Evidence map›Paper›PMID 27659168›Full record

ArticleStatistical methods in medical research2018

Comparison of statistical approaches dealing with time-dependent confounding in drug effectiveness studies.

Mohammad Ehsanul Karim, John Petkau, Paul Gustafson, Robert W Platt, Helen Tremlett, BeAMS Study Group

Open access · greenAbstract read
In one paragraph

Article in Statistical methods in medical research, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers.

0numbers the graph read from it
0cells of the map it votes in
10citing papers in PubMed
3.3field-weighted citation impact, top 7% of its field
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

10 citing papers in PubMed, 22 citations in OpenAlex.

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4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

6 authors at 3 institutions in 1 country.

Mohammad Ehsanul Karim1 Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada.
John Petkau3 Department of Statistics, University of British Columbia, Vancouver, Canada.
Paul Gustafson3 Department of Statistics, University of British Columbia, Vancouver, Canada.
Robert W Platt1 Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada.
Helen Tremlett6 Department of Medicine, Division of Neurology and Centre for Brain Health, University of British Columbia, Vancouver, Canada.
BeAMS Study Group7 "The BeAMS Study, Long-term Benefits and Adverse Effects of Beta-Interferon for Multiple Sclerosis": A Shirani, Y Zhao, C Evans, E Kingwell, ML van der Kop and J Oger.
University of British Columbia · CAMcGill University · CAMcGill University Health Centre · CA

Funding

CIHR MOP-93646
6 · The paper itself

Abstract

In longitudinal studies, if the time-dependent covariates are affected by the past treatment, time-dependent confounding may be present. For a time-to-event response, marginal structural Cox models are frequently used to deal with such confounding. To avoid some of the problems of fitting marginal structural Cox model, the sequential Cox approach has been suggested as an alternative. Although the estimation mechanisms are different, both approaches claim to estimate the causal effect of treatment by appropriately adjusting for time-dependent confounding. We carry out simulation studies to assess the suitability of the sequential Cox approach for analyzing time-to-event data in the presence of a time-dependent covariate that may or may not be a time-dependent confounder. Results from these simulations revealed that the sequential Cox approach is not as effective as marginal structural Cox model in addressing the time-dependent confounding. The sequential Cox approach was also found to be inadequate in the presence of a time-dependent covariate. We propose a modified version of the sequential Cox approach that correctly estimates the treatment effect in both of the above scenarios. All approaches are applied to investigate the impact of beta-interferon treatment in delaying disability progression in the British Columbia Multiple Sclerosis cohort (1995-2008).

Indexed as

Confounding Factors, EpidemiologicDose-Response Relationship, DrugProportional Hazards ModelsAlgorithmsDisease ProgressionHumansMonte Carlo MethodSurvival AnalysisBias (epidemiology)causalityconfounding factors (epidemiology)epidemiologic methodsinverse probability weightinglongitudinal studiesmodelssurvival analysis

Identifiers

PMID27659168
PMCPMC5770217
OpenAlexW2521300970

What OpenQuestion holds

Textmetadata
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.