An investigation by Healthwatch England into the health and social care complaints system has led to it being described as 'utterly bewildering and largely ineffective'.
The report, Suffering in silence: Listening to consumer experiences of the health and social care complaints system found the system made complaining difficult, lacked independent advice and support and provided little incentive for the public to come forward about their experiences.
Anna Bradley, chair of Healthwatch England, said: "Complaining about poor care is an incredibly difficult thing to do, especially for those who are suffering either physically or emotionally as a result of the way they have been treated by a hospital or care home.
"The professionals and policy makers cannot look on complaints merely as raw intelligence about performance. They need to be compassionate and supportive of those that have been let down."
For a second year in a row almost two thirds of those who received poor care didn't report it or make a complaint, Healthwatch England estimates at least 250,000 incidents of poor care were unreported in the NHS alone.
Figures for social care complaints are not complied nationally as complaints are made to local authorities, 174,872 complaints were made to the NHS in 2013/14.
Bradley added, "There is already universal support for the need to improve complaints handling and the public has helped us highlight some quick wins for the system. But having examined the experiences of thousands of patients, it is clear that the problem goes much deeper than a bit of tinkering with what we already have.
Prof Sir Mike Richards, Chief Inspector of Hospitals at the Care Quality Commission, said: "This is a very timely report from Healthwatch England. Investigating how the NHS listens to and acts on complaints and concerns from its patients is a vital part on our new inspection regime that we are formally rolling out this month."
