Physical activity assessment for public health: efficacious use of the single-item measure

Abstract

Telephone -(+44) 013 812 9107Single-Item Physical Activity Measures 2 Objectives: The accurate mass assessment of physical activity is essential for effective Public Health policy and practice. Combined with a desire to minimise participant burden, the selfreported single-item physical activity screening measure has become increasingly attractive and widespread. To help reduce any potential misclassification, refining this instrumentation in line with any changes in prescribed activity levels is essential to optimise accuracy. Study design: This study compares the levels of agreement, sensitivity and specificity for the singleitem measure versus IPAQ using current physical activity recommendations. Methods:Agreement was assessed in a non-probability sample of 7650 adults. The  statistic, sensitivity and specificity were used to assess agreement between the tools for classifying participants as sufficiently active for health (≥150 minutes of physical activity per week) or not, and being classified as inactive (<30 of minutes of physical activity per week) or not. Results: The singleitem measure showed weak agreement with the IPAQ for identifying participants who met the current physical activity guidelines (= 0.13, 95% CI 0.12 to 0.14), sensitivity was 18.7% and specificity was 97.2%. For the classification of inactive participants it showed a moderate agreement with IPAQ (= 0.45, 95% CI 0.43 to 0.47), sensitivity was 74.2% and specificity was 79.7%. Conclusions: The single-item measure has a low diagnostic capacity compared to IPAQ. Further research is needed if it is to be used in large scale surveys and interventions where screening for sufficiently active or inactive individuals is the goal.

Responsiveness of the single item measure to detect change in physical activity

“…Single item measures of PA have been developed to assess the physical activity of population segments, including older adults [13,14,15] and adolescents [16] in settings where time and resources are limited. The single item measure (SIM) developed by Milton and colleagues [1] has been used widely to assess the PA of adults [17,19] and asks respondents to report the number of days in the last week that they undertook at least 30 minutes of moderate to vigorous physical activity (MVPA) related to leisure or transport. Given the SIM can provide a parsimonious measure of activity, it has been used to assess population levels of PA [17,18] and the effectiveness of programs designed to increase PA [19].…”

“…The single item measure (SIM) developed by Milton and colleagues [1] has been used widely to assess the PA of adults [17,19] and asks respondents to report the number of days in the last week that they undertook at least 30 minutes of moderate to vigorous physical activity (MVPA) related to leisure or transport. Given the SIM can provide a parsimonious measure of activity, it has been used to assess population levels of PA [17,18] and the effectiveness of programs designed to increase PA [19]. There is emerging supportive evidence for the measurement properties of the SIM, that includes test-retest reliability [1] and concurrent validity, based on comparisons with accelerometer data [2,20].…”

Taking a Stand for Office-Based Workers' Mental Health: The Return of the Microbreak

“…Thus, our intervention strategy offers the first evidence that organizational stress can possibly be attenuated by having desk-based workers take a break from their tasks to engage in some self-determined movement activity. Second, despite the evidence that employees' probability of signing up and adhering to workplace programs is related to prior exercise habits, time costs, taste for fitness, confidence, and positive attitude toward fitness (54,55) our intervention realized a positive outcome for adherence and compliance in a non-exercising population. We argue that this result was achieved by having movement break activities that were self-determined, office-appropriate, did not require specialized equipment or a change of clothing, and were short in duration.…”

Physical activity of future health care professionals: adherence to current recommendations

“…However, some marginal notes have to be made. Although IPAQ is a common research tool used to compare PA, and its validity and reliability has been proven many times [30], it is not considered the gold standard indicator and may misclassify some participants [31]. The objectively measured PA, using accelerometers, could give a more precise evaluation of the PA level, but what was the authors' main concern in this study was the cost and feasibility.…”