Abstract

Citation

Liggett L, Gray A, Parnell W, McGee R, McKenzie Y. Validation and reliability of the New Lifestyles NL-1000 accelerometer in New Zealand preschoolers. J Phys Act Health 2012 Feb;9(2):295-9.

Abstract

BACKGROUND: Objective measures, such as accelerometers, are increasingly being used to measure physical activity (PA) levels in children, and the use of validated and reliable instruments is desirable when measuring the effectiveness of programs. The purpose of this study was to determine the validity and reliability of the New Lifestyles NL-1000 accelerometer among preschoolers using a modified version of the Children's Activity Rating Scale (CARS). METHODS: Fourteen preschoolers wore the NL-1000 at their waist while the device measured activity levels [in seconds of moderate-to-vigorous physical activity (MVPA)]. They were also videoed for approximately 12 minutes while participating in normal activities at an early childhood center. At approximately 2-minute intervals, activity level readings derived from the NL-1000 were recorded. The video footage was analyzed using a modified CARS technique and the CARS scores compared with data obtained from the accelerometer. RESULTS: Within subject reliability was measured using intraclass correlation coefficients (0.58 for CARS and 0.59 for NL-1000). Furthermore, 95% of the variation in CARS could be explained by variation in the accelerometer counts, with 2.4% of the variation being participant-specific. CONCLUSION: The NL-1000 is a sufficiently reliable and valid tool for assessing MVPA in preschoolers.

Full Text

not available

At A Glance

Individual Physical Activity Behavior Variables

Expenditure
Moderate Physical Activity
Vigorous Physical Activity
Step/Activity Counts

Domain(s)

Individual Physical Activity Behavior

Measure Type

Electronic monitor (e.g., accelerometer, pedometer, heart rate)

Measure Availability

Cost associated. Contact New Lifestyles, Inc., Lee's Summit, Missouri, USA

Number of Items

Not applicable

Study location

Metro/Urban

Invercargill, New

Languages

Not applicable

Information about Development of Measure

New Lifestyles NL-1000 Accelerometer was pretested in children age 3 and 4 years to determine which settings best reflected observed moderate to vigorous physical activity (MVPA), when compared with direct observation. The device captures comparable information to that of an advanced pedometer, estimates distance traveled, takes into account stride lengths, and has a MVPA timer accumulation feature.

Study Design

Study Participants

Age

2 - 5 Years

Sex

Female

Male

Race/Ethnicity

Not reported

Predominantly Low-income/Low-SES

Not applicable

Sample Size

14

Study Design

Design Type

Validation/Reliability

Health Outcomes Assessed

None

Obesity Measures

Not reported

BMI Measured or Self-reported

Not reported

Covariates

Not reported

Data Reported on Race/Ethnicity

Not applicable

Data Reported on SES

Not applicable

SES-related Variables

Not applicable

How To Use

Administration

Who Administered

Researcher-administered

How Administered

In-person

Direct observation, hard-copy form

Time Required

12 minutes

Training Required

Yes, time not reported

Instructions on Use

Instructions on instrument use included in article

Data Analysis

Data Collection/Analysis Costs

Not available

Data Collection/Protocol

The NewLifestyles-1000 (NL-1000) was attached to the waistband of each child's clothing. Once the NL-1000 was attached, each child was observed for the next 15 to 20 minutes, producing in total approximately 12 minutes (or 5 to 6 observations) of usable video footage, which were later coded. Two observers recorded the child's activity. The researcher provided instructions to the child and also read aloud the details from the moderate to vigorous physical activity timer.

Instructions on Data Analysis

Instructions on analysis included in article

Validity (1)

Type of validity Construct/subscale assessed Criterion measure used Test/statistic used Result
Criterion The NewLifestyles-1000 (NL-1000) moderate to vigorous physical activity Children's Activity Rating Scale (CARS) observed moderate to vigorous physical activity Linear mixed model 95% of the variation in CARS could be explained by variation in the accelerometer counts, with 2.4% of the variation being participant-specific

Reliability (2)

Type of reliability Construct/subscale assessed Test/statistic used Result
Test-retest The NewLifestyles-1000 (NL-1000) measures of moderate to vigorous physical activity Intraclass correlation coefficients ICC = 0.59
Test-retest Children's Activity Rating Scale (CARS) observed moderate to vigorous physical activity Intraclass correlation coefficients ICC = 0.58