Workplace Sitting Breaks Questionnaire (SITBRQ): an assessment of concurrent validity and test-retest reliability

BMC Public Health Workplace Sitting Breaks Questionnaire (SITBRQ): an assessment of concurrent validity and test-retest reliability Zeljko Pedisic 0 1 Jason A Bennie 0 Anna F Timperio David A Crawford David W Dunstan Adrian E Bauman 0 Jo Salmon 0 Prevention Research Collaboration, Sydney School of Public Health, The University of Sydney , Sydney , Australia 1 Faculty of Kinesiology, University of Zagreb , Zagreb , Croatia Background: Breaks in prolonged sitting may have beneficial cardiometabolic and musculoskeletal health outcomes. Desk-based work settings are an important environment to promote and support breaks in sitting time. However, few studies have reported the psychometric properties of self-report measures to assess the frequency and duration of breaks from sitting. This study examined the concurrent validity and test-retest reliability of the Workplace Sitting Breaks Questionnaire (SITBRQ) designed to assess frequency and duration of breaks in sitting within desk-based work settings. Methods: To assess the concurrent validity, a sample of 147 desk-based employees completed the SITBRQ and wore an Actigraph GT1M accelerometer for seven consecutive days. To establish test-retest reliability, SITBRQ was administered on two separate occasions 7-14 days apart to a separate sample of 96 desk-based employees. Results: A low relative agreement with accelerometry (Spearman's r = 0.24 [95% CI 0.07 - 0.40]) was determined for self-reported frequency, but not for the duration of sitting breaks (Spearman's r = 0.05 [95% CI 0.12 - 0.22]). Adequate reliability was determined for both self-reported frequency (Spearman's r = 0.71 [95% CI 0.59 - 0.79], Cohen's kappa = 0.74 [95% CI 0.64 - 0.84]) and duration of sitting breaks (Spearman's r = 0.59 [95% CI 0.45 - 0.71], Cohen's kappa = 0.61 [95% CI 0.38 - 0.85]). Conclusion: SITBRQ may be used for assessment of the frequency of sitting breaks within desk-based work settings with validity and reliability similar to other self-reports in the field of sedentary behaviour research. However, until adequately improved and re-evaluated, it should not be used to collect data about the duration of breaks in sitting time. Breaks in sitting time; Physical activity; Sedentary behaviour; Desk-based employees; Light-intensity physical activity; Reliability; Validity; Accelerometer; Self-report - Background Physical inactivity is one of the leading global public health issues in developed countries [1]. There is wellestablished epidemiological evidence to suggest that a minimum of 150 minutes of moderate or 75 minutes of vigorous-intensity physical activity a week, or an equivalent combination of both, significantly reduces the risk of a number of chronic diseases [2]. Recently, sedentary behaviour (too much sitting as opposed to too little physical activity) has emerged as a candidate independent risk factor [3]. Several reviews have shown that high volumes of time spent sitting or engaged in sedentary behaviour have been associated with an increased all-cause mortality and chronic disease (e.g., diabetes, cardiovascular disease) and obesity risk [4-6]. In some studies, associations between sedentary behaviour and all-cause mortality and chronic disease risk occurred irrespective of whether an individual meets the public health physical activity recommendations [7-10]. Researchers have recently investigated the potential for health benefits associated with light-intensity physical activity [11,12]. This type of activity is defined as being between 1.8-2.9 metabolic equivalent units of rest (METs) and is typically non-structured and incidental in nature [13]. Examples of light-intensity physical activity include common habitual free-living activities such as routine occupational (e.g. standing, retail serving and food preparation) or domestic tasks (e.g. ironing, washing up, gardening) [13]. Studies have shown that time spent in light-intensity physical activity is highly inversely correlated (r = 0.95) with time spent in sedentary behaviour [14]. Hence, if an individual has low levels of lightintensity physical activity, it is likely that he or she is highly engaged in sedentary behaviours. While the evidence base is still developing, data from experimental studies [15,16] and several cross-sectional observational studies [12,17-19] suggest that higher levels of light-intensity physical activity are associated with a reduced risk of cardiometabolic disease biomarkers and being overweight/obese. Importantly, some of these findings were present even after adjustment for time spent in moderate-to-vigorous physical activity and sedentary behaviour. These insights have prompted some health agencies and professional societies to provide formal documents outlining some behavioural modification strategies to reduce time spent in sedentary behaviour among adults and children, and suggest strategies generally based around increasing volumes of light-intensity physical activity [20-22]. One of the main strategies is to periodically take short breaks in sitting time within the occupational and home settings [20-22]. It is suggested, for example, that workers periodically take a short break in sitting at least once every 30 minutes, walk to their co-workers instead of telephoning or emailing, stand up during meetings/presentations and install height adjustable sit-stand workstations [22]. Studies have indicated that taking short breaks may assist in reducing detrimental biomechanical consequences of prolonged sitting, such as posture-related musculoskeletal disorders [23] as well as the risk of cardiometabolic disorders and obesity [15,19,24,25]. In addition to spending approximately half their waking hours in this setting [26,27], employees in computercentric work environments may be sitting for up to 80% of their working time [28,29]. It has also been shown that office workers take significantly fewer breaks in sedentary time during working hours compared to non-occupational time [28,30]. Desk-based and computer-centric work environments may, therefore, be the key behavioural settings to support and promote breaks in sitting time [31]. With the emerging public health interest around the positive health consequences of breaks in sitting time, it is important to develop valid and reliable assessments of this behaviour. Although self-report measures have been the most commonly used method in large-scale epidemiological studies on physical activity and sedentary behavior [32,33], almost all studies assessing breaks in sedentary behavior have used objective measures, such as accelerometers [19,24,34,35], multi-sensor devices [36], inclinometers [29] and sitting pads [25]. While this may in part be due to reduced cost and increased availability of objective devices in the last decade, few self-report instruments are available and psychometric data are lacking. Several previous studies have developed self-report instruments that assess occupationa (...truncated)