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1.
Neural Plast ; 2017: 8361290, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28255463

RESUMO

Autism spectrum disorder (ASD) is a neurodevelopmental disorder typified by impaired social communication and restrictive and repetitive behaviors. Mice serve as an ideal candidate organism for studying the neural mechanisms that subserve these symptoms. The Neuroligin-3 (NL3) mouse, expressing a R451C mutation discovered in two Swedish brothers with ASD, exhibits impaired social interactions and heightened aggressive behavior towards male mice. Social interactions with female mice have not been characterized and in the present study were assessed in male NL3R451C and WT mice. Mice were housed in social and isolation conditions to test for isolation-induced increases in social interaction. Tests were repeated to investigate potential differences in interaction in naïve and experienced mice. We identified heightened interest in mating and atypical aggressive behavior in NL3R451C mice. NL3R451C mice exhibited normal social interaction with WT females, indicating that abnormal aggressive behavior towards females is not due to altered motivation to engage. Social isolation rearing heightened interest in social behavior in all mice. Isolation housing selectively modulated the response to female pheromones in NL3R451C mice. This study is the first to show altered mating behavior in the NL3R451C mouse and has provided new insights into the aggressive phenotype in this model.


Assuntos
Agressão/fisiologia , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/psicologia , Moléculas de Adesão Celular Neuronais/genética , Proteínas de Membrana/genética , Proteínas do Tecido Nervoso/genética , Comportamento Sexual Animal/fisiologia , Isolamento Social , Animais , Comportamento Animal , Modelos Animais de Doenças , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação , Comportamento Social
2.
Health Technol Assess ; 17(8): 1-240, v-vi, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23449335

RESUMO

BACKGROUND: Women in England (aged 25-64 years) are invited for cervical screening every 3-5 years to assess for cervical intraepithelial neoplasia (CIN) or cancer. CIN is a term describing abnormal changes in the cells of the cervix, ranging from CIN1 to CIN3, which is precancerous. Colposcopy is used to visualise the cervix. Three adjunctive colposcopy technologies for examination of the cervix have been included in this assessment: Dynamic Spectral Imaging System (DySIS), the LuViva Advanced Cervical Scan and the Niris Imaging System. OBJECTIVE: To determine the clinical effectiveness and cost-effectiveness of adjunctive colposcopy technologies for examination of the uterine cervix for patients referred for colposcopy through the NHS Cervical Screening Programme. DATA SOURCES: Sixteen electronic databases [Allied and Complementary Medicine Database (AMED), BIOSIS Previews, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Register of Controlled Trials (CENTRAL), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Database of Abstracts of Reviews of Effects (DARE), EMBASE, Health Management Information Consortium (HMIC), Health Technology Assessment (HTA) database; Inspec, Inside Conferences, MEDLINE, NHS Economic Evaluation Database (NHS EED), PASCAL, Science Citation Index Expanded (SCIE) and Science Citation Index (SCI) - Conference Proceedings], and two clinical trial registries [ClinicalTrials.gov and Current Controlled Trials (CCT)] were searched to September-October 2011. REVIEW METHODS: Studies comparing DySIS, LuViva or Niris with conventional colposcopy were sought; a narrative synthesis was undertaken. A decision-analytic model was developed, which measured outcomes in terms of quality-adjusted life-years (QALYs) and costs were evaluated from the perspective of the NHS and Personal Social Services with a time horizon of 50 years. RESULTS: Six studies were included: two studies of DySIS, one study of LuViva and three studies of Niris. The DySIS studies were well reported and had a low risk of bias; they found higher sensitivity with DySIS (both the DySISmap alone and in combination with colposcopy) than colposcopy alone for identifying CIN2+ disease, although specificity was lower with DySIS. The studies of LuViva and Niris were poorly reported and had limitations, which indicated that their results were subject to a high risk of bias; the results of these studies cannot be considered reliable. The base-case cost-effectiveness analysis suggests that both DySIS treatment options are less costly and more effective than colposcopy alone in the overall weighted population; these results were robust to the ranges tested in the sensitivity analysis. DySISmap alone was more costly and more effective in several of the referral groups but the incremental cost-effectiveness ratio (ICER) was never higher than £1687 per QALY. DySIS plus colposcopy was less costly and more effective in all reasons for referral. Only indicative analyses were carried out on Niris and LuViva and no conclusions could be made on their cost-effectiveness. LIMITATIONS: The assessment is limited by the available evidence on the new technologies, natural history of the disease area and current treatment patterns. CONCLUSIONS: DySIS, particularly in combination with colposcopy, has higher sensitivity than colposcopy alone. There is no reliable evidence on the clinical effectiveness of LuViva and Niris. DySIS plus colposcopy appears to be less costly and more effective than both the DySISmap alone and colposcopy alone; these results were robust to the sensitivity analyses undertaken. Given the lack of reliable evidence on LuViva and Niris, no conclusions on their potential cost-effectiveness can be drawn. There is some uncertainty about how generalisable these findings will be to the population of women referred for colposcopy in the future, owing to the introduction of the human papillomavirus (HPV) triage test and uptake of the HPV vaccine.


Assuntos
Colposcópios/normas , Colposcopia/instrumentação , Avaliação da Tecnologia Biomédica , Displasia do Colo do Útero/diagnóstico , Adulto , Colposcopia/economia , Análise Custo-Benefício , Inglaterra , Feminino , Humanos , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Medicina Estatal
3.
Eur J Appl Physiol ; 113(5): 1199-211, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23138148

RESUMO

Aim of the study was to determine the influence of classic altitude training on hemoglobin mass (Hb-mass) in elite swimmers under the following aspects: (1) normal oscillation of Hb-mass at sea level; (2) time course of adaptation and de-adaptation; (3) sex influences; (4) influences of illness and injury; (5) interaction of Hb-mass and competition performance. Hb-mass of 45 top swimmers (male 24; female 21) was repeatedly measured (~6 times) over the course of 2 years using the optimized CO-rebreathing method. Twenty-five athletes trained between one and three times for 3-4 weeks at altitude training camps (ATCs) at 2,320 m (3 ATCs) and 1,360 m (1 ATC). Performance was determined by analyzing 726 competitions according to the German point system. The variation of Hb-mass without hypoxic influence was 3.0 % (m) and 2.7 % (f). At altitude, Hb-mass increased by 7.2 ± 3.3 % (p < 0.001; 2,320 m) and by 3.8 ± 3.4 % (p < 0.05; 1,360 m). The response at 2,320 m was not sex-related, and no increase was found in ill and injured athletes (n = 8). Hb-mass was found increased on day 13 and was still elevated 24 days after return (4.0 ± 2.7 %, p < 0.05). Hb-mass had only a small positive effect on swimming performance; an increase in performance was only observed 25-35 days after return from altitude. In conclusion, the altitude (2,320 m) effect on Hb-mass is still present 3 weeks after return, it decisively depends on the health status, but is not influenced by sex. In healthy subjects it exceeds by far the oscillation occurring at sea level. After return from altitude performance increases after a delay of 3 weeks.


