ESTIMATING SAMPLE SIZES FOR BINARY, ORDERED CATEGORICAL, AND CONTINUOUS OUTCOMES IN 2 GROUP COMPARISONS

被引:359
作者
CAMPBELL, MJ [1 ]
JULIOUS, SA [1 ]
ALTMAN, DG [1 ]
机构
[1] IMPERIAL CANC RES FUND,MED STAT LAB,LONDON WC2A 3PX,ENGLAND
关键词
D O I
10.1136/bmj.311.7013.1145
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
Sample size calculations are now mandatory for many research protocols, but the ones useful in common situations are not all easily accessible. This paper outlines the ways of calculating sample sizes in two group studies for binary, ordered categorical, and continuous outcomes. Formulas and worked examples are given. Maximum power is usually achieved by having equal numbers in the two groups. However, this is not always possible and calculations for unequal group sizes are given.
引用
收藏
页码:1145 / 1148
页数:4
相关论文
共 28 条
[1]   PLANNING FOR PRECISION IN SURVIVAL STUDIES [J].
BORENSTEIN, M .
JOURNAL OF CLINICAL EPIDEMIOLOGY, 1994, 47 (11) :1277-1285
[2]   INDEXES AND BOUNDARIES FOR QUANTITATIVE SIGNIFICANCE IN STATISTICAL DECISIONS [J].
BURNAND, B ;
KERNAN, WN ;
FEINSTEIN, AR .
JOURNAL OF CLINICAL EPIDEMIOLOGY, 1990, 43 (12) :1273-1284
[3]  
Conover W.J., 1999, PRACTICAL NONPARAMET, P428, DOI DOI 10.1002/BIMJ.19730150311
[5]   SAMPLE-SIZE ESTIMATION FOR COMPARING 2 OR MORE TREATMENT GROUPS IN CLINICAL-TRIALS [J].
DAY, SJ ;
GRAHAM, DF .
STATISTICS IN MEDICINE, 1991, 10 (01) :33-43
[6]  
DILETTI E, 1991, INT J CLIN PHARM TH, V29, P1
[8]  
Drummond M, 1993, Health Econ, V2, P205, DOI 10.1002/hec.4730020303
[9]   POWER AND SAMPLE-SIZE CALCULATIONS - A REVIEW AND COMPUTER-PROGRAM [J].
DUPONT, WD ;
PLUMMER, WD .
CONTROLLED CLINICAL TRIALS, 1990, 11 (02) :116-128
[10]   SAMPLE-SIZE - HOW MANY PATIENTS ARE NECESSARY [J].
FAYERS, PM ;
MACHIN, D .
BRITISH JOURNAL OF CANCER, 1995, 72 (01) :1-9