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Biomedical subjects

C Cave

Publications and source records attributed to C Cave.

At least 19 recordsLinked to original sources
PubMed2005

Clinical effectiveness and cost-effectiveness of drotrecogin alfa (activated) (Xigris) for the treatment of severe sepsis in adults: a systematic review and economic evaluation.

OBJECTIVES: To assess the clinical and cost-effectiveness of drotrecogin alfa (activated) for the treatment of adults with severe sepsis in a UK context. DATA SOURCES: Electronic databases. Data from the commercial use of the drug up to April 2002. Data from the manufacturer submission to the National Institute for Clinical Excellence (NICE). REVIEW METHODS: A systematic review of the literature and an economic evaluation were undertaken. Data were synthesised through a narrative review with full tabulation of results from included studies. RESULTS: The evidence on the effectiveness of drotrecogin alfa (activated) for the treatment of severe sepsis came primarily from one large pivotal randomised controlled trial, the PROWESS study. This study demonstrated a statistically significant absolute reduction in 28-day mortality of 6.5%. Longer term survival benefit was maintained to 90 days. By 9 months, the trend towards increased median survival was non-significant, although the survival curves did not cross. Results presented by the number of organ dysfunctions were not statistically significant, but when mortality rates for those with two or more organ failures were combined, the relative risk of death was significantly lower in those treated with drotrecogin alfa (activated) compared with placebo. However, this report highlights a number of considerations relevant to the subgroup analyses reported for the PROWESS study. Published cost-effectiveness studies of treatment with drotrecogin alfa (activated) have applied a range of methods to the estimation of benefits, estimating an incremental gain per treated patient of between 0.38 and 0.68 life-years (for patients with severe sepsis). For patients with severe sepsis and multiple organ dysfunction, the manufacturer (Eli Lilly) estimated an incremental gain of 1.115 life-years per treated patient, compared to 1.351 life-years per treated patient estimated by the Southampton Health Technology Assessments Centre (SHTAC). These latter UK analyses are based on a patient group that is more severely affected by disease, where effectiveness is greater and the baseline risk of all-cause mortality is much higher (SHTAC analysis), these factors are associated with the noted difference in effect. The three published cost-effectiveness studies report cost for US and Canadian patient groups; for those patients with severe sepsis they report the additional cost per patient treated in a range around 10,000-16,000 dollars. The manufacturer's submission reports analysis for the UK, based on 28-day survival data in patients with severe sepsis and multiple organ dysfunction (the European licence indication), with the additional mean cost per treated patient estimated to be 5106 pounds. The analysis undertaken by SHTAC, for a UK group of patients with severe sepsis and multiple organ dysfunction, estimates an additional mean cost per patient treated of 6661 pounds. The manufacturer's submission to NICE presents cost-effectiveness estimates for drotrecogin alfa (activated) in the UK, in patients with severe sepsis and multiple organ dysfunction, at 6637 pounds per quality-adjusted life-year (QALY) based on 28-day effectiveness data, and 10,937 pounds per QALY based on longer term follow-up data. SHTAC developed an independent cost-effectiveness model and estimated a base-case cost per QALY of 8228 pounds in patients with severe sepsis and multiple organ failure (based on 28-day survival data). Simulation results indicate that where the NHS is willing to pay 20,000 pounds per QALY, drotrecogin alfa (activated) is a cost-effective use of resources in 98.7% of cases. Published economic evaluations report various sensitivity analyses, with results sensitive to changes in the measure of treatment effect, but otherwise studies reported that results were robust to variations in most assumptions used in the cost-effectiveness analysis. CONCLUSIONS: Drotrecogin alfa (activated) plus best supportive care appears clinically and cost-effective compared with best supportive care alone, in a UK cohort of severe sepsis patients, and in the subgroup of more severely affected patients with severe sepsis and multiple organ failure. The introduction of drotrecogin alfa (activated) will involve a substantial additional cost to the NHS. The treatment-eligible population in England and Wales may comprise up to 16,570 patients, with an estimated annual drug acquisition cost of over 80 million pounds, excluding VAT. Further research is required on the longer term impact of drotrecogin alfa (activated) on both mortality and morbidity in UK patients with severe sepsis, on the clinical and cost-effectiveness of drotrecogin alfa (activated) in children (under 18 years) with severe sepsis, and on the effect of the timing of dosage and duration of treatment on outcomes in severe sepsis.