Assuntos
Altitude , Hemoglobinas/análise , Natação/fisiologia , Aclimatação , Adaptação Fisiológica , Adolescente , Adulto , Atletas , Desempenho Atlético , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Fatores Sexuais
4.
Int J Sports Med ; 33(9): 691-5, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22706938

RESUMO

Sensitivity of the Athlete Blood Passport for blood doping could be improved by including total haemoglobin mass (Hb(mass)), but this measure may be unreliable immediately following strenuous exercise. We examined the stability of Hb(mass) following ultra-endurance triathlon (3.8 km swim, 180 km bike, 42.2 km run). 26 male sub-elite triathletes, 18 Racers and 8 Controls, were tested for Hb(mass) using CO re-breathing, twice 1-5 days apart. Racers were measured before and 1-3 h after the triathlon. Controls did no vigorous exercise on either test day. Serum haptoglobin concentration and urine haemoglobin concentration were measured to assess intravascular haemolysis. There was a 3.2% (p<0.01) increase in Racers' Hb(mass) from pre-race (976 g ± 14.6%, mean ±% coefficient of variation) to post-race (1 007 g ± 13.8%), as opposed to a - 0.5% decrease in Controls (pre-race 900 g ± 13.9%, post-race 896 g ± 12.4%). Haptoglobin was - 67% (p<0.01) reduced in Racers (pre-race 0.48 g / L ± 150%, post-race 0.16 g / L ± 432%), compared to - 6% reduced in Controls (pre-race 1.08 g / L ± 37%, post-race 1.02 g / L ± 37%). Decreased serum haptoglobin concentration in Racers, which is suggestive of mild intravascular blood loss, was contrary to the apparent Hb(mass) increase post-race. Ultra-endurance triathlon racing may confound the accuracy of post-exercise Hb(mass) measures, possibly due to splenic contraction or an increased rate of CO diffusion to intramuscular myoglobin.


Assuntos
Ciclismo/fisiologia , Hemoglobinas/metabolismo , Corrida/fisiologia , Natação/fisiologia , Adulto , Atletas , Monóxido de Carbono/metabolismo , Dopagem Esportivo/prevenção & controle , Exercício Físico/fisiologia , Haptoglobinas/metabolismo , Hemólise/fisiologia , Humanos , Masculino , Mioglobina/metabolismo , Resistência Física/fisiologia
5.
Health Technol Assess ; 16(28): 1-130, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22642789

RESUMO

BACKGROUND: Depression is the most common mental disorder in community settings and a major cause of disability across the world. The objective of treatment is to achieve remission or at least adequate control of depressive symptoms; however, even after successful treatment, the risk of relapse after remission is significant. Although the effectiveness of low-intensity interventions has been extensively evaluated to treat primary symptoms of psychological difficulties, there has been substantially less research examining the use of these interventions as a relapse prevention strategy. OBJECTIVE: To systematically review the clinical effectiveness and cost-effectiveness of low-intensity psychological or psychosocial interventions to prevent relapse or recurrence in patients with depression. As the broader definition of 'low-intensity' psychological intervention is somewhat contested, the review was conducted in two parts: A, a systematic review of all evaluations of 'low-intensity' interventions that were delivered by para-professionals, peer supporters or psychological well-being practitioners as defined by the Improving Access to Psychological Therapies programme; and B, a scoping review of relevant evaluations of interventions involving qualified mental health professionals (e.g. psychiatrists, clinical psychologists, cognitive behavioural therapists) involving < 6 hours of contact per patient. DATA SOURCES: Comprehensive literature searches were developed; electronic databases were searched from inception until September 2010 (including MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, PsycINFO, EMBASE, The Cochrane Library), internet resources were used to identify guidelines on the treatment of depression, and the bibliographies of relevant reviews, guidelines and included studies were scrutinised. REVIEW METHODS: Two reviewers independently screened titles and abstracts; data were extracted independently by one reviewer using a standardised data extraction form and checked by another. Discrepancies were resolved by consensus, with involvement of a third reviewer when necessary. The inclusion criteria were population - adults or adolescents who had received treatment for depression; intervention - part A, low-intensity interventions, specifically any unsupported psychological/psychosocial interventions or any supported interventions that did not involve highly qualified mental health professionals, and, part B, interventions carried out by qualified mental health professionals that involved < 6 hours of contact per patient; comparator - any, including no treatment, placebo, psychological or pharmacological interventions; outcomes - relapse or recurrence, other outcomes (e.g. social function, quality of life) were recorded where reported; and study design - for clinical effectiveness, randomised, quasi-randomised and non-randomised studies with concurrent control patients. For cost-effectiveness, full economic evaluations that compared two or more treatment options and considered both costs and consequences. No studies met the main part A inclusion criteria. RESULTS: For the clinical effectiveness review, 17 studies (14 completed, three ongoing), reported in 27 publications, met the part B inclusion criteria. These studies were clinically and methodologically diverse, and reported differing degrees of efficacy for the evaluated interventions. One randomised controlled trial (RCT), which evaluated a collaborative care-type programme, was potentially relevant to part A; this study reported no difference between patients receiving the intervention and those receiving usual care in terms of relapse of depression over 12 months. For the cost-effectiveness review, two studies met the criteria for part B. One of these was an economic evaluation of the RCT above, which was potentially relevant to part A. This evaluation found that the intervention may be a cost-effective use of resources when compared with usual care; however, it was unclear how valid these estimates were for the NHS. LIMITATIONS: Although any definition of 'brief' is likely to be somewhat arbitrary, an inclusion threshold of 6 hours contact per patient was used to select brief high-intensity intervention studies. Most excluded studies evaluated clearly resource-intensive interventions, though occasionally, studies were excluded on the basis of having only slightly more than 6 hours contact per patient. CONCLUSIONS: There is inadequate evidence to determine the clinical effectiveness or cost-effectiveness of low-intensity interventions for the prevention of relapse or recurrence of depression. A scoping review of brief high-intensity therapies indicates that some approaches have shown promise in some studies, but findings have not been consistent. Many uncertainties remain and further primary research is required. Careful consideration should be given to the scope of such research; it is important to evaluate the broader patient pathway accounting for the heterogeneous patient groups of interest. Future RCTs conducted in a UK primary care setting should include adult participants in remission or recovery from depression, and evaluate the quality of the intervention and consistency of delivery across practitioners where appropriate. The occurrence of relapse or recurrence should be measured using established methods, and functional outcomes as well as symptoms should be measured; data on quality of life using a generic instrument, such as the European Quality of Life-5 Dimensions (EQ-5D), should be collected. FUNDING: The National Institute for Health Research Health Technology Assessment programme.


