14 research outputs found

    Occupational exposures to solvents and metals are associated with fixed airflow obstruction

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    peer-reviewedOur study is the first to investigate the associations between exposures to solvents and metals using lifetime work history calendars and fixed airflow obstruction (AO). We have shown that increasing cumulative exposure-unit years to chlorinated solvents is associated with fixed AO. We found that women were at increased risk of fixed AO with increasing cumulative exposed-unit-years to chlorinated solvents but not men

    Violation of research integrity principles occurs more often than we think

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    The science community generally believes that the violation of research integrity is rare. Built upon this belief, the scientific system makes little effort to examine the trustworthiness of research. Research misconduct refers to an intentional violation of research integrity principles, which has an extensive and far-reaching impact on the trustworthiness and reputation of science. Emerging evidence has suggested that research misconduct is far more common than we normally perceive. Far more problematic papers should be retracted than are being retracted because of poor actions when confronting research misconduct. Research misconduct is usually driven by incentives in the form of pursuing publications for researchers' career needs and is further facilitated by poor research governance. The current strategy that tackles potential research misconduct focuses on protecting the reputation of authors and their institutions but neglects the interests of patients, clinicians and honest researchers. Removing improper incentives, training researchers and imposing better governance are vital to reducing research misconduct. Awareness of the possibility of misconduct and formalized procedures that scrutinize study trustworthiness are important during peer review and in systematic reviews

    Data integrity of 35 randomised controlled trials in women’ health

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    While updating a systematic review on the topic of ovulation of induction, we observed unusual similarities in a number of randomised controlled trials (RCTs) published by two authors from the same institute in the same disease spectrum in a short period of time. We therefore undertook a focused analysis of the data integrity of all RCTs published by the two authors. We made pairwise comparisons to find identical or similar values in baseline characteristics and outcome tables between trials. We also assessed whether baseline characteristics were compatible with chance, using Monte Carlo simulations and Kolmogorov-Smirnov test. For 35 trials published between September 2006 and January 2016, we found a large number of similarities in both the baseline characteristics and outcomes of 26. Analysis of the baseline characteristics of the trials indicated that their distribution was unlikely to be the result of proper randomisation. The procedures demonstrated in this paper may help to assess data integrity in future attempts to verify the authenticity of published RCTs.Esmée M Bordewijk, Rui Wang, Lisa M.Askie, Lyle C.Gurrin, Jim G.Thornton ... Ben W.Mol ... et al

    To share or not to share data: how valid are trials evaluating first-line ovulation induction for polycystic ovary syndrome?

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    BACKGROUND In our recent individual participant data (IPD) meta-analysis evaluating the effectiveness of first-line ovulation induction for polycystic ovary syndrome (PCOS), IPD were only available from 20 studies of 53 randomized controlled trials (RCTs). We noticed that the summary effect sizes of meta-analyses of RCTs without IPD sharing were different from those of RCTs with IPD sharing. Granting access to IPD for secondary analysis has implications for promoting fair and transparent conduct of RCTs. It is, however, still common for authors to choose to withhold IPD, limiting the impact of and confidence in the results of RCTs and systematic reviews based on aggregate data. OBJECTIVE AND RATIONALE We performed a meta-epidemiologic study to elucidate if RCTs without IPD sharing have lower quality and more methodological issues than those with IPD sharing in an IPD meta-analysis evaluating first-line ovulation induction for PCOS. SEARCH METHODS We included RCTs identified for the IPD meta-analysis. We dichotomized RCTs according to whether they provided IPD (shared group) or not (non-shared group) in the IPD meta-analysis. We restricted RCTs to full-text published trials written in English. We assessed and compared RCTs in the shared and non-shared groups on the following criteria: Risk of Bias (RoB 2.0), GRADE approach, adequacy of trial registration; description of statistical methods and reproducibility of univariable statistical analysis; excessive similarity or difference in baseline characteristics that is not compatible with chance; and other miscellaneous methodological issues. OUTCOMES In total, 45 trials (8697 women) were included in this study. IPD were available from 17 RCTs and 28 trials were categorized as the non-shared IPD group. Pooled risk rates obtained from the shared and non-shared groups were different. Overall low risk of bias was associated with 13/17 (76%) of shared RCTs versus 7/28 (25%) of non-shared RCTs. For RCTs that started recruitment after 1 July 2005, adequate trial registration was found in 3/9 (33%) of shared IPD RCTs versus 0/16 (0%) in non-shared RCTs. In total, 7/17 (41%) of shared RCTs and 19/28 (68%) of non-shared RCTs had issues with the statistical methods described. The median (range) of inconsistency rate per study, between reported and reproduced analyses for baseline variables, was 0% (0–92%) (6 RCTs applicable) in the shared group and 54% (0–100%) (13 RCTs applicable) in the non-shared group. The median (range) of inconsistency rate of univariable statistical results for the outcome(s) per study was 0% (0–63%) (14 RCTs applicable) in the shared group and 44% (0–100%) (24 RCTs applicable) in the non-shared group. The distributions of simulation-generated P-values from comparisons of baseline continuous variables between intervention and control arms suggested that RCTs in the shared group are likely to be consistent with properly conducted randomization (P = 0.163), whereas this was not the case for the RCTs in the non-shared group (P = 4.535 × 10−8). WIDER IMPLICATIONS IPD meta-analysis on evaluating first-line ovulation induction for PCOS preserves validity and generates more accurate estimates of risk than meta-analyses using aggregate data, which enables more transparent assessments of benefits and risks. The availability of IPD and the willingness to share these data may be a good indicator of quality, methodological soundness and integrity of RCTs when they are being considered for inclusion in systematic reviews and meta-analyses.Esmee M Bordewijk, Rui Wang, Madelon van Wely, Michael F Costello, Robert J Norman, Helena Teede, Lyle C Gurrin, Ben W Mol, Wentao L

