Nursing Staff Reductions, Workload Increases, and Adverse Events in Florida Hospitals 1992-2004: New Variable and Longitudinal Approaches
- Presenter:
Chair: Sally Stearns; Discussant: Joanne Spetz Tue June 6, 2006 13:45-15:15 Room 325
Nurse staffing/outcomes studies have primarily used common staffing measures and crosssectional or repeated measures approaches. However, given new explanatory variables such as “nursing staff reductions” and “workload,” a latent response variable called “patient outcomes,” longitudinal data, and the use of growth curve modeling, additional information and more causal conclusions can be derived. This study examines the relationship between nursing staff reductions, workload increases, and patient adverse events in Florida hospitals, 1992-2004. Hypotheses are: 1) An increase in nursing workload during a one year period is associated with a proportional increase in adverse events in that same year; 2) A 5 percent or more reduction of the licensed nursing staff during year ti-1 is associated with higher rates of adverse events and worse patient outcomes in year ti-1 and year ti; 3) A 5 percent or more reduction of the licensed nursing staff during year ti-1 is associated with a higher nursing workload in year ti-1 and year ti; 4) A hospital characteristic such as for-profit status is associated with higher nursing workloads, and vice versa for a characteristic such as teaching status; and 5) Higher nursing workloads in year ti are associated with higher rates of adverse events and worse patient outcomes in year ti. Nursing staff reductions in year ti is a dichotomous variable defined as a drop in licensed nursing staff of 5 percent or more measured from the beginning of time ti-1 to the beginning of time ti. Nursing workload is the ratio of adjusted patient days of care to the numbers of RNs and LPNs taken separately and together (licensed nurses). Patient days of care are adjusted for outpatient care and for patient turnover, which affects the intensity of nursing care. Adverse events are hospital-level rates of nursing sensitive events such as urinary tract infections, atelectasis, pneumonia, decubitus ulcers, and failure to rescue. The patient outcomes variable is a latent measure derived from the adverse events rates in the measurement model. Other measures are patient case mix, and hospital characteristics such as ownership, size, location and teaching status. Staffing measures and hospital characteristics are from the American Hospital Association Annual Survey. Adverse events and case mix are extracted from patient discharge records obtained from the Agency for Health Care Administration in Florida. Multi-wave, multivariate, latent growth curve modeling is used to define the relationships between the trajectories of endogenous and exogenous variables over 13 waves of data, time invariant and time-varying covariates included. The time invariant variables are the hospital characteristics, while the time varying variables are the rest of the variables. Rates of adverse events are transformed into approximately normally distributed variables prior to introduction into the model. Maximum likelihood estimation methods are used.
