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 .
Reproducibility and validity of a self-administered physical activity questionnaire.
BACKGROUND The reproducibility and validity of self-administered question naires on physical activity and inactivity  were examined in a r and om ( representative ) sample of the Nurses ' Health Study II cohort and a r and om sample of African-American women in that cohort . METHODS Repeat question naires were administered 2 years apart . Past-week activity recalls and 7-day activity diaries were the referent methods ; these instruments were sent to participants four times over a 1-year period . RESULTS The 2-year test-retest correlation for activity was 0.59 for the representative sample ( n = 147 ) and 0.39 for the African-American sample ( n = 84 ) . Correlations between activity reported on recalls and that reported on question naire were 0.79 and 0.83 for the representative and African-American sample s , respectively . Correlations between activity reported in diaries and that reported on question naire were 0.62 and 0.59 , respectively . Test-retest coefficients for inactivity were 0.52 and 0.55 , respectively . Correlations between inactivity reported in diaries and that reported on question naire were 0.41 and 0.44 , respectively . CONCLUSION The simple , short question naires on activity and inactivity used in the Nurses ' Health Study II are reasonably valid measures for epidemiological research
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 .