Meta-analyses of observational studies
Small prospective case-control studies, involving just a few hundred patients with the outcome of interest, may be sufficient to identify a risk factor, but due to their inherent statistical uncertainties, do not generally suffice to assess the age-specific quantitative importance of such factors or any interactions with other risk factors, so CTSU established the Prospective Studies Collaboration. This collaborative meta-analysis of data on over one million individuals in prospective observational studies of blood pressure and cholesterol throughout the world provides reliable and unbiased estimates of the age-specific relevance of those risk factors, as well as of measures of adiposity and of diabetes mellitus, to particular causes of death.
CTSU has also established a meta-analysis of case-control studies of residential radon to improve our understanding of the relationship between exposure to radon in homes and the risk of lung cancer.