A study at the University of California, San Francisco School of Nursing found the law that raised nursing home reimbursement rates from $124 per day in 2004 to $152 per day in 2006 was followed by a 19 percent increase in administrative costs, but staffing levels remained significantly lower than recommended and staff turnover actually increased.

The number of complaints about poor quality of care increased, as did documented deficiencies -- including those that caused harm and jeopardy, the study said.

Wages and benefits for nursing assistants, who provide the majority of nursing home care, did not keep pace with inflation between 2004 and 2006, but administrative salaries increased substantially, the researchers said.

"The quality of nursing home care has been a serious problem in California and nationwide for many years," study lead author Charlene Harrington said in a statement. "This legislation was designed to address that, but so far it has not met the challenge."