Assuntos
Depressão/prevenção & controle , Psicoterapia/métodos , Prevenção Secundária/métodos , Análise Custo-Benefício , Depressão/economia , Depressão/terapia , Humanos , Psicoterapia/economia , Recidiva , Prevenção Secundária/economia , Resultado do Tratamento , Reino Unido
6.
Int J Sports Med ; 33(4): 253-7, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22318561

RESUMO

Haemoglobin mass (Hbmass) determination using CO rebreathing may assist to detect illegal blood doping practices, however variations in Hbmass with periods of intensive training and detraining must be quantified. This study aimed to determine the effect of a 30-day period of detraining on Hbmass in ultra-endurance triathletes. 9 male recreational triathletes (29-44 years) participated in the study. Hbmass was assessed using CO rebreathing 30 days and 10 days before an ultra-endurance triathlon and after ~10, 20 and 30 days of detraining following the race. V˙O2max was assessed 10 days before the race and also after the 30-day detraining period, which consisted of an 87% reduction in training hours. After 30-days of detraining there was a 3.1% decrease in mean Hbmass from 868±99 to 840±94 g, (p=0.03), and a 4.7% decrease in mean V˙O2max from 4.83±0.29 to 4.61±0.41 L/min as well as a 2.8% increase of body mass from 75.1±6.4 to 77.1±6.1 kg and a 28% increase in skinfold total from 43.9±14.2 to 55.1±14.0 mm. Individual decreases in Hbmass following detraining would need to be considered if using Hbmass for anti-doping purposes.


Assuntos
Ciclismo/fisiologia , Hemoglobinas/fisiologia , Consumo de Oxigênio/fisiologia , Educação Física e Treinamento , Corrida/fisiologia , Natação/fisiologia , Adulto , Volume Sanguíneo , Carboxihemoglobina/análise , Dopagem Esportivo/prevenção & controle , Humanos , Masculino , Resistência Física/fisiologia , Fatores de Tempo
7.
Scand J Med Sci Sports ; 22(6): 722-8, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21477205

RESUMO

A high hemoglobin mass (Hb(mass)) is associated with a high maximum aerobic power (VO(2max)), however, the extent to which Hb(mass) is influenced by training is currently unclear. Accordingly, this study monitored changes in Hb(mass) and VO(2max) in 12 previously untrained adults (aged 18-25 years) following 40 days of regular physical activity. Hb(mass) and VO(2max) were assessed at the start and end of a 40-day physical activity program, which comprised of approximately 40 min of daily, moderate-intensity physical activity. Relative VO(2max) increased by 11.3%, yet there was no significant change in relative Hb(mass) (1.7%) and body mass (0.2%) during the 40-day period. There was a significant correlation between Hb(mass) and VO(2max) at the start of the study (r=0.58, P=0.05), but not between the change in relative VO(2max) and the change in relative Hb(mass) (r=-0.07, P=0.83). Our results support the concept of relative stability in Hb(mass) with approximately 1 month of moderate-intensity physical activity suggesting that Hb(mass) may be used for talent identification and possibly for anti-doping purposes.


Assuntos
Exercício Físico/fisiologia , Hemoglobinas/metabolismo , Consumo de Oxigênio/fisiologia , Adolescente , Adulto , Volume Sanguíneo , Dopagem Esportivo/prevenção & controle , Feminino , Humanos , Masculino , Adulto Jovem
8.
Health Technol Assess ; 15 Suppl 1: 1-12, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21609648

RESUMO

This paper presents a summary of the evidence review group (ERG) report into the use of bevacizumab (Avastin®, Roche) in combination with a taxane for the treatment of untreated metastatic breast cancer (mBC). The main clinical effectiveness data were derived from a single, open-label randomised controlled trial (RCT) (E2100) that evaluated the addition of bevacizumab to weekly (q.w.) paclitaxel in patients with human epidermal growth factor receptor 2-negative mBC who had not previously received chemotherapy for advanced disease. This trial reported statistically significant increases in median progression-free survival (PFS) for the addition of bevacizumab (5.8-11.3 months). Median overall survival was not significantly different between the two groups; whether this is a true null finding or due to crossover between treatment arms cannot be established, as relevant data were not collected. The manufacturer reported that the addition of bevacizumab to paclitaxel q.w. therapy was associated with a significant improvement in quality of life, as measured by FACT-B (functional assessment of cancer therapy for breast cancer) scores. However, the ERG noted that these results were based on extreme imputed values, the removal of which led to non-significant differences in quality of life. The manufacturer conducted an indirect comparison. However, owing to methodological limitations and concerns about the validity and exchangeability of the included trials, the ERG did not consider the findings to be reliable. One additional relevant RCT [AVADO (Avastin and Docetaxel); BO17708] evaluating the addition of bevacizumab to docetaxel was excluded from the manufacturer's submission. This was summarised by the ERG. In terms of response rate and PFS, AVADO reported a markedly smaller benefit of adding bevacizumab to docetaxel than that reported for adding bevacizumab to q.w. paclitaxel in E2100. AVADO also reported no statistically significant effect of combination therapy versus docetaxel in terms of overall survival. The manufacturer developed a de novo economic model that considered patients with the same baseline characteristics as women in the E2100 trial. The model assessed BEV + PAC - bevacizumab 10 mg/kg every 2 weeks in combination with paclitaxel 90 mg/m2 weekly for 3 weeks followed by 1 week of rest; PAC q.w. - paclitaxel (monotherapy) 90 mg/m2 weekly for 3 weeks followed by 1 week of rest; DOC - docetaxel (monotherapy) 75 mg/m2 on day 1 every 21 days (considered current UK NHS clinical practice in the submission); and GEM + PAC - gemcitabine 1250 mg/m2 on days 1 and 8 plus paclitaxel 175 mg/m2 on day 1 every 21 days. Pairwise comparisons were made between BEV + PAC and PAC (using the E2100 trial), BEV + PAC and DOC, and BEV + PAC and GEM + PAC. Based on NHS list prices, the manufacturer's model estimated incremental cost-effectiveness ratios (ICERs) for BEV + PAC of £ 117,803, £ 115,059 and £ 105,777 per QALY gained, relative to PAC, DOC and GEM + PAC regimens, respectively. If the NHS Purchasing and Supply Agency prices for PAC with a 10-g cap on the cost per patient of BEV were used instead, the ICERs for BEV + PAC were estimated at £ 77,314, £ 57,753 and £ 60,101 per QALY, respectively. The submission suggested that the regimen of BEV + DOC is not cost-effective because it is considered less effective and more costly than BEV + PAC. Analysis by the ERG suggested that alternative assumptions can increase the ICERs further and, based on current prices, no plausible changes to the model assumptions will bring the ICERs for BEV + PAC lower.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Hidrocarbonetos Aromáticos com Pontes/uso terapêutico , Taxoides/uso terapêutico , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/economia , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/economia , Antineoplásicos/administração & dosagem , Antineoplásicos/economia , Bevacizumab , Neoplasias da Mama/patologia , Hidrocarbonetos Aromáticos com Pontes/administração & dosagem , Hidrocarbonetos Aromáticos com Pontes/economia , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Intervalo Livre de Doença , Docetaxel , Quimioterapia Combinada , Feminino , Humanos , Metástase Neoplásica , Paclitaxel/uso terapêutico , Anos de Vida Ajustados por Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Receptor ErbB-2 , Taxoides/administração & dosagem , Taxoides/economia , Gencitabina
9.
Health Technol Assess ; 15 Suppl 1: 33-42, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21609651

