Hospitals might want to start stocking up on warm milk. According to a new study published by Johns Hopkins Bloomberg School of Public Health researchers in the Journal of Gerontology, insomnia experience by middle-aged and older adults has been associated with higher future hospitalization rates and health care costs.

"In a large representative sample of US middle-aged and older adults, we found that individuals with a greater number of insomnia symptoms were more likely to be hospitalized, and to use home healthcare services," said senior author Adam Spira in a Johns Hopkins press release. "Over 40 percent of our sample reported at least one insomnia symptom, consistent with previous studies that showed insomnia to be very common in this population."

The team used data from the 2006 and 2008 participants in the University of Michigan's Health and Retirement Study, and found a statistically significant correlation between patient reports of insomnia in 2006 and increased use of health services two years later.

If the link is found to be causal, Spira added in the press statement, then preventing insomnia in middle-aged and older adults could decrease the use of health services by about six percent to 14 percent in this patient population.

Kaufmann C, Canham S, Mojtabai R, Gum AM, Dautovich ND, Kohn R, Spira AP. Insomnia and Health Services Utilization in Middle-Aged and Older Adults: Results from the Health and Retirement Study. Journal of Gerontology. 2013; Doi: 10.1093. Accessed May 10, 2013.