Cited by 5.9k
(1955). A Multiple Comparison Procedure for Comparing Several Treatments with a Control. Journal of the American Statistical Association: Vol. 50, No. 272, pp. 1096-1121.
Natural Sciences and Engineering Research Council of Canada
Publishes on Statistical Methods in Clinical Trials, Optimal Experimental Design Methods, Statistical Methods and Bayesian Inference. 81 papers and 12.1k citations.
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(1955). A Multiple Comparison Procedure for Comparing Several Treatments with a Control. Journal of the American Statistical Association: Vol. 50, No. 272, pp. 1096-1121.
The efficiency of a standardised inhalation test procedure was studied by examining the reproducibility of responses to histamine and methacholine. In addition, the responses to the two agents were compared. Each set of duplicate tests was carried out on a separate day within one week, and all factors known or presumed to influence responses were carefully controlled. The results were expressed as the provocative concentration of the agent causing a 20% fall in forced expired volume in one second (PC20). Responses to histamine and methacholine were highly reproducible (coefficients of determination [r2] = 0.994 and 0.990 respectively). Responsiveness to histamine correlated closely with responsiveness to methacholine (r2 = 0.85). There was a small but significant cumulative dose effect with methacholine (P less than 0.01) but not with histamine. Side effects of throat irritation, flushing, and headache were more frequent with histamine than methacholine, and were dose-related. The high level of reproducibility indicates the efficiency of the test procedure. The similar severity of effects by agents with different mechanisms of action suggests that the primary cause of non-specific bronchial hyperreactivity lies at the level of bronchial smooth muscle.
Abstract Four pairwise multiple comparison procedures for the case in which the variances in the groups are unequal were compared by computer simulation: the GH procedure based on the Studentized range and the Welch formula for approximate degrees of freedom (df), the C procedure based on a weighted average of two Studentized range points, the T2 procedure based on Student's t, and the T3 procedure based on the Studentized maximum modulus. The results indicate that C, T2, and T3 have the desirable property of being conservative, whereas GH sometimes is not. Of the three conservative procedures, T3 always has shorter confidence interval length than T2, whereas C has shorter length than T3 for large df, but longer length for small df.
C. W. Dunnett, M. Gent, Significance Testing to Establish Equivalence between Treatments, with Special Reference to Data in the Form of 2 x 2 Tables, Biometrics, Vol. 33, No. 4 (Dec., 1977), pp. 593-602