Previous studies suggest that many people will use the new coverage to obtain medical care for conditions that went untreated while they were uninsured.
The new health law reduces special payments to hospitals serving large numbers of low-income patients, on the assumption that many of the uninsured will gain coverage through Medicaid.
But hospital executives are unsure that the savings will materialize. Dr. Campbell said the cuts could create serious financial problems for hospitals treating large numbers of Medicaid patients.
Recent research in other states has raised similar questions.