The heart rate hypothesis: ready to be tested

There is increasing evidence that increased heart rate may be an independent risk factor for cardiovascular morbidity and mortality both in patients with ischaemic heart disease and in the general population. Elevated heart rate in coronary artery disease is a major determinant of oxygen consumption and appears to evoke most episodes of ischaemia. Increased resting heart rate may also contribute to the development of atherosclerosis, facilitate plaque destabilisation and initiate arrhythmias, leading to acute coronary events and sudden death. Reducing heart rate is a central aim in the treatment of stable angina pectoris; this therapeutic approach may have an essential role in lowering the incidence of cardiovascular morbidity and mortality in patients with pre-existing ischaemic heart disease. However, this heart rate hypothesis has not thus far been proven. Evidence suggests that the use of heart rate-lowering drugs may have a beneficial effect; however, most treatments for angina have additional negative inotropic effects on the heart. This hypothesis can now be tested following the recent development of selective heart rate drugs.

Multimedia materials for education, training, and advocacy in international health: experiences with the Schistosomiasis Control Initiative CD-ROM

We describe an innovative use of multimedia materials to support training and advocacy within a schistosomiasis control programme. The Schistosomiasis Control Initiative (SCI) at Imperial College London works with selected sub-Saharan African countries to develop schistosomiasis control programmes. Two elements of the SCI programme were supported by multimedia materials developed at the Wellcome Trust in collaboration with the SCI: (1) training of programme managers, district health officers, and those delivering practical elements of the programme; and (2) advocacy targeted at decision-makers and donors. Evaluation of the materials revealed high reported ratings for both user satisfaction and impact from use of the product. From this experience we draw out several general messages about development of multimedia materials and how these will play a growing future role in promoting training within international health.

The cost-effectiveness of etanercept and infliximab for the treatment of patients with psoriatic arthritis

OBJECTIVE

Tumour necrosis factor (TNF) antagonists have been shown to improve the outcomes in patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA). We assess the cost-effectiveness of two TNF antagonists and so-called 'palliative care' for the treatment of active PsA from the perspective of the UK National Health Service (NHS).

METHODS

Bayesian statistical methods were used to synthesize evidence from three Phase III trials, identified through a systematic review, and estimate the relative efficacy of etanercept, infliximab and palliative care. A probabilistic decision analytic model was then used to compare these treatments after the failure of at least two conventional disease-modifying anti-rheumatic drugs (DMARDs), following the British Society for Rheumatology (BSR) guidelines for use. The primary outcome measure, quality-adjusted life years (QALYs), was derived from utility values estimated as a function of disability measured by the Health Assessment Questionnaire (HAQ). The deterioration experienced in HAQ at treatment withdrawal (rebound) was incorporated using alternative scenarios to represent best- and worst-case assumptions. The model was extended beyond the trial duration to a 10-yr and lifetime horizon, using available evidence and expert opinion-based assumptions on disease progression. Resource utilization was based on literature, national databases and expert opinion. Prices were obtained from routine NHS sources and published literature.

RESULTS

At a 10-yr time horizon, the incremental cost-effectiveness ratio (ICER) for etanercept compared with palliative care was pound sterling26 361 per QALY gained for the best-case rebound scenario, which increased to pound sterling30 628 for the worst-case. The ICERs for infliximab compared with etanercept were pound sterling165 363 and pound sterling205 345 per QALY, respectively. These findings are mainly explained by the fact that infliximab has higher acquisition and administration costs without substantially superior effectiveness compared with etanercept. Results were sensitive to estimates of rebound assumptions at withdrawal and the time horizon.

CONCLUSIONS

Only results for etanercept remained within the range of cost-effectiveness estimates considered to represent value for money in the NHS by the National Institute for Health and Clinical Excellence. Further research appears most valuable in relation to the short-term effectiveness, utility parameters and assumptions regarding the effect of rebound.

Topotecan, pegylated liposomal doxorubicin hydrochloride and paclitaxel for second-line or subsequent treatment of advanced ovarian cancer: a systematic review and economic evaluation

OBJECTIVES

To examine the clinical effectiveness and cost-effectiveness of intravenous formulations of topotecan monotherapy, pegylated liposomal doxorubicin hydorocholoride (PLDH) monotherapy and paclitaxel used alone or in combination with a platinum-based compound for the second-line or subsequent treatment of advanced ovarian cancer.

DATA SOURCES

Electronic databases covering publication years 2000-4. Company submissions.

REVIEW METHODS

Seventeen databases were searched for randomised controlled trials (RCTs) and systematic reviews for the clinical effectiveness of PLDH, topotecan and paclitaxel and economic evaluations of the cost-effectiveness of PLDH, topotecan and paclitaxel. Selected studies were quality assessed and data extracted, as were the three company submissions. A new model was developed to assess the costs of the alternative treatments, the differential mean survival duration and the impact of health-related quality of life. Monte-Carlo simulation was used to reflect uncertainty in the cost-effectiveness results.

