Public release date: 22-Sep-2010
– On average, the antibiotic group had longer hospital stays and higher mortality rates than the non-antibiotic group.
Doctors frequently misuse antibiotics when treating patients hospitalized with respiratory tract infections (RTIs), according to a study to be published in the November issue of Infection Control and Hospital Epidemiology.
The study, which tracked patients in two Pennsylvania hospitals, found that doctors often use antibiotics to treat patients whose infections are known to be caused by viruses. The findings are alarming because antibiotics are not effective against viruses, and antibiotic overuse has been linked to the development of resistant bacterial strains.
“[T]hese data demonstrate at least one area where antibiotics are commonly used in hospitalized patients without clear reason,” write the study’s authors, Kevin T. Shiley, Ebbing Lautenbach and Ingi Lee, all from the University of Pennsylvania School of Medicine. “Recognition of this may be helpful in developing interventions to limit inappropriate antibiotic use in the future.”
In recent years, new diagnostic tests have been developed to distinguish infections caused by viruses from those caused by bacteria. In theory, more definitive diagnoses should reduce the inappropriate use of
antibiotics in patients with viral infections. But that does not appear to be happening, according to Shiley and his colleagues.
The researchers looked at data on RTI patients admitted to two hospitals over a two-year period. Of 196 patients who were diagnosed with viral infections, 125 remained on antibiotics after their diagnoses. It would be understandable to keep a patient on antibiotics if an abnormal chest x-ray suggests a concurrent bacterial infection, the researchers said. However, only 37% of these patients had abnormal chest x-rays. “It is less clear why the remaining 63% of patients with normal chest imaging were prescribed antibiotics,” Shiley and his colleagues write.
NO CLINICAL BENEFIT
Patients in the study who remained on antibiotics did not benefit from the treatment, the researchers found. In fact, antibiotics may have led to harm in some cases. For example, a significant number of antibiotic patients developed Clostridium difficile diarrhea, a condition linked with antibiotic use.
On average, the antibiotic group had longer hospital stays and higher mortality rates than the non-antibiotic group. While those poorer outcomes cannot be attributed directly toantibiotic treatment, they do suggest that there was no clinical benefit, the researchers say.
“This study highlights the crucial role of antimicrobial stewardship in improving patient care,” said Neil O. Fishman, M.D. at the University of Pennsylvania and president of the Society for Healthcare Epidemiology of America. “Appropriate use of antibiotics is not only essential to limiting emergence of resistance, but also may help improve clinical outcomes.”
Public release date: 23-Sep-2010
Declining breast cancer incidence in Canada with declining HRT usage
Breast cancer incidence declined among postmenopausal women in Canada as their use of hormone therapy declined, according to a study published online September 23 in The Journal of the National Cancer Institute.
The Women’s Health Initiative (WHI) trial of more than 16,000 postmenopausal women in the United States reported in 2002 that the risks of combined estrogen and progestin hormone replacement therapy outweighed the benefits. As a result, prescriptions for hormone therapy fell dramatically in several countries around the world and so did the incidence of breast cancer.
To determine whether a similar decline of hormone therapy use and breast cancer incidence occurred in Canada, Prithwish De, Ph.D., of the Canadian Cancer Society, and colleagues, analyzed data from various Canadian registries and from a national health survey for women aged 50-69 years. Specifically, the researchers looked at information on prescriptions for hormone replacement therapy, breast cancer incidence, mammography rates, and self-reported use of hormone replacement therapy.
The researchers found that “the nearly 10% drop in invasive breast cancer rates coincided with the decline in use of hormone replacement therapy reported among Canadian women aged 50-69 years.” The steepest decline in use occurred between 2002 and 2004, when use dropped from 12.7% to 4.9%. In that same period, breast cancer incidence dropped 9.6% but mammography rates remained stable.
The researchers write that the decline in breast cancer incidence “is likely explained by the concurrent decline in the use of hormone replacement therapy among Canadian women.” They also say the drop in hormone therapy use may be partly explained by the media’s coverage of results of both the WHI and the Million Women Study in the U.K., both of which showed that breast cancer risk was elevated with the use of combined hormone therapy. In Canada, cancer rates began to increase again in 2005 among women aged 50-69 years, which might be further evidence of a link between hormone therapy and breast cancer,
according to the authors.
“Such a rebound might be expected if occult hormone-sensitive tumors were merely slowed by the withdrawal of hormone replacement therapy rather than prevented by it. If so, hormone replacement therapy may be thought to act as a promoter, rather than a cause of breast cancer,” they write.
The study’s limitations include the fact that data on hormone replacement therapy use was self-reported— and therefore subject to recall bias—and that data on frequency or duration of use were not collected. Also, data on receptor status of breast tumors were not collected.
In conclusion, the authors write that “further long-term surveillance studies of trends between hormone replacement therapy and breast cancer incidence can help reconcile the potential population-level associations of these two factors.”