academic clinical trials analysis of clinical trials animal testing attributable risk bias biomedical research blind experiment case fatality case report case series case study clinical trial clinical trial management clinical trial protocol cohort study controlling for a variable cross-sectional study cumulative incidence design of experiments enzyme assay epidemiological methods epidemiology experiment first-in-man study glossary of clinical research hazard ratio in vitro in vivo infectivity list of clinical research topics longitudinal study medication morbidity mortality rate multicenter trial nested case-control study observational study odds ratio open-label trial patient period prevalence physician placebo point prevalence prevalence prospective cohort study randomized controlled trial relative risk retrospective cohort study risk-benefit analysis scientific method seeding trial sensitivity and specificity study design vaccine trial variable virulence