RESULTS

Nine RCTs were identified. In five of these trials, both the comparators were used within their licensed indications. Of these five, three included participants with both platinum-resistant and platinum-sensitive advanced ovarian cancer, and a further two only included participants with platinum-sensitive disease. The comparators that were assessed in the three trials that included both subtypes of participants were PLDH versus topotecan, topotecan versus paclitaxel and PLDH versus paclitaxel. In the further two trials that included participants with the subtype of platinum-sensitive disease, the comparators that were assessed were single-agent paclitaxel versus a combination of cyclophosphamide, doxorubicin and cisplatin (CAP) and paclitaxel plus platinum-based chemotherapy versus conventional platinum-based therapy alone. A further four trials were identified and included in the review in which one of the comparators in the trial was used outside its licensed indication. The comparators assessed in these trials were oxaliplatin versus paclitaxel, paclitaxel given weekly versus every 3 weeks, paclitaxel at two different dose levels and oral versus intravenous topotecan. Four studies met the inclusion criteria for the cost-effectiveness review. The review of the economic evidence from the literature and industry submissions identified a number of significant limitations in existing studies assessing the cost-effectiveness of PLDH, topotecan and paclitaxel. Analysis 1 assessed the cost-effectiveness of PLDH, topotecan and paclitaxel administered as monotherapies. Sensitivity analysis was undertaken to explore the impact of patient heterogeneity (e.g. platinum-sensitive and platinum-resistant/refractory patients), the inclusion of additional trial data and alternative assumptions regarding treatment and monitoring costs. In the base-case results for Analysis 1, paclitaxel monotherapy emerged as the cheapest treatment. When the incremental cost-effectiveness ratios (ICERs) were estimated, topotecan was dominated by PLDH. Hence the options considered in the estimation of the ICERs were paclitaxel and PLDH. The ICER for PLDH compared with paclitaxel was pound 7033 per quality-adjusted life-year (QALY) in the overall patient population (comprising platinum-sensitive, -refractory and -resistant patients). The ICER was more favourable in the platinum-sensitive group ( pound 5777 per QALY) and less favourable in the platinum-refractory/resistant group ( pound 9555 per QALY). The cost-effectiveness results for the base-case analysis were sensitive to the inclusion of additional trial data. Incorporating the results of the additional trial data resulted in less favourable estimates for the ICER for PLDH versus paclitaxel compared with the base-case results. The ICER of PLDH compared with paclitaxel was pound 20,620 per QALY in the overall patient population, pound 16,183 per QALY in the platinum-sensitive population and pound 26,867 per QALY in the platinum-resistant and -refractory population. The results from Analysis 2 explored the cost-effectiveness of the full range of treatment comparators for platinum-sensitive patients. The treatment options considered in this model comprised PLDH, topotecan, paclitaxel-monotherapy, CAP, paclitaxel/platinum combination therapy and platinum monotherapy. Owing to the less robust approaches that were employed to synthesise the available evidence and the heterogeneity between the different trials, the reliability of these results should be interpreted with some caution. Topotecan, paclitaxel monotherapy and PLDH were all dominated by platinum monotherapy (i.e. higher costs and lower QALYs). After excluding these alternatives, the treatments that remained under consideration were platinum monotherapy, CAP and paclitaxel-platinum combination therapy. Of these three alternatives, platinum monotherapy was the least costly and least effective. The ICER for CAP compared with platinum monotherapy was pound 16,421 per QALY. The ICER for paclitaxel-platinum combination therapy compared with CAP was pound 20,950 per QALY.

