Evidence map›Paper›PMID 23221975›Full record

ArticleStatistical methods in medical research2016

Power and sample size calculations for evaluating mediation effects in longitudinal studies.

Cuiling Wang, Xiaonan Xue

Abstract read
In one paragraph

Article in Statistical methods in medical research, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed
–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

5 citing papers in PubMed.

  1. Article
  2. Article
  3. Article
  4. Sample Size for Joint Testing of Indirect Effects.Prevention science : the official journal of the Society for Prevention Research · 2015
    Article
  5. Article
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.

Cuiling WangDepartment of Epidemiology and Population Health, Albert Einstein College of Medicine of Yeshiva University, New York, USA cuiling.wang@einstein.yu.edu.
Xiaonan XueDepartment of Epidemiology and Population Health, Albert Einstein College of Medicine of Yeshiva University, New York, USA.

Funding

Vascular Structure and Function in Cognitive AgingP01AG003949 · NIA · YESHIVA UNIVERSITY · PI Richard B. LIPTON · 1985 to 2026
$73.9M
Latent Mobility Abnormalities And FrailtyR01AG025119 · NIA · ALBERT EINSTEIN COL OF MED YESHIVA UNIV · PI VERGHESE, JOE · 2005 to 2009
$1.5M
NIA NIH HHS P01 AG003949NIA NIH HHS R01 AG025119
6 · The paper itself

Abstract

Current methods of power and sample size calculations for the design of longitudinal studies to evaluate mediation effects are mostly based on simulation studies and do not provide closed-form formulae. A further challenge due to the longitudinal study design is the consideration of missing data, which almost always occur in longitudinal studies due to staggered entry or drop out. In this article, we consider the product of coefficients as a measure for the longitudinal mediation effect and evaluate three methods for testing the hypothesis on the longitudinal mediation effect: the joint significant test, the normal approximation and the test of b methods. Formulae for power and sample size calculations are provided under each method while taking into account missing data. Performance of the three methods under limited sample size are examined using simulation studies. An example from the Einstein aging study is provided to illustrate the methods.

Indexed as

Data Interpretation, StatisticalLongitudinal StudiesSample SizeAgingHumansLinear ModelsResearch DesignDrop outjoint significance testlinear mixed effects modelmissing datapower analysisproduct of coefficients

Identifiers

PMID23221975
PMCPMC3883797

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Registered trials

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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.