Evidence map›Paper›PMID 36519565›Full record

ArticleBiostatistics (Oxford, England)2023

Distributional data analysis via quantile functions and its application to modeling digital biomarkers of gait in Alzheimer's Disease.

Rahul Ghosal, Vijay R Varma, Dmitri Volfson, Inbar Hillel, Jacek Urbanek, Jeffrey M Hausdorff, Amber Watts, Vadim Zipunnikov

Open access · greenAbstract read
In one paragraph

Article in Biostatistics (Oxford, England), 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 papers.

0numbers the graph read from it
0cells of the map it votes in
13citing papers in PubMed
3.8field-weighted citation impact, top 5% 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

13 citing papers in PubMed, 33 citations in OpenAlex.

  1. Article
  2. Functional quantile principal component analysis.Biostatistics (Oxford, England) · 2025
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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

8 authors at 6 institutions in 2 countries.

Rahul GhosalDepartment of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.ORCID 0000-0003-0939-4731
Vijay R VarmaNational Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, MD, USA.
Dmitri VolfsonNeuroscience Analytics, Computational Biology, Takeda, Cambridge, MA, USA.
Inbar HillelCenter for the Study of Movement, Cognition and Mobility, Neurological Institute, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
Jacek UrbanekDepartment of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.ORCID 0000-0002-1890-8899
Jeffrey M HausdorffCenter for the Study of Movement, Cognition and Mobility, Neurological Institute, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, Department of Physical Therapy, Sackler Faculty of Medicine, and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel, and Rush Alzheimer's Disease Center and Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, USA.
Amber WattsDepartment of Psychology, University of Kansas, Lawrence, KS, USA.
Vadim ZipunnikovDepartment of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Johns Hopkins University · USNational Institutes of Health · USRush University Medical Center · USTakeda (United States) · USTel Aviv Sourasky Medical Center · ILUniversity of Kansas · US

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

With the advent of continuous health monitoring with wearable devices, users now generate their unique streams of continuous data such as minute-level step counts or heartbeats. Summarizing these streams via scalar summaries often ignores the distributional nature of wearable data and almost unavoidably leads to the loss of critical information. We propose to capture the distributional nature of wearable data via user-specific quantile functions (QF) and use these QFs as predictors in scalar-on-quantile-function-regression (SOQFR). As an alternative approach, we also propose to represent QFs via user-specific L-moments, robust rank-based analogs of traditional moments, and use L-moments as predictors in SOQFR (SOQFR-L). These two approaches provide two mutually consistent interpretations: in terms of quantile levels by SOQFR and in terms of L-moments by SOQFR-L. We also demonstrate how to deal with multi-modal distributional data via Joint and Individual Variation Explained using L-moments. The proposed methods are illustrated in a study of association of digital gait biomarkers with cognitive function in Alzheimers disease. Our analysis shows that the proposed methods demonstrate higher predictive performance and attain much stronger associations with clinical cognitive scales compared to simple distributional summaries.

Indexed as

Alzheimer DiseaseWearable Electronic DevicesData AnalysisGaitHumansAlzheimer’s diseaseGaitJIVEL-MomentsQuantile functionsScalar-on-quantile-function regressionWearable data

Identifiers

PMID36519565
PMCPMC10544806
OpenAlexW4250576158

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.