["Health Expectations, Volume 29, Issue 2, April 2026. ", "\nABSTRACT\n\nBackground\nIn the United Kingdom and Sweden, men aged 65 are offered screening for Abdominal Aortic Aneurysm (AAA). Men with small AAA enter a surveillance programme to monitor growth until the AAA is large enough for referral for treatment. Some men develop anxiety related to having an AAA or being in surveillance.\n\n\nAim\nThe original aim was to develop and assess the acceptability of a new intervention to help men in surveillance manage anxiety. As the study progressed, the aim changed to developing an information booklet to address men's uncertainties about AAA and surveillance because uncertainties might lead to anxiety.\n\n\nMethod\nAn intervention development study was undertaken, following guidance in three phases: 1. Identifying need using surveys of screening staff and men, and qualitative interviews with men and family members; 2. Co‐design of an intervention using a literature review, programme theory development, and two workshops with men, family members, and a patient representative; 3. Assessing the acceptability of the intervention using a telephone survey of 23 men in AAA surveillance.\n\n\nResult\nAlthough the original aim was to develop an intervention to help men manage anxiety, men and screening staff identified the need for an information‐based intervention to address men's uncertainties about AAA. Published evidence identified that uncertainty about health conditions or treatment can lead to anxiety, so the intervention taken forward was an information booklet to address men's uncertainties about AAA. A 16‐page A5 booklet was developed with men and their family members, addressing why men had to wait for AAA to become large before referral for treatment, the risk of rupture for different sizes of AAA, and how to reduce the risk of rupture. In the telephone survey, 20/23 men in the AAA surveillance who read the draft booklet found it helpful because it addressed their uncertainties. They suggested minor refinements. A refined version of the prototype booklet was produced based on this feedback.\n\n\nConclusions\nA co‐designed information booklet is available that addresses the uncertainties of men with AAA in surveillance. Future research should measure the impact of the information booklet on AAA‐related anxiety.\n\n\nPatient and Public Contributions\nWe set up a patient panel specifically for this study. We identified five men from different sources including asking the vascular clinicians on the team to invite patients to consider joining the panel and approaching existing health research studies patient panels to identify men who had AAA. One member of our team was the patient representative on the research committee for the NHS AAA Screening Programme in England. He attended all our patient panel meetings. The panel reviewed all the documents we used to invite men to different parts of the study, offered advice about recruitment, and gave feedback about the findings. They offered advice about the prototypes of the information booklet.\n"]