A graphical method to assess treatment–covariate interactions using the Cox model on subsets of the data
✍ Scribed by Marco Bonetti; Richard D. Gelber
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 155 KB
- Volume
- 19
- Category
- Article
- ISSN
- 0277-6715
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✦ Synopsis
We introduce the subpopulation treatment e ect pattern plot (STEPP) method, designed to facilitate the interpretation of estimates of treatment e ect derived from di erent but potentially overlapping subsets of clinical trial data. In particular, we consider sequences of subpopulations deÿned with respect to a covariate, and obtain conÿdence bands for the collection of treatment e ects (here obtained from the Cox proportional hazards model) associated with the sequences. The method is aimed at determining whether the magnitude of the treatment e ect changes as a function of the values of the covariate. We apply STEPP to a breast cancer clinical trial data set to evaluate the treatment e ect as a function of the oestrogen receptor content of the primary tumour.