Validity of long-term and short-term recall of occupational sitting time in Finnish and Chinese office workers

摘要

Background:As sedentary behavior is a global health issue,there is a need for methods of self-reported sitting assessment.The accuracy and reliability of these methods should also be tested in various populations and different cultural contexts.This study examined the validity of longterm and short-term recall of occupational sitting time in Finnish and Chinese subgroups.Methods:Two cohort groups of office-based workers(58.6%female,age range 2267 years)participated:a Finnish group(FIN,n=34)and a Chinese group(CHI,n=36).Long-term(past 3-month sitting)and short-term(daily sitting assessed on 5 consecutive days)single-item measures were used to assess self-reported occupational sitting time.Values from each participant were compared to objectively measured occupational sitting time assessed via thigh-mounted accelerometers,with Spearman’s rho(r)used to assess validity and the Bland-Altman method used to evaluate agreement.Coefficients of variation depicted day-to-day variability of time spent on sitting at work.Results:In the total study sample,the results showed that both long-term and short-term recall correlated with accelerometer-derived sitting time(r=0.532,95%confidence intervals(CI):0.3360.684,p<0.001;r=0.533,95%CI:0.4490.607,p<0.001,respectively).Compared to objectively measured sitting time,self-reported occupational sitting time was 2.4%(95%CI:0.5%to 5.3%,p=0.091)and 2.2%(95%CI:0.7%3.6%,p=0.005)greater for long-term and short-term recall,respectively.The agreement level was within the range21.2%to 25.9%for long-term recall,and24.2%to 28.5%for short-term recall.During a 5-day work week,day-to-day variation of sitting time was 9.4%§11.4%according to short-term recall and 10.4%§8.4%according to accelerometry-derived occupational sitting time.Conclusion:Overall,both long-term and short-term self-reported instruments provide acceptable measures of occupational sitting time in an office-based workplace,but their utility at the individual level is limited due to large variability.