R. J. Beynon

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Published evidence suggests that aspects of trial design lead to biased intervention effect estimates, but findings from different studies are inconsistent. This study combined data from 7 meta-epidemiologic studies and removed overlaps to derive a final data set of 234 unique meta-analyses containing 1973 trials. Outcome measures were classified as(More)
BACKGROUND Randomized trials assessing BCG vaccine protection against tuberculosis have widely varying results, for reasons that are not well understood. METHODS We examined associations of trial setting and design with BCG efficacy against pulmonary and miliary or meningeal tuberculosis by conducting a systematic review, meta-analyses, and(More)
BACKGROUND Early recognition and treatment of rheumatoid arthritis is important to prevent irreversible joint damage. Anti-citrullinated peptide antibodies (ACPA) have been suggested for early diagnosis. PURPOSE To compare the accuracy of ACPA and rheumatoid factor in diagnosing rheumatoid arthritis in patients with early symptoms of the disease. DATA(More)
We systematically reviewed and meta-analyzed literature examining associations of vitamin D (dietary intake, circulating 25-hydroxy-vitamin-D (25(OH)D), and 1,25-dihydroxy-vitamin-D (1,25(OH)2D) concentrations) with prostate cancer. We searched over 24,000 papers from seven electronic databases (to October 2010) for exposures related to vitamin D. We(More)
BACKGROUND The design of randomised controlled trials (RCTs) should incorporate characteristics (such as concealment of randomised allocation and blinding of participants and personnel) that avoid biases resulting from lack of comparability of the intervention and control groups. Empirical evidence suggests that the absence of such characteristics leads to(More)
BACKGROUND Height, a marker of childhood environmental exposures, is positively associated with prostate cancer risk, perhaps through the insulin-like growth factor system. We investigated the relationship of prostate cancer with height and its components (leg and trunk length) in a nested case-control study and with height in a dose-response meta-analysis.(More)
OBJECTIVE To compare the performance of MEDLINE searches using index test(s) and target condition (subject searches) with the same searches combined with methodological filters for test accuracy studies. STUDY DESIGN AND SETTING We derived a reference set of 506 test accuracy studies indexed on MEDLINE from seven systematic reviews that conducted(More)
BACKGROUND Recent evidence suggests that the duration of protection by bacillus Calmette-Guérin (BCG) may exceed previous estimates with potential implications for estimating clinical and cost-efficacy. OBJECTIVES To estimate the protection and duration of protection provided by BCG vaccination against tuberculosis, explore how this protection changes(More)
BACKGROUND Prostate cancer is a growing public health problem. Several human studies have shown a potentially protective effect of selenium, but the conclusions from published reports are inconsistent. OBJECTIVE The objective was to examine the evidence for relations between selenium intake, selenium status, and prostate cancer risk. DESIGN This was a(More)
Epidemiologic investigations often report dose-response associations, which may be combined in meta-analyses. The authors examined how often the log odds, risk, or hazard ratio per unit increase in exposure, and its standard error, can be estimated from results reported from observational studies of diet and prostate or bladder cancer so that results are(More)