Abstract:
SUMMARY:We consider the analysis of clinical trials that involve randomization to an active treatment (T = 1) or a control treatment (T = 0), when the active treatment is subject to all-or-nothing compliance. We compare three approaches to estimating treatment efficacy in this situation: as-treated analysis, per-protocol analysis, and instrumental variable (IV) estimation, where the treatment effect is estimated using the randomization indicator as an IV. Both model- and method-of-moment based IV estimators are considered. The assumptions underlying these estimators are assessed, standard errors and mean squared errors of the estimates are compared, and design implications of the three methods are examined. Extensions of the methods to include observed covariates are then discussed, emphasizing the role of compliance propensity methods and the contrasting role of covariates in these extensions. Methods are illustrated on data from the Women Take Pride study, an assessment of behavioral treatments for women with heart disease.
journal_name
Biometricsjournal_title
Biometricsauthors
Little RJ,Long Q,Lin Xdoi
10.1111/j.1541-0420.2008.01066.xsubject
Has Abstractpub_date
2009-06-01 00:00:00pages
640-9issue
2eissn
0006-341Xissn
1541-0420pii
BIOM1066journal_volume
65pub_type
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