Online patient feedback: where's the evidence?

I wonder whether there is any evidence that relatives are less willing to provide negative feedback about an institution that has a high overall satisfaction rating, because their identity could easily be inferred even when reviews are anonymised. At the same time, there may be people who would not mind being identifiable—for example, when the care of their own relative has ended but others remain at risk—yet who are discouraged from submitting feedback precisely because the review site can publish only comments that do not risk revealing who wrote them. Is there any evidence showing whether anonymised feedback, as a pre-requisite, is sufficiently inclusive of the range of information that stakeholders might wish to provide?

I agree with this comment. My husband died in hospital after a catalogue of poor care, neglect, negligence and system failures. When I posted my story Care Opinion contacted the Trust which was able to identify my husband’s case and the Trust then persuaded Card Opinion not to publish my story, citing fictitious ongoing investigations. This was after a SAIR had identified 7 failings, all of which were accepted by the Trust. I would advise relatives like me to forget about Care Opinion as the so called moderation process permits the Trusts to “circle the wagons”. If you want similar instances of poor care and avoidable death to be prevented the only effective channels are an inquest and civil litigation.