Participants
Local NHS staff checked the hospital records of the 337 participants who were active in the trial at 12 months after randomisation (15 months after surgery) to confirm current address and vital status before sending an introduction letter. Two weeks later, a study pack was sent containing an approach letter, patient information booklet for the follow-up study, questionnaire, consent form (which included consent to obtain data from the patient’s medical records), and a postage-paid return envelope. An individually wrapped teabag was provided in each pack as a non-monetary incentive for participation; this was also provided in the main trial [