Below is the government’s leaflet about care.data which is
being delivered to every household. If you are unhappy about
your data being given to health insurance companies to help them price
insurance packages for the new privatised NHS (from which expensive
patients will be excluded),
contact your GP practice and tell them you wish to opt out
http://www.england.nhs.uk/wp-content/uploads/2014/01/cd-leaflet-01-14.pdf
Unfortunately, NHS England – the commissioning body that now runs the NHS in England – has decided not to include an opt out form with the leaflet, you can however find a form and further information at medconfidential.org