RESUMO

This paper presents a summary of the evidence review group (ERG) report into trastuzumab for the treatment of human epidermal growth factor receptor 2 (HER2)-positive metastatic adenocarcinoma of the stomach (mGC) or gastro-oesophageal junction. HER2 positivity is defined by immunohistochemistry (IHC)3+ or IHC2+/fluorescence in situ hybridisation (FISH)+. The decision problem addressed was the testing of the whole mGC population with IHC and, for IHC2+ patients, also with FISH, followed by treatment of HER2-positive patients with trastuzumab combined with cisplatin and either capecitabine or 5-fluorouracil (5-FU) [HCX (trastuzumab, cisplatin, capecitabine)/fluorouracil (F)] compared with current standard NHS therapy. The manufacturer's submission contained direct evidence from the ToGA trial, a well-conducted, multinational, phase III randomised controlled trial (RCT) that compared HCX/F with cisplatin and a fluoropyrimidine alone [cisplatin, capecitabine (CX)/F]. HCX/F showed statistically significantly better overall survival in the European Medicines Agency-licensed population subgroup (74%) (hazard ratio 0.65, 95% confidence interval 0.51 to 0.83), corresponding to median survival of 16 months versus 11.8 months. No other evidence exists for the efficacy of any therapy in a known HER2-positive mGC population; other comparisons extrapolate from trials in mixed HER2 status populations. The ERG accepted the manufacturer's view that a meaningful network meta-analysis to establish a comparison for HCX/F compared with current standard NHS therapy [epirubicin, cisplatin, capecitabine (ECX)/epirubicin, oxaliplatin, capecitabine (EOX)/epirubicin, cisplatin, 5-FU (ECF)] was not possible, but was unconvinced by arguments advanced in the alternative narrative synthesis. These involved disregarding evidence from a meta-analysis and interpreting non-significant results of small RCTs comparing epirubicin-containing triplets with cisplatin, 5-FU (CF)/capecitabine (X) doublets as evidence of no difference between triplet and doublet regimens. The high CX/F dose in the ToGA trial was an additional basis for the contention of equivalence. An appropriate de novo economic evaluation, including an economic model that separately compared HCX or trastuzumab, cisplatin, 5-FU (HCF) with the triplet regimens ECX, EOX and ECF, based on a simple, three-state cohort model (progression-free, disease, progression and death), was submitted. Utility weights were applied to estimate quality-adjusted life-years (QALYs). Costs were assessed from an NHS perspective, and incorporated the acquisition and monitoring costs of the alternative regimens, HER2 testing, adverse events and other supportive care costs. An 8-year time horizon was used to represent a lifetime analysis. Results from the ToGA trial were combined with a series of assumptions on relative treatment effects and testing strategies. The manufacturer's results produced an incremental cost-effectiveness ratio (ICER) of £ 53,010 per QALY for HCX versus ECX. Although the manufacturer undertook a detailed set of sensitivity analyses, several alternative model assumptions were not evaluated. The ERG undertook a series of alternative base-case analyses. As a result of these analyses, EOX replaced ECX as the appropriate comparator, and the ICER for the comparison of HCX vs EOX increased to between £ 66,982 and £ 71,636 per QALY. The impact of implementation of alternative testing strategies remained unclear. There is also considerable uncertainty surrounding the true estimate of effectiveness for the comparison between triplet regimens containing epirubicin (ECX/ECF/EOX) and doublet CX/F regimens. Consequently, the view of the ERG was that there is insufficient evidence on the efficacy of HCX/F compared with current NHS standard therapy for an ICER to be determined with any degree of certainty.


Assuntos
Adenocarcinoma/tratamento farmacológico , Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos/uso terapêutico , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Gástricas/tratamento farmacológico , Adenocarcinoma/patologia , Anticorpos Monoclonais Humanizados/administração & dosagem , Antineoplásicos/administração & dosagem , Antineoplásicos/economia , Capecitabina , Cisplatino/uso terapêutico , Ensaios Clínicos Fase III como Assunto , Análise Custo-Benefício , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Epirubicina/uso terapêutico , Neoplasias Esofágicas/patologia , Fluoruracila/análogos & derivados , Fluoruracila/uso terapêutico , Humanos , Hibridização in Situ Fluorescente , Metanálise como Assunto , Estudos Multicêntricos como Assunto , Metástase Neoplásica , Anos de Vida Ajustados por Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Receptor ErbB-2 , Neoplasias Gástricas/patologia , Trastuzumab
10.
Health Technol Assess ; 14(Suppl. 2): 11-7, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21047486

RESUMO

This paper presents a summary of the evidence review group (ERG) report into capecitabine for advanced gastric cancer (aGC). Capecitabine is an oral prodrug of 5-fluorouracil (5-FU). The decision problem addressed was the use of capecitabine (X) compared to 5-FU (F), in combination regimens with platinum agents [cisplatin (C) or oxaliplatin (O)] with or without epirubicin (E), in patients with inoperable aGC. Approximately 7000 new cases of gastric cancer are diagnosed in England and Wales every year. Of these, 80% are candidates for palliative chemotherapy and around 2900 receive such treatment. The standard UK practice for patients with aGC who are considered fit enough has consisted of a triplet regimen comprising intravenous 5-FU in combination with a platinum agent (capecitabine or oxaliplatin) and epirubicin. The manufacturer's submission (MS) focused on direct evidence from two phase III non-inferiority randomised controlled trials (RCTs), REAL-2 (Randomized ECF for Advanced and Locally advanced oesophagogastric cancer-2; n = 1002) and ML17032 (n = 316). REAL-2 randomised patients to four regimens (ECF, ECX, EOF and EOX) to compare 5-FU with capecitabine and cisplatin with oxaliplatin, whereas ML17032 compared CX with CF. Efficacy outcomes from these trials were pooled in an individual patient data (IPD) meta-analysis. Both RCTs demonstrated statistically significant non-inferiority of capecitabine on the outcome of overall survival (OS) assessed in the per-protocol population; equivalent results were also demonstrated for progression-free survival (PFS). The IPD meta-analysis found a statistically significant benefit in OS for capecitabine compared with 5-FU [unadjusted hazard ratio (HR): 0.87; 95% confidence interval (CI) 0.77 to 0.98, p = 0.027]. There was no evidence of a poorer safety profile for capecitabine overall, nor of any difference in quality of life (QoL) between the two fluoropyrimidines. The MS included a de novo economic evaluation based on a cost-minimisation analysis (CMA), where the costs of capecitabine-based regimens were compared with their equivalent 5-FU-based regimens in aGC. A time horizon of 5.5 cycles (each lasting for 21 days) was used in the base-case analysis, representing the duration of treatment. The results of the manufacturer's base-case analysis showed that capecitabine regimens are associated with mean net cost savings of 1620 pounds (ECX vs ECF), 1572 pounds (EOX vs EOF) and 4210 pounds (CX vs CF). The manufacturer failed to comment explicitly on the uncertainty around the estimates of efficacy and on the fact that the IPD meta-analysis suggests that capecitabine may actually be more effective on average. Further analyses exploring additional costs incurred by the UK NHS from extending survival duration showed that these are unlikely to have a material effect on conclusions. A full probabilistic analysis was not performed; however, the evidence explored by the MS and ERG is consistent in suggesting that capecitabine has a lower mean cost than 5-FU-based regimens. The submission was considered to contain convincing evidence of the non-inferiority of capecitabine to 5-FU on survival; this evidence was considered to be applicable to UK practice. Although some uncertainty remains, the ERG deemed CMA to be an appropriate framework with which to analyse this decision problem. Overall cost estimates for the CMA were generated appropriately and were robust to uncertainties regarding assumptions and sources. At the time of writing, the guidance document issued by NICE on 28 July 2010 states that capecitabine in combination with a platinum-based regimen is recommended for the first-line treatment of inoperable advanced gastric cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Capecitabina , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Fluoruracila/administração & dosagem , Fluoruracila/análogos & derivados , Fluoruracila/economia , Humanos , Cuidados Paliativos/métodos , Pró-Fármacos/administração & dosagem
11.
Health Technol Assess ; 14(37): 1-288, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20663420

