How many nurses per patient? Measurements of nurse staffing in health services research.

OBJECTIVE

To compare alternative measures of nurse staffing and assess the relative strengths and limitations of each measure.

DATA SOURCES/STUDY SETTING: Primary and secondary data from 2000 and 2002 on hospital nurse staffing from the American Hospital Association, California Office of Statewide Health Planning and Development, California Nursing Outcomes Coalition, and the California Workforce Initiative Survey.

STUDY DESIGN

Hospital-level and unit-level data were compared using summary statistics, t-tests, and correlations.

DATA COLLECTION/EXTRACTION METHODS: Data sources were matched for each hospital. When possible, hospital units or types of units were matched within each hospital. Productive nursing hours and direct patient care hours were converted to full-time equivalent employment and to nurse-to-patient ratios to compare nurse staffing as measured by different surveys.

PRINCIPAL FINDINGS

The greatest differences in staffing measurement arise when unit-level data are compared with hospital-level aggregated data reported in large administrative databases. There is greater dispersion in the data obtained from publicly available, administrative data sources than in unit-level data; however, the unit-level data sources are limited to a select set of hospitals and are not available to many researchers.

CONCLUSIONS

Unit-level data collection may be more precise. Differences between databases may account for differences in research findings.