Adolescent↗
PubMed2004

Pegylated interferon alpha-2a and -2b in combination with ribavirin in the treatment of chronic hepatitis C: a systematic review and economic evaluation.

OBJECTIVES: To assess the clinical-effectiveness and cost-effectiveness of pegylated interferon-alpha combined with ribavirin in the treatment of chronic hepatitis C. DATA SOURCES: Electronic databases, reference lists of retrieved reports, and the industry submissions to the National Institute for Clinical Excellence. REVIEW METHODS: Sources were rigorously searched and studies were selected that met the inclusion criteria of being randomised controlled trials (RCTs) involving comparisons between pegylated interferon-alpha plus ribavirin and non-pegylated interferon plus ribavirin (two trials) or pegylated interferon alone and non-pegylated interferon alone (four trials). The primary outcome in all trials was sustained virological response (SVR) at follow-up. The trials were generally of good quality, although reporting of methodological details could have been more thorough in places. A cost-effectiveness model followed a hypothetical cohort of 1000 individuals with chronic hepatitis C over a 30-year period. RESULTS: In the two trials that tested pegylated interferon plus ribavirin against non-pegylated interferon plus ribavirin the combined percentage of sustained virological response was 55%. The relative risk (RR) for remaining infected was reduced by 17% for pegylated interferon plus ribavirin compared with non-pegylated interferon plus ribavirin. Response to therapy varied according to viral genotype. Patients with genotype 1 had the lowest levels of sustained virological response and patients with genotype 2 or 3 had the highest. In the four trials that evaluated pegylated interferon monotherapy against non-pegylated interferon the combined sustained virological response rates were 31% for pegylated interferon and 14% for non-pegylated interferon. The RR for remaining infected with hepatitis C was reduced by 20% with the use of pegylated interferon. Patients with genotype 1 had the lowest levels of sustained virological response. There were also variations in sustained virological response according to other prognostic variables such as baseline viral load. Regimens involving pegylated interferon appear to be fairly well tolerated. Adverse events were been reported, but they did not differ substantially from levels of adverse events in regimens involving non-pegylated interferon. The incremental discounted cost per QALY for comparing no active treatment to 48 weeks of dual therapy with pegylated interferon and ribavirin (PEG + RBV) was 6045 pounds sterling. When moving from 48 weeks of dual therapy with non-pegylated interferon and ribavirin (IFN + RBV) to 48 weeks of dual therapy with PEG + RBV the figure was 12,123 pounds sterling. Subgroup analyses for dual PEG + RBV therapy demonstrated that the most favourable incremental discounted cost per QALY estimates were for patients infected with genotypes 2 and 3, and with low baseline viral load (3921 pounds sterling) compared with no active treatment. Results of one-way sensitivity analyses showed that the estimates varied according to differences in SVRs, drug costs and discount rates. In general estimates remained under 30,000 pounds sterling per QALY. The incremental discounted cost per QALY when moving from no active treatment to 48 weeks of monotherapy with pegylated interferon was 6484 pounds sterling. When moving from 48 weeks of monotherapy with IFN to 48 weeks of monotherapy with PEG the figure was 8404 pounds sterling. As with dual therapy, the lowest incremental cost per QALY was for patients with genotypes 2 and 3 and low baseline viral load, in the range 2641-4194 pounds sterling. The highest estimates were for patients with genotype 1 and high baseline viral load, around 30,000 pounds sterling. CONCLUSIONS: Well-designed RCTs show that patients treated with pegylated interferon, both as dual therapy and as monotherapy, experience higher sustained viral response rates than those treated with non-pegylated interferon. Patients with genotypes 2 and 3 experience the highest response, with rates in excess of 80%. Patients with the harder to treat genotype 1 nevertheless benefit, with up to 46% of patients experiencing an SVR in one of the trials. Pegylated interferon also appears to be relatively cost-effective in both monotherapy and dual therapy, with cost per QALY estimates remaining generally under 30,000 pounds sterling. The most favourable estimates were for patients with genotypes 2 and 3. Pegylated interferon is a relatively new intervention in the treatment of hepatitis C and therefore there are areas where further research is needed. These include: efficacies of therapy with PEG-alpha-2a vs PEG-alpha-2b; retreatment of previous non-responders using pegylated interferon; efficacy of treatments and long-term outcomes in patients who have other co-morbidities; prospective tests of rules governing stopping treatment; treating patients with acute hepatitis C; problems that may occur in a minority of patients with hepatitis C, such as cryoglobulinaemia and vasculitis; additional psychological effects on quality of life due to hepatitis C and also on the treatment of children and adolescents with hepatitis C.

