Background Sedentary behaviour has been linked with detrimental effects on morbidity and mortality. This study aims to identify the individual, social and environmental correlates of total sedentary behaviour as well as across the contexts that sitting time accumulates in an Irish adult cohort.

Methods Cross-sectional analysis of data from 7,305 adults of the nationally representative Healthy Ireland Survey. Multivariate regression analyses were used to examine participants’ socio-demographic characteristics, lifestyle factors, workplace activity patterns, physical and mental health status, and environmental factors, and their association with participants’ total daily sitting times and sitting times across the domains of work, travel, leisure and screen-time.

Results Overall median of sitting time per day was 360 minutes (6 hours). Workplace sitting was the strongest predictor of sedentary behaviour. Male gender, higher education attainment, higher socio-economic classification and living in an urban dwelling were all associated with increased total- and occupational- sitting time (p<0.05). Insufficient physical activity levels was also associated with total sitting time (p<0.001). Male gender, lower education attainment, a possible mental health problem, smoking and insufficient physical activity were all associated with increased screen-time sitting (p<0.05). Higher education attainment, physical illness, a possible mental health problem, alcohol consumption and lower perceived neighbourhood attributes were all associated with higher transportation/leisure sitting times (p<0.05). Variance of the multivariate model for occupational sitting was 39.0% and 25.8% for total sitting.

Conclusion Having a sedentary occupation was the strongest predictor of sitting time in this population. The results of this study provide a starting position for the development of targeted interventions aimed at the most sedentary groups, such as professional and higher educated males with sedentary occupations.