RESUMO

BACKGROUND: Photodynamic therapy (PDT) is the use of a light-sensitive drug, in combination with light of a visible wavelength, to destroy target cells. PDT is used either as a primary treatment or as an adjunctive treatment. It is fairly well accepted in clinical practice for some types of skin cancer but has yet to be fully explored as a treatment for other forms of cancer. OBJECTIVE: To systematically review the clinical effectiveness and safety of PDT in the treatment of Barrett's oesophagus, pre-cancerous skin conditions and the following cancers: biliary tract, brain, head and neck, lung, oesophageal and skin. DATA SOURCES: The search strategy included searching electronic databases (between August and October 2008), followed by update searches in May 2009, along with relevant bibliographies, existing reviews, conference abstracts and contact with experts in the field. STUDY DESIGNS: Randomised controlled trials (RCTs) in skin conditions and Barrett's oesophagus, non-randomised trials for all other sites. PARTICIPANTS: People with Barrett's oesophagus, pre-cancerous skin conditions or primary cancer in the following sites: biliary tract, brain, head and neck, lung, oesophageal and skin. INTERVENTION: Any type of PDT for either curative or palliative treatment. COMPARATORS: Any comparator including differing applications of PDT treatments (relevant comparators varied according to the condition). MAIN OUTCOMES: The outcomes measured were mortality, morbidity, quality of life, adverse events and resource use. REVIEW METHODS: A standardised data extraction form was used. The quality of RCTs and non-randomised controlled studies was assessed using standard checklists. Data extracted from the studies were tabulated and discussed in a narrative synthesis, and the influence of study quality on results was discussed. Meta-analysis was used to estimate a summary measure of effect on relevant outcomes, with assessment of both clinical and statistical heterogeneity. Two reviewers independently screened all titles and abstracts, and data extracted and quality assessed the trials, with discrepancies resolved by discussion or referral to a third reviewer. A scoping review was also undertaken. RESULTS: Overall, 88 trials reported in 141 publications were included, with some trials covering more than one condition. For actinic keratosis (AK), the only clear evidence of effectiveness was that PDT appeared to be superior to placebo. For Bowen's disease, better outcomes with PDT were suggested when compared with cryotherapy or fluorouracil. For basal cell carcinoma (BCC), PDT may result in similar lesion response rates to surgery or cryotherapy but with better cosmetic outcomes. For nodular lesions, PDT appeared to be superior to placebo and less effective than surgery but suggestive of better cosmetic outcome. For Barrett's oesophagus, PDT in addition to omeprazole appeared to be more effective than omeprazole alone at long-term ablation of high-grade dysplasia and slowing/preventing progression to cancer. No firm conclusions could be drawn for PDT in oesophageal cancer. Further research into the role of PDT in lung cancer is needed. For cholangiocarcinoma, PDT may improve survival when compared with stenting alone. There was limited evidence on PDT for brain cancer and cancers of the head and neck. A wide variety of photosensitisers were used and, overall, no serious adverse effects were linked to PDT. LIMITATIONS: There were few well-conducted, adequately powered RCTs, and quality of life (QoL) and resource outcomes were under-reported. Problems were identified with reporting of key study features and quality parameters, making the reliability of some studies uncertain. Methodological limitations and gaps in the evidence base made it difficult to draw firm conclusions. CONCLUSIONS: Evidence of effectiveness was found for PDT in the treatment of AK and nodular BCC in relation to placebo, and possibly for treating Barrett's oesophagus. However, the effectiveness of PDT in relation to other treatments is not yet apparent. High-quality trials are needed to compare PDT with relevant comparators for all meaningful outcomes, including QoL and adverse effects. Further research is also needed on patient experience of PDT, as well as on the cost-effectiveness of PDT.


Assuntos
Neoplasias/tratamento farmacológico , Fotoquimioterapia/métodos , Lesões Pré-Cancerosas/tratamento farmacológico , Esôfago de Barrett/tratamento farmacológico , Esôfago de Barrett/mortalidade , Neoplasias do Sistema Biliar/tratamento farmacológico , Neoplasias do Sistema Biliar/mortalidade , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/mortalidade , Ensaios Clínicos como Assunto , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/mortalidade , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/mortalidade , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/mortalidade , Neoplasias/mortalidade , Fotoquimioterapia/efeitos adversos , Qualidade de Vida , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/mortalidade
12.
Health Technol Assess ; 14 Suppl 1: 55-62, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20507804

