Should we adjust for covariates in nonlinear regression analyses of randomized trials?

Controlled Clinical Trials

Volumn 19, Issue 3, 1998, Pages 249-256

  Hauck, Walter W ^a   Anderson, Sharon ^a,b   Marcus, Sue M ^a  

^a THOMAS JEFFERSON UNIVERSITY   (United States)

^b BRISTOL MYERS SQUIBB   (United States)

Author keywords

Cox regression; Logistic regression; Meta analyses; Omitted covariates; Randomized trials

Indexed keywords

ARTICLE; COVARIANCE; DRUG SCREENING; META ANALYSIS; REGRESSION ANALYSIS; STATISTICAL MODEL;

EID: 0031777876     PISSN: 01972456     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0197-2456(97)00147-5     Document Type: Article

References (36)

1. Snedecor GW, Cochran WG. Statistical Methods 6th ed. Ames, Iowa: Iowa State University Press; 1967.
2. Gail MH, Wieand S, Piantadosi S. Biased estimates of treatment effect in randomized experiments with nonlinear regressions and omitted covariates. Biometrika 1984;71:431-444.
3. Hauck WW, Neuhaus JM, Kalbfleisch JD, et al. A consequence of omitted covariates when estimating odds ratios. J Clin Epidemiol 1991;44:77-81.
4. Lagakos SW, Schoenfeld DA. Properties of proportional-hazards score tests under misspecified regression models. Biometrics 1984;40:1037-1048.
5. Gail MH, Tan WY, Piantadosi S. Tests for no treatment effect in randomized clinical trials. Biometrika 1988;75:57-64.
6. Gail MH. The effect of pooling across strata in perfectly balanced studies. Biometrics 1988;44:151-163.
7. Struthers CA, Kalbfleisch JD. Misspecified proportional hazard models. Biometrika 1986;73:363-369.
8. Schumacher M, Olschewski M, Schmoor C. The impact of heterogeneity on the comparison of survival times. Stat Med 1987;6:773-784.
9. Bretagnolle J, Huber-Carol C. Effects of omitting covariates in Cox's model for survival data. Scand J Stat 1988;15:125-138.
10. Brännäs K, Pohjanpalo J. Small sample properties of the likelihood estimator in proportional hazard regression models with omitted covariates. Biomet J 1986; 28:219-228.
11. Chastang C, Byar D, Piantadosi S. A quantitative study of the bias in estimating the treatment effect cause by omitting a balanced covariate in survival models. Stat Med 1988;7:1243-1255.
12. Robinson LD, Jewell NP. Some surprising results about covariate adjustment in logistic regression models. Int Stat Rev 1991;58:227-240.
13. Begg MD, Lagakos S. Loss in efficiency caused by omitting covariates and misspecifying exposure in logistic regression models. J Am Stat Assoc 1993;88:166-170.
14. Morgan TM. Omitting covariates from the proportional hazards model. Biometrics 1986;42:993-995.
15. Akazawa K, Nakamura T, Palesch Y. Power of logrank test and Cox regression model in clinical trials with heterogeneous samples. Stat Med 1997;16:583-597.
16. Breslow NE, Day NE. Statistical Methods in Cancer Research, Vol. 1. The Analysis of Case-Control Studies. Lyon, France: International Agency for Research on Cancer; 1980.
17. Beach ML, Meier P. Choosing covariates in the analysis of clinical trials. Controlled Clin Trials 1989;10:161S-175S.
18. Meier P, Ferguson DJ, Karrison T. A controlled trial of extended radical mastectomy. Cancer 1985;55:880-891.
19. Neuhaus JM, Kalbfleisch JD, Hauck WW. A comparison of cluster-specific and population-averaged approaches for analyzing correlated binary data. Int Stat Rev 1991;59:25-35.
20. Zeger SL, Liang K-Y, Albert PS. Models for longitudinal data: A generalized estimating equation approach. Biometrics 1988;44:1049-1060.
21. Yusuf S, Collins R, Peto R. Why do we need large, simple randomized trials? Stat Med 1984;3:409-422.
22. Hedges LV, Olkin I. Statistical Methods for Meta-Analysis. San Diego: Academic Press; Harcourt Brace, Jovanovich; 1985.
23. Cooper H, Hedges LV, eds. The Handbook of Research Synthesis. New York: Russell Sage Foundation; 1994.
24. Anello C, Fleiss JL. Exploratory or analytic meta-analysis: should we distinguish between them? J Clin Epidemiol 1995;48:109-116.
25. Greenland S. Quantitative methods in the review of epidemiologic literature. Epidemiol Rev 1987;9:1-30.
26. Ford I, Norrie J, Ahmadi S. Model inconsistency, illustrated by the Cox proportional hazards model. Stat Med 1995;14:735-746.
27. Senn SJ. Covariate imbalance and random allocation in clinical trials. Stat Med 1989;8:467-475.
28. Lynch CJ, Lachenbruch PA. Statistical issues in biologics submissions to the FDA. Drug Info J 1996;30:921-932.
29. Altman DG. Comparability of randomized groups. Statistician 1985;34:125-136.
30. Sather HN. The use of prognostic factors in clinical trials. Cancer 1986;58:461-467.
31. Cochran WG. The planning of observational studies of human populations (with discussion). J Roy Stat Soc, Ser A 1965;128:134-155.
32. Schluchter MD, Forsythe AB. Post-hoc selection of covariates in randomized experiments. Commun Stat - Theor Meth 1985;14:679-699.
33. Flack VF, Chang PC. Frequency of selecting noise variables in subset regression analysis: a simulation study. Am Stat 1987;41:84-86.
34. Zhang P. Inference after variable selection in linear regression models. Biometrika 1992;79:741-746.
35. Chatfield C. Model uncertainty, data mining and statistical inference (with discussion). J Roy Stat Soc, Ser A 1995;158:419-466.
36. Neuhaus JM, Jewell NP. A geometric approach to assess bias due to omitted covariates in generalized linear models. Biometrika 1993;80:807-815.