Socioeconomic status and risk of osteoporotic fractures and the use of DXA scans: data from the Danish population-based ROSE study.

There is a need of studies exploring the link between socioeconomic status and DXA scans and osteoporotic fracture, which was the aim of the present study. No differences in socioeconomic status and risk of osteoporotic fractures were found. However, women with further/higher education and higher income are more often DXA-scanned. INTRODUCTION: Lower socioeconomic status is known to be associated with a range of chronic conditions and with access to health care services. The link between socioeconomic status and the use of DXA scans and osteoporotic fracture, however, needs to be explored more closely. Therefore, the aim of this study was to examine the relationship between socioeconomic status and both DXA scan utilization and major osteoporotic fractures (MOF) using a population-based cohort of Danish women and national registers. METHODS: The study included 17,155 women (65-81 years) sampled from the Risk-stratified Osteoporosis Strategy Evaluation study (ROSE). Information on socioeconomic background, DXA scans, and MOFs was retrieved from national registers. Competing-risk regression analyses were performed. Mean follow-up was 4.8 years. RESULTS: A total of 4245 women had a DXA scan (24.7%) and 1719 (10.0%) had an incident MOF during follow-up. Analyses showed that women with basic education had a lower probability of undergoing DXA scans than women with further or higher education (greater than upper secondary education and vocational training education) (subhazard ratio (SHR) = 0.82; 95% CI 0.75-0.89, adjusted for age and comorbidity). Moreover, women with disposable income in the low and medium tertiles had a lower probability of undergoing DXA scans than women in the high-income tertile (SHR = 0.90; 95% CI 0.84-0.97 and SHR = 0.88, 95% CI 0.82-0.95, respectively, adjusted for age and comorbidity). No association between socioeconomic background and probability of DXA was found in adjusted analyses. CONCLUSION: The study found no differences in risk of osteoporotic fractures depending on socioeconomic status. However, women with further or higher education as well as higher income are more often DXA-scanned.

Intra-individual variability in day-to-day and month-to-month measurements of physical activity and sedentary behaviour at work and in leisure-time among Danish adults.

BACKGROUND: Accelerometers can obtain precise measurements of movements during the day. However, the individual activity pattern varies from day-to-day and there is limited evidence on measurement days needed to obtain sufficient reliability. The aim of this study was to examine variability in accelerometer derived data on sedentary behaviour and physical activity at work and in leisure-time during week days among Danish office employees. METHODS: We included control participants (n = 135) from the Take a Stand! Intervention; a cluster randomized controlled trial conducted in 19 offices. Sitting time and physical activity were measured using an ActiGraph GT3X+ fixed on the thigh and data were processed using Acti4 software. Variability was examined for sitting time, standing time, steps and time spent in moderate-to-vigorous physical activity (MVPA) per day by multilevel mixed linear regression modelling. RESULTS: Results of this study showed that the number of days needed to obtain a reliability of 80% when measuring sitting time was 4.7 days for work and 5.5 days for leisure time. For physical activity at work, 4.0 days and 4.2 days were required to measure steps and MVPA, respectively. During leisure time, more monitoring time was needed to reliably estimate physical activity (6.8 days for steps and 5.8 days for MVPA). CONCLUSIONS: The number of measurement days needed to reliably estimate activity patterns was greater for leisure time than for work time. The domain specific variability is of great importance to researchers and health promotion workers planning to use objective measures of sedentary behaviour and physical activity. TRIAL REGISTRATION: Clinical trials NCT01996176 .