Overview of a paediatric renal transplant programme

INTRODUCTION: Renal transplantation is the therapy of choice for children with end-stage renal failure. There are many challenges associated with a paediatric programme in a developing country where organs are limited. METHODS: A retrospective review was undertaken of 149 paediatric renal transplants performed between 1968 and 2006 with specific emphasis on transplants performed in the last 10 years. Survival of patients and grafts was analysed and specific problems related to drugs and infections were reviewed. RESULTS: On review of the total programme, 60% of the transplants have been performed in the last 10 years, with satisfactory overall patient and graft survival for the first 8 years post transplant. At this point, transfer to adult units with non-compliance becomes a significant problem. Rejection is less of a problem than previously but infection is now a bigger issue--specifically tuberculosis (TB), cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections with related complications. A wide variety of drugs are available for tailoring immunosuppression to minimise side-effects. CONCLUSION: It is possible to have a successful paediatric transplant programme in a developing country. However, to improve long-term outcomes certain issues need to be addressed, including reduction of nephrotoxic drugs and cardiovascular risk factors and providing successful adolescent to adult unit transition

Overview of a paediatric renal transplant programme

No Abstract. South African Medical Journal Vol. 96(9) (Part 2) 2006: 955-95

Rapid tests and urine sampling techniques for the diagnosis of urinary tract infection (UTI) in children under five years: a systematic review

Background: Urinary tract infection (UTI) is one of the most common sources of infection in children under five. Prompt diagnosis and treatment is important to reduce the risk of renal scarring. Rapid, cost-effective, methods of UTI diagnosis are required as an alternative to culture. Methods: We conducted a systematic review to determine the diagnostic accuracy of rapid tests for detecting UTI in children under five years of age. Results: The evidence supports the use of dipstick positive for both leukocyte esterase and nitrite (pooled LR+ = 28.2, 95% CI: 17.3, 46.0) or microscopy positive for both pyuria and bacteriuria (pooled LR+ = 37.0, 95% CI: 11.0, 125.9) to rule in UTI. Similarly dipstick negative for both LE and nitrite (Pooled LR- = 0.20, 95% CI: 0.16, 0.26) or microscopy negative for both pyuria and bacteriuria (Pooled LR- = 0.11, 95% CI: 0.05, 0.23) can be used to rule out UTI. A test for glucose showed promise in potty-trained children. However, all studies were over 30 years old. Further evaluation of this test may be useful. Conclusion: Dipstick negative for both LE and nitrite or microscopic analysis negative for both pyuria and bacteriuria of a clean voided urine, bag, or nappy/pad specimen may reasonably be used to rule out UTI. These patients can then reasonably be excluded from further investigation, without the need for confirmatory culture. Similarly, combinations of positive tests could be used to rule in UTI, and trigger further investigation

How does study quality affect the results of a diagnostic meta-analysis?

Background: The use of systematic literature review to inform evidence based practice in diagnostics is rapidly expanding. Although the primary diagnostic literature is extensive, studies are often of low methodological quality or poorly reported. There has been no rigorously evaluated, evidence based tool to assess the methodological quality of diagnostic studies. The primary objective of this study was to determine the extent to which variations in the quality of primary studies impact the results of a diagnostic meta-analysis and whether this differs with diagnostic test type. A secondary objective was to contribute to the evaluation of QUADAS, an evidence-based tool for the assessment of quality in diagnostic accuracy studies. Methods: This study was conducted as part of large systematic review of tests used in the diagnosis and further investigation of urinary tract infection (UTI) in children. All studies included in this review were assessed using QUADAS, an evidence-based tool for the assessment of quality in systematic reviews of diagnostic accuracy studies. The impact of individual components of QUADAS on a summary measure of diagnostic accuracy was investigated using regression analysis. The review divided the diagnosis and further investigation of UTI into the following three clinical stages: diagnosis of UTI, localisation of infection, and further investigation of the UTI. Each stage used different types of diagnostic test, which were considered to involve different quality concerns. Results: Many of the studies included in our review were poorly reported. The proportion of QUADAS items fulfilled was similar for studies in different sections of the review. However, as might be expected, the individual items fulfilled differed between the three clinical stages. Regression analysis found that different items showed a strong association with test performance for the different tests evaluated. These differences were observed both within and between the three clinical stages assessed by the review. The results of regression analyses were also affected by whether or not a weighting (by sample size) was applied. Our analysis was severely limited by the completeness of reporting and the differences between the index tests evaluated and the reference standards used to confirm diagnoses in the primary studies. Few tests were evaluated by sufficient studies to allow meaningful use of meta-analytic pooling and investigation of heterogeneity. This meant that further analysis to investigate heterogeneity could only be undertaken using a subset of studies, and that the findings are open to various interpretations. Conclusion: Further work is needed to investigate the influence of methodological quality on the results of diagnostic meta-analyses. Large data sets of well-reported primary studies are needed to address this question. Without significant improvements in the completeness of reporting of primary studies, progress in this area will be limited

Review of investment model cost parameters for VSC HVDC transmission infrastructure

Cost parameters for VSC HVDC transmission infrastructure have been gathered from an extensive collection of techno-economic sources. These cost parameter sets have been converted to a common format, based on a linear investment cost model depending on the branch length and the power rating of cable systems and converter stations. In addition, an average parameter set was determined as the arithmetic mean of the collected parameter sets, and included in the study. The uniform format allowed for a comparison of the parameter sets with each other, which revealed large differences between the cost parameter sets. The identified disparity between the parameter sets reflects a high level of uncertainty which can only in part be explained by a varying focus and modelling approach of their sources. This implies limitations regarding the validity of the parameters sets as well as of the results from grid expansion studies carried out on the basis of these parameter sets. Comprehensive cost reference data has been collected from realised and contracted VSC HVDC projects (back-to-back, interconnector, and offshore wind connection). The cost parameter sets have been evaluated against the reference project cost data. This evaluation has again shown large variations between the parameter sets. On average, the cost for back-to-back systems are slightly underestimated, interconnectors are overestimated, and offshore wind connections are heavily underestimated. To clearly state the validity and limitations of this comparison and evaluation, the applied methodology with its compromises and drawbacks is discussed in detail. Considering the interest in and momentum of offshore grid development, as well as the number of offshore grid investment and evaluation studies being conducted, both the availability of reliable cost reference data and the validity of investment model cost parameters need continuing attention

Offshore wind competitiveness in mature markets without subsidy

Offshore wind energy development has been driven by government support schemes; however, recent cost reductions raise the prospect of offshore wind power becoming cheaper than conventional power generation. Many countries use auctions to provide financial support; however, differences in auction design make their results difficult to compare. Here, we harmonize the auction results from five countries based on their design features, showing that offshore wind power generation can be considered commercially competitive in mature markets. Between 2015 and 2019, the price paid for power from offshore wind farms across northern Europe fell by 11.9 ± 1.6% per year. The bids received in 2019 translate to an average price of €51 ± 3 MWh−1, and substantially different auction designs have received comparably low bids. The level of subsidy implied by the auction results depends on future power prices; however, projects in Germany and the Netherlands are already subsidy-free, and it appears likely that in 2019 the United Kingdom will have auctioned the world’s first negative-subsidy offshore wind farm