-risk patients, the choice of non-selective NSAID comparator and whether that NSAID was combined with a PPI. With reduced costs of PPIs, future primary research needs to compare the effectiveness and cost-effectiveness of COX-2 selective NSAIDs relative to non-selective NSAIDs with a PPI. Direct comparisons of different COX-2 selective NSAIDs, using equivalent doses, that compare GI and MI risk are needed. Pragmatic studies that include a wider range of people, including the older age groups with a greater burden of arthritis, are also necessary to inform clinical practice.
Assuntos
Artrite Reumatoide/tratamento farmacológico , Inibidores de Ciclo-Oxigenase 2/economia , Inibidores de Ciclo-Oxigenase 2/uso terapêutico , Osteoartrite/tratamento farmacológico , Antiulcerosos/economia , Antiulcerosos/uso terapêutico , Artrite Reumatoide/economia , Análise Custo-Benefício , Inibidores de Ciclo-Oxigenase 2/efeitos adversos , Gastroenteropatias/induzido quimicamente , Humanos , Cadeias de Markov , Modelos Econométricos , Omeprazol/economia , Omeprazol/uso terapêutico , Osteoartrite/economia , Anos de Vida Ajustados por Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco , Avaliação da Tecnologia Biomédica/economia , Trombose/induzido quimicamenteRESUMO
OBJECTIVES: To examine the clinical effectiveness and cost-effectiveness of self-testing and self-management of oral anticoagulation treatment compared with clinic-based monitoring. DATA SOURCES: Major electronic databases were searched up to September 2005. REVIEW METHODS: A systematic review was undertaken of relevant data from selected studies. Results about complication events and deaths were pooled in meta-analyses using risk difference (RD) as the outcome statistic. Heterogeneity across trials and possible publication bias were statistically measured. Subgroup analyses (post hoc) were conducted to compare results of self-testing versus self-management, low versus high trial quality, trials conducted in the UK versus trials in other countries and industry versus other sponsors. A Markov-type, state-transition model was developed. Stochastic simulations using the model were conducted to investigate uncertainty in estimated model parameters. RESULTS: In the 16 randomised and eight non-randomised trials selected, patient self-monitoring of oral anticoagulation therapy was found to be more effective than poor-quality usual care provided by family doctors and as effective as good-quality specialised anticoagulation clinics in maintaining the quality of anticoagulation therapy. There was no significant RD of major bleeding events between patient self-monitoring and usual care controls and pooled analyses found that compared with primary care or anticoagulation control (AC) clinics, self-monitoring was statistically significantly associated with fewer thromboembolic events. However, the reduction in complication events and deaths was not consistently associated with the improvement of AC; in some trials this may be due to alternative explanations, including patient education and patient empowerment. Also, the improved AC and the reduction of major complications and deaths by patient self-monitoring were mainly observed in trials conducted outside the UK. According to UK-specific data, for every 100 eligible patients, 24% would agree to conduct self-monitoring, 17 of the 24 patients (70%) could be successfully trained and able to carry out self-monitoring and only 14 of these (80%) would conduct long-term self-monitoring. Seven cost-effectiveness studies were identified and the study that provided the most relevant UK data found that patient self-management was more expensive than current routine care (417 pounds versus 122 pounds per patient-year) and concluded that using a cost-effectiveness threshold of 30,000 pounds per quality-adjusted life-year (QALY) gained, patient self-management does not appear to be cost-effective. De novo modelling for this report found that the incremental cost per QALY gained by patient self-monitoring is 122,365 pounds over 5 years and 63,655 pounds over 10 years. The estimated probability that patient self-monitoring is cost-effective (up to 30,000 pounds/QALY) is 44% over a 10-year period. Wide adoption of patient self-monitoring of anticoagulation therapy would cost the NHS an estimated additional 8-14 million pounds per year. CONCLUSIONS: For selected and successfully trained patients, self-monitoring is effective and safe for long-term oral anticoagulation therapy. In general, patient self-management (PSM) is unlikely to be more cost-effective than the current specialised anticoagulation clinics in the UK; self-monitoring may enhance the quality of life for some patients who are frequently away from home, who are in employment or education, or those who find it difficult to travel to clinics. Further research is needed into alternative dosing regimes, the clinical effectiveness and cost-effectiveness of patient education and training in long-term oral anticoagulation therapy, UK-relevant cost-effectiveness, the effectiveness of PSM in children, and the potential future developments of near-patient testing devices.
