A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed patient access to clinical trials sponsored by the National Institutes of Health (NIH), focusing on: (1) how health insurers' coverage policies and practices affect patient participation in clinical trials; (2) researchers' experience in enrolling patients for trials sponsored by the National Cancer Institute (NCI) and factors that may explain this experience; and (3) whether NIH has evidence of recent difficulties in enrolling patients in clinical trials."