Impact of comorbidities on hospital-acquired infections in a geriatric rehabilitation unit: prospective study of 252 patients

Abstract

Objectives: Hospital-acquired infections (HAIs) remain a major source of morbidity and mortality in long-term care units, despite advances in antimicrobial therapy and preventive measures. Our aim was to investigate risk factors for HAIs, especially in the elderly, and to describe the relationship between comorbidities (number, severity, and specific diseases) and HAIs using a comprehensive inventory of comorbidities.

Design: Prospective cohort study

Setting: Geriatric rehabilitation unit in a university hospital in the Paris metropolitan area.

Participants: Participants were 252 consecutive patients aged 75 years or older (mean age, 85 ± 6.2 years) and admitted between 2006 and 2008.

Measurements: Surveillance of HAI was conducted. A complete inventory of comorbidities was done using the Cumulative Illness Rating Scale for Geriatrics (CIRS-G). Potential risk factors were evaluated in 2 risk models, one with HAI acquisition, CIRS-G, activities of daily living score less than 10, and at least 1 invasive procedure (yes/no) and the other with HAI acquisition and specific invasive procedures and diseases.

Results: Of the 252 patients, 97 experienced HAIs, for an incidence of 5.6 infections per 1000 bed-days. The most common HAI sites were the respiratory tract (48%; 65/136) and urinary tract (37%; 51/136). The CIRS-G global score and comorbidity index were higher in patients with than without HAIs. Among HAI categories, respiratory and urogenital diseases were more prevalent in the group with HAIs. In the model combining CIRS-G, activities of daily living score less than 10, and at least 1 invasive procedure, independent risk factors for HAI were CIRS-G index (odds ratio [OR], 1.55; 95% confidence interval [95% CI], 1.13-2.11; P = .005) and invasive procedures (OR, 5.18; 95% CI, 2.77-9.71; P < .001). In the model including specific procedures and diseases, independent risk factors for HAI were intravenous catheter (OR, 7.39; 95% CI, 2.94-18.56; P < .001), urinary catheter (OR, 3.33; 95% CI, 1.40-7.88; P = .006), gastrointestinal endoscopy (OR, 3.69; 95% CI, 1.12-12.16; P = .03), pressure sores (OR, 2.52; 95% CI, 1.04-6.10; P = .03), and swallowing impairment (OR, 3.37; 95% CI, 1.16-9.74; P = .02).

Conclusions: This study identified several important risk factors for HAIs. There is a need for HAI prevention via the implementation of infection-control programs, including surveillance, in rehabilitation units.