Patient turnover and nursing staff adequacy

Health Services Research, April, 2006 by Lynn Y. Unruh, Myron D. Fottler

Table 3 shows the percentage change in staffing ratios from 1994 to 2001 before and after adjustments, the mean differences between the measures, and the t-values of these differences. The percentage change in unadjusted staffing ratios barely changed year-to-year, whereas the turnover-adjusted measures fell 1-4 percent per year, and those adjusted for both turnover and severity fell up to 18 percent in some years. Instead of a continual improvement in RN staffing through 1996, as indicated by the unadjusted measure, all adjusted measures show declines starting in 1994. Then, between 1996 and 2000, measures adjusted for turnover show much deeper decreases in RN staffing than the unadjusted measures. Because patient severity peaked in 1999, measures adjusted for both turnover and severity decrease deeply until 1999, then show increases in percent change. Overall, unadjusted RN/APDC fell only 1 percent, whereas adjusted RN/APDC fell from 10 to 26 percent.

Although there were varying degrees of difference between the adjusted and unadjusted measures, there was a highly significant statistical difference between unadjusted and all four adjusted measures for most of the 8 years. The maximum year-to-year difference between measures occurred between 1997 and 1998, with t-values from 8 to 14 at p < .0001. The difference between the unadjusted and adjusted ratios was reduced from 2000 to 2001, and was even positive between the unadjusted and dually adjusted measures (because patient severity peaked in 1999). For the period overall, t-values of the mean difference in measures were 14-24 with p < .0001.

DISCUSSION

Our study adjusts RN staffing ratios in Pennsylvania hospitals from 1994 to 2001 using two different ad hoc patient turnover adjustments and a severity adjustment. Our results indicate significant declines in average length of stay, increases in patient turnover, and declines in adjusted RN staffing ratios over this time period irrespective of which adjustment is used. RN staffing levels were significantly lower after adjustment for patient turnover, alone or together with patient severity adjustments. The significance of this finding is that unadjusted RN staffing measures overestimate RN staffing, although the use of ad hoc measures does not allow us to speculate as to what degree.

No previous research has adjusted RN staffing ratios for patient turnover or both patient turnover and patient severity. As both significantly impact RN workloads, the present study suggests that future research regarding nurse staffing or nurse workload should consider adjusting for patient turnover, or both turnover and severity.

Which of the adjustments should researchers use? In Table 4 we compare our findings to those of Graf et al. (2003). In the Graf et al. (2003) study, workload increased nearly 90 percent of the amount of the drop in length of stay in a 7-year-period. In the present study, the first turnover adjustment based on the full inverse of the length of stay increased staffing needs by nearly the same amount as the fall in length of stay in the 8-year period, thus slightly overestimating the impact compared with the Graf et al. (2003) study. The second turnover adjustment understated the impact by one-half. The first turnover adjustment along with patient severity overstated the amount of impact slightly. Finally, the second turnover adjustment along with severity slightly understated the staffing needs compared with the Graf findings (Graf et al. 2003).