Despite declining fatalities, infection rates are climbing, especially among those on Medicare.
Despite increasing Clostridium difficile infection rates, in-hospital fatalities decreased more than twofold in the United States over the past decade, according to a new report.
Researchers from the University of Arizona College of Medicine analyzed patients principally diagnosed with C. difficile from 2004—2014 and examined their fatality rates within hospitals. They also explored associated trends in length of hospital stay and total cost incurred by patients discharged with a principal C. difficile diagnosis.
The patient records were collected from the National Inpatient Sample (NIS), the largest all-payer inpatient database in the United States. Researchers collected data about patient age, gender, insurance status (the expected payment source) and income status (the median household income for their zip code).
About 1.9 million people discharged from U.S. hospitals were infected with C. difficile during the study period, but the infection was the primary diagnosis for just 600,000 patients, the study authors learned.
45% of infected patients were aged 65—84 years and two-thirds of the patients were female. A quarter of the patients came from a low median household income zip code. Most of the patients were insured with Medicare (66.9%), 8.3% were insured with Medicaid, 20.4% with private insurance and 4.4% were uninsured.
Throughout the 10-year study period, the number of patients with C. difficile as their primary diagnosis ranged 60,000—120,000 per year. However, infections for this period varied significantly by age. For example, the percentage of infected patients aged 45-64 increased from 20% in 2004 to 26% in 2014, but patients aged 65-84 decreased from 49% in 2004 to 41% in 2014.
Over the course of the study, the percentage of uninsured patients compared to patients with private insurance varied from 4% and 5%, to 20% and 22%, respectively. Medicare patients decreased from 67% in 2004 to 64% in 2014, however Medicaid patients rose from 7% in 2004 to 12% after 10 years.
Fatality decreased from 1.2% to 0.7% over the study period in patients aged 45—64 years with C. difficile infection.
“The most surprising finding of our study is the declining mortality rate of inpatient C. difficile infection even as the rate of inpatient C. difficile infection has increased,” study author Dr. Sasha Taleban told MD Magazine. “The decreasing mortality rate is most likely due to a number of factors including improved infection control and new treatment options. Also the widespread use of the more sensitive PCR stool testing may be contributing to the increased misclassification of C. difficile carriers as having pathogenic C. difficile infection.”
Hospital length of stay decreased by about 1 day for patients with a principal diagnosis of C. difficile. In 2004, the average length was 6.9 days, but in 2014 it measured 5.8 days.
“The findings indicate the importance of appropriate use and interpretation of C. difficile diagnostic testing,” added Dr. Taleban. “While diagnostic tests like immunoassays are less sensitive than PCR assays for detecting C. difficile, they may be more indicative of a true infection.”
The paper, titled “Decreasing Clostridium Difficile-Associated Fatality Rates among Hospitalized Patients in the Unites States: 2004-2014,” was published in The American Journal of Medicine.