Linked Life Data

12384199

Source:http://linkedlifedata.com/resource/pubmed/id/12384199

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2002-10-17
pubmed:abstractText
A causal relation between drug benefit policy change and the increase in adverse outcomes can be tested by comparing the experience of a group of patients affected by the policy vs. the (counterfactual) experience of the same patients if the policy had not been implemented. Because counterfactual experiences cannot be observed, it must be assumed that the counterfactual is correctly described by extrapolating from the same population's previous experience. The null hypothesis of no policy effect can be empirically tested using quasi-experimental longitudinal designs with repeated measures. If compliance to a policy is low, results may be biased towards the null, but a subgroup analysis of compliers may be biased by nonignorable treatment selection. Using the example of reference drug pricing in British Columbia we discuss assumptions for causal interpretations of such analyses, and provide supplementary analyses to assess and improve the validity of findings. Results from nonrandomized comparisons of subgroups defined by their compliance to a policy change should generally be interpreted cautiously, and several biases should be explored.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0895-4356
pubmed:author
pubmed:issnType
Print
pubmed:volume
55
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
833-41
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Quasi-experimental longitudinal designs to evaluate drug benefit policy changes with low policy compliance.
pubmed:affiliation
Divison of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 221 Longwood Ave (BLI-341), Boston, MA 02115, USA. schneeweiss@post.harvard.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't