WEDNESDAY, Oct. 13 (HealthDay News) --Being black and/or being on Medicaid significantly increases the likelihood that hospitalized patients will be readmitted to the hospital within a month of their initial release, new research reveals.

Re-hospitalization risk also goes up among patients taking high-risk medications and those struggling with specific health issues, including congestive heart failure, kidney disease, cancer, weight loss and iron deficiency anemia, the study authors found.

The findings are published in the October issue of the Journal of Hospital Medicine.

"Many health-care systems are now making efforts to improve the transition from hospital to home or nursing facility to try to reduce preventable readmissions, but they need to know which patients to focus on to have the biggest impact," study author Dr. Nazima Allaudeen, from the University of California, San Francisco, noted in a press release from the publisher. "Studies like ours should give practitioners direction to non-clinical factors to identify."

About 20 percent of Medicare patients are readmitted to a hospital within 30 days of being released, the study authors noted.

Their observations are gleaned from an analysis of readmission statistics concerning 6,805 patients who were seen 10,359 times at UCSF hospitals between 2006 and 2008.

The authors found that 17 percent of the total admissions were readmissions, and almost half of these readmissions took place within 10 days of the patient's initial hospital release.

A second, much smaller study published in the same journal found that the largest predictor of patient readmission was a diagnosis of a chronic disease. But more surprisingly, according to a research team from the Royal Brisbane and Women's Hospital in Australia, body mass index also played a key role.

Underweight and obese patients faced a higher risk for readmission within six months of initial release, with 72 percent of the former and 50 percent of the latter readmitted in that time-frame (compared with just 27 percent of normal weight patients and 37 percent of overweight patients).

Being depressed was also linked to a higher risk for quick readmission, the research team observed.

The Brisbane researchers based their findings on detailed clinical assessments of more than 140 patients over the age of 50 who had been hospitalized at least twice within a six-month period between 2006 and 2007.

More information

For more on hospital admission trends, visit the U.S. Centers for Disease Control and Prevention.