Table 1.

The cluster sizes and averages for the eight detected clusters of working hours in employees of the Hospital District of Southwest Finland. [FIOH=Finnish Institute of Occupational Health; TM=employee’s time median value.]

Cluster	#1	#2	#3	#4	#5	#6	#7	#8
Number of employees (N)	289	55	893	151	4065	562	8	6
Men (%)	5.54	0.00	12.99	8.61	7.43	10.32	12.50	0.00
Contract days a	4210.42	4119.58	3847.69	4222.47	2579.82	4124.01	4205.38	4067.33
Consecutive contract days b	2343.63	2293.11	1916.23	2394.31	1053.38	2189.93	2428.25	2307.50
Age (years)	42.43	47.16	39.92	43.94	38.17	43.42	45.00	44.50
FIOH risk score for long work spells c	0.19	0.09	0.19	0.08	0.15	0.17	0.03	0.03
FIOH risk score for night shifts c	0.02	0.01	0.48	0.01	0.28	0.04	0.00	0.00
FIOH risk score for short recovery c	0.26	0.01	0.35	0.01	0.22	0.03	0.02	0.24
TM work-shift length	7.97	7.98	8.25	7.98	8.26	7.98	8.00	8.00
TM length of rest hours	16.23	16.66	16.49	16.08	16.79	16.09	16.03	16.38
TM shift starting hours	7.44	7.73	9.89	7.56	8.96	7.70	8.36	8.50
Sickness absence days d	8.58	11.35	11.76	5.81	13.03	11.62	9.67	5.59
Sickness absence trend e	1.07	1.81	2.41 f	2.36 f	5.25 f	3.18 f	2.54	-3.16

^aContract days in our register sampling (employed days between dates 2008-01-01 to 2019-08-27)

^bWork days in the longest consecutive stretch of data (without > 4-day interruptions in contract)

^cRecommendation-based burden scores (range 0–3), with values growing with work overload (see supplementary material for exact units)

^dUnit is a rate (days/year)

^eChange from 1st to 2nd half of longest consecutive time series

^fP <0.05.