Age has minimal impact on risk for C. difficile infection among elderly

SAN DIEGO — Among elderly patients, chronological age only minimally contributed to the risk for Clostridium difficile infection, according to data presented at IDWeek 2015.

“The question that we were asking was how much of the increased incidence in CDI with age is due to chronologic age vs. biologic age,” Margaret Olsen, PhD, MPH, from Washington University School of Medicine in St. Louis, said during her presentation.

Olsen and colleagues performed a retrospective cohort study using Medicare claims data to identify 174,903 individuals aged 66 years and older who were diagnosed with new-onset CDI in 2011, and compared them to controls without CDI from the Medicare 5% random sample. They used multivariable logistic regression to determine risk factors for CDI, including age, gender, race, recent infections, acute and chronic conditions and health care utilization in the previous year.

Margaret Olsen

They found whites had an increased risk for CDI compared with other races (OR = 1.42; 95% CI, 1.39-1.45), and women had an increased risk compared with men (OR = 1.07; 95% CI, 1.05-1.08).

Chronic conditions associated with increased risk for CDI included chronic renal failure (OR = 1.26; 95% CI, 1.23-1.28), rheumatoid arthritis (OR = 1.26; 95% CI, 1.22-1.3), lymphoma/leukeumia (OR = 1.63; 95% CI, 1.56-1.71), metastatic cancer (OR = 1.23; 95% CI, 1.18-1.29), deficiency anemia (OR = 1.27; 95% CI, 1.25-1.29) and dementia (OR = 1.2; 95% CI, 1.18-1.23).

Infections in the 3 months before CDI that were associated with increased risk for CDI included septicemia (OR = 4.08; 95% CI, 3.97-4.19), pneumonia (OR = 2.06; 95% CI, 2.01-2.1), osteomyelitis (OR = 1.29; 95% CI, 1.21-1.37), surgical site infection (OR = 1.54; 95% CI, 1.45-1.63), urinary tract infection (OR = 1.23; 95% CI, 1.21-1.25), skin/soft tissue infection (OR = 1.36; 95% CI, 1.33-1.39), oral infection (OR = 1.42; 95% CI, 1.26-1.6) and viral infection (OR = 1.19; 95% CI, 1.14-1.25).

Risk factors regarding health care utilization included emergent hospitalization (OR = 3.87; 95% CI, 3.8-3.94), elective hospitalization (OR = 1.76; 95% CI, 1.73-1.79), treat-and-release emergency department visits (OR = 1.58; 95% CI, 1.56-1.61), nursing home residence (1.54; 95% CI, 1.51-1.57), short-term skilled nursing facility care (OR = 2.84; 95% CI, 2.79-2.89) and invasive procedures (OR = 0.85; 95% CI, 0.83-0.86).

“We found that the increased risk of CDI associated with age was almost completely removed when we controlled for this variety of different exposures in the prior year, suggesting that overall health status is actually the most important determinant of CDI risk rather than chronologic age,” Olsen said. “In conclusion, we believe that it’s important to consider the role of deteriorating health status to identify individuals at higher risk of CDI. At the individual level there is variation in health status by age … and the question that we got from this is, ‘Would the same pattern be observed in a younger population?’, and we suggest that younger persons with poorer overall health status may have the same risk of CDI as a much older person.” – by Adam Leitenberger

Reference:

Olsen M, et al. Abstract 69. Presented at: IDWeek; Oct. 7-11, 2015; San Diego.

Disclosures: This study was funded by Sanofi Pasteur. Olsen reports she has performed consultant work for Merck, Pfizer and Sanofi Pasteur, and has received grant funding from Pfizer and Sanofi Pasteur.