RESUMO

This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of topotecan in combination with cisplatin for the treatment of recurrent and stage IVB carcinoma of the cervix, in accordance with the licensed indication, based upon the evidence submission from the manufacturer to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The outcomes measured were overall survival, progression-free survival, response rates, adverse effects of treatment, health-related quality of life (HRQoL) and quality-adjusted life-years (QALYs) gained. The manufacturer stated that topotecan plus cisplatin is the only combination regimen to date to have demonstrated a statistically significant survival advantage compared to cisplatin monotherapy in the licensed population. The clinical evidence came from three clinical trials comparing topotecan plus cisplatin with cisplatin monotherapy (GOG-0179), topotecan plus cisplatin with paclitaxel plus cisplatin (GOG-0169), and four cisplatin-based combination therapies: topotecan plus cisplatin, paclitaxel plus cisplatin, gemcitabine plus cisplatin, and vinorelbine plus cisplatin (GOG-0204). Results from GOG-0179 showed greater median overall survival with topotecan plus cisplatin than with cisplatin monotherapy: 9.4 months versus 6.5 months. Similar results were also reported for median progression-free survival. Response rates also showed an advantage with topotecan plus cisplatin compared with cisplatin monotherapy. The response rates in patients receiving cisplatin monotherapy were very low, but the potential reasons for this were not discussed in the manufacturer's submission. Patients receiving topotecan plus cisplatin experienced a greater number of adverse events and the ERG was concerned with some of the assumptions related to HRQoL. In the base-case direct comparison, the incremental cost-effectiveness ratio (ICER) of topotecan plus cisplatin versus cisplatin monotherapy was 17,974 pounds per QALY in the main licensed population, 10,928 pounds per QALY in the cisplatin-naive population (including stage IVB patients) and 32,463 pounds per QALY in sustained cisplatin-free interval patients. In response to the point for clarification raised by the ERG, the manufacturer submitted a revised indirect comparison incorporating HRQoL and a longer time horizon. Where the hazard ratio derived from GOG-0169 was employed, paclitaxel plus cisplatin was dominated by topotecan plus cisplatin, but, where the hazard ratio from GOG-0204 was adopted, paclitaxel plus cisplatin was found to have an ICER of 13,260 pounds per QALY versus topotecan plus cisplatin. At present there is a paucity of evidence available on the clinical effects of topotecan plus cisplatin and the effects of palliative treatment in general for women with advanced and recurrent carcinoma of the cervix. Further trials, or the implementation of registries, are required to establish the efficacy and safety of topotecan plus cisplatin. The guidance issued by NICE on 28 October 2009 as a result of the STA states that topotecan in combination with cisplatin is recommended as a treatment option for women with recurrent or stage IVB cervical cancer, only if they have not previously received cisplatin. Women who have previously received cisplatin and are currently being treated with topotecan in combination with cisplatin for the treatment of cervical cancer should have the option to continue therapy until they and their clinicians consider it appropriate to stop.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma/tratamento farmacológico , Cisplatino/uso terapêutico , Topotecan/uso terapêutico , Neoplasias do Colo do Útero/tratamento farmacológico , Antimetabólitos Antineoplásicos/uso terapêutico , Antineoplásicos Fitogênicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/economia , Carcinoma/economia , Carcinoma/mortalidade , Carcinoma/patologia , Cisplatino/economia , Análise Custo-Benefício , Reagentes de Ligações Cruzadas/uso terapêutico , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Progressão da Doença , Quimioterapia Combinada/economia , Feminino , Humanos , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Qualidade de Vida , Anos de Vida Ajustados por Qualidade de Vida , Radiossensibilizantes/uso terapêutico , Topotecan/economia , Resultado do Tratamento , Reino Unido , Neoplasias do Colo do Útero/economia , Neoplasias do Colo do Útero/mortalidade , Neoplasias do Colo do Útero/patologia , Vimblastina/análogos & derivados , Vimblastina/uso terapêutico , Vinorelbina , Gencitabina
13.
Br J Cancer ; 98(4): 697-707, 2008 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-18268497

RESUMO

The objectives of this study were to assess the effectiveness and safety of parenteral oestrogen in the treatment of prostate cancer, and to examine any dose relationship. A systematic review was undertaken. Electronic databases, published paper and internet resources were searched to locate published and unpublished studies with no restriction by language or publication date. Studies included were randomised controlled trials of parenteral oestrogen in patients with prostate cancer; other study designs were also included to examine dose-response. Study selection, appraisal, data extraction and quality assessment were performed by one reviewer and independently checked by another. Twenty trials were included in the review. The trials differed with regard to the included patients, formulation and dose of parenteral oestrogen, comparator used, outcome measures reported and the duration of follow-up. The results provide no evidence to suggest that parenteral oestrogen, in doses sufficient to produce castrate levels of testosterone, is less effective than luteinising hormone-releasing hormone (LHRH) or orchidectomy in controlling prostate cancer, or that it is consistently associated with an increase in cardiovascular mortality. Further well-conducted trials of parenteral oestrogen are required. A pilot randomised controlled trial comparing transdermal oestrogen to LHRH analogues in men with locally advanced or metastatic prostate cancer is underway in the United Kingdom.


Assuntos
Estrogênios/administração & dosagem , Neoplasias da Próstata/tratamento farmacológico , Ensaios Clínicos como Assunto , Humanos , Infusões Parenterais , Masculino
14.
Health Technol Assess ; 12(1): iii-iv, xi-xii, 1-147, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18093447

RESUMO

OBJECTIVES: To determine whether there is a level of methicillin-resistant Staphylococcus aureus (MRSA) prevalence at which a switch from non-glycopeptide to glycopeptide antibiotics for routine prophylaxis is indicated in surgical environments with a high risk of MRSA infection. DATA SOURCES: Major electronic databases were searched up to September 2005. REVIEW METHODS: The effectiveness review included controlled clinical trials comparing a glycopeptide with an alternative antibiotic regimen that reported effectiveness and/or adverse events. Controlled observational studies were also included for adverse events. The cost-effectiveness review included economic evaluations comparing glycopeptide prophylaxis with any alternative comparator. Study validity was assessed using standard checklists. The supplementary economic reviews assessed evaluations of non-glycopeptide antibiotic prophylaxis; evaluations where antibiotic resistance is a problem; methods of modelling resistance in infectious diseases; and developing a conceptual framework. An indicative decision analytic model was developed to compare vancomycin with a cephalosporin and with a combination of vancomycin and cephalosporin, using hip arthroplasty as an exemplar. Available data on, for example, surgical site infection (SSI) rates, MRSA rates, effectiveness of the antibiotics, were incorporated into the model. Costs were estimated from the perspective of the NHS. RESULTS: The effectiveness review included 16 randomised controlled trials, with a further three studies included for adverse events only. There was no evidence that glycopeptides were more effective than non-glycopeptides in preventing SSIs. Most of the trials did not report either the baseline prevalence of MRSA at the participating surgical units or MRSA infections as an outcome. The cost-effectiveness review included five economic evaluations of glycopeptide prophylaxis. Only one study incorporated health-related quality of life and undertook a cost-utility analysis. None of the studies was undertaken in the UK and none explicitly modelled antibiotic resistance. The supplementary reviews provided few insights into how to assess cost-effectiveness in the context of resistance. No studies modelled cost-effectiveness alongside epidemiological models of resistance. There was little information regarding the impact of surgical infections on costs post-discharge and patient quality of life. The lack of available clinical evidence limited the development of the cost-effectiveness model and meant that the modelling could only be indicative in nature. The model can be used to show the threshold baseline risk at which the use of vancomycin as prophylaxis might be cost-effective (the model did not include teicoplanin). The indicative model suggests that the baseline risk of MRSA can be fairly modest at below the national average and it would still appear cost-effective to use glycopeptide prophylaxis. The model indicates that the use of glycopeptides as a form of prophylaxis in addition to a treatment for MRSA infections is unlikely to decrease the total usage and hence reduce the risk of future problems with glycopeptide-resistant bacteria. CONCLUSIONS: There is insufficient evidence to determine whether there is a threshold prevalence of MRSA at which switching from non-glycopeptide to glycopeptide antibiotic prophylaxis might be clinically effective and cost-effective. Future research needs to address the complexities of decision-making relating to the prevention of MRSA and infection control in general. Research including evidence synthesis and decision modelling comparing a full range of interventions for infection control, which extends to other infections, not just MRSA, is needed. A long-term research programme to predict the pattern of drug resistance and its implications for future costs and health is also needed.