Assuntos
Anticoagulantes , Autocuidado/normas , Trombose/tratamento farmacológico , Resultado do Tratamento , Administração Oral , Anticoagulantes/administração & dosagem , Anticoagulantes/efeitos adversos , Anticoagulantes/economia , Anticoagulantes/uso terapêutico , Ensaios Clínicos Controlados como Assunto , Análise Custo-Benefício , Bases de Dados Bibliográficas , Hemorragia/induzido quimicamente , Hemorragia/mortalidade , Humanos , Cadeias de Markov , Modelos Econômicos , Cooperação do Paciente , Educação de Pacientes como Assunto , Satisfação do Paciente , Seleção de Pacientes , Tempo de Protrombina , Anos de Vida Ajustados por Qualidade de Vida , Autocuidado/economia , Trombose/mortalidade , Trombose/prevenção & controle , Reino Unido , Varfarina/administração & dosagem , Varfarina/efeitos adversos , Varfarina/economia , Varfarina/uso terapêuticoRESUMO
OBJECTIVES: To examine the clinical effectiveness and cost-effectiveness of newer antiepileptic drugs (AEDs) for epilepsy in children: gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine, topiramate and vigabatrin. DATA SOURCES: Electronic databases. Drug company submissions. REVIEW METHODS: For the systematic review of clinical and cost-effectiveness, studies were assessed for inclusion according to predefined criteria. Data extraction and quality assessment were also undertaken. A decision-analytic model was constructed to estimate the cost-effectiveness of the newer agents in children with partial seizures, the only condition where there were sufficient trial data to inform a model. RESULTS: The quality of the randomised controlled trial (RCT) data was generally poor. For each of the epilepsy subtypes considered in RCTs identified for this review (partial epilepsy with or without secondary generalisation, Lennox-Gastaut syndrome, infantile spasms, absence epilepsy and benign epilepsy with centrotemporal spikes), there is some evidence from placebo-controlled trials that the newer agents tested are of some value in the treatment of these conditions. Where active controls have been used, the limited evidence available does not indicate a difference in effectiveness between newer and older drugs. The data are not sufficient to inform a prescribing strategy for any of the newer agents in any of these conditions. In particular, there is no clinical evidence to suggest that the newer agents should be considered as a first-choice treatment in any form of epilepsy in children. Annual drug costs of the newer agents ranges from around 400 pound to 1200 pound, depending on age and concomitant medications. An AED that is ineffective or has intolerable side-effects will only be used for a short period of time, and many patients achieving seizure freedom will successfully withdraw from drug treatment without relapsing. The results of the decision-analytic model do not suggest that the use of the newer agents in any of the scenarios considered is clearly cost-effective but, similarly, do not indicate that they are clearly not cost-effective. CONCLUSIONS: The prognosis for children diagnosed with epilepsy is generally good, with a large proportion responding well to the first treatment given. A substantial proportion, however, will not respond well to treatment, and for these patients the clinical goal is to find an optimal balance between the benefits and side-effects of any treatment given. For the newly, or recently, diagnosed population, the key question for the newer drugs is how soon they should be tried. The cost-effectiveness of using these agents early, in place of one of the older agents, will depend on the effectiveness and tolerability of these agents compared with the older agents; the evidence from the available trial data so far suggests that the newer agents are no more effective but may be somewhat better tolerated than the older agents, and so the cost-effectiveness for early use will depend on the trade-off between effectiveness and tolerability, both in terms of overall (long-term) treatment retention and overall utility associated with effects on seizure rate and side-effects. There are insufficient data available to estimate accurately the nature of this trade off either in terms of long-term treatment retention or utility. Better information is required from RCTs before any rational evidence-based prescribing strategy could be developed. Ideally, RCTs should be conducted from a 'public health' perspective, making relevant comparisons and incorporating outcomes of interest to clinicians and patients, with sufficiently long-term follow-up to determine reliably the clinical utility of different treatments, particularly with respect to treatment retention and the balance between effectiveness and tolerability. RCTs should mirror clinical practice with respect to diagnosis, focusing on defined syndromes or, where no syndrome is identified, on groups defined by specific seizure type(s) and aetiology. Epilepsy in children is a complex disease, with a variety of distinct syndromes and many alternative treatment options and outcomes. Diagnosis-specific decision-analytic models are required; further research may be required to inform parameter values adequately with respect to epidemiology and clinical practice.
