Assessing SB as a sum of behaviours and using a previous day recall were the most promising features of existing tools .
Accuracy was poor for all existing tools , with underestimation and overestimation of SB .
There was a lack of evidence about sensitivity to change .
OBJECTIVE Sedentary behaviour ( SB ) has distinct deleterious health outcomes , yet there is no consensus on best practice for measurement .
This study aim ed to identify the optimal self-report tool for population surveillance of SB , using a systematic framework .
Longitudinal association of physical activity and sedentary behavior during leisure time with health-related quality of life in community-dwelling older adults
Background Evidence on the relation between leisure-time physical activity ( LTPA ) and health-related quality of life ( HRQoL )  in older adults is based primarily on clinical trials of physical exercise programs in institutionalized persons and on cross-sectional studies of community-dwelling persons . Moreover , there is no evidence on whether leisure-time sedentary behavior ( LTSB ) is associated with HRQoL independently of LTPA . This study examined the longitudinal association between LTPA , LTSB , and HRQoL in older community-dwelling adults in Spain . Methods Prospect i ve cohort study of 1,097 persons aged 62 and over . In 2003 LTPA in MET-hr/week was measured with a vali date d question naire , and LTSB was estimated by the number of sitting hours per week . In 2009 HRQoL was measured with the SF-36 question naire . Analyses were done with linear regression and adjusted for the main confounders . Results Compared with those who did no LTPA , subjects in the upper quartile of LTPA had better scores on the SF-36 scales of physical functioning ( β 5.65 ; 95 % confidence interval [ CI ] 1.32 - 9.98 ; p linear trend < 0.001 ) , physical role ( β 7.38 ; 95 % CI 0.16 - 14.93 ; p linear trend < 0.001 ) , bodily pain ( β 6.92 ; 95 % CI 1.86 - 11.98 ; p linear trend < 0.01 ) , vitality ( β 5.09 ; 95 % CI 0.76 - 9.41 ; p linear trend < 0.004 ) social functioning ( β 7.83 ; 95 % CI 2.89 - 12.75 ; p linear trend < 0.001 ) , emotional role ( β 8.59 ; 95 % CI 1.97 - 15.21 ; p linear trend < 0.02 ) and mental health ( β 4.20 ; 95 % CI 0.26 - 8.13 ; p linear trend < 0.06 ) . As suggested by previous work in this field , these associations were clinical ly relevant because the β regression coefficients were higher than 3 points . Finally , the number of sitting hours showed a gradual and inverse relation with the scores on most of the SF-36 scales , which was also clinical ly relevant . Conclusions Greater LTPA and less LTSB were independently associated with better long-term HRQoL in older adults
Assessing SB as a sum of behaviours and using a previous day recall were the most promising features of existing tools .
Accuracy was poor for all existing tools , with underestimation and overestimation of SB .
There was a lack of evidence about sensitivity to change .
OBJECTIVE Sedentary behaviour ( SB ) has distinct deleterious health outcomes , yet there is no consensus on best practice for measurement .
This study aim ed to identify the optimal self-report tool for population surveillance of SB , using a systematic framework .