Assuntos
Antibacterianos , Antibioticoprofilaxia , Cefalosporinas , Glicopeptídeos , Procedimentos Cirúrgicos Operatórios , Infecção da Ferida Cirúrgica , Antibacterianos/efeitos adversos , Antibacterianos/economia , Antibacterianos/uso terapêutico , Antibioticoprofilaxia/efeitos adversos , Antibioticoprofilaxia/economia , Antibioticoprofilaxia/métodos , Cefalosporinas/efeitos adversos , Cefalosporinas/economia , Cefalosporinas/uso terapêutico , Análise Custo-Benefício , Uso de Medicamentos , Glicopeptídeos/efeitos adversos , Glicopeptídeos/economia , Glicopeptídeos/uso terapêutico , Humanos , Resistência a Meticilina , Modelos Econométricos , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Infecções Estafilocócicas/economia , Infecções Estafilocócicas/prevenção & controle , Procedimentos Cirúrgicos Operatórios/economia , Procedimentos Cirúrgicos Operatórios/métodos , Infecção da Ferida Cirúrgica/economia , Infecção da Ferida Cirúrgica/prevenção & controle
15.
Health Technol Assess ; 9(27): iii-iv, ix-xi, 1-158, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16022802

RESUMO

OBJECTIVES: To identify and prioritise key areas of clinical uncertainty regarding the medical management of non-ST elevation acute coronary syndrome (ACS) in current UK practice. DATA SOURCES: Electronic databases. Consultations with clinical advisors. Postal survey of cardiologists. REVIEW METHODS: Potential areas of important uncertainty were identified and 'decision problems' prioritised. A systematic literature review was carried out using standard methods. The constructed decision model consisted of a short-term phase that applied the results of the systematic review and a long-term phase that included relevant information from a UK observational study to extrapolate estimated costs and effects. Sensitivity analyses were undertaken to examine the dependence of the results on baseline parameters, using alternative data sources. Expected value of information analysis was undertaken to estimate the expected value of perfect information associated with the decision problem. This provided an upper bound on the monetary value associated with additional research in the area. RESULTS: Seven current areas of clinical uncertainty (decision problems) in the drug treatment of unstable angina patients were identified. The agents concerned were clopidogrel, low molecular weight heparin, hirudin and intravenous glycoprotein antagonists (GPAs). Twelve published clinical guidelines for unstable angina or non-ST elevation ACS were identified, but few contained recommendations about the specified decision problems. The postal survey of clinicians showed that the greatest disagreement existed for the use of small molecule GPAs, and the greatest uncertainty existed for decisions relating to the use of abciximab (a large molecule GPA). Overall, decision problems concerning the GPA class of drugs were considered to be the highest priority for further study. Selected papers describing the clinical efficacy of treatment were divided into three groups, each representing an alternative strategy. The strategy involving the use of GPAs as part of the initial medical management of all non-ST elevation ACS was the optimal choice, with an incremental cost-effectiveness ratio (ICER) of 5738 pounds per quality-adjusted life-year (QALY) compared with no use of GPAs. Stochastic analysis showed that if the health service is willing to pay 10,000 pounds per additional QALY, the probability of this strategy being cost-effective was around 82%, increasing to 95% at a threshold of 50,000 pounds per QALY. A sensitivity analysis including an additional strategy of using GPAs as part of initial medical management only in patients at particular high risk (as defined by age, ST depression or diabetes) showed that this additional strategy was yet more cost-effective, with an ICER of 3996 pounds per QALY compared with no treatment with GPA. Value of information analysis suggested that there was considerable merit in additional research to reduce the level of uncertainty in the optimal decision. At a threshold of 10,000 pounds per QALY, the maximum potential value of such research in the base case was calculated as 12.7 million pounds per annum for the UK as a whole. Taking account of the greater uncertainty in the sensitivity analyses including clopidogrel, this figure was increased to approximately 50 million pounds. CONCLUSIONS: This study suggests the use of GPAs in all non-ST elevation ACS patients as part of their initial medical management. Sensitivity analysis showed that virtually all of the benefit could be realised by treating only high-risk patients. Further clarification of the optimum role of GPAs in the UK NHS depends on the availability of further high-quality observational and trial data. Value of information analysis derived from the model suggests that a relatively large investment in such research may be worthwhile. Further research should focus on the identification of the characteristics of patients who benefit most from GPAs as part of medical management, the comparison of GPAs with clopidogrel as an adjunct to standard care, follow-up cohort studies of the costs and outcomes of high-risk non-ST elevation ACS over several years, and exploring how clinicians' decisions combine a normative evidence-based decision model with their own personal behavioural perspective.


Assuntos
Angina Instável/tratamento farmacológico , Análise Custo-Benefício , Infarto do Miocárdio/tratamento farmacológico , Doença Aguda , Antagonistas Adrenérgicos beta/economia , Antagonistas Adrenérgicos beta/uso terapêutico , Anticoagulantes/economia , Anticoagulantes/uso terapêutico , Bloqueadores dos Canais de Cálcio/economia , Bloqueadores dos Canais de Cálcio/uso terapêutico , Técnicas de Apoio para a Decisão , Quimioterapia Combinada , Medicina Baseada em Evidências , Humanos , Inibidores da Agregação Plaquetária/economia , Inibidores da Agregação Plaquetária/uso terapêutico , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Prognóstico , Anos de Vida Ajustados por Qualidade de Vida , Medição de Risco , Síndrome
16.
Health Technol Assess ; 9(26): 1-134, iii-iv, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16014203