Antiviral Agents↗
PubMed2003

Recombinant growth hormone for idiopathic short stature in children and adolescents.

BACKGROUND: Idiopathic short stature (ISS) refers to children who are very short compared with their peers for unknown or hereditary reasons. Recombinant human growth hormone has been used to increase growth and final height in children with idiopathic short stature. OBJECTIVES: To assess the effects of recombinant human growth hormone on short-term growth and final height in children with idiopathic short stature. SEARCH STRATEGY: Randomised controlled trials (RCTs) were sought by searching The Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, PubMed, Science Citation Index, BIOSIS and Current Controlled Trials (date of last search 10 December 2002). Article reference lists were assessed for trials and experts and pharmaceutical companies were contacted. SELECTION CRITERIA: Randomised controlled trials were included if they were carried out in children with ISS with normal growth hormone secretion. Growth hormone (GH) had to be administered for a minimum of six months and be compared with placebo or no treatment. A growth or height outcome measure had to be assessed. DATA COLLECTION AND ANALYSIS: Two reviewers assessed studies for inclusion criteria and for methodological quality. Data were extracted by one reviewer and checked by a second. The primary outcome was final height and secondary outcomes included short term growth, health related quality of life and adverse effects. To estimate summary treatment effects, data were pooled, when appropriate using a random effects model. MAIN RESULTS: Nine randomised controlled trials were included. One trial reported near final height in girls and found that girls treated with growth hormone were 7.5 cm taller than untreated controls (GH group, 155.3 cm +/- 6.4; control, 147.8 cm +/- 2.6; p = 0.003). The other trials reported short term outcomes. Results suggest that short-term height gains can range from none to approximately 0.7 SD over one year. One study reported health related quality of life and showed no significant improvement in growth hormone treated children compared with those in the control group. No serious adverse effects of treatment have been reported. REVIEWER'S CONCLUSIONS: Results suggest that growth hormone therapy can increase short-term growth and improve (near) final height. Increases in height are such that treated individuals remain relatively short when compared with peers of normal stature. Further research in the form of large, multicentre RCTs are required. These should focus on final height, which is the best outcome for assessing the effects of growth hormone, and address quality of life and cost issues.

Adolescent↗
PubMed2003

The clinical and cost-effectiveness of patient education models for diabetes: a systematic review and economic evaluation.

