Nature

Study design II. Issues of chance, bias, confounding and contamination

In the first article in the series I explained the importance of study design and gave an overview of the main types of design. Here, I describe the ways in which the results of a study may deviate ...
ascopubs.org

Adjustments for confounding variables in observational population-based studies in oncology and comparison to results from randomized controlled trials.

Collection and utilization of oncology big data. This is an ASCO Meeting Abstract from the 2017 ASCO Annual Meeting I. This abstract does not include a full text component.
CMAJ

Testing group differences for confounder selection in nonrandomized studies: flawed practice

Using observed imbalances between study groups (e.g., exposed and unexposed) to determine variables for confounding adjustment in nonrandomized studies may misguide the selection of variables to ...
TES

VARIABLES Research methods

For AQA Psychology Specification. It covers Independent and Dependent Variables, Conditions, Extraneous and Confounding Variables, and Operationalisation. It is a powerpoint with a notes sheet that ...
CMAJ

Testing group differences for confounder selection in nonrandomized studies: flawed practice

Using observed imbalances between study groups (e.g., exposed and unexposed) to determine variables for confounding adjustment in nonrandomized studies may misguide the selection of variables to ...