CONCLUSIONS

For participants with platinum-resistant disease there was a low probability of response to treatment with PLDH, topotecan or paclitaxel. Furthermore, there was little difference between the three comparators in relation to overall survival. The comparators did, however, differ considerably in their toxicity profiles. Given the low survival times and response rates, it appears that the maintenance of quality of life and the control of symptoms and toxicity are paramount in this patient group. As the three comparators differed significantly in terms of their toxicity profiles, patient and physician choice is also an important element that should be addressed when decisions are made regarding second-line therapy. It can also be suggested that this group of patients may benefit from being included in further clinical trials of new drugs. For participants with platinum-sensitive disease there was a considerable range of median survival times observed across the trials. The most favourable survival times and response rates were observed for paclitaxel and platinum combination therapy. This suggests that treatment with combination therapy may be more beneficial than treatment with a single-agent chemotherapeutic regimen. In terms of single-agent compounds, the evidence suggests that PLDH is more effective than topotecan. Evidence from a further trial that compared PLDH and paclitaxel suggests that there is no significant difference between these two comparators in this trial. The three comparators did, however, differ significantly in terms of their toxicity profiles across the trials. Although treatment with PLDH may therefore be more beneficial than that with topotecan, patient and physician choice as to the potential toxicities associated with each of the comparators and the patient's ability and willingness to tolerate these are of importance. Assuming the NHS is willing to pay up to pound 20,000-40,000 per additional QALY, PLDH appears to be cost-effective compared with topotecan and paclitaxel monotherapy, in terms of the overall patient population and the main subgroups considered. The cost-effectiveness results for the base-case analysis were sensitive to the inclusion of additional trial data. Incorporating the results of additional trial data gave less favourable estimates for the ICER for PLDH versus paclitaxel monotherapy, compared with the base-case results. Although the ICER of PLDH compared with paclitaxel monotherapy was less favourable, PLDH was still cost-effective compared with topotecan and paclitaxel monotherapy. For platinum-sensitive patients, the combination of paclitaxel and platinum appears to be cost-effective. On the strength of the evidence reviewed here, it can be suggested that participants with platinum-resistant disease may benefit from being included in further clinical trials of new drugs. To assess the effectiveness of combination therapy against a single-agent non-platinum-based compound, it can be suggested that a trial that compared paclitaxel in combination with a platinum-based therapy versus single-agent PLDH would be a reasonable option.

A systematic review and economic model of the clinical effectiveness and cost-effectiveness of interventions for preventing relapse in people with bipolar disorder

OBJECTIVES

To determine the clinical effectiveness and cost-effectiveness of pharmacological and/or psychosocial interventions for the prevention of relapse in people with bipolar disorder.

DATA SOURCES

Major electronic databases were searched up to September 2005.

REVIEW METHODS

Systematic reviews were undertaken on the clinical and economic effectiveness of treatments. An analysis was performed using the methods of mixed treatment comparison (MTC) to enable indirect comparisons to be made between the treatments. An economic model of treatments for the prevention of relapse in bipolar disorder was developed.

RESULTS

Forty-five trials were included in the clinical effectiveness review; all but one studied adults. This review found that for the prevention of all relapses, lithium, valproate, lamotrigine and olanzapine performed better than placebo, with lithium and lamotrigine having the strongest evidence. For depressive relapse prevention, valproate, lamotrigine and imipramine performed better than placebo, with evidence strongest for lamotrigine and weakest for imipramine. For manic relapses, lithium and olanzapine performed significantly better than placebo. The MTC found that the best treatment for bipolar I patients with mainly depressive symptoms was valproate, followed by lithium plus imipramine. For bipolar I patients with mainly manic symptoms, olanzapine was the best treatment. From the studies investigating psychosocial interventions, there were few data for each comparison and outcome. The evidence suggests that cognitive behaviour therapy (CBT), in combination with usual treatment, is effective for the prevention of relapse. Group psychoeducation and possibly family therapy may also have roles as adjunctive therapy for preventing relapse. The results from the decision analytic model developed on the cost-effectiveness of long-term maintenance treatments of bipolar I patients suggest that the choice of treatment is dependent upon a number of factors: the previous episode history of a patient and the mortality benefit assumed for lithium strategies. The results from the base-case analysis for patients with a recent history of depression suggest that valproate, lithium and the combination of lithium and imipramine are potentially cost-effective depending upon the amount that a decision-maker is willing to pay for additional health gain. Using conventional amounts that the NHS is prepared to pay for health gain, then the lithium-based strategies appear to be potentially cost-effective for this group. For patients with a recent history of mania, the choice of pharmacological intervention appears to be between olanzapine and lithium monotherapy. Again using conventional threshold as a reference point, the results suggest that lithium is the most cost-effective therapy. Excluding the additional mortality benefit associated with lithium-based strategies resulted in all treatments for patients with a recent history of a depressive episode being dominated by valproate and, in the case of patients with a recent history of a manic episode, by olanzapine.

CONCLUSIONS

Lithium, valproate, lamotrigine and olanzapine are effective as maintenance therapy for the prevention of relapse in bipolar disorder. Olanzapine and lithium are efficacious for the prevention of manic relapses and valproate, lamotrigine and imipramine for the prevention of depressive relapse. There is some evidence that CBT, group psychoeducation and family therapy might be beneficial as adjuncts to pharmacological maintenance treatments. Insufficient information is available regarding the relative tolerability of the treatments or their relative effects on suicide rate and mortality. For patients with a recent depressive episode, valproate, lithium monotherapy and the combination of lithium and imipramine are potentially cost-effective. For patients with a recent manic episode, olanzapine and lithium monotherapy are potentially cost-effective. The cost-effectiveness estimates in both groups of patients were shown to be sensitive to the assumption of a reduced suicidal risk associated with lithium-based strategies. Further research is needed into the adverse effects of all treatments and the differential effects of agents. Good-quality trials of valproate, of combination therapy, e.g. lithium plus a selective serotonin reuptake inhibitor antidepressant, of psychosocial interventions and of the disorder in children are also required.

