Sample size: how many patients are necessary?
P M Fayers, D Machin, P M Fayers, D Machin
Abstract
The need for sample size calculations is briefly reviewed: many of the arguments against small trials are already well known, and we only cursorily repeat them in passing. Problems that arise in the estimation of sample size are then discussed, with particular reference to survival studies. However, most of the issues which we discuss are equally applicable to other types of study. Finally, prognostic factor analysis designs are discussed, since this is another area in which experience shows that far too many studies are of an inadequate size and yield misleading results.
References
- J Chronic Dis. 1976 Mar;29(3):175-88
- Stat Med. 1992 May;11(7):875-9
- N Engl J Med. 1978 Sep 28;299(13):690-4
- Br Med J. 1980 Nov 15;281(6251):1336-8
- Arch Intern Med. 1983 Apr;143(4):753-5
- Br Med J (Clin Res Ed). 1983 May 7;286(6376):1489-93
- Stat Med. 1982 Apr-Jun;1(2):121-9
- Stat Med. 1984 Oct-Dec;3(4):315-24
- Stat Med. 1984 Oct-Dec;3(4):409-22
- Cancer Treat Rep. 1985 Oct;69(10):1071-77
- Control Clin Trials. 1985 Dec;6(4):259-70
- Br Med J (Clin Res Ed). 1986 Mar 22;292(6523):810-2
- Stat Med. 1986 Jan-Feb;5(1):1-13
- J Clin Oncol. 1986 Jul;4(7):1114-20
- J Clin Oncol. 1986 Oct;4(10):1529-41
- Br Med J (Clin Res Ed). 1987 Sep 12;295(6599):656-9
- Control Clin Trials. 1987 Dec;8(4):343-53
- Br J Cancer. 1989 Mar;59(3):396-400
- Stat Med. 1990 Jan-Feb;9(1-2):65-71; discussion 71-2
- Br J Cancer. 1990 Oct;62(4):687-91
- Cancer. 1992 Nov 1;70(9):2367-77
- Eur J Cancer. 1993;29A(6):907-12
- Stat Med. 1993 Aug;12(15-16):1501-11; discussion 1513-7
- Br J Cancer. 1994 Jun;69(6):979-85
- Ann Intern Med. 1994 Aug 1;121(3):200-6
- Stat Med. 1994 Nov 15;13(21):2249-60
- N Engl J Med. 1977 Nov 17;297(20):1091-6
Source: PubMed