The Legislature should give state health regulators more authority to monitor consumer complaints against health maintenance organizations (HMOs), especially quality-of-care complaints, the legislative auditor recommended Friday.

As part of a program evaluation, the Office of the Legislative Auditor reviewed oversight of the HMO complaint process by the Minnesota Department of Health. About 18 percent of the state’s residents are covered by HMOs.

The review discovered that health officials lack the authority to monitor quality-of-care complaints made by enrollees against their HMOs. Complaints could include, for instance, a denial of payment because the HMO determined that a procedure was medically unnecessary.

Currently, the Health Department forwards those complaints to the HMO against which it was filed. The HMO then conducts an investigation, which usually is confidential because it involves individual medical information as well as critiques and assessments made by doctors and other health care professionals.

By law, these reviews are confidential, meaning that health regulators get no information about them, including whatever resolution was made as a result of the investigation.

In the report, the legislative auditor recommended that the results of quality-of-care investigations be opened up to state regulators, showing them how thorough and complete the HMO investigation was.

The Minnesota Council of Health Plans, a trade group representing the state’s HMOs, said the auditor’s recommendation raises questions about confidentiality. Officials should consider whether “opening that information up [would] make health care providers less candid or less open,” said Eileen Smith, communications director for the council.

The auditor’s report also recommended that HMOs report the number and type of complaints to the Health Department annually, a practice that was abandoned in 2012. It also said the department should forward any quality-of-care complaints involving providers to the appropriate licensing board.