ArticleJournal of biometrics & biostatistics2018
Simple Power and Sample Size Estimation for Non-Randomized Longitudinal Difference in Differences Studies.
Article in Journal of biometrics & biostatistics, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers.
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.
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.
Who cites it
7 citing papers in PubMed.
- Prehospital triage of patients with suspected acute stroke (PRESTO-2): protocol for a controlled before-and-after intervention trial.European stroke journal · 2026Article
- Digital support for female students in physical education universities in Japan.Scientific reports · 2025Article
- Routine antenatal ultrasound by nurse-midwives in rural Kenya: a pragmatic trial assessing feasibility and effects of theFrontiers in global women's health · 2025Article
- Subsidized Marketplace Purchases Reduced Racial Disparities in Private Coverage Under the Affordable Care Act.Journal of racial and ethnic health disparities · 2023Article
- Resilience in maternal and child nutrition outcomes in a refugee-hosting community in Cameroon: A quasi-experimental study.Heliyon · 2022Article
- Increased dynamic flexibility in the medial temporal lobe network following an exercise intervention mediates generalization of prior learning.Neurobiology of learning and memory · 2021Article
- The effect of Medicaid expansion on female gynecologic cancer-related inpatient admissions.Women's health (London, England)Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors.
Funding
Abstract
Intervention effects on continuous longitudinal normal outcomes are often estimated in two-arm pre-post interventional studies with b≥1 pre- and k≥1 post-intervention measures using "Difference-in-Differences" (DD) analysis. Although randomization is preferred, non-randomized designs are often necessary due to practical constraints. Power/sample size estimation methods for non-randomized DD designs that incorporate the correlation structure of repeated measures are needed. We derive Generalized Least Squares (GLS) variance estimate of the intervention effect. For the commonly assumed compound symmetry (CS) correlation structure (where the correlation between all repeated measures is a constant
Indexed as
Identifiers
31360594PMC6663085What OpenQuestion holds
Registered trials
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.