Original article Br J Sports Med 2010;44:1178–1183. doi:10.1136/bjsm.2009.061085 1178 Evaluation of a commercially available pedometer used to promote physical activity as part of a national programme S A Clemes, S O’Connell, L M Rogan, P L Griffiths ABSTRACT Objective (manufactured by Silva) currently being used as part of a national programme to promote physical activity in the UK. Methods Laboratory study: 68 participants (aged 19.2 years (SD 2.7), body mass index (BMI) 22.5 kg/m 2 (SD 3.3)) wore two Silva pedometers (over the right and left hips) while walking on a motorised treadmill at 2, 2.5, 3, 3.5 and 4 mph. Pedometer step counts were compared with actual steps counted. Free-living study: 134 participants (aged 36.4 years (SD 18.1), BMI 26.3 kg/m 2 (SD 5.1)) wore one Silva pedometer, one New-Lifestyles NL-1000 pedometer and an ActiGraph GT1M acceler- ometer (the criterion) during waking hours for one day. Step counts registered by the Silva and NL-1000 pedometers were compared with ActiGraph step counts. Percentage error of the pedometers were compared across normal-weight (n = 58), overweight (n = 45) and obese (n = 31) participants. Results Laboratory study: Across the speeds tested percentage error in steps ranged from 6.7 (4 mph) to 46.9% (2 mph). Free-living study: Overall percentage errors of the Silva and NL-1000 pedometers relative to the criterion were 36.3% and 9%, respectively. Significant differences in percentage error of the Silva pedometer were observed across BMI groups (normal-weight 21%, overweight 40.2%, obese 59.2%, p,0.001). Conclusion unacceptably inaccurate for activity promotion purposes, particularly in overweight and obese adults. Pedometers are an excellent tool for activity promotion; however, the use of inexpensive, untested pedometers is not recom- mended as they will lead to user frustration, low intervention compliance and adverse reaction to the instrument, potentially impacting future public health campaigns. Physical inactivity is currently a major public health concern, with latest estimates stating that approximately one third of all deaths in the UK are caused by diseases that could be at least partly reduced by increased physical activity. The direct cost of physical inactivity to the NHS is estimated to be approximately £1.06 billion per year. 1 Increasing the nation’s level of physical activity is therefore currently a high government priority. 2–4 Walking has been described as an ideal form of exercise, 5 it is fundamental to most of our daily activities, 6 and is reportedly the most popular form of physical activity in the UK. 7 Indeed, walking at a pace of 3 miles per hour (5 km/h) expends sufficient energy to be classified as moderate intensity activity. 8 Pedometers provide an inexpen- sive objective measure of ambulatory (walking) activity by counting the number of steps taken per day, and they have become a popular motivational tool for activity promotion among healthcare providers and among the general public. 9 Used in interventions, pedometers have been associated with significant increases in physical activity and improvements in some key (body weight, body mass index (BMI) and blood pressure) health outcomes, particularly when interventions have incorporated step count recording and goal setting. 10 Considerable variations in the accuracy of different pedometer brands have been reported, 11– 17 and according to Tudor-Locke et al 11 if we are to standardise recommendations for physical activity in terms of steps per day, it is essential that pedometers conform to a reasonable degree of accuracy. Furthermore, if commercially available pedometers are to be used to promote physical activity in large-scale programmes, it is essential that they give individuals accurate daily step counts. Many resources are put into making sure that messages for such campaigns are evidence based and it is important that the same level of attention is given to the tools used to monitor the success of participants achieving those messages. 18 The aim of the current study was to assess the accuracy of a pedometer (Silva model 56012; Silva, Sweden) currently being used as part of a UK national programme (National Step-O-Meter Programme) to promote physical activity. Despite this campaign having already been launched within the UK, there are no published validation studies for the Silva pedometer, which is used by all participants in this campaign to monitor one of the key objectives of this programme, to build towards achieving 10 000 steps per day. The Silva pedometer has a spring-suspended pendulum mechanism, it has a step count display and two reset buttons on the front and a clip on the back and costs approximately £9. Unlike most ped- ometers, the Silva pedometer contains a filter function designed to filter out non-step move- ments. With the filter function, this pedometer only begins to record steps after six consecutive steps have been taken, meaning an individual taking five steps and stopping would not have these steps counted. A secondary aim was to compare the accuracy of the Silva pedometer with that of the New Lifestyles NL-1000 pedometer (New Lifestyles, Lees Summit, Missouri, USA). An earlier model of this range of pedometer (NL-2000) has been shown to be highly accurate, 13–15 19 but the To assess the accuracy of a pedometer The findings suggest the Silva pedometer is Department of Human Sciences, Loughborough University, Loughborough, Leicestershire, UK Correspondence to Dr S A Clemes, Department of Human Sciences, Loughborough University, Loughborough, Leics LE11 3TU, UK; S.A.Clemes@lboro.ac.uk Accepted 15 May 2009 Published Online First 28 May 2009 group.bmj.com on March 18, 2013 - Published by bjsm.bmj.com Downloaded from