The LRC haplotype project: a resource for killer immunoglobulin-like receptor-linked association studies

There is increasing evidence for epistatic interactions between gene products (e.g. KIR) encoded within the Leukocyte Receptor Complex (LRC) with those (e.g. HLA) of the Major Histocompatibility Complex (MHC), resulting in susceptibility to disease. Identification of such associations at the DNA level requires comprehensive knowledge of the genetic variation and haplotype structure of the underlying loci. The LRC haplotype project aims to provide this knowledge by sequencing common LRC haplotypes.

Development and evaluation of a test for tuberculosis in live European badgers (Meles meles) based on measurement of gamma interferon mRNA by real-time PCR

A real-time PCR assay for the measurement of gamma interferon (IFN-gamma) mRNA in European badger (Meles meles) blood cultures was developed. The levels of IFN-gamma mRNA in blood cultures stimulated with either bovine or avian tuberculin or specific mycobacterial antigens were compared with those in a nonstimulated control blood culture as the basis for determining the tuberculosis (TB) status of live badgers. The assay was validated by testing 247 animals for which there were matching data from postmortem examination and culture of tissues. Relative changes in the levels of IFN-gamma mRNA in response to bovine tuberculin and specific antigens were found to be greater among badgers with tissues positive for TB on culture. The test was at its most accurate (87% of test results were correct) by using blood cultures containing bovine tuberculin as the antigen and when the response to avian tuberculin was taken into account by subtracting the avian tuberculin response from the bovine tuberculin response. At a specificity of 90.7%, the test was 70.6% sensitive. At the same specificity, the current serological enzyme-linked immunosorbent assay for TB in badgers was only 53% sensitive. This work demonstrates that measurement of IFN-gamma mRNA by real-time PCR is a valid method for the detection of TB in live badgers and may provide an alternative to the current serological methods of diagnosis, the Brock test. The testing procedure can be completed within 5 h of receipt of the blood culture samples. In addition, the use of a molecular biology-based test offers the potential to fully automate the testing procedure through the use of robotics.

A systematic review and economic model of the clinical effectiveness and cost-effectiveness of docetaxel in combination with prednisone or prednisolone for the treatment of hormone-refractory metastatic prostate cancer

OBJECTIVES

A systematic review was undertaken and an economic model constructed to evaluate the clinical effectiveness and cost-effectiveness of docetaxel (Taxotere, Sanofi-Aventis) in combination with prednisone/prednisolone for the treatment of metastatic hormone-refractory prostate cancer (mHRPC). The main comparators considered were other established chemotherapy regimens and best supportive care.

DATA SOURCES

Twenty-one resources (including MEDLINE, EMBASE and the Cochrane Library) were searched to April 2005.

REVIEW METHODS

Two reviewers independently assessed studies for inclusion. Data from included studies were extracted and quality assessed. Where appropriate, outcomes were synthesised using formal analytic approaches. A new economic model was developed in order to establish the cost-effectiveness of docetaxel compared with a range of potential comparators. A separate review was undertaken to identify sources of utility data required to estimate quality-adjusted life-years (QALYs). Sensitivity analyses were also undertaken to explore the robustness of the main analysis to alternative assumptions related to quality of life. Monte Carlo simulation was used to propagate uncertainty in input parameters through the model in such a way that the results of the analysis could be presented with their uncertainty. The impact of uncertainty surrounding the decision was established using value of information and implementation approaches.

RESULTS

Seven randomised controlled trials were identified that met the inclusion criteria. A direct comparison of docetaxel plus prednisone versus mitoxantrone plus prednisone in an open-label randomised trial showed improved outcomes for docetaxel plus prednisone in terms of overall survival, quality of life, pain and prostate-specific antigen decline. Two other chemotherapy regimens that included docetaxel: docetaxel plus estramustine and docetaxel plus prednisone plus estramustine, also showed improved outcomes in comparison with mitoxantrone plus prednisone. Indirect comparison suggested that docetaxel plus prednisone seems to be superior to corticosteroids alone in terms of overall survival. Conclusions on cost-effectiveness were primarily informed by the results of the in-house model. This indicated that mitoxantrone plus a corticosteroid is probably cheaper and more effective than corticosteroid alone. Compared with mitoxantrone plus prednisone/prednisolone, the use of docetaxel plus prednisone/prednisolone (3-weekly) appears cost-effective only if the NHS is prepared to pay 33,000 pounds per QALY. The incremental cost-effectiveness ratio associated with docetaxel plus prednisone (3-weekly) remained fairly robust to these variations with estimates ranging from 28,000 pounds to 33,000 pounds per QALY. Value of information analysis revealed that further research is potentially valuable. Given a maximum acceptable ratio of 30,000 pounds per QALY, the expected value of information was estimated to be approximately 13 million pounds.

