BackgroundInternationally, continuous efforts have been put into developing patient complaint channels to understand patients' experience and expectation of care, which can guide the improvement of health service quality. Despite agreement among the value of patient feedback, limited attention has been paid to using patient feedback to predict and promote the actual quality improvement initiatives.ObjectiveTo determine whether patient feedback collected from a public feedback hotline can be used to predict the effect of hospital quality service improvement initiatives.MethodsA retrospective analysis of patient complaint data of a tertiary hospital from 2018 to 2021 was performed. Patient complaints were first coded by the standard classification method of the Australian Hospital Patient Experience Question Set. The characteristics of patients' complaints were then analysed by frequency and contingency table analysis. Finally, through Nonparametric Mann‐Kendall test and Joinpoint regression model, the trends of each complaint characteristics were tested.ResultsAmongst the 771 complaints received against clinicians, approximately 75% of them were concerning doctors. ‘Harm and distress’ was the key reason of complaints, followed by ‘not cared for’, ‘lack of confidence’, ‘needs unmet’ and ‘not informed’. In 2021, the number of complaints received in relation to moderate ‘harm and distress’ caused by doctors increased by 667% from 2020. The categories of ‘not informed’, ‘not cared for’ and ‘harm and distress’ were also on the rise with statistical significance. In addition, complaints related to the lack of respect, bad attitude and unprofessional behaviour demonstrated by nurses (n = 83) and doctors (n = 121) were also recorded.ConclusionPatient feedbacks collected via a public feedback hotline provides a useful platform to gain insight into patient experience of care which are valuable to guide quality care improvement. To improve the care quality, clinicians need to participate in quality improvement strategies development at an early stage. Efforts in improving communication and interaction between doctors and patients are needed to improve patients' experience of care and developing patients' trust in both of the clinicians and the medical services. The study highlights the value of using public feedback hotline to generate evidence that can guide hospital service improvement.