Studies on nurse staffing and health care-associated infection: methodologic challenges and potential solutions

Researchers have been studying hospital nurse staffing in relation to health care-associated infections (HAIs) for >2 decades, and the results have been mixed. We summarized published research examining these issues, critically analyzed the commonly used approaches, identified methodologic challenges, proposed potential solutions, and suggested the possible benefits of applying an electronic health record (EHR) system.

A scoping review was conducted using MEDLINE and CINAHL from 1990 onward. Original research studies examining relationships between nurse staffing and HAIs in the hospital setting and published in peer-reviewed English-language journals were selected.

A total of 125 articles and abstracts were identified, and 45 met inclusion criteria. Findings from these studies were mixed. The methodologic challenges identified included database selection, variable measurement, methods to link the nurse staffing and HAI data, and temporality. Administrative staffing data were often not precise or specific. The most common method to link staffing and HAI data did not assess the temporal relationship. We proposed using daily staffing information 2-4 days prior to HAI onset linked to individual patient HAI data.

To assess the relationships between nurse staffing and HAIs, methodologic decisions are necessary based on what data are available and feasible to obtain. National efforts to promote an EHR may offer solutions for future studies by providing more comprehensive data on HAIs and nurse staffing.