• trial recruitment
• questionnaire

Few publications have examined maximising recruitment to randomised controlled trials in primary care. Mass mailings have been used as a recruitment strategy,1-3 but have had low response rates. Short messages in mass mailings have acheived better recruitment rates than longer messages.4 Within a primary care injury prevention trial we assessed response and recruitment rates to the trial using mass mailing, comparing an invitation to participate with and without a home safety questionnaire. We considered that sending a questionnaire may reduce the recruitment rate because of the time and effort needed for completion4 or because questions on safety behaviours and previous injury may be perceived as intrusive; alternatively we considered that the questionnaire may raise awareness of risk of injury and through this might increase the recruitment rate.5