OBJECTIVES: To assess the clinical effectiveness and cost-effectiveness of educational interventions for patients with diabetes, compared with usual care or other educational interventions. DATA SOURCES: Electronic databases, reference lists and experts were all consulted in this study. Sponsor submissions to the National Institute of Clinical Excellence were also reviewed. REVIEW METHODS: Electronic databases were searched, references of all retrieved articles were checked for relevant studies, and experts were contacted for advice and peer review and to identify additional published and unpublished references. Randomised clinical trials (RCTs) and controlled clinical trials (CCTs) were included if they fulfilled pre-specified criteria, among which was follow-up from inception for 12 months or longer. Data were synthesised through a narrative review because the diversity of studies prevented a meta-analysis. RESULTS: Twenty-four studies (18 RCTs and six CCTs) that compared education with either a control group or with another educational intervention were included. The quality of reporting and methodology was generally found to be poor by today's standards. As part of treatment intensification, education in Type 1 diabetes (four studies) resulted in significant and long-lasting improvements in metabolic control and reductions in complications. In Type 2 diabetes (16 studies) a diversity of educational programmes did not yield consistent results on measures of metabolic control. Inconsistent results on metabolic control were also found in studies of diabetes of either type (four studies), with studies of lower quality producing significant effects. Few studies evaluated quality of life. Economic evaluations comparing education with usual care or other educational interventions were not identified. CONCLUSIONS: Education as part of intensification of treatment produces improvement in diabetic control in Type 1 diabetes. Mixed results in Type 2 diabetes mean that no clear characterisation is possible as to what features of education may be beneficial. Cost analysis and information from sponsor submissions indicated that where costs associated with patient education were in the region of 500-600 pounds sterling per patients, the benefits over time would have to be very modest to offer an attractive cost-effectiveness profile. Further research should focus on RCTs with clear designs based on explicit hypotheses and with a range of outcomes evaluated after long follow-up intervals.

Cost-Benefit Analysis↗
PubMed2002

A rapid and systematic review of the effectiveness of temozolomide for the treatment of recurrent malignant glioma.

A rapid and systematic review of the effectiveness and cost-effectiveness of temozolomide in the treatment of recurrent malignant glioma was commissioned by the NHS HTA Programme on behalf of NICE. The full report has been published elsewhere. This paper summarizes the results for the effectiveness of temozolomide in people with recurrent glioblastoma multiforme and anaplastic astrocytoma. The review was conducted using standard systematic review methodology involving a systematic literature search, quality assessment of included studies with systematic data extraction and data synthesis. One randomized controlled trial and four uncontrolled studies were identified for inclusion. The key results were that temozolomide may increase progression-free survival but has no significant impact on overall length of survival. The main effect from temozolomide may have been in those patients who had not received any prior chemotherapy regimens, however further randomized controlled trials are required to confirm this suggestion. Temozolomide appears to produce few serious adverse effects and may also have a positive impact on health-related quality of life. Overall the evidence-base is weak and few strong conclusions can be drawn regarding the effectiveness of temozolomide. Large, well-designed randomized controlled trails conducted in a wider patient population are needed.

Antineoplastic Agents, Alkylating↗
PubMed2002

Endocrinology trial design: adverse event reporting in randomised controlled trials of recombinant human GH in GH-deficient adults.

We have evaluated the reporting of withdrawals due to adverse effects and specific adverse effects in randomised controlled trials of recombinant human GH in adults. A systematic review was carried out of randomised controlled trials of the clinical effectiveness of recombinant human GH in adults with GH deficiency in relation to impact on quality of life. Trials were identified from searching electronic databases, bibliographies of related articles and consulting experts. There was reporting of withdrawals due to adverse effects and specific adverse effects. Rates of oedema and arthralgia were reported in included trials. Seventeen randomised controlled trials, published between 1990 and 1999, met the inclusion criteria for the review. Nine trials reported data on the effectiveness of GH on quality of life in adults. Only five trials (29%) reported both withdrawals from the study because of adverse events and specific adverse events with numbers per study arm and per type. Six further trials (35%) reported either withdrawal details or specific adverse event details or partial data on specific adverse events. Six trials (35%), however, did not report information on either withdrawals or specific adverse events. Ten of the 17 studies (59%) reported the number of patients who withdrew from the study due to adverse events per study arm and type of adverse event per study arm. Seven of the 17 trials (41%) reported the number of specific adverse events per study arm and six (35%) reported the type per study arm. The reporting of adverse events in randomised controlled trials of GH is variable and not consistent across trials. It is not possible to assess the impact that adverse events may have had on unblinding patients, and therefore the extent to which the effects of GH may have been overestimated. Therefore those conducting endocrinology trials in the future need to pay attention to the reporting of withdrawals due to adverse events and specific adverse events.

