Trajectories of nursing hours over the course of hospitalization and estimated additional nurse staffing requirements to reduce the length of stay

Abstract Purpose The aims of this study are to examine the trajectories of nursing hours per patient day (NHPPD) over the course of hospitalization according to the patient's length of stay (LOS) and to estimate changes in the total nursing hours during hospitalization, average NHPPD, and the number of nurses additionally required when the LOS was reduced by 1 day. Design This retrospective longitudinal study analyzed patient data collected from a tertiary university hospital located in Seoul, South Korea. The study sample included 11,316 inpatients who were discharged between September 1 and October 31, 2022. Methods NHPPD over the course of each patient's hospitalization was estimated using the total score of the Korean Patient Classification System‐1 (KPCS‐1), which nurses evaluated and recorded every day from admission to discharge. The NHPPD trajectories were examined using linear mixed models to analyze repeated KPCS‐1 measurements and control for the effects of patient characteristics. The changes in the average NHPPD when LOS was reduced by 1 day were estimated using maximum and minimum estimations. The impact of a 1‐day reduction in LOS on staffing requirements was calculated as the number of nurses additionally required to work each shift and to be hired. Findings The average LOS was 5.6 days, and the short (1–6 days) and medium (7–14 days) LOS groups accounted for 78.9% and 14.3% of patients, respectively. The NHPPD trajectories showed a “rise‐peak‐decline” pattern. Patients in the short LOS group received the most NHPPD on day 1 (day of admission) or day 2, whereas the NHPPD for patients in the medium LOS group peaked on days 3–6. After peaking, the NHPPD tended to decrease toward the end of hospitalization, with the least NHPPD on the day of discharge, followed by the day before discharge. When LOS was reduced by 1 day, the average NHPPD was estimated to increase by 7.7–50.0% in the maximum estimation, and 0.9–12.5% in the minimum estimation. In response to a 1‐day reduction, 1.10–7.44 nurses were additionally required to care for 100 patients each shift and 5.28–35.70 additional nurses needed to be hired in the maximum estimation. In the minimum estimation, these values were 0.13–1.85 additional nurses per shift and 0.65–8.90 additional nurses to be hired, respectively. Conclusions Since NHPPD exhibited a “rise‐peak‐decline” trajectory, reducing the LOS by 1 day was estimated to increase the average NHPPD and lead to additional staffing requirements. The additional nurse requirement for a 1‐day reduction was not constant; instead, it increased with each day subtracted from an already shorter LOS. Clinical Relevance Sufficient nurse staffing is necessary to provide increased NHPPD as a result of shortened LOS. Changes in the LOS should be considered when determining nurse staffing requirements.