Addressing inpatient crowding by smoothing occupancy at children's hospitals

Abstract

Objective: To quantify the difference in weekday versus weekend occupancy, and the opportunity to smooth inpatient occupancy to reduce crowding at children's hospitals.

Methods: Daily inpatient census data for 39 freestanding, tertiary-care children's hospitals were used to calculate occupancy and to model the impact of reducing variation in occupancy and the change in the number of patients, patient-days, and hospitals exposed to high occupancy pre- and post-smoothing. We also calculated the proportion of weekly admissions that would require different scheduling to achieve within-week smoothing.

Results: Overall, hospitals' mean occupancy ranged from 70.9% to 108.1% on weekdays, and 65.7% to 94.9% on weekends. Weekday occupancy exceeded weekend occupancy with a median difference of 8.2% points. The mean post-smoothing reduction in weekly maximum occupancy across all hospitals was 6.6% points. Through smoothing, 39,607 patients from the 39 hospitals were removed from exposure to occupancy levels >95%. To achieve within-week smoothing, a median 2.6% of admissions would have to be scheduled on a different day of the week; this equates to a median of 7.4 patients per week (range: 2.3-14.4).

Conclusion: Hospitals do have substantial unused capacity, and smoothing occupancy over the course of a week could be a useful strategy that hospitals can use to reduce crowding and protect patients from crowded conditions.

Figure 1. Differences between weekday and weekend percent occupancy by hospital for each week in 2007

Each box represents data from one participating hospital. On each boxplot, the box spans the interquartile range for differences between weekday and weekend occupancy while the line through the box denotes the median value. The vertical lines or “whiskers” extend upward or downward up to 1.5 times the interquartile range.

Figure 2. Percent change in weekly hospital maximum occupancy after smoothing

Within the hospitals, each week’s maximum occupancy was reduced by smoothing. The box plot displays the distribution of the reductions (in percentage points) across the 52 weeks of 2007. The midline of the box represents the median percentage point reduction in maximum occupancy, and the box comprises the 25^th to 75^th percentiles (i.e. the interquartile range). The whiskers extend to 1.5 times the IQR.

Figure 3. Categories of hospitals by occupancy and effect of smoothing at 95% threshold

The solid, grey, horizontal line indicates 95% occupancy; the solid black line indicates pre-smoothing occupancy, and the dashed line represents post-smoothing occupancy.