Premium
SURVIVAL ANALYSES OF RANDOMIZED CLINICAL TRIALS ADJUSTED FOR PATIENTS WHO SWITCH TREATMENTS
Author(s) -
LAW MATTHEW G.,
KALDOR JOHN M.
Publication year - 1996
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/(sici)1097-0258(19961015)15:19<2069::aid-sim347>3.0.co;2-v
Subject(s) - randomized controlled trial , medicine , clinical trial , statistics , mathematics
Patients who switch treatment groups in randomized clinical trials can cause problems in the interpretation of the results. Although the intention‐to‐treat method is recognized as being the most reliable analysis, it may result in an underestimate of the treatment effect if there have been patients who switch treatments. In this paper, an adjusted analysis, based on a Cox model, is proposed which estimates the treatment effect allowing for patients who switch treatments. Because this analysis requires much weaker assumptions than ‘as treated’ analyses, it is likely to be much more reliable. The method is illustrated by a trial comparing radical radiotherapy with radiotherapy followed by cystectomy in the treatment of invasive bladder cancer.