Table 1

Variables measured by each of the four study methods (collection methods in parentheses)

VariablesObservational survey (observation)Interview/inspection (observation/ inspection/self report)Self administered questionnaire (self report)Focus group (self report)
    Household incomeNoYesYesYes
    Seat belt useYesYesNoNo
    Relationship to child(ren)NoYesYesYes
    Where manufacturedNoYesNoNo
    Number in householdNoNoYesNo
CRD use
    Position in carYesYesNoNo
    Frequency of removalNoYesYesYes
    Ease of useNoYesYesYes
    Fitting in vehicle examinedNoYesNoNo
    Placement of child examinedNoYesNoNo
    Reasons for non useNoYesYesExtensive
    Barriers to useNoLimitedLimitedExtensive
    Potential to give rate of use of CRDYesYesNoNo