Need, demand, supply.

Ideally, health needs should arouse a proportionate and appropriate demand for health care, which can then be supplied in a systematic way. In real life, this desirable process is distorted by faulty perception of actual need; by failure of even perceived need to generate demand, while at the same time demands are made which bear little relation to need; and finally by the inappropriateness of some service provision to either need or demand. One approach to making a more objective assessment of what is needed in service provision is described, in the shape of a system of five indices of the burden cast by various types of illness on sufferers and on the health services.