Adult↗
PubMed2001

Mechanisms of human neutrophil oxidant production after severe injury.

BACKGROUND: The purpose of this study was to determine the mechanisms of enhanced oxidant production after severe injury. METHODS: Neutrophils were harvested from patients within 24 hours of admission who had an injury severity score greater than 16. Nonadherent and adherent neutrophil oxidant production was measured after N-formyl-methionyl-leucyl-phenylalanine (fMLP) stimulation. Translocation of cytochrome b558 and cytosolic components p47phox and p67phox were determined by oxidation-reduction spectroscopy and immunoblotting, respectively. Flow cytometry measured integrin expression. Integrin and p47phox colocalization was examined by confocal microscopy. RESULTS: Eighteen patients were studied within 15 +/- 1.4 hours. Four women and 14 men suffered a blunt injury and had a mean injury severity score of 22 (range, 16 to 34). Nonadherent patient neutrophils showed a decrease in fMLP-stimulated oxidant production, whereas adherent neutrophil oxidant production was increased in both the vehicle control and fMLP-stimulated groups. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase components p47phox and cytochrome b558 were mobilized to the plasma membrane, whereas p67phox showed minimal change. Integrin CD11b a chain showed a significant increase in expression. Confocal microscopy showed colocalization of p47phox and a chain CD11b on the plasma membrane of patient neutrophils. CONCLUSIONS: Colocalization of NADPH oxidase components and integrins may regulate the enhanced oxidant production in human neutrophils after severe injury.

Adolescent↗
PubMed2001

CXCR2 regulation of tumor necrosis factor-alpha adherence-dependent peroxide production is significantly diminished after severe injury in human neutrophils.

BACKGROUND: Primed neutrophils are thought to play a key role in inflammatory pathology. We have shown though in vitro studies that interleukin (IL)-8 and growth-related oncogene-alpha (GROalpha) (CXCR2-specific chemokines) regulate the respiratory burst via the CXCR2 receptor. We have also shown in vivo, CXCR2 receptors are down-regulated in severely injured patients. Our hypothesis is that regulation of the respiratory burst by CXCR2 is lost after severe injury. METHODS: Patient neutrophils were studied within 24 hours of admission to the hospital; excluded were severe head injury and patients with Injury Severity Score < 16. Patient and normal neutrophils were isolated by Ficoll-Hypaque centrifugation after dextran sedimentation. Neutrophils were plated with buffer, 50 nmol/L IL-8 or GROalpha on fibronectin-coated plates for 15 minutes, then stimulated with 10 ng/mL of TNFalpha. CXCR2 expression was measured by flow cytometry. Receptor function was assessed by calcium mobilization. RESULTS: One female and 10 male patients with an average age of 37 +/- 3 and Injury Severity Score of 24 +/- 5 suffered blunt injury. CXCR2 showed a 32% +/- 7% loss, whereas CXCR1 showed 15% +/- 6% reduction. GROalpha stimulation of patient neutrophils showed 60% +/- 16% decrease in calcium mobilization, whereas IL-8 showed no decline. At 40 minutes, IL-8 and GROalpha significantly inhibited TNFalpha adherence-dependent peroxide production in normal neutrophils (35% +/- 4% and 45% +/- 3%, respectively; p < 0.05). Both IL-8 and GROalpha lost the ability to suppress the respiratory burst in severely injured patients, but GROalpha had a significantly greater loss of this suppression (p = 0.004). CONCLUSION: IL-8 and GROalpha lose the ability to regulate the TNFalpha-induced respiratory burst. This may contribute to neutrophil dysregulation after injury and result in organ injury.