CONCLUSIONS

This systematic review of the research suggests that docetaxel plus prednisone seems to be the most effective treatment for men with mHRPC. The economic model suggests that treatment with docetaxel plus prednisone/prednisolone is cost-effective in patients with mHRPC provided the NHS is prepared to pay 33,000 pounds per additional QALY. Future research should include the direct assessment of quality of life and utility gain associated with different treatments, including the effect of adverse events of treatment, using generic instruments, which are suitable for the purposes of cost-effectiveness analyses.

Etanercept and infliximab for the treatment of psoriatic arthritis: a systematic review and economic evaluation

OBJECTIVES

To evaluate the clinical effectiveness, safety, tolerability and cost-effectiveness of etanercept and infliximab for the treatment of active and progressive psoriatic arthritis (PsA) in patients who have inadequate response to standard treatment, including disease-modifying antirheumatic drug (DMARD) therapy.

DATA SOURCES

Electronic databases were searched up to July 2004.

REVIEW METHODS

A systematic review evaluated the clinical efficacy and adverse effects of etanercept and infliximab. The efficacy of DMARDs in the treatment of PsA was also reviewed and treatments were compared using Bayesian evidence synthesis methods. Following evaluation of existing economic evaluations of etanercept and infliximab in PsA, a new economic model was developed (the York Model). This utilised the results from the evidence synthesis and data from a range of other sources.

RESULTS

Across the two trials, at 12 weeks, around 65% of patients treated with etanercept achieved an American College of Rheumatology (ACR) 20 {pooled relative risk (RR) 4.19 [95% confidence interval (CI) 2.74 to 6.42]}, demonstrating a basic degree of efficacy in terms of arthritis-related symptoms. In addition, around 45% of patients treated with etanercept achieved an ACR 50 [pooled RR 10.84 (95% CI 4.47 to 26.28)] and around 12% achieved an ACR 70 [pooled RR 16.28 (95% CI 2.20 to 120.54)], demonstrating a good level of efficacy. The subgroup analyses conducted in one trial revealed that the effect of etanercept was not dependent upon patients' concomitant use of methotrexate. In addition, almost 85% of patients treated with etanercept achieved a Psoriatic Arthritis Response Criteria (PsARC) [pooled RR 2.60 (95% CI 1.96 to 3.45). The Psoriatic Area and Severity Index (PASI) results indicate some beneficial effect on psoriasis at 12 weeks; however, the data are sparse. The statistically significant reduction (improvement) in Health Assessment Questionnaire (HAQ) score with etanercept compared with placebo indicates a beneficial effect of etanercept on function. Similar results were seen at 24 weeks, except that the results for PASI 75 and PASI 50 now achieved statistical significance and data for Total Sharp Score annualised rate of progression were available; this was statistically significantly lower in etanercept-treated patients than in placebo-treated patients. Uncontrolled follow-up of patients indicates that treatment benefit may be maintained for at least 50 weeks. At 16 weeks, 65% of patients treated with infliximab achieved an ACR 20 [RR 6.80 (95% CI 2.89 to 16.01)], demonstrating a basic degree of efficacy in terms of arthritis-related symptoms. This level of efficacy was not dependent upon patients' concomitant use of methotrexate. Almost half the patients treated with infliximab achieved an ACR 50 [RR 49.00 (95% CI 3.06 to 785.06)] and over one-quarter achieved an ACR 70 [RR 31.00 (95% CI 1.90 to 504.86)] compared with none of the placebo group, demonstrating a good level of efficacy. In addition, 75% of patients treated with infliximab achieved a PsARC [RR 3.55 (95% CI 2.05 to 6.13)]. The beneficial treatment effect on psoriasis was also statistically significant with a mean difference in percentage change from baseline in PASI of -5 (95% CI -6.8 to -3.3), as was the percentage improvement from baseline in HAQ score with infliximab compared with placebo [mean difference 51.4 (95% CI 48.08 to 54.72)], indicating a beneficial effect of infliximab on functional status. Uncontrolled data from all measures of joint disease, psoriasis and HAQ collected up to 50 weeks of follow-up reflect those at 16 weeks. There were no radiographic assessments, so nothing can be determined about the potential or otherwise of infliximab to delay the progression of joint disease. Using the York cost-effectiveness model, infliximab was consistently dominated by etanercept because of its higher acquisition and administration costs without superior effectiveness. The incremental cost per quality-adjusted life-year (QALY) gained of etanercept compared with palliative care ranged from 14,818 pounds (females, 40-year time horizon) to 49,374 pounds (males, 1-year time horizon) if it is assumed that, when patients eventually fail on biological therapy, their disability (in terms of HAQ score) deteriorates by the same amount as it improved when they initially respond to treatment (rebound equal to gain). Results for etanercept ranged from 25,443 pounds (females, 40-year time horizon) to 49,441 pounds (males, 1-year time horizon) per QALY gained under the assumption that, when patients fail on therapy, their disability level returns to what it would have been had they never responded (rebound equal to natural history).

