Fig. 1

Flow chart showing study population: responders and non-responders to the first postal questionnaire and proportions with pain; and responders and non-responders to the second postal questionnaire at the 9-week follow-up
Flow chart showing study population: responders and non-responders to the first postal questionnaire and proportions with pain; and responders and non-responders to the second postal questionnaire at the 9-week follow-up