RESUMO
BACKGROUND: The Community Mental Health Survey (CMHS) is a valuable resource of information on experiences of mental health care in England; however, response rates are declining. AIM: To increase the overall response rate and response rate of young adult service users. METHODS: Four interventions were trialled in a randomised controlled study design alongside the 2017 CMHS. The questionnaire and information letters were modified based on an established framework for influencing behaviour. The modified materials plus a pre-notification card were tested to increase the overall response rate, identified by one-sided z-tests between the intervention and control groups. An information flyer was modified to target service users age 18 to 35, tested using multilevel logistic regression. RESULTS: The overall response rate significantly increased with the modified information letters compared to the control (29.1% vs. 25.1%; p = 0.007). The targeted information flyer did not increase responses from younger service users; though the combination of modified information letters and questionnaire did (24.6% vs. 15.8%; p = 0.01). CONCLUSIONS: Modifying information letters based on the easy, attractive, social and timely (EAST) framework can increase response rate in postal surveys evaluating community mental health care. Modified letters combined with a modified questionnaire can increase the response from younger service users.