Table 2

Quality assessment of the prospective cohort studies according to the Newcastle-Ottawa Scale*9

SelectionComparabilityOutcome
StudyRepresentativeness of exposed cohortSelection of non-exposed cohortAscertainments of exposureOutcome not present at onsetControls for other PAControls for additional factorAssessmentLength of follow-upAdequacy of follow-upOverall quality†
Berentzen et al18Truly representative‡Drawn from same community‡Written self-reportYes‡Yes‡Yes‡Independent blind‡10 years‡Drop-outs had higher WC at onset7/9
Chakravarty et al14Selected groupDrawn from different sourceWritten self-reportYes‡Yes‡Yes‡Self-report21 years‡Complete follow-up‡5/9
Chase et al21Selected groupDrawn from same community‡Written self-reportYes‡NoYes‡Record linkage‡13.4 years‡Small number lost‡6/9
Chomistek et al17Selected groupDrawn from same community‡Written self-reportYes‡Yes‡Yes‡Record linkage‡22 years‡Low follow-up rate6/9
Farahmand et al22Selected groupDrawn from different sourceSecure record‡Yes‡Yes‡NoRecord linkage‡15 months‡Small number lost‡6/9
Johnsen et al19Somewhat representative‡Drawn from same community‡Structured interview‡Yes‡Yes‡Yes‡Record linkage‡7.6 years‡Small number lost‡9/9
Littman et al15Somewhat representative‡Drawn from same community‡Written self-reportYes‡Yes‡Yes‡Self-report10 years‡Small number lost‡7/9
Mekary et al16Selected groupDrawn from same community‡Written self-reportYes‡Yes‡NoSelf-report8 years‡Low follow-up rate4/9
Sahlqvist et al20Somewhat representative‡Drawn from same community‡Written self-reportYes‡Yes‡Yes‡Record linkage‡11.5 years‡Complete follow-up‡8/9

  • *http://www.ohri.ca/programs/clinical_epidemiology/oxford.htm

  • †The selection domain is given four stars, the comparability domain two stars, and the outcome domain three stars for high rating, resulting in a total of zero to nine stars for overall quality.

  • ‡A ‘Star’ is provided if the defined quality has been achieved.

  • PA, physical activity; WC, waist circumference.