Antibiotic Use High Among Nursing Home Patients With Advanced Dementia

"The extensive antibiotic use demonstrated in this study is concerning given the lack of demonstrable benefits and the potential burdens of treatment in this terminally ill population for whom the goal of care is often palliation," write study authors Susan L. Mitchell, M.D., M.P.H., of Hebrew SeniorLife's Institute for Aging Research, and Erika D'Agata, M.D., M.P.H., of Beth Israel Deaconess Medical Center. "Moreover, we believe that the widespread use of antibiotics in advanced dementia may pose a potential public health risk through the emergence of antibiotic resistance."

Nearly 70 percent of the 5 million Americans with dementia--a progressive decline in cognitive function due to damage or disease in the brain beyond what is expected in normal aging--will live in a nursing home during the final stage of their disease. Recurrent infections and fevers typically occur during this stage; therefore, nursing home residents with advanced dementia are at high risk for exposure to antibiotic medications. Exposure to drugs, however, can lead to the emergence of antibiotic-resistant bacteria, which are associated with higher mortality rates and more frequent and prolonged hospitalizations.

The researchers followed 241 residents with advanced dementia from 21 Boston-area nursing homes who were recruited for a study called Choices, Attitudes and Strategies for Care of Advanced Dementia at End-of-Life (CASCADE), a five year study funded by the National Institutes of Health. The primary goal of the CASCADE study is to describe the multiple facets of the end-of-life experience for nursing home dementia patients and their families. As one component of this larger study, the use of antimicrobial medications (drugs that kill or inhibit the growth of bacteria) among these residents every 3 months for 18 months or until their death.

More than 66 percent of residents with advanced dementia received at least one course of antibiotic therapy during an average of 322 days of follow-up. Among the 99 residents who died during the observation period, nearly 52 percent received at least one course of antibiotics within eight weeks of death, and 42% received antibiotics during the 2 weeks prior to death. As subjects approached death, the number of antibiotic therapy courses increased significantly.

This is the first comprehensive study to describe the quantity, type and pattern of antibiotics prescribed for advanced dementia patients. Earlier studies focused on the treatment of specific infections, such as pneumonia, or studied residents in only a single institution.

"Despite these differences," the researchers say, "our study corroborates that antimicrobial agents are commonly prescribed in advanced dementia and extends these findings by a marked increase in antimicrobial use as death becomes imminent."

In an accompanying editorial, two epidemiologists from Tel Aviv Medical Center in Israel argue that physicians must "consider every decision to use antibiotics in this population as we would decisions regarding other treatment modalities, including resuscitation and major surgery." That is, physicians must determine if using these medications for specific patients justifies the risk placed on others by antimicrobial resistance. "We must challenge the assumptions that it is always acceptable to treat bacterial infection with antibiotics, and that deliberation is required only in the event that one wishes not to treat."

Drs. Mitchell and D'Agata say their findings are a "first step" toward a better understanding of the public health risks posed by antibiotic resistance and that the development of programs and guidelines to reduce the use of antimicrobial agents in advanced dementia is warranted.

Journal reference: Arch Intern Med. 2008;168[4]:357-362 February 25,2008.