Linked Life Data

10407233

Source:http://linkedlifedata.com/resource/pubmed/id/10407233

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
1999-8-31
pubmed:abstractText
Randomized clinical trials often are planned to study a specific intervention. However, the collection of data on treatment actually received often reveals variable levels of treatment exposure (or 'dose') across subjects, due to non-compliance or other reasons. This paper presents a new method, using such 'dose' data as well as control group responses, to assess a causal dose-response relationship. The specific model utilizes a threshold function and incorporates a random effect term to allow for heterogeneous treatment responses among subjects. Further modelling of the random effects allows for reduction of error variance and control for potential confounders. The threshold dose is estimated using a residual variance criterion based on a transformed model. Estimates of standard errors and confidence intervals are obtained using a bootstrap procedure. The method is applied to data from an AIDS clinical trial. A simulation study demonstrates the adequacy of the threshold estimates for particular sample sizes and error variances. The limitations of this essentially exploratory method, as well as some possible extensions, are discussed. Published in 1999 by John Wiley & Sons, Ltd. This article is a US Government Work and is in the public domain in the United States.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0277-6715
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1615-26
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
A threshold causal model for clinical trials with departures from intended treatment.
pubmed:affiliation
Department of Epidemiology and Biostatistics, School of Medicine, BRB-G19, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-4945, USA. jma13@po.cwru.edu
pubmed:publicationType
Journal Article, Clinical Trial, Randomized Controlled Trial