Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2005-11-8
pubmed:abstractText
The authors compared five methods of studying survival bias associated with time-to-treatment initiation in a drug effectiveness study using medical administrative databases (1996-2002) from Quebec, Canada. The first two methods illustrated how survival bias could be introduced. Three additional methods were considered to control for this bias. Methods were compared in the context of evaluating statins for secondary prevention in elderly patients post-acute myocardial infarction who initiated statins within 90 days after discharge and those who did not. Method 1 that classified patients into users and nonusers at discharge resulted in an overestimation of the benefit (38% relative risk reduction at 1 year). In method 2, following users from the time of the first prescription and nonusers from a randomly selected time between 0 and 90 days attenuated the effect toward the null (10% relative risk reduction). Method 3 controlled for survival bias by following patients from the end of the 90-day time window; however, it suffered a major loss of statistical efficiency and precision. Method 4 matched prescription time distribution between users and nonusers at cohort entry. Method 5 used a time-dependent variable for treatment initiation. Methods 4 and 5 better controlled for survival bias and yielded similar results, suggesting a 20% risk reduction of recurrent myocardial infarction or death events.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0002-9262
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
162
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1016-23
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:16192344-Aged, pubmed-meshheading:16192344-Aged, 80 and over, pubmed-meshheading:16192344-Bias (Epidemiology), pubmed-meshheading:16192344-Cohort Studies, pubmed-meshheading:16192344-Drug Administration Schedule, pubmed-meshheading:16192344-Drug Prescriptions, pubmed-meshheading:16192344-Female, pubmed-meshheading:16192344-Follow-Up Studies, pubmed-meshheading:16192344-Humans, pubmed-meshheading:16192344-Hydroxymethylglutaryl-CoA Reductase Inhibitors, pubmed-meshheading:16192344-Male, pubmed-meshheading:16192344-Myocardial Infarction, pubmed-meshheading:16192344-Outcome and Process Assessment (Health Care), pubmed-meshheading:16192344-Quebec, pubmed-meshheading:16192344-Recurrence, pubmed-meshheading:16192344-Retrospective Studies, pubmed-meshheading:16192344-Survival Analysis
pubmed:year
2005
pubmed:articleTitle
Survival bias associated with time-to-treatment initiation in drug effectiveness evaluation: a comparison of methods.
pubmed:affiliation
Department of Epidemiology and Biostatistics, McGill University, Montréal, Quebec, Canada.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't, Evaluation Studies