A defined set of data which give a minimum description of a hospital episode or admission. Collection of a UHDDS is required upon discharge for all hospital stays reimbursed under Medicare and Medicaid. The UHDDS was defined in a policy statement of the Secretary of HEW (HEW publication number HSM 73-1451, series 4, no. 14, as extended by a policy statement approved 6/24/74) and includes data on the age, sex, race and residence of the patient, length of stay, diagnosis, responsible physicians, procedures performed, disposition of the patient and sources of payment. The PSRO program uses a slightly larger data set called the PSRO Hospital Discharge Data Set (PHDDS). The Uniform Hospital Discharge Abstract (UDHA) used to collect the UHDDS is one example of a discharge abstract.