This annual report reviews the monitoring & data collection system that was implemented under the Oregon Death With Dignity Act, & summarizes the information collected on patients & physicians who participated in the Act in its fourth year of implementation (January 1-December 31, 2001). Using physician reports & interviews, & death certificates, the following questions were examined: are numbers of patients using legal physician-assisted suicide in Oregon increasing? do patients who participated in 2001 resemble patients using physician-assisted suicide in previous years & other Oregonians dying from similar diseases? have any changes occurred in the physician-assisted suicide process during the past four years? (12 refs.)