Assuntos
Anticonvulsivantes/economia , Anticonvulsivantes/uso terapêutico , Análise Custo-Benefício , Epilepsia/tratamento farmacológico , Resultado do Tratamento , Anticonvulsivantes/classificação , Criança , Epilepsia/economia , Humanos , Anos de Vida Ajustados por Qualidade de VidaRESUMO
BACKGROUND: Multiple sclerosis (MS) is an important problem both for people with the disease and for society. There is no cure, and alleviation of symptoms forms the cornerstone of care. Excessive fatigue that severely limits activity is experienced by at least two-thirds of the estimated 60,000 people with MS in the UK. OBJECTIVES: (1) To identify current treatments for fatigue in MS and their evidence-base. (2) To systematically review the evidence for those treatments that have been investigated in more than one rigorous study, in order to determine their effectiveness and cost-effectiveness. METHODS: The review was carried out in two stages: a formal scoping review (to assess the range of interventions used by people with MS), and a systematic review for treatments that had been identified as promising and that had been investigated in clinical trials (as identified in the scoping review). A systematic review of research on costs and cost-effectiveness of those interventions identified as promising was also performed. Electronic databases, including MEDLINE and EMBASE, were searched for the period 1991-June 1999 (scoping review) and 1966-December 1999 (systematic review). Reference lists from publications were also searched, and experts were contacted for any additional information not already identified. RESULTS: Interventions identified for the treatment of fatigue in MS (1) Behavioural advice. This is the main element of initial clinical management and no rigorous research of its effectiveness was identified. (2) Drugs (amantadine, pemoline, potassium-channel blockers and antidepressants). (3) Training, rehabilitation and devices (cooling vests and electromagnetic fields). (4) Alternative therapies (bee venom, cannabis, acupuncture/acupressure and yoga). Only two drugs, amantadine and pemoline, met the criteria for full systematic review. RESULTS - EFFECTIVENESS OF AMANTADINE: One parallel and three crossover trials were found, involving a total of 236 people with MS. All studies were open to bias. All studies showed a pattern in favour of amantadine compared with placebo, but there is considerable uncertainty about the validity and clinical significance of this finding. This pattern of benefit was considerably undermined when different assumptions were used in the sensitivity analysis. RESULTS - EFFECTIVENESS OF PEMOLINE: One parallel and one crossover trial were found involving a total of 126 people with MS. Both studies were open to bias. There was no overall tendency in favour of pemoline over placebo and an excess of reports of adverse effects with pemoline. RESULTS - HEALTH ECONOMIC ANALYSIS: The drug costs of amantadine and pemoline are modest (pound 200 and pound 80 per annum, respectively). No economic evaluations were identified in the systematic review, and available data were insufficient to allow modelling of cost-effectiveness in this rapid review. CONCLUSIONS: There is insufficient evidence to allow people with MS, clinicians or policy makers to make informed decisions on the appropriate use of the many treatments on offer. Only amantadine appears to have some proven ability to alleviate the fatigue in MS, though only a proportion of users will obtain benefit and then only some of these patients will benefit sufficiently to take the drug in the long term. CONCLUSIONS - RECOMMENDATIONS FOR RESEARCH: The frequency, severity and impact of fatigue, the poverty of available research, and the absence of any ongoing research, suggest that new research is an urgent priority. People with MS, clinicians and policy makers should work together to ensure that the evidence required is collected as quickly as possible by encouraging involvement in rigorous research. Research should not be restricted to the two drugs reviewed in depth in this report. All interventions identified in the scoping review (see above) should be considered, as should basic scientific research into the underlying mechanism of fatigue in MS.