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

A digital technique for recording of plant population data in permanent plots

A mobile system to rapidly record demographic and spatial data of plant populations on permanent plots has been developed based on digital image processing equipment for personal computers. It offers considerable savings in field and data handling time and can record data from large plots. This system will facilitate broader application of plant demographic studies to arid and semi-arid ecosystems.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Excellent passivation of p + silicon surfaces by inline plasma enhanced chemical vapor deposited SiO x/AlO x stacks

10.1143/JJAP.51.10NA17Japanese Journal of Applied Physics5110 PART 2

Screening for abdominal aortic aneurysm: does it affect men's quality of life?

A prospective study investigated the psychological wellbeing and quality of life of older rural men after a community-based screening for abdominal aortic aneurysm (AAA). Five hundred and sixteen men aged 65-74 years attended the screening program; 53 had an abnormal aorta detected. These and a subsample of men with a normal aorta were followed up 6 months post-screening. All men completed a pre-screening questionnaire including the Medical Outcomes Short Form 36v 2 (MOSF36) and Hospital Anxiety and Depression Scale (HADS). Six months after screening all 53 men with an abnormal and 130 with a normal aorta were sent a questionnaire including MOSF36 and HADS. Baseline and 6 month scores for both MOSF36 and HADS scores were compared between the two groups and within each group. Baseline scores for both MOSF36 and HADS were not significantly different between men who were subsequently diagnosed with an abnormal aorta and those with a normal aorta. After 6 months there was no difference in HADS scores but a significant increase in the MOSF36 dimension of general health. Those with a normal aorta reported better general health, social functioning andgreater freedom from bodily pain. AAA screening appears highly acceptable to men in the target age group and future research should focus on implementation, cost effectiveness and collateral benefits of AAA screening

19% efficient inline-diffused large-area screen-printed Al-LBSF silicon wafer solar cells

10.1016/j.egypro.2012.07.091Energy Procedia27444-44