Evidence map›Paper›PMID 19655038›Full record

ArticleThe international journal of biostatistics2007

Preference-based instrumental variable methods for the estimation of treatment effects: assessing validity and interpreting results.

M Alan Brookhart, Sebastian Schneeweiss

Abstract readComparative Study
In one paragraph

Article in The international journal of biostatistics, 2007. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 89 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
89citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

89 citing papers in PubMed, 1 synthesis or guideline pooled it.

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29 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors.

M Alan BrookhartDivision of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women's Hospital & Harvard Medical School, Boston, MA, USA.
Sebastian Schneeweiss

Funding

Hierarchical models of prescription drug use in the elderlyK25AG027400 · NIA · UNIV OF NORTH CAROLINA CHAPEL HILL · PI BROOKHART, MAURICE ALAN · 2006 to 2010
$653k
NIA NIH HHS AG027400NIA NIH HHS K25 AG027400PHS HHS 290-2005-0016-I-TO3-WA1
6 · The paper itself

Abstract

Observational studies of drugs and medical procedures based on administrative data are increasingly used to inform regulatory and clinical decisions. However, the validity of such studies is often questioned because available data may not contain measurements of many important prognostic variables that guide treatment decisions. Recently, approaches to this problem have been proposed that use instrumental variables (IV) defined at the level of an individual health care provider or aggregation of providers. Implicitly, these approaches attempt to estimate causal effects by using differences in medical practice patterns as a quasi-experiment. Although preference-based IV methods may usefully complement standard statistical approaches, they make assumptions that are unfamiliar to most biomedical researchers and therefore the validity of such analyses can be hard to evaluate. Here, we propose a simple framework based on a single unobserved dichotomous variable that can be used to explore how violations of IV assumptions and treatment effect heterogeneity may bias the standard IV estimator with respect to the average treatment effect in the population. This framework suggests various ways to anticipate the likely direction of bias using both empirical data and commonly available subject matter knowledge, such as whether medications or medical procedures tend to be overused, underused, or often misused. This approach is described in the context of a study comparing the gastrointestinal bleeding risk attributable to different non-steroidal anti-inflammatory drugs.

Indexed as

Data Interpretation, StatisticalPractice Patterns, Physicians'AgedAnti-Inflammatory Agents, Non-SteroidalGastrointestinal DiseasesHumansPhysiciansRandom AllocationTreatment OutcomeAnti-Inflammatory Agents, Non-Steroidalcausal inferencehealth services researchinstrumental variablesoutcomes researchpharmacoepidemiologyunmeasured confounding

Identifiers

PMID19655038
PMCPMC2719903

What OpenQuestion holds

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Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.