A new survey challenges the long-held assumption that having health insurance is synonymous with having access to health care.

Researchers at the Center for Healthcare Research & Transformation, Ann Arbor, Mich., commissioned an August 2009 survey of 1,022 Michigan adults.

About 40% of the uninsured individuals surveyed said they have delayed seeking needed care, but so did 17% of the insured survey participants. The chief reason given for putting off getting care was cost concerns.

The researchers found that some low-income urban dwellers had less trouble getting care than any other survey participants but high-income suburban dwellers. This may reflect greater availability of health care “safety net” providers in urban areas, and less availability of safety net care in rural communities and small towns, according to CHRT researchers.

The CHRT researchers found “no significant connection” between having health insurance and self perceptions of health. About 49% of those with health insurance reported themselves to be in excellent or very good health, whereas 47% of those with no health insurance reported themselves to be in excellent or very good health.