TABLE 4.

Sleep Measures for Project Fire Deployments According to Shift Characteristics

			Mean ± SD
Analysis	Shift Category	Sample Size (n)	TST (min)	SE (%)	WASO (min)
Shift length (hr)	<12	10	380.7 ± 61.9	87.6 ± 7.4	57.8 ± 38.4
	12–13	70	375.3 ± 48.7	87.7 ± 7.7	49.3 ± 28.9
	>13	23	364.0 ± 66.3	86.3 ± 8.8	59.2 ± 43.4
Shift start (am)	5–6	14	323.4 ± 46.3a	88.1 ± 4.6	43.7 ± 18.2
	6–7	40	399.3 ± 57.3	87.4 ± 7.9	58.3 ± 38.9
	7–8	48	367.9 ± 45.3	88.2 ± 8.8	44.9 ± 31.4
Shift end (pm)	≤7	25	391.5 ± 54.1	88.3 ± 6.2	53.3 ± 31.3
	7–8	44	357.2 ± 52.0	88.9 ± 7.4	41.5 ± 24.1
	8–9	27	381.2 ± 55.0	84.4 ± 9.4	67.0 ± 42.8
	>9	7	378.4 ± 41.7	86.3 ± 7.4	60.9 ± 34.0

am, morning period; pm, evening period; SD, standard deviation; SE, sleep efficiency; TST, total sleep time; WASO, wake after sleep onset.

^aSignificant differences within each shift characteristic category.