Cited by 852Statistical Methods and Bayesian InferenceMeta-analysis and systematic reviewsStatistical Methods in Clinical Trials

Effect sizes for growth-modeling analysis for controlled clinical trials in the same metric as for classical analysis

Open access
Feingold, Alan·2009·Psychological Methods

Abstract

The use of growth-modeling analysis (GMA)--including hierarchical linear models, latent growth models, and general estimating equations--to evaluate interventions in psychology, psychiatry, and prevention science has grown rapidly over the last decade. However, an effect size associated with the difference between the trajectories of the intervention and control groups that captures the treatment effect is rarely reported. This article first reviews 2 classes of formulas for effect sizes associated with classical repeated-measures designs that use the standard deviation of either change scores or raw scores for the denominator. It then broadens the scope to subsume GMA and demonstrates that the independent groups, within-subjects, pretest-posttest control-group, and GMA designs all estimate the same effect size when the standard deviation of raw scores is uniformly used. Finally, the article shows that the correct effect size for treatment efficacy in GMA--the difference between the estimated means of the 2 groups at end of study (determined from the coefficient for the slope difference and length of study) divided by the baseline standard deviation--is not reported in clinical trials.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1037/a0014699

Cites

56 of 56 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

2 of the 58 references couldn’t be matched to a known paper.

Research works printed but not linked: 2

  1. Becker BJ Synthesizing standardized mean-change scores. British Journal of Mathematical and Statistical Psychology 1988 41 257 278
  2. Gibbons RD Hedeker DR Davis JM Estimation of effect sizes from a series of experiments involving paired comparisons. Journal of Educational Statistics 1993 18 271 279

Cited by

Sorted by citations

Authors
Feingold, A.
Affiliations
Oregon Social Learning Center (US)
Corresponding author
Feingold, Alan
Venue
Psychological Methods
Published
2009
Volume
14
Issue
1
Pages
43-53
ISSN
  • 1082-989X (ISSN-L)
  • 1939-1463
OpenAlex
W2089811587
Cited by
851
References
58
Citations by year
2026: 56 · 2025: 60 · 2024: 61 · 2023: 54 · 2022: 56 · 2021: 72 · 2020: 61 · 2019: 47 · 2018: 56 · 2017: 51 · 2016: 65 · 2015: 65 · 2014: 63 · 2013: 35 · 2012: 24
FWCI
13.56
Type
journal article
Language
en
Open access
Locations
  • Psychological Methods (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
Funders
Eunice Kennedy Shriver National Institute of Child Health and Human Development (R01HD046364)
Topics
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods and Bayesian Inference
  • Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Clinical Trials
Keywords
effect size, growth models, latent growth curve models, multilevel analysis, repeated measures designs, change scores, treatment effects, intervention efficacy, pretest-posttest control group design
MeSH terms
Humans, Psychology, Social, Research Design, Meta-Analysis as Topic, Reproducibility of Results, Models, Statistical, Linear Models, Treatment Outcome, Controlled Clinical Trials as Topic

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review