Evidence map›Paper›PMID 34100950›Full record

ArticleJournal of the American Medical Informatics Association : JAMIA2021

Bidirectional imputation of spatial GPS trajectories with missingness using sparse online Gaussian Process.

Gang Liu, Jukka-Pekka Onnela

Abstract read
In one paragraph

Article in Journal of the American Medical Informatics Association : JAMIA, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 14 papers.

0numbers the graph read from it
0cells of the map it votes in
14citing 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

14 citing papers in PubMed.

  1. Observational
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  13. Statistical inference for complete and incomplete mobility trajectories under the flight-pause model.Journal of the Royal Statistical Society. Series C, Applied statistics · 2024
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  14. Observational
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.

Gang LiuDepartment of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.ORCID 0000-0003-3544-363X
Jukka-Pekka OnnelaDepartment of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.

Funding

Integrating lifecourse approaches, biologic and digital phenotypes in support of heart and lung disease epidemiologic researchU01HL145386 · NHLBI · HARVARD UNIVERSITY D/B/A HARVARD SCHOOL OF PUBLIC HEALTH · PI CHAVARRO, JORGE EDUARDO, MANSON, JOANN ELISABETH · 2019 to 2025
$17.8M
Intensive longitudinal study of suicidal behaviors and related health outcomesU01MH116928 · NIMH · HARVARD UNIVERSITY · PI NOCK, MATTHEW K · 2018 to 2022
$4.3M
NHLBI NIH HHS U01 HL145386NIMH NIH HHS U01 MH116928
6 · The paper itself

Abstract

objectiveWe propose a bidirectional GPS imputation method that can recover real-world mobility trajectories even when a substantial proportion of the data are missing. The time complexity of our online method is linear in the sample size, and it provides accurate estimates on daily or hourly summary statistics such as time spent at home and distance traveled. MATERIALS AND

methodsTo preserve a smartphone's battery, GPS may be sampled only for a small portion of time, frequently <10%, which leads to a substantial missing data problem. We developed an algorithm that simulates an individual's trajectory based on observed GPS location traces using sparse online Gaussian Process to addresses the high computational complexity of the existing method. The method also retains the spherical geometry of the problem, and imputes the missing trajectory in a bidirectional fashion with multiple condition checks to improve accuracy.

resultsWe demonstrated that (1) the imputed trajectories mimic the real-world trajectories, (2) the confidence intervals of summary statistics cover the ground truth in most cases, and (3) our algorithm is much faster than existing methods if we have more than 3 months of observations; (4) we also provide guidelines on optimal sampling strategies.

conclusionsOur approach outperformed existing methods and was significantly faster. It can be used in settings in which data need to be analyzed and acted on continuously, for example, to detect behavioral anomalies that might affect treatment adherence, or to learn about colocations of individuals during an epidemic.

Indexed as

AlgorithmsResearch DesignHumansNormal DistributionSample Sizedigital phenotypingGaussian processGPS imputationmissing datasmartphone

Identifiers

PMID34100950
PMCPMC8324229

What Socratic holds

Textmetadata
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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 Socratic graph.