Impaired self-monitoring ability on reaction times of psychomotor vigilance task of nurses after a night shift

Figures & data

Table 1. Number of assignments, number of working hours, and preceding sleep durations for the day, evening, and night shifts.

	Shift (scheduled working time)
	Day (8:15–17:00)	Evening (15:45–0:30)	Night (0:00–8:45)
Number of assignments per participant^*1	6.0 ± 1.9	2.6 ± 1.0	2.3 ± 1.0
Hours of duty^*2	11.7 ± 0.7	10.5 ± 0.5	10.9 ± 0.7
Timing of PVT [hh:mm]	18:56 ± 0:27	1:09 ± 0:18	9:28 ± 0:21
Awake hours from last sleep to PVT	12.6 ± 1.1	14.4 ± 2.0	14.8 ± 3.3
Total hours of prior sleep^*3	5.1 ± 1.5	8.8 ± 2.6	8.3 ± 3.4

Summary of 305 measurements by 30 participants in 22 days. Mean ± SD. *1: Number of assigned shift types during the study period per participant. *2: Including legal break time (i.e., 1 h). *3: Total hours of sleep(s) started 24 h before the check-in time.

PVT: psychomotor vigilance task.

Figure 1. Differences in psychomotor vigilance task measures and subjective sleepiness of day, evening, and night shifts. The fitted values for the day, evening, and night shifts are shown as filled circles, triangles, squares, and vertical lines along with their associated 95% confidence intervals. To determine the Δ reaction time, the anticipated RT was subtracted from the median RT.

Table 2. Relationships between predicted reaction time and actual median reaction time in each shift.

	df	R (95% CI)	R^2	P
Day shift	136	0.42 (0.27, 0.55)	0.17	<0.001
Evening shift	59	0.47 (0.24, 0.64)	0.22	<0.001
Night shift	44	0.20 (−0.09, 0.47)	0.04	0.175

Results of Pearson’s product – moment correlation tests conducted using consolidated data from each shift.

Data availability statement

The data supporting this study’s findings are available from the corresponding author upon reasonable request.