RESUMO

OBJECTIVES: To survey the frequency of use of indirect comparisons in systematic reviews and evaluate the methods used in their analysis and interpretation. Also to identify alternative statistical approaches for the analysis of indirect comparisons, to assess the properties of different statistical methods used for performing indirect comparisons and to compare direct and indirect estimates of the same effects within reviews. DATA SOURCES: Electronic databases. REVIEW METHODS: The Database of Abstracts of Reviews of Effects (DARE) was searched for systematic reviews involving meta-analysis of randomised controlled trials (RCTs) that reported both direct and indirect comparisons, or indirect comparisons alone. A systematic review of MEDLINE and other databases was carried out to identify published methods for analysing indirect comparisons. Study designs were created using data from the International Stroke Trial. Random samples of patients receiving aspirin, heparin or placebo in 16 centres were used to create meta-analyses, with half of the trials comparing aspirin and placebo and half heparin and placebo. Methods for indirect comparisons were used to estimate the contrast between aspirin and heparin. The whole process was repeated 1000 times and the results were compared with direct comparisons and also theoretical results. Further detailed case studies comparing the results from both direct and indirect comparisons of the same effects were undertaken. RESULTS: Of the reviews identified through DARE, 31/327 (9.5%) included indirect comparisons. A further five reviews including indirect comparisons were identified through electronic searching. Few reviews carried out a formal analysis and some based analysis on the naive addition of data from the treatment arms of interest. Few methodological papers were identified. Some valid approaches for aggregate data that could be applied using standard software were found: the adjusted indirect comparison, meta-regression and, for binary data only, multiple logistic regression (fixed effect models only). Simulation studies showed that the naive method is liable to bias and also produces over-precise answers. Several methods provide correct answers if strong but unverifiable assumptions are fulfilled. Four times as many similarly sized trials are needed for the indirect approach to have the same power as directly randomised comparisons. Detailed case studies comparing direct and indirect comparisons of the same effect show considerable statistical discrepancies, but the direction of such discrepancy is unpredictable. CONCLUSIONS: Direct evidence from good-quality RCTs should be used wherever possible. Without this evidence, it may be necessary to look for indirect comparisons from RCTs. However, the results may be susceptible to bias. When making indirect comparisons within a systematic review, an adjusted indirect comparison method should ideally be used employing the random effects model. If both direct and indirect comparisons are possible within a review, it is recommended that these be done separately before considering whether to pool data. There is a need to evaluate methods for the analysis of indirect comparisons for continuous data and for empirical research into how different methods of indirect comparison perform in cases where there is a large treatment effect. Further study is needed into when it is appropriate to look at indirect comparisons and when to combine both direct and indirect comparisons. Research into how evidence from indirect comparisons compares to that from non-randomised studies may also be warranted. Investigations using individual patient data from a meta-analysis of several RCTs using different protocols and an evaluation of the impact of choosing different binary effect measures for the inverse variance method would also be useful.


Assuntos
Pesquisa Biomédica/métodos , Metanálise como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Literatura de Revisão como Assunto , Viés , Humanos , Projetos de Pesquisa , Resultado do Tratamento
18.
Qual Saf Health Care ; 14(1): 62-6, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15692007

RESUMO

A summary of a systematic review of clinical audits of cancer referrals in England and Wales.


Assuntos
Auditoria Administrativa , Neoplasias/terapia , Listas de Espera , Inglaterra , Feminino , Humanos , Masculino , Garantia da Qualidade dos Cuidados de Saúde , País de Gales
19.
Health Technol Assess ; 8(49): iii-iv, 1-192, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15544708

RESUMO

OBJECTIVES: To review, and to develop further, the methods used to assess and to increase the generalisability of economic evaluation studies. DATA SOURCES: Electronic databases. REVIEW METHODS: Methodological studies relating to economic evaluation in healthcare were searched. This included electronic searches of a range of databases, including PREMEDLINE, MEDLINE, EMBASE and EconLit, and manual searches of key journals. The case studies of a decision analytic model involved highlighting specific features of previously published economic studies related to generalisability and location-related variability. The case-study involving the secondary analysis of cost-effectiveness analyses was based on the secondary analysis of three economic studies using data from randomised trials. RESULTS: The factor most frequently cited as generating variability in economic results between locations was the unit costs associated with particular resources. In the context of studies based on the analysis of patient-level data, regression analysis has been advocated as a means of looking at variability in economic results across locations. These methods have generally accepted that some components of resource use and outcomes are exchangeable across locations. Recent studies have also explored, in cost-effectiveness analysis, the use of tests of heterogeneity similar to those used in clinical evaluation in trials. The decision analytic model has been the main means by which cost-effectiveness has been adapted from trial to non-trial locations. Most models have focused on changes to the cost side of the analysis, but it is clear that the effectiveness side may also need to be adapted between locations. There have been weaknesses in some aspects of the reporting in applied cost-effectiveness studies. These may limit decision-makers' ability to judge the relevance of a study to their specific situations. The case study demonstrated the potential value of multilevel modelling (MLM). Where clustering exists by location (e.g. centre or country), MLM can facilitate correct estimates of the uncertainty in cost-effectiveness results, and also a means of estimating location-specific cost-effectiveness. The review of applied economic studies based on decision analytic models showed that few studies were explicit about their target decision-maker(s)/jurisdictions. The studies in the review generally made more effort to ensure that their cost inputs were specific to their target jurisdiction than their effectiveness parameters. Standard sensitivity analysis was the main way of dealing with uncertainty in the models, although few studies looked explicitly at variability between locations. The modelling case study illustrated how effectiveness and cost data can be made location-specific. In particular, on the effectiveness side, the example showed the separation of location-specific baseline events and pooled estimates of relative treatment effect, where the latter are assumed exchangeable across locations. CONCLUSIONS: A large number of factors are mentioned in the literature that might be expected to generate variation in the cost-effectiveness of healthcare interventions across locations. Several papers have demonstrated differences in the volume and cost of resource use between locations, but few studies have looked at variability in outcomes. In applied trial-based cost-effectiveness studies, few studies provide sufficient evidence for decision-makers to establish the relevance or to adjust the results of the study to their location of interest. Very few studies utilised statistical methods formally to assess the variability in results between locations. In applied economic studies based on decision models, most studies either stated their target decision-maker/jurisdiction or provided sufficient information from which this could be inferred. There was a greater tendency to ensure that cost inputs were specific to the target jurisdiction than clinical parameters. Methods to assess generalisability and variability in economic evaluation studies have been discussed extensively in the literature relating to both trial-based and modelling studies. Regression-based methods are likely to offer a systematic approach to quantifying variability in patient-level data. In particular, MLM has the potential to facilitate estimates of cost-effectiveness, which both reflect the variation in costs and outcomes between locations and also enable the consistency of cost-effectiveness estimates between locations to be assessed directly. Decision analytic models will retain an important role in adapting the results of cost-effectiveness studies between locations. Recommendations for further research include: the development of methods of evidence synthesis which model the exchangeability of data across locations and allow for the additional uncertainty in this process; assessment of alternative approaches to specifying multilevel models to the analysis of cost-effectiveness data alongside multilocation randomised trials; identification of a range of appropriate covariates relating to locations (e.g. hospitals) in multilevel models; and further assessment of the role of econometric methods (e.g. selection models) for cost-effectiveness analysis alongside observational datasets, and to increase the generalisability of randomised trials.


Assuntos
Doença das Coronárias/economia , Análise Custo-Benefício , Atenção à Saúde/economia , Modelos Econométricos , Osteoporose Pós-Menopausa/economia , Doença das Coronárias/tratamento farmacológico , Tomada de Decisões , Feminino , Humanos , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Anos de Vida Ajustados por Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto
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