    Emulating a target trial of intensive nurse home visiting in the policy-relevant population using linked administrative data

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    OnlinePublBackground: Populations willing to participate in randomized trials may not correspond well to policy-relevant target populations. Evidence of effectiveness that is complementary to randomized trials may be obtained by combining the ‘target trial’ causal inference framework with whole-of-population linked administrative data. Methods: We demonstrate this approach in an evaluation of the South Australian Family Home Visiting Program, a nurse home visiting programme targeting socially disadvantaged families. Using de-identified data from 2004–10 in the ethics-approved Better Evidence Better Outcomes Linked Data (BEBOLD) platform, we characterized the policy-relevant population and emulated a trial evaluating effects on child developmental vulnerability at 5years (n¼4160) and academic achievement at 9 years (n¼6370). Linkage to seven health, welfare and education data sources allowed adjustment for 29 confounders using Targeted Maximum Likelihood Estimation (TMLE) with SuperLearner. Sensitivity analyses assessed robustness to analytical choices. Results: We demonstrated how the target trial framework may be used with linked administrative data to generate evidence for an intervention as it is delivered in practice in the community in the policy-relevant target population, and considering effects on VC outcomes years down the track. The target trial lens also aided in understanding and limiting the increased measurement, confounding and selection bias risks arising with such data. Substantively, we did not find robust evidence of a meaningful beneficial intervention effect. Conclusions: This approach could be a valuable avenue for generating high-quality, policy-relevant evidence that is complementary to trials, particularly when the target populations are multiply disadvantaged and less likely to participate in trials.Margarita Moreno-Betancur, JohnW. Lynch, Rhiannon M. Pilkington, Helena S. Schuch, Angela Gialamas, Michael G. Sawyer, Catherine R. Chittleborough, Stefanie Schurer, and Lyle C. Gurri

    Iron-Overload–Related Disease in HFE Hereditary hemochromatosis

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    Background: Most persons who are homozygous for C282Y, the HFE allele most commonly asssociated with hereditary hemochromatosis, have elevated levels of serum ferritin and transferrin saturation. Diseases related to iron overload develop in some C282Y homozygotes, but the extent of the risk is controversial. Methods: We assessed HFE mutations in 31,192 persons of northern European descent between the ages of 40 and 69 years who participated in the Melbourne Collaborative Cohort Study and were followed for an average of 12 years. In a random sample of 1438 subjects stratified according to HFE genotype, including all 203 C282Y homozygotes (of whom 108 were women and 95 were men), we obtained clinical and biochemical data, including two sets of iron measurements performed 12 years apart. Disease related to iron overload was defined as documented iron overload and one or more of the following conditions: cirrhosis, liver fibrosis, hepatocellular carcinoma, elevated aminotransferase levels, physician-diagnosed symptomatic hemochromatosis, and arthropathy of the second and third metacarpophalangeal joints. Results: The proportion of C282Y homozygotes with documented iron-overload–related disease was 28.4% (95% confidence interval [CI], 18.8 to 40.2) for men and 1.2% (95% CI, 0.03 to 6.5) for women. Only one non-C282Y homozygote (a compound heterozygote) had documented iron-overload–related disease. Male C282Y homozygotes with a serum ferritin level of 1000 μg per liter or more were more likely to report fatigue, use of arthritis medicine, and a history of liver disease than were men who had the wild-type gene. Conclusions: In persons who are homozygous for the C282Y mutation, iron-overload–related disease developed in a substantial proportion of men but in a small proportion of women

    Give Life a Chance: John Lennon e l'utopia del pacifismo

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    This essay concentrates on the final years of John Lennon's collaboration with the Beatles, and on the very first years of his solo career when he decides to get into the world struggle for peace and freedom. One of the key texts here analyzed is "Imagine" whose impact is also studied through some of the italian translations and mis- translations by Ornella Vanoni and Gino Paoli

    A novel association between a SNP in CYBRD1 and serum ferritin levels in a cohort study of HFE hereditary haemochromatosis

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    There is emerging evidence that there are genetic modifiers of iron indices for HFE gene mutation carriers at risk of hereditary hemochromatosis. A random sample, stratified by HFE genotype, of 863 from a cohort of 31 192 people of northern European descent provided blood samples for genotyping of 476 single nucleotide polymorphisms (SNPs) in 44 genes involved in iron metabolism. Single SNP association testing, using linear regression models adjusted for sex, menopause and HFE genotype, was conducted for four continuously distributed outcomes: serum ferritin (log transformed), transferrin saturation, serum transferrin, and serum iron. The SNP rs884409 in CYBRD1 is a novel modifier specific to HFE C282Y homozygotes. Median unadjusted serum ferritin concentration decreased from 1194 microg/l (N = 27) to 387 microg/l (N = 16) for male C282Y homozygotes and from 357 microg/l (N = 42) to 69 microg/l (N = 12) for females, comparing those with no copies to those with one copy of rs884409. Functional testing of this CYBRD1 promoter polymorphism using a heterologous expression assay resulted in a 30% decrease in basal promoter activity relative to the common genotype (P = 0.004). This putative genetic modifier of iron overload expression accounts for 11% (95% CI 0.4%, 22.6%) of the variance in serum ferritin levels of C282Y homozygotes
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