Table 1.

Number of errors, error-related adverse events and process indicators, by weekend–weekday admission and epoch

	Both epochs			Epoch 1			Epoch 2
	Total	W/E	W/D	Total	W/E	W/D	Total	W/E	W/D
	n (%)	n (%)	n (%)	n (%)	n (%)	n (%)	n (%)	n (%)	n (%)
Total	4000	2000	2000	2000	1000	1000	2000	1000	1000
Total number of errors	1618	803	815	914	440	474	704	363	341
Number of errors
None	2970 (74.3)	1486 (74.3)	1484 (74.2)	1447 (72.4)	723 (72.3)	724 (72.4)	1523 (76.2)	763 (76.3)	760 (76.0)
Any error	996 (24.9)	497 (24.9)	499 (25.0)	541 (27.1)	269 (26.9)	272 (27.2)	455 (22.8)	228 (22.8)	227 (22.7)
1	645 (16.1)	328 (16.4)	317 (15.9)	338 (16.9)	178 (17.8)	160(16)	307 (15.4)	150 (15.0)	157 (15.7)
2	208 (5.2)	100 (5.0)	108 (5.4)	121 (6.1)	53 (5.3)	68 (6.8)	87 (4.4)	47 (4.7)	40 (4.0)
3	83 (2.1)	36 (1.8)	47 (2.4)	43 (2.2)	18 (1.8)	25 (2.5)	40 (2.0)	18 (1.8)	22 (2.2)
4	31 (0.8)	17 (0.9)	14 (0.7)	22 (1.1)	12 (1.2)	10 (1.0)	9 (0.5)	5 (0.5)	4 (0.4)
5 or more	29 (0.7)	16 (0.8)	13 (0.7)	17 (0.9)	8 (0.8)	9 (0.9)	12 (0.6)	8 (0.8)	4 (0.4)
Missing	34 (0.9)	17 (0.9)	17 (0.9)	12 (0.6)	8 (0.8)	4 (0.4)	22 (1.1)	9 (0.9)	13 (1.3)
Mean number of errors per patient admission*	0.408	0.405	0.411	0.460	0.444	0.476	0.356	0.366	0.345
Patients with one or more adverse events	103	49	54	68	31	37	35	18	17
Process indicators
Location not appropriate	118 (3.0)	59 (3.0)	59 (3.0)	61 (3.1)	29 (2.9)	32 (3.2)	57 (2.9)	30 (3.0)	27 (2.7)
Incomplete vital signs	1280 (32.0)	596 (29.8)	684 (34.2)	597 (29.9)	280 (28.0)	317 (31.7)	683 (34.2)	316 (31.6)	367 (36.7)
NEWS not recorded	2060 (51.5)	982 (49.1)	1078 (53.9)	1090 (54.5)	521 (52.1)	569 (56.9)	970 (48.5)	461 (46.1)	509 (50.9)
No specialist review <14 hours documented	2811 (70.3)	1393 (69.7)	1418 (70.9)	1448 (72.4)	727 (72.7)	721 (72.1)	1363 (68.2)	666 (66.6)	697 (69.7)

*Calculated using 'total number of errors ÷ (all records excluding errors missing)'.

NEWS, National Early Warning Score; W/D, weekday; W/E, weekend.