In the October issue of Critical Care Medicine, Law and colleagues published an evaluation of the impact of changes in Massachusetts state regulations mandating that nurse staffing levels on critical care units be set at 1:1 or 1:2, and that they be based on patient acuity tools. These regulations took effect in academic medical centers in March 2016. Law and colleagues' study used databases and benchmarking systems to examine about 30,000 ICU admissions in six academic ICUs in the state and about 570,000 ICU admissions in 114 medical centers outside Massachusetts. Measurements were taken at three points in time in the year before the legislation was announced, the year before it took effect, and the year afterward. The authors took into account that the patient populations in different ICUs vary, and that there can be overall trends in patient care over time that affect at least four outcomes: central line-associated bloodstream infections (CLABSIs), catheter-associated urinary tract infections (CAUTIs), hospital-acquired pressure ulcers, and falls with injury.
Researchers compared Massachusetts hospitals to hospitals outside the state and restricted their analysis to academic hospital ICUs to avoid comparing ICUs from different types of hospitals. They also used a "difference-in-difference" approach, where trends over time on various measures in the same hospitals were tracked-which is considered a rigorous evaluation approach. They also examined risk-adjusted mortality rates-that is, they didn't just examine overall mortality in ICUs (which was about 10%); the main variable they studied was the ratio of patients who actually died in relation to how many were expected to die based on their clinical presentations. They calculated a combined rate of CLABSIs, CAUTIs, hospital-acquired pressure ulcers, and falls with injury-only 0.7% of the patients in Massachusetts and elsewhere experienced them.
The researchers found no net increases/improvements in hospitals' ICU staffing, nor did they see any evidence of improvements in patient outcomes over time, suggesting that the impact of the legislation may have been minimal.
The study conclusions may not have been surprising-perhaps staffing levels in academic hospital ICUs were unlikely to change all that much as a result of the new regulations. Still, caution is needed in extrapolating its conclusions to all ICUs in Massachusetts-this was a study of one type of ICU and was restricted to a relatively small number of hospitals in the benchmarking database. Furthermore, potential changes in outcomes from the regulations on specific subpopulations in ICUs cannot be ruled out, nor can changes in financial or other patient or nurse outcomes not assessed in the study. In sum, this study joins a body of evaluations of the impact of mandatory staffing ratio legislation or regulations that fail to show any benefits; and while rigorous, was relatively narrow in its scope.-Sean Clarke, PhD, RN, FAAN
Editor's note: Sean Clarke is professor and associate dean of the undergraduate program at the William F. Connell School of Nursing, Boston College, in Chestnut Hill, MA.