UCR: cf. usual, customary and reasonable.

Ulcerative colitis (UC): idiopathic inflammatory disease of the large intestine; symptoms include pain, diarrhoea mixed with blood because of the presence of open sores (ulcers); often confused with irritable bowel syndrome (cf.) wrzodziejące zapalenie jelita grubego

Ultraviolet (UV) rays: radiation from the sun that can be useful or potentially harmful: UV-A enhance plant life and are useful in some medical and dental procedures; UV-B can cause skin cancer or other tissue damage. The ozone layer in the atmosphere partly shields the Earth from ultraviolet rays. promieniowanie ultrafioletowe/nadfioletowe

UM: cf. utilisation management.

Unbiased estimator: estimator whose expectation is the true parameter. estymator nieobciążony

Unbundling: practice of providers billing for a package of health care procedures on an individual basis when a single procedure could be used to describe the combined service. fakturowanie w rozbiciu na podusługi

Uncertainty: 1. situation in which an individual has incomplete information as to what is going to happen in the future; cf. risk; 2. (safety factor): factor that reflects the degree of uncertainty that must be incorporated into the extrapolation from experimental data to the human population. niepewność

Uncompensated care: care rendered by hospitals or other providers without payment from the patient or a from third-party payers; includes both charity care, which is provided without the expectation of payment, and bad debts, for which the provider has made an unsuccessful effort to collect payment due from the patient. opieka bezpłatna

Underfund: to provide with insufficient funding.