title: Randomization is essential for progress in transplant medicine.
abstract: Improvements in immunosuppressive regimens are likely to be moderate in size. Therefore, studies to detect them reliably require a guarantee of small biases (so randomization is essential) and small random errors. Even after adjustment, nonrandomized studies may have large biases, so are not a suitable alternative to large randomized trials.
authors.affiliation: Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), University of Oxford, Oxford, United Kingdom. colin.baigent@ctsu.ox.ac.uk
authors.forename: Colin
authors.initials: C
authors.lastname: Baigent
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Emberson
mesh_terms: D015982:Bias; D019317:Evidence-Based Medicine; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D019370:Observation; D016377:Organ Transplantation; D016032:Randomized Controlled Trials as Topic; D012042:Registries; D016896:Treatment Outcome
chemical_list: D007166:Immunosuppressive Agents