Adult↗
PubMed1999

Preferential loss of CXCR-2 receptor expression and function in patients who have undergone trauma.

BACKGROUND: In response to traumatic injury or infection, human neutrophils are directed to the site of injury or infection by CXC chemokines that signal via 2 receptors, CXCR-1 and CXCR-2. In vitro studies have shown preferential loss of CXCR-2 expression and function after exposure to interleukin 8, N-formyl-methionyl-leucyl-phenylalanine (fMLP), C5a, and tumor necrosis factor alpha. HYPOTHESIS: CXCR-2 expression and function are preferentially down-regulated in severely injured patients. METHODS: We studied 20 patients within 24 hours of admission to the hospital. Patients with head injuries were excluded. Injury Severity Scores (range, 1-50; mean, 35) were calculated for each patient. To determine expression of CXCR-1 and CXCR-2, flow cytometry was used. Intracellular calcium mobilization and neutrophil migration to 10 nmol of interleukin 8, growth-related oncogene alpha, and fMLP was measured to determine receptor function. RESULTS: Compared with CXCR-1, there is a greater loss of CXCR-2 receptor expression in the severely injured group (P = .01). Neutrophils from patients with Injury Severity Scores greater than 16 did not mobilize calcium in response to growth-related oncogene alpha. However, there was no loss of calcium mobilization to interleukin 8 or fMLP. Chemotaxis to various stimulants is decreased in all injury groups. CONCLUSIONS: CXCR-2 expression and function are preferentially down-regulated in severely injured patients. Our data suggest that there are multiple mechanisms, in addition to receptor down-regulation, that play a role in the loss of migration and calcium flux in human neutrophils after injury.

Adolescent↗
PubMed1998

Transcutaneous monitoring of blood gases: is it comparable with arterialized earlobe sampling?

Researchers are increasingly looking for reliable non-invasive methods of assessing blood gas concentrations, and several new techniques have recently become available. Values derived using arterialized earlobe samples have been found to be comparable with conventional arterial samples, and recent studies have compared transcutaneous blood gas analysis with the traditional arterial samples and found a reasonable level of agreement in particular for the partial pressure of carbon dioxide. There are no data comparing oxygen and carbon dioxide partial pressures (pO2, pCO2) derived from arterialized samples with one of the newer transcutaneous techniques. We therefore simultaneously studied arterialized earlobe blood gas samples and values for pO2 and pCO2 obtained by a transcutaneous monitor (TINA, Radiometer, Copenhagen) in 26 subjects with varying blood gas values. There was a close agreement between the two methods for assessment of pCO2 [mean difference (95% C.I.) between transcutaneous and earlobe values 0.25 kPa (-0.004, 0.5 kPa)], but not for pO2 [1.71 kPa (0.35, 3.07 kPa)]. Similarly, the limits of agreement were narrow for pCO2 compared to those for pO2 (-0.98, 1.47 kPa and -6.44, 3.02 kPa respectively). We conclude that transcutaneous measurement of pCO2 using the TINA is acceptable in the research setting, whereas assessment of pO2 cannot reliably be made using this technique.

Adult↗
PubMedDate not supplied

Passage of allophanoyl-gamma-lactones through the kidney.

In order to establish if allophanoyl-gamma lactones (B compounds) can pass through the kidney or if only the corresponding delta-hydroxybarbiturates (A compounds), formed by intramolecular alcoholysis, are able to do so, nine experiments were performed to study the urinary excretion of four different allophanoyl gamma-lactones B after administration to dogs. Excreted compounds were extracted, identified and quantised. From the amounts of unmodified administered lactones that were recovered, it is concluded that B compounds can pass through the kidney before isomerisation into the corresponding barbiturates A.

Animals↗