Toggle Main Menu Toggle Search

Open Access padlockePrints

Agreement between pedometer and accelerometer in measuring physical activity in overweight and obese pregnant women

Lookup NU author(s): Peter Tennant, Catherine McParlin, Professor Steve RobsonORCiD, Dr Ruth Bell



BACKGROUND: Inexpensive, reliable objective methods are needed to measure physical activity (PA) in large scale trials. This study compared the number of pedometer step counts with accelerometer data in pregnant women in free-living conditions to assess agreement between these measures. METHODS: Pregnant women (n=58) with body mass index ≥25 kg/m² at median 13 weeks’ gestation wore a GT1M Actigraph accelerometer and a Yamax Digi-Walker CW-701 pedometer for four consecutive days. The Spearman rank correlation coefficients were determined between pedometer step counts and various accelerometer measures of PA. Total agreement between accelerometer and pedometer step counts was evaluated by determining the 95% limits of agreement estimated using a regression-based method. Agreement between the monitors in categorising participants as active or inactive was assessed by determining Kappa. RESULTS: Pedometer step counts correlated moderately (r= 0.36 to 0.54) with most accelerometer measures of PA. Overall step counts recorded by the pedometer and the accelerometer were not significantly different (medians 5961 vs. 5687 steps/day, p=0.37). However, the 95% limits of agreement ranged from -2690 to 2656 steps/day for the mean step count value (6026 steps/day) and changed substantially over the range of values. Agreement between the monitors in categorising participants to active and inactive varied from moderate to good depending on the criteria adopted. CONCLUSIONS: Despite statistically significant correlations and similar median step counts, the overall agreement between pedometer and accelerometer step counts was poor and varied with activity level. Pedometer and accelerometer steps cannot be used interchangeably in overweight and obese pregnant women.

Publication metadata

Author(s): Kinnunen KI, Tennant PWG, McParlin C, Poston L, Robson SC, Bell R

Publication type: Article

Publication status: Published

Journal: BMC Public Health

Year: 2011

Volume: 11

Issue: 1

Pages: 501

Print publication date: 27/06/2011

Date deposited: 08/08/2011

ISSN (electronic): 1471-2458

Publisher: BioMed Central Ltd


DOI: 10.1186/1471-2458-11-501


Altmetrics provided by Altmetric


Funder referenceFunder name
Academy of Finland, Finland
National Institute for Health Research, UK
RP-PG0407-10452-National Institute for Health Research (NIHR)