CONCLUSIONS

The limited data available indicated that etanercept and infliximab are efficacious in the treatment of PsA with beneficial effects on both joint and psoriasis symptoms and on functional status. Short-term data indicated that etanercept can delay joint disease progression, but long-term data are needed. There are no controlled data as yet to indicate that infliximab can delay joint disease progression. Treatment with both etanercept and infliximab for 12 weeks demonstrated a significant degree of efficacy, with no statistically significant difference between them. For both drugs, adverse events were common with mild injection/infusion reactions being the main treatment-related effect. The York model indicated that etanercept is more cost-effective than infliximab as it has a lower cost with little difference in outcomes. The cost-effectiveness of etanercept is also sensitive to assumptions made about the extent of disease progression when patients are responding to therapy. The number of years for which a patient can be safely on biologicals is uncertain so these results should be considered with caution. Further research should include long-term controlled trials to confirm benefits, review adverse events and to explore further the implications of biologic therapy.

High-risk febrile neutropenia in Auckland 2003-2004: the influence of the microbiology laboratory on patient treatment and the use of pathogen-specific therapy

BACKGROUND

International guidelines recommend routine microbiological assessment of patients with febrile neutropenia, but do not recommend a change from broad-spectrum antibiotic therapy to pathogen-specific therapy when a clinically relevant organism has been isolated. The aim of the study was to determine the aetiology of febrile neutropenia in adult haematology patients at Auckland City Hospital, to document the changes in treatment made following isolation of a clinically relevant organism and to assess adverse outcomes in any patient who received pathogen-specific therapy after a positive culture result.

METHODS

The results of all microbiological tests together with antibiotic therapy were recorded from consecutive patients with fever and a neutrophil count <0.5 x 10(9)/L over 1 year beginning in May 2003.

RESULTS

One thousand one hundred and ninety-six specimens were collected from 81 patients during 116 episodes of febrile neutropenia. A pathogen was isolated from blood cultures in 40 episodes: Gram-positive cocci accounted for 46% of isolates and Gram-negative bacilli for 35%. Isolation of a pathogen from blood cultures resulted in a change of treatment in 25 of 40 (62.5%, 95%CI 46-77%) episodes. In 12 of these episodes, antibiotic therapy was optimized to a single pathogen-specific agent. No adverse events or subsequent changes in antibiotic therapy occurred in any of these 12 patients. Isolation of a pathogen from specimens other than blood seldom led to a change in therapy.

CONCLUSION

Isolation of a pathogen from blood cultures often allows antibiotic therapy to be simplified to a pathogen-specific regimen. Further study of this approach is warranted.

The efficacy of intra-articular bupivacaine for relief of pain following arthroscopy of the ankle

The intra-articular injection of local anaesthetic is frequently used for pain relief after arthroscopy. There is, however, no published evidence of the analgesic effect of bupivacaine in the ankle. In a randomised, double-blind study, 35 patients undergoing arthroscopy of the ankle were allocated to receive intra-articular saline or bupivacaine. Pain was assessed using pain scores and additional analgesic requirements. Intra-articular bupivacaine had a significant analgesic effect in the immediate post-operative period, reducing pain scores and the need for additional analgesics.

We recommend the use of intra-articular bupivacaine for post-operative analgesia in ankle surgery.

Clinical effectiveness and cost-effectiveness of tests for the diagnosis and investigation of urinary tract infection in children: a systematic review and economic model

OBJECTIVES

To determine the diagnostic accuracy of tests for detecting urinary tract infection (UTI) in children under 5 years of age and to evaluate the effectiveness of tests used to investigate further children with confirmed UTI. Also, to evaluate the effectiveness of following up children with UTI and the cost-effectiveness of diagnostic and imaging tests for the diagnosis and follow-up of UTI in children under 5. An additional objective was to develop a preliminary diagnostic algorithm for healthcare professionals.

DATA SOURCES

Electronic databases were searched up to the end of 2002/early 2003. Consultation with experts in the field.

REVIEW METHODS

A systematic review was undertaken using published guidelines and results were analysed according to test grouping: diagnosis of UTI and further investigation of UTI. The cost-effectiveness results from existing evaluations were synthesised. A separate cost-effectiveness model was developed using the best available evidence, in part derived from the results of the systematic review, to illustrate the potential cost-effectiveness of some alternative management strategies in a UK setting. The results of the systematic review were used to propose diagnostic algorithms for the diagnosis and further investigation of UTI in children. Economic analyses did not contribute directly to the development of these algorithms.

