4Concato J, Shah N, Horwitz RI. Randomized, controlled trials, observational studies and the hierarchy of research designs. N Engl J Med, 2000, 342(25): 1887-1892.
5Britton A, McKee M, Black N, et al. Choosing between randomized and non-randomised studies: A systematic review. Health Technology Assessment, 1998, 2(13): 1-124.
6Robins JM, Hernan MA, Brumback B. Marginal structural models and causal inference in epidemiology. Epidemiology, 2000, 11(5): 550-560.
7Horwitz RI, Viscoli CM, Clemens JD, et al. Developing improved observational methods for evaluating therapeutic effectiveness. Am J Med, 1990, 89(5): 630-638.
8de Almeida Neto AC, Chen TF. When pharmacotherapeutic recommendations may lead to the reverse effect on physician decisionmaking. Pharm World Sci, 2008, 30(1): 3-8.
9Black N. Why we need observational studies to evaluate the effectiveness of health care. BMJ, 1996, 312(7040): 1215-1218.
10Benson K, Hartz AJ. A comparison of observational and randomized controlled trials. N Engl JMed, 2000, 342: 1878-1886.
5David Ogilvie,Charles E Foster,Helen Rothnie,Nick Cavill,Val Hamilton,Claire F Fitzsimons,Nanette Mutrie,钱招昕(译).促进步行的干预措施：系统性综述[J].英国医学杂志中文版,2008,11(1):16-25.
