Background Understanding a patient's hospital experience is fundamental to improving health services and policy, yet, little is known about their experiences of adverse events (AEs). This study redresses this deficit by investigating the experiences of patients in New South Wales hospitals who suffered an AE.

Methods Data linkage was used to identify a random sample of 20 000 participants in the 45 and Up Cohort Study, out of 267 153 adults aged 45 years and over, who had been hospitalised in the prior 6 months. A cross-sectional survey was administered to these patients to capture their experiences, including whether they had an AE and received honest communication about it.

Results Of the 18 993 eligible participants, 7661 completed surveys were received (40% response rate) and 474 (7%) reported having an AE. Most AEs related to clinical processes and procedures (33%), or medications and intravenous fluids (21%). Country of birth and admission through emergency were significant predictors of the occurrence of an event. An earlier admission in the prior 6 months or a transfer to another healthcare facility was also associated with more AEs. Of those who suffered an AE, 58% reported serious or moderate effects.

Conclusions Given the exclusions in our sample population (under 45 years), the AE rate reported by patients of 7% is similar to the approximately 10% rate reported in the general population by retrospective medical record reviews. AE data that include patient experience may provide contextual information currently missing. Capturing and using patient experience data more effectively is critical; there may be opportunities for applying co-design methodology to improve the management of AEs and be more responsive to patients' concerns.