Unmet health needs of uninsured adults in the United States.

CONTEXT: In 1998, 33 million US adults aged 18 to 64 years lacked health insurance. Determining the unmet health needs of this population may aid efforts to improve access to care. OBJECTIVE: To compare nationally representative estimates of the unmet health needs of uninsured and insured adults, particularly among persons with major health risks. DESIGN AND SETTING: Random household telephone survey conducted in all 50 states and the District of Columbia through the Behavioral Risk Factor Surveillance System. PARTICIPANTS: A total of 105,764 adults aged 18 to 64 years in 1997 and 117,364 in 1998, classified as long-term (>/=1 year) uninsured (9.7%), short-term (