Table 1

Nurse staffing and proportion of understaffed shifts, by staff category, unit type and shift

Variable	ICUs	Medical units	Med/Surg units	Step-down units	All
Day shift
No. of shifts	27 331	18 793	10 016	10 731	66 871
RN
RN nursing hours/patients (mean (SD))	11.5 (6.6)	3.4 (2.2)	2.6 (2.1)	3.8 (1.6)	6.7 (6.0)
75% of RN staffing median	7.8	2.1	1.8	2.8	4.5
Understaffed shifts (%)	13	8	6	10	10
NS
NS nursing hours/patients (mean (SD))	2.3 (2.3)	1.8 (1.0)	2.0 (1.3)	1.5 (0.8)	2.0 (1.7)
75% of NS staffing median	1.4	1.3	1.4	1.1	1.3
Understaffed shifts (%)	28	15	18	23	22
Night shift
No. of shifts	27 331	18 793	10 016	10 731	66 871
RN
RN nursing hours/patients (mean (SD))	11.1 (6.6)	3.2 (2.1)	2.4 (2.0)	3.7 (1.5)	6.4 (5.9)
75% of RN staffing median	7.4	2.0	1.6	2.7	4.3
Understaffed shifts (%)	13	6	3	8	9
NS
NS nursing hours/patients (mean (SD))	1.9 (2.1)	1.5 (1.0)	1.6 (1.2)	1.3 (0.7)	1.6 (1.5)
75% of NS staffing median	1.2	1.0	1.2	1.0	1.1
Understaffed shifts (%)	28	19	17	22	23

Understaffing defined as the staffing is lower than 75% of the shift median for each unit type and each type of nursing staff.
ICU, intensive care unit; NS, nursing supporting staff; RN, registered nurses.