RESULTS

The studies included in the review provided very little data on the accuracy of clinical investigations for the diagnosis of UTI, and criteria for clinical suspicion of UTI were not further defined. The majority of studies included in the review found that clean voided midstream urine (CVU) samples had similar accuracy to suprapubic aspiration (SPA) samples when cultured with the advantage of being a non-invasive collection method that can be used in the GP's surgery. Pad, nappy or bag specimens may be appropriate methods for obtaining a urine sample in non-toilet-trained children, although only limited data were available. Although the glucose test was reported to have the highest accuracy in terms of both ruling in and ruling out disease, only a limited number of studies of this test were included and these were conducted over 30 years ago. Dipstick tests are easy to perform in the GP's surgery, give an immediate result and are relatively cheap. The results of the systematic review showed that a dipstick for leucocyte esterase (LE) and nitrite, where both test results are interpreted in combination, was a good test both for ruling in (both positive) and ruling out (both negative) a UTI. A dipstick positive for either LE or nitrite and negative for the other provides inconclusive diagnostic information and further testing is therefore required in these patients. Microscopy is more time consuming and expensive to perform than a dipstick test, but potentially quicker and cheaper than culture. As with dipstick tests, a combination of microscopy for pyuria and bacteriuria can be used accurately to rule in and rule out a UTI. An indeterminate test result is again obtained if microscopy is positive for either pyuria or bacteriuria, and negative for the other. Confirmatory culture is required in these patients. In patients considered to have a UTI, further culture to determine antibiotic sensitivities may be an option to inform treatment decisions. Only one study satisfied the inclusion criteria of the economic review and the review highlighted a number of potential limitations of this study for NHS decision-making. A separate decision-analytic model was therefore developed to provide a more reliable estimate of the optimal strategy regarding the diagnosis and further investigation of children under 5 with suspected UTI from the perspective of the NHS. The economic model found that the optimal diagnostic strategy for children presenting with symptoms suggestive of UTI depends on a number of key factors. These included the relevant subgroup of children concerned, in terms of gender and age, and the health service's maximum willingness to pay for an additional quality-adjusted life-year.

CONCLUSIONS

The results of the systematic review were used to derive an algorithm for the diagnosis of UTI in children under 5. This algorithm represents the conclusions of the review in terms of effective practice. There were insufficient data to propose an algorithm for the further investigation of UTI in children under 5. The quality assessment highlighted several areas that could be improved upon in future diagnostic accuracy studies.

A systematic review of the effectiveness of docetaxel and mitoxantrone for the treatment of metastatic hormone-refractory prostate cancer

A systematic review was performed to evaluate the clinical effectiveness of docetaxel in combination with prednisolone (docetaxel is licensed in the UK for use in combination with prednisone or prednisolone for the treatment of patients with metastatic hormone-refractory prostate cancer. Prednisone is not used in the UK, but it is reasonable to use docetaxel plus prednisone data in this review of docetaxel plus prednisolone) for the treatment of metastatic hormone-refractory prostate cancer. A scoping search identified a trial of docetaxel plus prednisone vs mitoxantrone plus prednisone, but did not identify any trials comparing docetaxel plus prednisolone/prednisone with any other treatments. Therefore, we considered additional indirect evidence that would enable a comparison of docetaxel plus prednisolone/prednisone with other chemotherapy regimens and active supportive care. Systematic searching (upto April 2005) identified seven randomised controlled trials. One large well-conducted trial assessed docetaxel plus prednisone vs mitoxantrone plus prednisone; this showed statistically significant improvements with 3-weekly docetaxel in terms of overall survival, quality of life, pain response and PSA decline. Two other chemotherapy regimens that included docetaxel with estramustine also showed improved outcomes in comparison with mitoxantrone plus prednisone. Three trials that compared mitoxantrone plus corticosteroids with corticosteroids alone were identified and their results for overall survival combined, which showed very little difference between the two groups. The addition of clodronate to mitoxantrone plus prednisone showed no significant differences in comparison with mitoxantrone plus prednisone alone. The evidence suggests that chemotherapy regimens containing 3-weekly docetaxel are superior to mitoxantrone or corticosteroids alone.

