The long-term care population has grown more diverse in age and ethnicity over recent decades, according to new research published in JAMDA: The Journal of Post-Acute and Long-Term Care Medicine.

Researchers with the Johns Hopkins University School of Medicine used data from the Centers of Medicare & Medicaid Services, the Medicare Payment Advisory Commission, nursing home surveys and the Nursing Home Data Compendium to identify trends in long-term care utilization and demographics.

The results, published Tuesday, found the proportions of nursing home residents younger than 65 and those older than 85 increased 7% and 4.5%, respectively, from 1995 to 2012. The majority of residents were still between 65- and 85-years-old, researchers noted.

The number of African American and Hispanic residents has increased by 9% and 3.9%, respectively. The number of male nursing home residents grew nearly 50% from the early 1970s to 2012, although the ratio of male to female residents remained the same. The proportion of married residents also increased to 33% by 2012.

On the clinical side, the number of nursing home residents requiring assistance with five or more activities of daily living dropped significantly between 2004 and 2012, from around half of residents to roughly a fourth.

Four of the five most common causes of preventable hospital readmissions for nursing home residents matched with their leading diagnoses in the skilled nursing setting, which researchers said reflects increasing frailty and comorbidities. The leading diagnoses in the skilled nursing settings were in the circulatory, respiratory and musculoskeletal systems.

“Given these significant differences in clinical complexity and resource utilization by this population, we propose that further research and dialogue is needed to define quality and cost metrics for the providers dedicated to caring for these frailest of the frail,” researchers wrote.