Table 1

Assumed optimal workload, and daily mean values of workload, staff resources and adverse events per ward in the data

	Optimal load, lower bound	Optimal load, upper bound	OPC per nurse	Patients per nurse	OPC	OPC per patient	Number of nurses	Incident	Patient affected	Harm to patient	>1 incident	Death	n	Number of OPC classifications
Ward, id
D Infectious*	18.90	25.56	21.06	1.48	251.22	14.20	12.03	0.09	0.06	0.02	0.01	0.04	365	17.70
D Internal†	21.85	29.55	24.45	1.60	308.81	15.28	12.74	0.13	0.07	0.04	0.02	0.07	362	20.18
D Cardiology	21.88	29.60	25.98	1.89	355.99	13.75	13.98	0.26	0.11	0.08	0.03	0.08	365	25.90
D Surgical	16.85	22.79	23.88	1.41	425.36	16.87	17.80	0.05	0.02	0.01	0.00	0.08	365	25.19
D Orthopaedics	15.99	21.63	21.92	1.41	350.84	15.52	16.15	0.12	0.08	0.04	0.02	0.05	365	22.62
D Surgical	14.54	19.66	17.58	1.24	243.46	14.18	13.75	0.07	0.05	0.04	0.01	0.02	330	17.15
D Maternal	25.47	34.47	33.83	2.48	343.10	13.62	10.12	0.04	0.02	0.01	0.00	0.00	364	25.17
D Oncology	14.36	20.12	22.84	1.38	249.46	16.50	10.88	0.26	0.11	0.05	0.03	0.18	362	15.10
D Neurology	20.05	27.13	25.12	1.34	392.29	18.69	15.76	0.13	0.05	0.03	0.02	0.08	365	20.96
B Internal†	16.14	21.83	20.40	1.49	182.62	13.75	8.95	0.12	0.09	0.07	0.02	0.06	341	13.29
B Internal†	20.37	27.56	25.13	2.00	290.05	12.61	11.59	0.23	0.16	0.10	0.06	0.08	365	23.04
B Internal†	17.16	23.21	19.94	1.47	171.98	13.54	8.59	0.20	0.11	0.07	0.06	0.05	365	12.69
B Internal†	19.65	26.59	24.16	1.82	292.34	13.24	12.11	0.11	0.07	0.05	0.01	0.13	365	22.09
B Surgical	21.47	29.04	29.16	2.00	544.95	14.59	18.73	0.20	0.16	0.10	0.01	0.16	365	37.34
B Surgical	18.50	25.10	23.29	1.77	355.67	13.18	15.37	0.08	0.05	0.03	0.02	0.08	365	26.95
B Surgical	23.27	31.48	28.04	1.88	474.66	14.90	17.01	0.12	0.08	0.01	0.02	0.05	365	31.85
B Gynaecology	18.87	25.54	23.17	1.68	131.87	14.04	6.21	0.13	0.10	0.02	0.02	0.02	177	9.45
B Maternity	19.05	25.78	20.69	1.37	338.39	15.04	16.40	0.03	0.02	0.02	0.00	0.00	365	22.48
B Paediatrics	11.51	15.58	13.08	0.75	134.87	17.39	10.23	0.04	0.03	0.01	0.00	0.00	362	7.72
B Paediatrics	12.16	16.45	8.65	0.49	108.10	17.52	12.38	0.02	0.01	0.00	0.00	0.00	365	6.17
B Otology	17.45	23.60	22.45	1.81	224.67	12.36	9.87	0.11	0.07	0.04	0.01	0.01	298	18.12
B Neurology	16.25	21.98	19.37	1.37	245.29	14.24	12.68	0.08	0.06	0.01	0.01	0.07	365	17.30
B Lung	20.02	27.09	19.43	1.50	273.30	12.97	14.05	0.10	0.08	0.01	0.02	0.11	365	21.05
C Surgical	22.60	30.60	24.33	1.41	321.42	17.29	13.22	0.17	0.08	0.03	0.07	0.06	365	18.58
C Internal†	18.70	25.30	25.15	1.65	397.05	15.20	15.93	0.17	0.09	0.01	0.05	0.15	366	26.12
C Internal†	20.40	27.60	21.77	1.29	208.62	16.87	9.52	0.10	0.09	0.01	0.02	0.03	291	12.33
C Surgical	19.40	26.30	23.70	1.51	228.64	15.64	9.49	0.04	0.03	0.00	0.01	0.00	291	14.58
A Gynaecology	19.50	26.40	24.92	1.83	290.61	13.60	11.39	0.03	0.02	0.01	0.00	0.00	366	21.14
A Gynaecology	25.60	42.10	39.84	2.81	510.25	14.21	12.83	0.04	0.03	0.02	0.00	0.00	225	35.94
A Gynaecology	33.50	45.30	40.54	2.85	607.06	14.22	15.06	0.04	0.02	0.02	0.00	0.00	366	42.64
A Orthopaedics	16.80	22.70	20.29	1.33	430.29	15.18	21.19	0.10	0.05	0.02	0.02	0.04	366	28.30
A Paediatrics	12.30	14.90	13.33	0.97	165.18	13.85	12.34	0.15	0.10	0.08	0.04	0.00	366	11.95
A Paediatrics	11.00	14.20	11.16	0.70	117.12	16.05	10.57	0.09	0.06	0.02	0.01	0.01	360	7.31
A Paediatrics	8.90	12.00	9.29	0.54	91.18	17.36	9.67	0.09	0.06	0.02	0.01	0.00	363	5.24
A Surgical	21.10	28.50	24.45	1.48	273.20	16.50	11.24	0.02	0.02	0.01	0.00	0.06	364	16.54
A Rehabilitation	15.10	20.50	20.57	1.49	198.98	13.89	9.51	0.14	0.12	0.03	0.04	0.00	315	14.52
Total	18.52	25.22	22.41	1.53	294.59	14.97	12.93	0.11	0.07	0.03	0.02	0.05	12 475	19.97

Assumed optimal load refers to the established interval of optimal workload according to the PAONCIL measurement (OPC per nurse).
The variables are described in more detail in the main text.
*Infectious diseases.
†Internal medicine.
OPC, Oulu Patient Classification; PAONCIL, Professional Assessment of Optimal Nursing Care Intensity Level.