The safety and immunogenicity of Bacillus Calmette-Guérin (BCG) vaccine in European badgers (Meles meles)

European badgers (Meles meles) are a wildlife reservoir for Mycobacterium bovis (M. bovis) in Great Britain (GB) and the Republic of Ireland and therefore constitute a potential source of infection for cattle. Reduction of badger densities in the Republic of Ireland has resulted in an associated reduction in the risk of a herd break-down with bovine tuberculosis and a study to determine whether this is also the case in GB has been running since 1997. If badgers are a significant source of M. bovis infection for cattle, vaccinating badgers with Bacillus Calmette-Guérin (BCG) might prove to be a long term, cost-effective strategy for controlling bovine tuberculosis whilst preserving badger populations. As a first step towards BCG vaccination of wild badgers, it was necessary to demonstrate safety of the vaccine in captive badgers. Therefore, captive badgers were vaccinated with a commercial source of BCG that is already licensed for administration to humans in GB-BCG Danish SSI. Using a protocol prescribed by the Veterinary Medicines Directorate (VMD) of GB, badgers were vaccinated with two consecutive doses of BCG via either the subcutaneous (s.c.) or intra-muscular (i.m.) routes. The first dose was high, ranging from 16 to 22 x 10(7) colony-forming units (CFU), and was followed 15 weeks later by a lower dose in the range of 4-7 x 10(5)CFU. Local reaction at the site of injection and general responses (body temperature, haematology and blood serum chemistry), behaviour and excretion of BCG were monitored for 28 weeks from the time of the first vaccination. The only side-effect observed was the occurrence of localised swelling at the site of BCG injection that disappeared 48 days after i.m. vaccination but persisted longer in the group vaccinated by the s.c. route. Immunological responses were measured at regular intervals. Strong cellular responses were observed 13 days after the first vaccination, which persisted for 76 days. The lower dose induced a weaker and shorter-lived response.

Evaluation of HER-2 expression in breast cancer using image analysis incorporating automatic feature recognition

20007

The currently favoured method for evaluation of HER-2 in routine clinical practice and research studies is immunohistochemistry (IHC). As standardised scoring of protein expression, using a scale of 0 - 3+, generates a significant number of false positives, fluorescent in situ hybridisation (FISH) is used to confirm the presence of gene amplification. Both techniques are laborious, and in the case of by-eye scoring of IHC, semi-quantitative at best. We have developed a high-throughput platform for the quantitative analysis of immunostained slides, based on fast, high-resolution scanning followed by analysis of digitised images (IA) using proprietary software, and in this study compared results obtained using this platform with those obtained using conventional methods. Archival sections of primary breast cancers collected at Nottingham City Hospital in 2004 and 2005 were stained for HER-2 (Herceptest, Dako), and evaluated by eye. Equal numbers of slides from scoring categories 0–3+ were then selected for further image analysis. The digitised images were subjected to automatic delineation to define areas of tumour parenchyma, and these areas further analysed using colour segmentation. Between 100 and 2000 fields were quantified on each section. Staining was expressed as a product of field fraction of coloured pixels and optical density. The results of IA demonstrate a continuum of staining values over the four conventional by-eye categories, with a non-linear correlation to by-eye scores. Inter-sample variation was greatest in the 3+ category, although the mean was much higher than that of the 2+ samples. The 2+ samples showed some variation, with several values not rising above baseline. To further investigate the relationship between FISH scores and IA results in the 2+ category, we analysed an additional set of slides in this group, and found a correlation between FISH and automated IA scores. We conclude that automated image analysis is sensitive to small differences in protein expression, has a wide dynamic range, and provides data superior to conventional by-eye scoring. In undecided cases HER-2 protein expression correlates with FISH data; therefore ultimately IA of HER-2 protein expression alone may provide a basis for clinical decisions.

[Table: see text]

Persistence of nevirapine-resistant HIV-1 in women after single-dose nevirapine therapy for prevention of maternal-to-fetal HIV-1 transmission

Single-dose nevirapine (sdNVP) for prevention of mother-to-child transmission of HIV-1 can select nevirapine (NVP)-resistant variants, but the frequency, duration, and clinical significance of this resistance is not well defined. We used a sensitive allele-specific PCR assay to assess the emergence and persistence of NVP-resistant variants in plasma samples from 22 women with HIV-1 subtype C infection who participated in a study of sdNVP for prevention of mother-to-child transmission of HIV-1. The women were categorized into three groups on the basis of detection of NVP resistance by standard genotype analysis. Group 1 (n = 6) had NVP resistance detected at 2 and 6 mo after sdNVP, but not at 12 mo. Group 2 (n = 9) had NVP resistance detected at 2 mo, but not 6 mo. Group 3 (n = 7) had no NVP resistance detected at any time point. Allele-specific PCR analysis for the two most common NVP resistance mutations (K103N and Y181C) detected NVP-resistant variants in most (16 of 21) samples that were negative for NVP resistance by standard genotype, at levels ranging from 0.1% to 20% 1 yr after treatment. The frequency of NVP-resistant mutations decreased over time, but persisted above predose levels for more than 1 yr in > or = 23% of the women. These findings highlight the urgent need for studies assessing the impact of sdNVP on the efficacy of subsequent antiretroviral therapy containing NVP or other nonnucleoside reverse transcriptase inhibitors.