Exploring if Patients Can Safely and Easily Swab Their Own Surgical Wounds at Home

The goal of this observational feasibility study is to learn if patients can safely, acceptably, and effectively collect their own wound swabs at home to detect clinically significant organisms in adults aged 18 and over who have had cardiac surgery via median sternotomy (central chest wound). Participants will be recruited from two sites: Harefield Hospital (Guy's and St Thomas' NHS Foundation Trust, London) and the Royal Sussex County Hospital (University Hospitals Sussex, Brighton). The main questions it aims to answer are: * Can home-based patient self-swabbing of surgical wounds provide swabs of sufficient quality for microbiological testing? * Is self-swabbing at home safe and acceptable to patients following cardiac surgery? * Could this approach be a cost-effective way to monitor for surgical wound infections? Participants will: * Receive a co-designed self-swabbing instruction pack, created in collaboration with a patient and public working group and clinical experts. * Be observed via Microsoft Teams by a research practitioner while self-swabbing (or having their carer do so) to assess usability and adherence to instructions. * Participate in a brief interview to share their experiences and feedback on the instructions and swabbing process. * Send completed swabs to the hospital laboratory for analysis to determine the usability and timeliness of the samples.