Interpreting the evidence: choosing between randomised and non-randomised studies

Comparisons of randomised and non-randomised studies of the same intervention

Antman K, Amoto D, Wood W, Corson J, Suit H, Proppe K, et al. Selection bias in clinical trials. J Clin Oncol 1985;3:1142-7.

CASS Principal Investigators and Their Associates. Coronary artery surgery study (CASS): A randomised trial of coronary artery bypass surgery. Comparability of entry characteristics and survival in randomised patients and nonrandomised patients meeting randomization criteria. J Am Coll Cardiol 1984;3:114-28.

Colditz GA, Miller JN, Mosteller F. How study design affects outcomes in comparisons of therapy. I: Medical. Stat Med 1989;8:441-54.

Emanuel EJ. Cost savings at the end of life. What do the data show? JAMA 1996;275:1907-14.

Garenne M, Leroy O, Beau JP, Sene I. Efficacy of measles vaccines after controlling for exposure. Am J Epidemiol 1993;138:182-95.

Hlatky MA, Califf RM, Harrell FE, Lee KL, Mark DB, Pryer DB. Comparison of predictions based on observational data with the results of randomised controlled clinical trials of coronary artery bypass surgery. J Am Coll Cardiol 1988;11:237-45.

Horwitz RI, Viscoli CM, Clemens JD, Sadock RT. Developing improved observational methods for evaluating therapeutic effectiveness. Am J Med 1990;89:630-8.

Jha P, Flather M, Lonn E, Farkouhn M, Yusuf S. The antioxidants vitamins and cardiovascular diseaseCa critical review of epidemiological and clinical trial data. Ann Intern Med 1995;123:860-72.

McKay JR, Alterman AI, McLellan T, Snider EC, O'Brien CP. Effect of random versus nonrandom assignment in a comparison of inpatient and day hospital rehabilitation for male alcoholics. J Consulting Clin Psychol 1995;63:70-8.

Miller JN, Colditz GA, Mosteller F. How study design affects outcomes in comparisons of therapy. II: Surgical. Stat Med 1989;8:455-66.

Nicolaides K, de Lourdes Brizot M, Patel F, Snijders R. Comparison of chorionic villus sampling and amniocentesis for fetal karyotyping at 10-13 weeks' gestation. Lancet 1994;344:435-9.

Paradise JL, Bluestone CD, Bachman RZ, Colborn DK, Bernard BJ, Tayler FH, et al. Efficacy of tonsillectomy for recurrent throat infection in severely affected children. Results of parallel randomised and nonrandomised clinical trials. N Engl J Med 1984;310:674-83.

Paradise JL, Bluestone CD, Rogers KD, Taylor FH, Colborn DK, Bachman RZ, et al. Efficacy of adenoidectomy for recurrent otitis media in children previously treated with tympanostomy-tube replacement. Results of parallel randomised and nonrandomised trials. JAMA 1990;263:2066-73.

Pyorala S, Huttunen NP, Uhari M. A review and meta-analysis of hormonal treatment of cryptorchidism. J Clin Endocrin Metab 1995;80:2795-9.

Recurrent Miscarriage Immunotherapy Trialists Group. Worldwide collaborative observational study and meta-analysis on allogenic leukocyte immunotherapy for recurrent spontaneous abortion. Am J Repro Immunol 1994;32:55-72.

Reimold SC, Chalmers TC, Berlin JA, Antman EM. Assessment of the efficacy and safety of antiarrhythmic therapy for chronic atrial fibrillation: observations on the role of trial design and implications of drug-related mortality. Am Heart J1992;124:924-32.

Schmoor C, Olschewski M, Schumacher M. Randomised and non-randomised patients in clinical trials: experiences with comprehensive cohort studies. Stat Med 1996;15:236-7.

Shapiro CL, Recht A. Late effects of adjuvant therapy for breast cancer. JNCI Monographs 1994;16:101-12.

Watson A, Vail A, Vandekerckhove P, Brosens I, Lilford R, Hughes E. A meta-analysis of the therapeutic role of oil soluble contrast media at hysterosalpingography: a surprising result? Fertil Steril 1994;61:470-7.

Yamamoto H, Hughes RW, Schroeder KW, Viggiano TR, Dimagno EP. Treatment esophageal stricture by eder-puestow or balloon dilators. A comparison between randomized and prospective nonrandomized trials. Mayo Clin Proc 1992;67:228-36.