van Staa, TP; Smeeth, L; Persson, I; Parkinson, J; Leufkens, HGM; (2008) Evaluating drug toxicity signals: is a hierarchical classification of evidence useful or a hindrance? Pharmacoepidemiology and drug safety, 17 (5). pp. 475-484. ISSN 1053-8569 DOI: https://doi.org/10.1002/pds.1568 Full text not available from this repository.