Figure 1

Study design. MVA = Motor Vehicle Accident; NDI = Neck Disability Index; QB = first (basic) postal questionnaire; Q6W = Postal questionnaire 6 weeks after enrolment; Q3M = Postal questionnaire 3 months after enrolment; Q6M = Postal questionnaire 6 months after enrolment; Q12M = Postal questionnaire 12 months after enrolment;