Patient choice, competition and transparency are beginning to make the care system more open, but patients still find it difficult to get a clear sense of what is a good service. Data may help us make judgments, but a piece of the jigsaw is missing.
Healthcare is about personal experience. It is about the attitude of the doctor, the attention of the nurse, the empathy of the carer.
Patients should be able to make choices based on other patients' experiences. In other walks of life, crowd power helps individuals to do just that - think of the role TripAdvisor plays in helping people to choose a hotel. There is a direct relationship between giving consumers power and improving standards.
After cardiac surgeons in New York State began publishing outcomes data, mortality rates fell by more than 40%. Openness drives improvement.
So too does public participation. In New York today, more than 90,000 citizens routinely call a special number to let authorities know in real time whether bins are being emptied or potholes repaired. Services have markedly improved.
David Cameron is introducing a friends and family test this month for every NHS hospital, so everyone can see whether previous patients would recommend a hospital's services.
He should go further. He should insist real-time, open reporting from patients and carers becomes the norm across the whole care system by the next election - this should include primary care, general practice and elderly care, where we know there is wide variation in outcomes and safety. The test will be a major step forward in making open transparency core to the culture of UK healthcare.
Some doctors fear that open, continuous patient feedback will attract only negative comments and will be abused, but these fears are misplaced.
In the UK and overseas it has been shown that such approaches attract fair, representative and valuable insights that predict and correlate with clinical outcomes.
Dr Bacon is cofounder of medical rating website iWantGreatCare