15 30 Nevertheless, our English and the Scottish studies demonstrate that when education, occupational social class and income are combined into a single measure

(SEP score) they are a much more powerful predictor of ST than any single indicator, perhaps because they collectively capture actual SEP more thoroughly than any single indicator. kinase inhibitor Imatinib Mesylate Composite SEP score showed a clear and consistent pattern with all ST outcomes, although each of the individual/household-level SEP indicators seemed to influence each ST outcome in various ways, suggesting there are complex, interacting, multidimensional influences of SEP on ST. Accelerometry-measured ST was the only sedentary behaviour variable that showed clear and consistent (positive) associations with all SEP variables (except from area-level deprivation). Although the cross-sectional design of this study precludes causal inferences, the pattern of the accelerometry-based associations we observed

suggests that it is unlikely that total sedentary behaviour contributes to the well-documented socioeconomic inequalities in health.11 Strengths of our study include the availability of objectively-measured and self-reported indicators of sedentary behaviour which allowed us to be more thorough and detailed when examining the associations of interest. Accelerometers can capture total ST more comprehensively than any partial self-reported indicator and as such are able

to better quantify the socioeconomic gradient of ST as a contributor to health inequalities, however, a limitation is that accelerometers do not distinguish between sitting and standing which have different health implications, this also applies to occupational sitting/standing time. It has been argued that standing should not be considered a sedentary behaviour.31 This limitation is also pertinent to the self-reported ST assessment as standing time was included in the occupational ST question. The lack of information on work times did not allow us to examine the possibility that ST differences between SEP groups are partly due to longer work hours in higher SEP groups. Taken together, these limitations of the measurements may, to some extent, have confounded the associations of SEP Batimastat with total and occupational ST we reported. Another limitation is that our study was limited to the accelerometry sample of HSE 2008 and this might have led to our sample being less representative of the target population. Although those in the subsample offered the accelerometer were older and more likely to be retired and to be less healthy than the rest of the adult Health Survey for England sample, those who refused to wear an accelerometer were similar in terms of employment status and area-level deprivation compared to those who wore the accelerometers for at least 4 days a week.