A model for presenting accelerometer paradata in large studies: ISCOLE.
BACKGROUND
We present a model for reporting accelerometer paradata (process-related data produced from survey administration) collected in the International Study of Childhood Obesity Lifestyle and the Environment (ISCOLE), a multi-national investigation of >7000 children (averaging 10.5 years of age) sampled from 12 different developed and developing countries and five continents.


METHODS
ISCOLE employed a 24-hr waist worn 7-day protocol using the ActiGraph GT3X+. Checklists, flow charts, and systematic data queries documented accelerometer paradata from enrollment to data collection and treatment. Paradata included counts of consented and eligible participants, accelerometers distributed for initial and additional monitoring (site specific decisions in the face of initial monitoring failure), inadequate data (e.g., lost/malfunction, insufficient wear time), and averages for waking wear time, valid days of data, participants with valid data (≥4 valid days of data, including 1 weekend day), and minutes with implausibly high values (≥20,000 activity counts/min).


RESULTS
Of 7806 consented participants, 7372 were deemed eligible to participate, 7314 accelerometers were distributed for initial monitoring and another 106 for additional monitoring. 414 accelerometer data files were inadequate (primarily due to insufficient wear time). Only 29 accelerometers were lost during the implementation of ISCOLE worldwide. The final locked data file consisted of 6553 participant files (90.0% relative to number of participants who completed monitoring) with valid waking wear time, averaging 6.5 valid days and 888.4 minutes/day (14.8 hours). We documented 4762 minutes with implausibly high activity count values from 695 unique participants (9.4% of eligible participants and <0.01% of all minutes).


CONCLUSIONS
Detailed accelerometer paradata is useful for standardizing communication, facilitating study management, improving the representative qualities of surveys, tracking study endpoint attainment, comparing studies, and ultimately anticipating and controlling costs.


BACKGROUND
ClinicalTrials.gov: NCT01722500.
Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA, 70808, USA. tudor-locke@pbrc.edu.
Catrine
C
Tudor-Locke
Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA, 70808, USA. emily.mire@pbrc.edu.
Emily F
EF
Mire
Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA, 70808, USA. kara.dentro@pbrc.edu.
Kara N
KN
Dentro
Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA, 70808, USA. tvbarrei@syr.edu.|Syracuse University, Syracuse, USA. tvbarrei@syr.edu.
Tiago V
TV
Barreira
Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA, 70808, USA. John.Schuna@oregonstate.edu.|Oregon State University, Corvallis, USA. John.Schuna@oregonstate.edu.
John M
JM
Schuna
Tianjin Women's and Children's Health Center, Tianjin, China. juliapeizhao@qq.com.
Pei
P
Zhao
Children's Hospital of Eastern Ontario Research Institute, Ottawa, Canada. mtremblay@cheo.on.ca.
Mark S
MS
Tremblay
University of Bath, Bath, UK. m.standage@bath.ac.uk.
Martyn
M
Standage
School of Medicine Universidad de los Andes, Bogota, Colombia. osarmien@uniandes.edu.co.
Olga L
OL
Sarmiento
Kenyatta University, Nairobi, Kenya. vonywera@gmail.com.
Vincent
V
Onywera
University of South Australia, Adelaide, Australia. timothy.olds@unisa.edu.au.
Tim
T
Olds
Centro de Estudos do Laboratório de Aptidão Física de São Caetano do Sul (CELAFISCS), Sao Paulo, Brazil. matsudo@celafiscs.org.br.
Victor
V
Matsudo
Faculdade de Desporto, University of Porto, Porto, Portugal. jmaia@fade.up.pt.
José
J
Maia
Centro de Estudos do Laboratório de Aptidão Física de São Caetano do Sul (CELAFISCS), Sao Paulo, Brazil. carol.maher@unisa.edu.au.
Carol
C
Maher
University of Cape Town, Cape Town, South Africa. vicki.lambert@uct.ac.za.
Estelle V
EV
Lambert
St. Johns Research Institute, Bangalore, India. a.kurpad@sjri.res.in.
Anura
A
Kurpad
St. Johns Research Institute, Bangalore, India. rebecca@sjri.res.in.
Rebecca
R
Kuriyan
Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA, 70808, USA. gang.hu@pbrc.edu.
Gang
G
Hu
University of Helsinki, Helsinki, Finland. mikael.fogelholm@helsinki.fi.
Mikael
M
Fogelholm
Children's Hospital of Eastern Ontario Research Institute, Ottawa, Canada. jpchaput@cheo.on.ca.
Jean-Philippe
JP
Chaput
Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA, 70808, USA. timothy.church@pbrc.edu.
Timothy S
TS
Church
Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA, 70808, USA. peter.katzmarzyk@pbrc.edu.
Peter T
PT
Katzmarzyk
D061725:Accelerometry; D056044:Actigraphy; D002648:Child; D003625:Data Collection; D015444:Exercise; D006801:Humans; D008019:Life Style; D018670:Monitoring, Ambulatory; D009043:Motor Activity; D063766:Pediatric Obesity / Q000209:etiology / Q000517:prevention & control; D011795:Surveys and Questionnaires