Before the development of medical expense insurance, patients were expected to pay health care costs out of their own pockets, under what is known as the fee-for-service business model. During the middle-to-late 20th century, traditional disability insurance evolved into modern health insurance programs. One major obstacle to this development was that early forms of comprehensive health insurance were enjoined by courts for violating the traditional ban on corporate practice of the professions by for-profit corporations. State legislatures had to intervene and expressly legalize health insurance as an exception to that traditional rule. Today, most comprehensive private health insurance programs cover the cost of routine, preventive, and emergency health care procedures, and most prescription drugs (but this is not always the case).
Recently (2009) the main representative body of British Medical physicians, the British Medical Association, adopted a policy statement expressing concerns about developments in the health insurance market in the UK. In its Annual Representative Meeting which had been agreed earlier by the Consultants Policy Group (i.e. Senior physicians) stating that the BMA was "extremely concerned that the policies of some private healthcare insurance companies are preventing or restricting patients exercising choice about (i) the consultants who treat them; (ii) the hospital at which they are treated; (iii) making top up payments to cover any gap between the funding provided by their insurance company and the cost of their chosen private treatment." It went in to "call on the BMA to publicise these concerns so that patients are fully informed when making choices about private healthcare insurance." The practice of insurance companies deciding which consultant a patient may see as opposed to GPs or patients is referred to as Open Referral. The NHS offers patients a choice of hospitals and consultants and does not charge for its services.
The great positive impact of public health programs is widely acknowledged. Due in part to the policies and actions developed through public health, the 20th century registered a decrease in the mortality rates for infants and children and a continual increase in life expectancy in most parts of the world. For example, it is estimated that life expectancy has increased for Americans by thirty years since 1900, and worldwide by six years since 1990.