Pairwise comparisons in the analysis of carcinogenicity data
- 1 Division of Biometrics-6, Office of Biostatistics, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, USA
- 2 Office of Biostatistics, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, USA
Abstract
Analysis of carcinogenicity data generally involves a trend test across all dose groups and a pairwise comparison of the high dose group with the control. The most commonly used test for a positive trend is the Cochran-Armitage test. This test is asymptotically normal. For the pairwise comparison of the high dose group with the control group, we propose two modifications: the first modification is to apply the test on the data from high dose and control groups after dropping the data from the low and the medium dose groups; the second modification is to adjust the test conditional on data from all dose groups. We compare the power performance of these two modifications for the pairwise comparisons.
- Cochran, W.G. (1954) Some methods of strengthening the common χ2 tests. Biometrics, 10, 417-451. Hdoi:10.2307/3001616
- Armitage, P. (1955) Tests for linear trend in proportions and frequencies. Biometrics, 11, 375-386. Hdoi:10.2307/3001775
- Tarone, R.E. (1975) Test for trend in life table analysis. Biometrika, 62, 679-690. Hdoi:10.1093/biomet/62.3.679
- Tarone, R.E. (1982) The use of historical control information in testing for a trend in Poisson means. Biometrics, 38, 457-462. Hdoi:10.2307/2530459
- Hoel, D.G. and Yanagawa, T. (1986) Incorporating historical controls in testing for a trend in proportions. Journal of the American Statistical Association, 81, 1095-1099. Hdoi:10.1080/01621459.1986.10478379
- Tamura, R.N. and Young, S.S. (1986) The incorporation of historical control information in tests and proportions: Simulation study of Tarone’s Procedure. Biometrics, 42, 343-349. Hdoi:10.2307/2531054
- Peto, R., Pike, M.C., Day, N.E., Gray, R.G.K, Lee, P.N. Parish, S., Peto, J., Richards, S. and Wahrendorf, J. (1980) Guidelines for sample sensitive significance test for carcinogenic effects in long-term animal experiments. IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans, Suppl. 2, Long-Term and Short-Term Screening Assays for Carcinogens: A Critical Appraisal, IARC, Lyon, 311-426.
- Bailer, A.J. and Portier, C.J. (1988) Effects of treatment-induced mortality and tumor-induced mortality on tests for carcinogenicity in small samples. Biometrics, 44, 417-431. Hdoi:10.2307/2531856
- Mehta, C.R. and Patel, N.R. and Senchaudhuri, P. (1998) Exact power and sample-size computations for the Cochran-Armitage trend test. Biometrics, 54, 1615-1621. Hdoi:10.2307/2533685
- Hothorn, L.A., Sill, M. and Schaarschmidt, F. (2010) Evaluation of incidence rates in pre-clinical studies using a Williams-type procedure. The International Journal of Biostatistics, 6, 1557-4679. Hdoi:10.2202/1557-4679.1180
- Hothorn, L.A. and Bretz, F. (2000) Evaluation of animal carcinogenicity studies: Cochran-armitage trend test vs. multiple contrast tests. Biometrical Journal, 42, 553-567. Hdoi:10.1002/1521-4036(200009)42:5 3.0.CO;2-R
- SAS Institute Inc., (2009) Multtest Procedure. SAS User’s Guide 9.2, 2nd Edition, SAS Institute Inc., Cary, 4176-4242.