FRIDAY, May 4 (HealthDay News) -- Patients with mental health emergencies wait an average of 11.5 hours -- nearly half a day -- in hospital emergency departments, and those who are older, uninsured or intoxicated wait even longer, a new study says.

Overall, patients with psychiatric emergencies wait about 42 percent longer in the emergency department than other patients, according to the findings published online May 1 in the Annals of Emergency Medicine.

"These patients are waiting the longest for care, and shrinking resources are having a disproportionate effect on these very vulnerable people," lead study author Dr. Anthony Weiss, of Massachusetts General Hospital in Boston, said in a journal news release.

The researchers looked at five hospital-based ERs within the greater Boston area.

Weiss and colleagues analyzed the records of nearly 1,100 adults patients with psychiatric emergencies to determine how long it took patients to see a doctor and get a psychiatric evaluation. Patients who were sent home after being seen by medical staff spent an average of 8.6 hours in the emergency department, while patients who were eventually admitted to a psychiatric unit within the hospital had an average emergency department stay of 11 hours.

Patients who were transferred to an outside unit within the local health care system stayed in the emergency department for an average of 12.9 hours, while those transferred to a facility outside the local health care system stayed 15 hours.

The average length of emergency department stay was 10.7 hours for patients aged 18 to 39 and 12.6 hours for patients older than 60. The one-third of patients who tested positive for alcohol had an average stay of 14.5 hours.

There were no differences in how long it took for patients with public insurance such as Medicare or Medicaid or private insurance to be treated; however, uninsured patients spent four more hours in the ER than these other groups, according to researchers.

"Between 2000 and 2007, psychiatric visits to ERs grew by 231 percent," Weiss said. "This increase in volume, when combined with fewer resources outside the ER, has led to a real crisis for this population. Long waits for care aren't good for anyone but they are especially harmful to patients in psychiatric distress."

More information

The American College of Emergency Physicians has more about emergency department waiting times.