Bradley C. Johnston

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BACKGROUND The accessibility to improved water and sanitation has been understood as a crucial mechanism to save infants and children from the adverse health outcomes associated with diarrheal disease. This knowledge stimulated the worldwide donor community to develop a specific category of aid aimed at the water and sanitation sector. The actual impact of(More)
OBJECTIVE To investigate the credibility of authors' claims of subgroup effects using a representative sample of recently published randomised controlled trials. DESIGN Systematic review. DATA SOURCE Core clinical journals, as defined by the National Library of Medicine, in Medline. STUDY SELECTION Randomised controlled trials published in 2007. Using(More)
Presenting continuous outcomes in Summary of Findings tables presents particular challenges to interpretation. When each study uses the same outcome measure, and the units of that measure are intuitively interpretable (e.g., duration of hospitalization, duration of symptoms), presenting differences in means is usually desirable. When the natural units of(More)
OBJECTIVE To assess the reporting, extent, and handling of loss to follow-up and its potential impact on the estimates of the effect of treatment in randomised controlled trials. DESIGN Systematic review. We calculated the percentage of trials for which the relative risk would no longer be significant under a number of assumptions about the outcomes of(More)
BACKGROUND Assessment of heterogeneity is essential in systematic reviews and meta-analyses of clinical trials. The most commonly used heterogeneity measure, I(2), provides an estimate of the proportion of variability in a meta-analysis that is explained by differences between the included trials rather than by sampling error. Recent studies have raised(More)
The 4-anilinoquinazoline (4-AQ) derivative gefitinib (Iressa) is an oral epidermal growth factor receptor tyrosine kinase inhibitor. Oral administration of 4-AQ molecules, such as gefitinib, inhibits ATP-binding cassette (ABC) transporter-mediated drug efflux and strongly increases the apparent bioavailability of coadministered drug molecules that are(More)
IMPORTANCE Many claims have been made regarding the superiority of one diet or another for inducing weight loss. Which diet is best remains unclear. OBJECTIVE To determine weight loss outcomes for popular diets based on diet class (macronutrient composition) and named diet. DATA SOURCES Search of 6 electronic databases: AMED, CDSR, CENTRAL, CINAHL,(More)
BACKGROUND Patients across North America are using complementary and alternative medicine (CAM) with increasing frequency as part of their management of many different health conditions. The objective of this study was to develop a guide for academic health sciences centers that may wish to consider starting an integrative medicine program. METHODS We(More)
INTRODUCTION Systematic reviewer authors intending to include all randomized participants in their meta-analyses need to make assumptions about the outcomes of participants with missing data. OBJECTIVE The objective of this paper is to provide systematic reviewer authors with a relatively simple guidance for addressing dichotomous data for participants(More)
Systematic reviews of randomized trials that include measurements of health-related quality of life potentially provide critical information for patient and clinicians facing challenging health care decisions. When, as is most often the case, individual randomized trials use different measurement instruments for the same construct (such as physical or(More)