According to this study:
* Higher nurse-to-patient ratios could lower the risk of infection.
The authors examined the effects of nurse staffing levels at a single medical ICU on the incidence of nosocomial infection. They hypothesize that the demanding workloads that accompany lower staffing make it difficult for nurses to practice infection control procedures.
In an observational study conducted over four years, patients admitted to the ICU were prospectively followed daily for a mean length of stay of five days. Only patients who remained in the ICU for more than 48 hours and only infections that developed more than 48 hours after admission were evaluated to account for the two- to four-day incubation period that characteristically separates exposure and infection. The nursing workload was determined according to a 24-hour nurse-to-patient ratio, calculated by dividing the total number of nurses working by the patient census on that day. Other variables considered in the analysis were the use of invasive devices and antibiotics, the admission diagnosis, the patient illness severity score, demographic characteristics, and comorbidities.
Of 1,883 patients who were followed for a total of 10,637 patient-days, 415 (22%) had at least one nosocomial infection during their stay in the ICU, for a total infection rate of 64.5 per 1,000 patient-days. Patients who remained in the ICU for seven or more days had an infection rate that was more than two times higher than those who stayed less than seven days. The infections occurred principally in the lower respiratory tract (45.8%); catheter exit site (11.8%); ears, eyes, nose, and throat (11.1%); bloodstream (7.4%); and urinary tract (7.1%). After adjusting for risk factors such as the use of invasive devices and antibiotics, increasing the nurse-to-patient ratio was associated with a more than 30% lower risk of infection. The median 24-hour nurse-to-patient ratio in the study was 1.9, and the researchers estimated that 26.7% of all the nosocomial infections could have been prevented if that ratio had been greater than 2.2.
This study joins the growing body of literature documenting the critical association between nurse staffing levels and the risk of nosocomial infection.
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